Aros/User/Docs

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==What is AROS==

Google translation 
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*Computer Hardware
*AROS (operating system)
*Applications and Games
*User


[http://www.osnews.com/story/15819 AROS] is one of the intermediate levels between the computer hardware and the user. It is an open-source, clean-room implementation of AmigaOS 3.x that can be run on many different computer architectures. It runs primarily on PC x86 64bit and also PC 32bit hardware but also on motorola 68k and compatibles, some ARM and PowerPC. 

This page will cover enough to be able to write the downloaded image to your preferred media, to run a LiveUSB, LiveCD or LiveDVD on your office/home PC (Live meaning you can test without changing your existing setup) and, ultimately, to use it.  

Intel / AMD PC hardware support mostly covers the years 2000 to 2010 but work is under way to cover recent PC hardware. At the moment, AROS is '''not''' recommended to be '''installed''' on a working vital data holding machine. Instead, writing to and booting from a '''USB stick''' could be a much better option. 

AROS is an hobby OS and can co-exist with Windows(TM), MacOSX(TM), Android(TM) or Linux(TM) and act as an alternative. 
Unfortunately, Aros has few developers so upgrades and improvements can take [https://sourceforge.net/p/aros/mailman/aros-cvs/ time to appear]. 

AROS core is now [http://en.wikibooks.org/wiki/Aros/Developer/IncompleteAPIs ~80%] finished and is usable, so keep in mind that the software is still considered ALPHA/BETA and in development. Currently AROS is fun to play with on a curiosity level, but it is also interesting to program. AROS has some multimedia features and has internet access.  

Most importantly, use AROS to its maximum potential as it stands now, find ways to have fun with it and share your experiences. 


Good Sites to visit 

: [https://www.arosworld.org/home.php Aros World User forum] 
: [https://ae.arosworld.org/ Aros Exec site relocated] 
: [https://arosnews.github.io/ AROS News]
: [https://www.facebook.com/ArosWorkshop/ Aros Workshop], 
: [https://www.osnews.com/topic/amiga-aros/ OSNews] 
: [https://www.reddit.com/r/aros/ Reddit]


: [https://archives.arosworld.org Aros Archives] 
: [https://aminet.net/ Aminet]
: [http://www.amiga-news.de/en/ English translation of German site]


: [https://aros.sourceforge.io AROS]
: [https://github.com/aros-development-team/AROS Codebase]
: [https://github.com/aros-development-team/AROS/issues Issues] and [https://sourceforge.net/p/aros/bugs/ old defunct bugs site] 
: [https://github.com/deadwood2 Deadwood's builds], [https://www.axrt.org/download/aros/v11/ v11 builds], [https://axrt.org/downloads-aros Updated i386 32bit PC builds], 
: [https://github.com/ezrec Ezrec x86 m68k mirror of old svn version]


: [https://sites.google.com/view/arosone Aros One x86, x64] 
: [https://tinyarosdistro.flazio.com/ Tiny Aros x86 and x64]
: [https://arosnews.github.io/aros-portable/ AROS portable USB3 stick images of hosted Aros One x86 and x64 on debian] 
: [http://vmwaros.blogspot.com Icaros Desktop x86 now on sabbatical, very old edition] 
: [https://sites.google.com/site/arosaspireone AspireOS, of the netbook Aspire One, very old edition] 


: [http://arosalive.blogspot.co.uk/p/10-basic-aros-how-tos-tutorials.html Basic How To guides] 
: [http://arosgamer.blogspot.co.uk/ AROS Playground], [http://thewetmachine.net/tag/aros/ Jess Wet Machine], [https://aroshacking.wordpress.com/ Jon Robertson's AROS Experiences and FPC Free Pascal], [], 
:[http://www.apollo-accelerators.com/ Apollo Accelerators m68k], [http://www.amigablogs.net/ Amiga Blogs], [http://blog.a-eon.biz/blog/ Trevor Dickinson blog], [http://www.pegasos.org/index.php Genesi activity], 


: [https://forum.amiga.org/ Amiga OS AOS 3.x forum] 
: [http://eab.abime.net/ EAB Amiga] 
: [http://www.amigaworld.net/ AmigaWorld] 
: [http://www.ppa.pl/ Polish Amiga Like News] 
: [http://www.apollo-core.com/ Apollo Forum] 
: [https://amigaalive.blogspot.com/ AmigaAlive]
: [https://www.amigalove.com/software Disk Mags]
: [https://amigachristmastree.ultimateamiga.com/ Xmas Amiga Game Jam]
: [https://www.reddit.com/r/amiga/ Amiga]


== Distributions aka Distros ==

For end users there are distributions (ready made with selected apps aiming to be easy to use), mostly created and maintained by one person in their own workflow/style. They reuse the nightly boot compiles to suit their needs and possibly other end users. You are free to create your own if required. 

* For native 64bit Intel/AMD: [https://sites.google.com/view/arosone Aros One x64], [https://tinyarosdistro.flazio.com/ Tiny Aros],
* For native 32bit Intel/AMD which will run on 64bit machines: [https://sites.google.com/view/arosone Aros One x86], [https://www.tinyaros.it/ Tiny Aros], 
* For native 68k [https://sites.google.com/view/arosone Aros One m68k], [http://www.aros-platform.de/ AROS Vision], 


* For hosted Linux usb drive image [https://arosnews.github.io/aros-portable/ x64 Debian hosted version of Aros One], 
* For hosted ARM there is Aeros and wip native RaspberryPi 


AROS was originally developed on Linux but can run on an Intel-based Linux distro as an app. As time has gone on, it can be run as an app on many more operating systems (Windows, FreeBSD, Linux and limited on MacOS). This may sound strange: an OS running on top of another OS. 
Basically, this is to take advantage of drivers (audio, internet, graphics, etc.) and compiler environments, in the existing OS, with which people may be already familiar. The term we use for what AROS does is &quot;Hosted&quot;. 

AROS Native is the term coined to describe AROS being run without any OS underneath it. It runs alone just like AmigaOS(TM) did. As this version does not benefit from &quot;Hosted&quot; drivers, dedicated ones have to be ported/written. Hence the smaller range of supported hardware / peripherals. We have other pages highlighting this support 


AROS is open source so basically everyone can take part. The source is public on github and there are new commits most days. AROS is automatically compiled daily, result are the nightly builds hosted on Sourceforge. The nightly builds are only used for testing changes, testing software and the starting point for distribution maintainers or even your own distribution. They are very basic, miss some functionality and apps like web browsers and are not suited for end users. 

* The [https://sourceforge.net/projects/aros/files/nightly2/ Nightly2], [http://aros.sourceforge.net/download.php nightly builds File Release Service] or [http://aros.sourceforge.net/downloads/ Sourceforge Project Web builds] are made automatically every night directly from the Github and in the past, SVN (Subversion) tree and contain the latest code for the AROS operating system. It should be noted that the builds have not been tested in any way and can be horrible broken. 

There are two standards ABIv0 (old) and ABIv1 (newest). 
*ABIv1 ABIv11 nightly builds for 64bit PC builds, it is where the most work is done by developers 
*ABIv0 is needed for 32bit (which also runs on 64bit) intel / amd distributions 


==Media==

AROS media tends to boot in this tier list of media types, first internal HDD SSD, CD DVD drive, and finally usb drive (last two can depend on bios boot order) 

* USB .VHD 

[https://sites.google.com/view/arosone Aros One x86 and x64], with md5 below 

&lt;pre&gt;
7dd7119ab3e56d75ee852c137226b4d7 *ArosOne-USB-v1.2-x86_64-v11.zip
cf906eeaad4a83b3520b1896bdc6b0d3 *ArosOne-USB-v1.1-x86_64-v11.zip

e2eb8fe8cfd61c567b0152a61cf85251 *ArosOne-x86-v2.8-USB-IMG.zip
559909c75c2f56472c74267a7d075355 *ArosOne-x86-v2.7-USB-IMG.zip
93da5898508c1a8c05bb8991ab7bd117 *AROS One Image-USB-2.4.zip
59fcabd7090e47f12d54f7eb78cf0f45 *ArosOne-x86-v2.2-USB-Image.zip
24fb8de726ae8fc5fe5bac6d30f03dc5  ArosOne-x86-v2.0-USB-Image.zip
f3d725e990072edce633b59747911b6b  ArosOne-x86-v1.8-USB-IMG.zip
e089a24ae310e92fcc407a0125602ce8  Aros-One x86-IMG-USB-v1.6.zip
&lt;/pre&gt; 


[https://tinyaros.flazio.com/ Tiny AROS]

22bc993625b7c75b17263c0cc7e7baaa *Tiny Aros_copy.vhd (March 2024) 


There is usually a vhd image inside the zip that can be written to USB sticks which is so much faster than the old ISO written to physical CD DVD method. This .vhd can be written to an USB stick / ssd with these pieces of software below but it will erase the previous contents from the usb 

Windows - [https://www.raspberrypi.com/software/ RPi Raspberry Imager, use custom and see all files], [https://hddguru.com/software/HDD-Raw-Copy-Tool/ HDD-Raw-Copy-Tool], [https://rufus.ie/ Rufus up to version 3.20 may work with VirtualBox HD vhd images with Win7 but not some Rufus 4.x versions], [https://etcher.balena.io/ Balena Etcher], 

Linux   - [https://www.raspberrypi.com/software/ Raspberry Imager Ubuntu], Suse Image / Multi writer, dd, 

Mac     - 


* Virtual Machine .ISO or CDs DVDs 

 The native iso images are currently not compatible with Ventoy, Yumi, MultiBootUSB, Easy2Boot E2B, or similar 

&lt;pre&gt;
11c8a147fcad7ecf52ae3a43e1934b69 *ArosOne-DVD-v1.2-x86_64-v11.zip
f93053d3b9ccf304d7e6ac3389e1987b *ArosOne-DVD-v1.1-x86_64-v11.zip

86d808a40dc7be389a758799a9b4f595 *ArosOne-x86-v2.0-ISO-DVD.zip
f1fc8599ef6a39e5df394e0f41d55526 *AROS-One-x86-ISO-DVD-v1.6.zip
&lt;/pre&gt;


You can use a virtual emulator like VirtualBox, VMWare to mount the iso image which can then be used to boot and/or install to USB. 

no software can write an AROS ISO to a Pendrive. The author of ‘Rufus’ (who used an Amiga 500 as a child) once tried, but when he saw the system composition, he said he was unable to do it.

The solution is to boot the ISO from a VM (WMware, VBox), then install the AROS build on the Pendrive, which will eventually become a Live Pendrive that can be booted on a PC.

The only precaution is that in some cases it is necessary to thoroughly clean the Pendrive of any partitions and remove any bootloader that is not AROS. The Pendrive must remain raw without any partitions.

You can clean the USB stick on a PC with a program that manages hard disks. You need to do a partition wipe. On some USB sticks, you can clean it with InstallAROS.


Previously the only installation option was CD-RW or DVD-RW, since the whole system can be burnt onto a single disk and can be reused when the next version is released. Good branded discs like Taiyo Yuden (later JVC) or Verbatim should be used to reduce frustration later. The days for this media is gone but kept here for information 

Since nobody currently sells AROS on any other media, you will need access to a CD/DVD burner to create the installation disk yourself. After it is on a CD or DVD, then access and writing to USB pendrives becomes available (this should be viewed as an outdated or last resort alternative method now), as well as using good USB manufacturers like Sandisk, Kingston, etc. rather than some other no-names. 

Try burning it to a CD-RW or DVD-RW using your CD/DVD burning program (most burning software have a burn iso option). The ideal writing speed is 2x or 4x, higher speeds can give errors and problems.  Check the writing integrity of your CD or DVD if your software has an option to do so before going any further. 

Standalone portable usb cd dvd drives do not boot physical burnt discs, please use an internal ide sata drive instead. 


* SD-card
For ARM Pi Aros, copy the files onto a FAT32 formatted SD card. 


==Booting==

The LiveUSB, and in the past LiveCD LiveDVD, is designed to trial (test drive) various operating systems without having to install them to your working system. 

Since 2011, UEFI was introduced to replace the original PC BIOS which made booting media more confusing. Some changes in the UEFI/bios may be needed 

*go into the bios using esc, f2 or f? and disable the Security -&gt; Secure Boot and maybe apply option for Legacy IDE mode 
*you may have to press F9, F10 or F12 or p on boot up to present a device boot options like USB or CD/DVD 
*disable the Fast Boot config so it would recognize portable DVD-drive and changed the Boot-sequence

Secure boot was introduced by Microsoft and later consortium control what operating systems work with Secure Boot via shims. 
For Aros, it is best to disable or be able to change Secure Boot (if you dual boot with Windows this may cause issues with Window boots after) 

The grub part of the boot should be fully automatic, and you should see a multiple choice graphic card screen after 10 seconds for USB or over 30s CDs and DVDs. 

After the grub graphics choice, AROS takes over the booting and any issues can arise here 


=====Advice for various machines=====

Some of the stages involved and shown on the display in a typical AROS boot start up 

&lt;pre&gt;
[MultiLoader]
[ELF Loader]
[Boot]

[HPET] 
[Kernel:ACPI]
[Kernel:APIC-IA32]
[Kernel:SMP APIC]
[HiddStorage]

ACPI: ????
ACPI Error 
[ACPI]AcpiOs????
[BattClock] Got RTC century offset 0x32 from ACPI 

[PCI] Scanning bus ? 
[AHCI] Sata 
[Vesa]  only if vesa is chosen as graphics option 

[ATA] detect hd &amp; cd drives 
[ATA0?] ata-identity 
[packet] fat.handler be.handler, etc. 
[DOS] 
[Storage:Bus]
[Storage:Controller]

[MSS] USB setup
[ehciInit] Port ? maps to controller ? 

[I2C] 
[ATI]
[drm] nouveau 
[AROSTCP]   if you have network driver prefs set up to start when booting 


&lt;/pre&gt;

; If boot fails, please give us some indication (pictures or videos) where the boot stops and the message(s) on screen. 


AROS's native SATA/AHCI driver doesn't always work. If you get errors related to ahci.device, try disabling it. At your chosen boot entry in the GRUB menu, Press E, scroll down to the ahci.device entry, and add a # or ; at the start of that line or delete it with Ctrl-K. Then press Ctrl-X or F10 to boot. 

If your disk isn't accessible at all with this change, you might need to change the SATA controller to IDE legacy mode in the BIOS: however, making this change will likely cause problems booting Windows on the same machine (if it's already installed). To disable ahci.device permanently, edit the text file &quot;SYS:Arch/pc/grub/grub.cfg&quot;, and remove the ahci.device line from all boot entries you intend to use.

SATA AHCI Timeout while waiting for device to complete operations with BIOS SATA entry set to AHCI mode stops at &quot;waiting for bootable media&quot; screen, changing BIOS SATA setting back to IDE mode may allow it to continue booting 

The ATA driver doesn't always work. If you get errors related to ata.device, try using the alternative in sys:devs/alt which is an older version.  Press E when your chosen boot entry is highlighted in the GRUB menu, scroll down to the ata.device entry, and change it to read &quot;module /Devs/Alt/ata.device&quot;. Then press Ctrl-X to boot. To make this change permanent, edit the text file &quot;SYS:Arch/pc/grub/grub.cfg&quot;, and change the path to ata.device in all boot entries you intend to use.


Further options (removing the &quot; &quot;) to add to the GRUB menus to disable certain other components for debugging:

&lt;pre&gt;
Disable AHCI                        &quot;AHCI=disable&quot;
Disable NVME                        &quot;NVME=disable&quot;

Disable ATA:                        &quot;ATA=disable&quot;
Disable ATA:                        &quot;ATA=nopci,nolegacy&quot;
ATA safe mode:                      &quot;ATA=nodma,32bit&quot;
Disable IDE from SATA:              &quot;ATA=32bit,nosata2pata&quot;
VIA / SIS with cdrom read io errors &quot;ATA=nodma,nopoll&quot; 

noacpi                   all [PCI] devices to be invisible to AROS. disk drives work but network, sound won't 
Set AHCI                            &quot;AHCI=force150/force300/force600&quot;

Disable AHCI/SATA:       comment out with a # ; or remove ahci.device line with Ctrl-K
Disable USB:             comment out # ; or remove pciusb.device and poseidon.library lines with Ctrl-K
Disable native graphics: &quot;nomonitors&quot;
USB3                     &quot;USB=xhci&quot; 
&lt;/pre&gt; 

Other useful grub command line options - nomonitors, noacpi, vesahack, nopoll 

Press Ctrl and X together (or F10) to exit and boot with the new options. Just experiment with different variations until successful. Those working options will need to be reused with every reboot of AROS until you can edit the grub.cfg and make it permanent i.e. install to hard disk or USB. 


* If you use VESA mode, you can see the debug log if you add 'vesahack' to the command  line.  This  will set up split-screen mode. In the upper half you'll see AROS screen, in the bottom - debug log. 
* ACPI ie. PCI hardware - If  you  get  crashes  at  early boot, try adding 'NOACPI' to the command line 


If you're having boot issues and have a null modem cable and a spare pc, a boot log is always useful. Edit your grub line to include debug=serial but would try with an with sysdebug=all in the line later as it can cause issues booting on machines with sysdebug=all enabled (corrupts the cpu initialization). 

However, if you feel you have found a genuine bug/fault in AROS that needs attention, please use the [http://sourceforge.net/tracker/?atid=439463&amp;group_id=43586&amp;func=browse bug submission form] to record as much information about what happened, why, and what hardware etc. you have so that people may try to assist you 


For Virtual machines VMWare VirtualBox, etc., attach and press play to start the ISO image 

 If booting hasn't worked then it could be down to Bios/UEFI settings or USB3 (2014 onwards)  


=====nvme.device=====

 Since 2018, nvme drives are standard on most machines 

Now as far as hardware goes on a newer machine with an NVME drive you may need to add NVME=disable as the NVME driver could potentially cause lockups. 


=====AHCI=====

 Starting taking over since 2011 on a lot of machines 

* Check that UEFI (replacement for PC BIOS) has options set to remove UEFI SecureBoot option and apply CSM 
* SATA drive is set for Legacy or a mixture AHCI/IDE and not AHCI 


 AHCI sata can be very difficult to get working

Most Windows installs are already set to AHCI sata, changing this to a legacy IDE mode setting can help but please check if Windows will still boot. Some hardware like Lenovo laptops do not always like being set in legacy mode so only use as a last resort and aware of issues that can be caused. 

Now as far as hardware goes on a newer machine with an NVME drive you may need to add NVME=disable as the NVME driver could potentially cause lockups. 

With a 16C/32T chip machine, disable SMT and it should boot. 


=====ata.device for old BIOS's =====

 Pre 2010 this was the de facto standard method of providing settings to the computer at a lower level 

Some adjustments to the BIOS setup options are necessary (usually by pressing a key like DEL, F1, F2, F12 or ESC, p on the very early boot up of the computer). 

*Adjust booting options like moving USB hdd, CDROM higher as it is quite often disabled or placed lower by default, i.e. USB hdd, CD/DVD are placed at the top above the hard drive. Try looking here [http://www.windowsreinstall.com/articles/bios/ Windows] or [http://www.hiren.info/pages/bios-boot-cdrom Bios] or [http://www.wikihow.com/Set-Bios-to-Boot-from-a-CD-ROM Boot] or web search &quot;BIOS BOOT CDROM&quot;

* At the '''SAME''' time, check if the SATA/AHCI option is set to Emulate or IDE Legacy, though this can have '''issues''' with any OS already on the hard disk. If in doubt, do nothing and seek advice. 

* check that under BIOS settings you '''DO NOT''' have plug&amp;play OS selected as Aros at this point is unable to route interrupts on its own and needs the BIOS to do that. 

'''Save''' options changed at the end. 

PCITool can show if the motherboard chipset is in IDE mode. 
Class = 0x01 means STORAGE, Subclass = 0x01 means IDE. Also ProductID 0x3a20 resolves to non-AHCI mode in Intel ICH10 documentation.


==Installing==

We have a separate section [https://en.wikibooks.org/wiki/Aros/Platforms/x86_installing here]

We have a specific section for each CPU platform under the Specific platforms in the NavBar navigation bar on the right hand side menu 

error code (-6) when using the ahci.device (has writing to disk problem but not reading) is enabled. change this line in your grub and reboot 

&lt;pre&gt;
#module /Devs/ahci.device      &lt;&lt; disable
module /Devs/Alt/ata.device    &lt;&lt; add this line instead
&lt;/pre&gt;


==File structure overview==

AROS' directory structure is mostly identical to AmigaOS directory structure, with some additions.

AROS: or SYS: also known as DH0: (i.e. the drive partition with AROS system) has the following simplified list of the main drawers (Amigas term for directories/folders). 


{| class=&quot;wikitable&quot;
|C:
| small apps, where AROS looks first for applications/games but will look at Tools, System afterwards
|----
|Devs:
| .audio, .hidd, network, graphics and other hardware device drivers are stored
|----
|L:
| where .handler files go 
|----
|Libs:
| where .library files go 
|----
|Prefs:
| applications that adjust or setup AROS functions and capabilities 
|----
|S:
| startup scripts (for the aros boot process '''not''' grub) are stored here
|----
|Storage:
| place to keep old or alternative device drivers
|----
|System:
| applications associated with AROS operating system
|----
|Tools:
| extra applications
|----
|}

See [[Aros/User/DOS#Drives.2C_Files.2C_Assigns.2C_Directories|DOS manual: Drives, Files, Assigns, Directories]]


=== Filesystem ===

Whilst the kernel is the heart, the filesystem is the blood of the system... 

*Journalling     - ZFS XFS ext4 NTFS SFS PFS3 
*Non-journaling  - BtrFS [http://aminet.net/disk/misc ext2] exFAT FAT32(VFAT) FFS 

Filesystem options for AROS to install 
* SFS default 
* Professional File System PFS3 [http://eab.abime.net/showthread.php?t=52234&amp;highlight=pfs3+free&amp;page=13 m68k] 
* FFS very old now but left for legacy usage 

Other [http://archives.aros-exec.org/index.php?function=browse&amp;cat=driver/filesystem filesystems] for storage purposes 
* FAT32 favorite as most OSs support 
* NTFS (can lock system) 
* exFAT 

PFS *minimises* the amount of fragmentation, but does not automatically defrags as it saves files to the drive 

SFS tries to do exactly the same thing, but in certain cases it doesn't do as well as PFS. But since you can defrag SFS 

The only filesystems that really NEED defragging are from Microsoft(TM) - exFAT/VFAT/NTFS

&lt;pre&gt;
Copy L/exfat-handler L:

DOSDriver or Mountlist entry for an exFAT partition make sure that the FileSystem and Handler are set as follows:

FileSystem     = exfat-handler
DosType        = 0x46415458
&lt;/pre&gt;

&lt;pre&gt;
Copy L/ntfs3g-handler L:

DOSDriver or Mountlist entry for an NTFS partition make sure that the FileSystem and Handler are set as follows:

FileSystem     = ntfs3g-handler
DosType        = 0x4e544653

Also to make a read-only mount you can set:

Control        = ro
&lt;/pre&gt;


The Smart File System (SFS) is a journaling filesystem used on Amiga computers and AmigaOS-derived operating systems. It is designed for performance, scalability and integrity, offering improvements over standard Amiga filesystems as well as some special or unique features.  

SFS is written in C and was originally created and released as freeware in 1998 by John Hendrikx. After the original author left the Amiga scene in 2000, the source code to SFS was released and its development continued by Ralph Schmidt in MorphOS. 

Its development has now forked; as well as the original Amiga version, there are now versions for MorphOS, AROS, AmigaOS 3, and a version for AmigaOS 4, which have different feature sets but remain compatible to each other.  Versions for AROS, AmigaOS and MorphOS are based on different branches.  

In addition, there is a driver for Linux to read Amiga SFS volumes, GRUB natively supports it and there are free drivers to use it from UEFI.  The Linux version is [http://home.elka.pw.edu.pl/~mszyprow/programy/asfs/ independent code].  

SFS (Smart File System) partially defragments itself while the filesystem is in use. The defragmentation process is almost completely stateless 

AROS SFS version has a 120GB partition size limit on hard disks and DVDs current 4gig size limit. 
The sources for the MorphOS 64-bit version of SFS were available but no porting to AROS has happened so far due to endian issues, etc. 

SFS Tools 
* GUI - arSFSDoctor, 
* CLI - sfscheck , [http://www.portacall.org/ sfsundelete], sfsformat, setcache hits a usability ceiling around the 10GB / 100,000 file mark, 

 sfscheck dh0: seek purge fraglist defragment

If there are two simultaneous file writes in progress and you reboot machine (or it locks up or crashes) you may end up with a corrupted filesystem. Although arSFSDoctor may help, you might have to copy the files to another partition, format the partition with the errors on and copy the files back. 

A bit error on the harddisk would give this error. 


PFS / SFS are way more advanced and much much faster than the FFS. FFS is supported for legacy reasons only. 
The Professional File System (PFS) is a filesystem originally developed commercially for the Amiga and now distributed on Aminet with a 4-clause BSD license. It is a compatible successor of AmiFileSafe (AFS), with an emphasis on added reliability and speed compared to standard Amiga filesystems.  It also features multi-user abilities like the older MuFS. 

PFS has so many advantages including the important things, speed, the ability to recover all deleted files even simply same name by typing the command &quot;. Deldir&quot; convenient if done in Directory Opus, virtually deleted files are copied normally as if they had never been deleted, other convenience is to not ever invalidate the filesystem, just put it on top of the startup-sequence command &quot;diskvalid&quot;, which automatically corrects any irregularities in the system startup; PFS also provides a device for floppy which makes them very fast and takes advantage of the full capacity of the floppy including the area dedicated to the bootloader.

The device is split into two main areas. At the beginning of the device is the metadata section, which consists of a root block, and a generic array of blocks that can be allocated to store metadata. The rest of the device is another contiguous generic array of blocks that can be allocated to store data. The metadata section usually uses a few percent of the device, depending on the size of the device.

The metadata is stored as a tree of single blocks in the metadata section. The entire directory structure is recorded in the metadata, so the data section purely contains data from files. The metadata describes the location of data in files with extents of blocks, which makes the metadata quite compact.   

When a metadata update occurs, the system looks at the block containing the metadata to be changed, and copies it to a newly allocated block from the metadata section, with the change made, then it recursively changes the metadata in the block that points to that block in the same way. This way, eventually the root block needs to be changed, which causes the atomic metadata update.   

The filesystem is reasonably good at keeping files unfragmented, although there is a defragmentation tool available which will work on an online filesystem ie whilst being used. 

It was the first filesystem to introduce the concept of the Recycle Bin natively at filesystem-level to the Amiga, holding the last few deleted files in a hidden directory on the disk root.  

PFS version 5.3 was developed in C and a small portion of assembly code by Michiel Pelt.  There are endian issues to be overcome and adapting the small amount of m68k to C before use on intel based machines, etc.  


Autoupdate of files in a directory is already implemented in Wanderer, but not all file systems handle dos.library/StartNotify() in its full extent. It seems to work correctly in Ram Disk (thanks to AmberRAM handler), and it also works on SFS formatted devices. Other file systems might not yet have it implemented correctly though. 

The PC equivalent of the Amiga's RDB is the master boot record (MBR).


===Installing Applications===

The typical means to install applications under AROS/AmigaOS involves simply copying/extracting the archive (.zip .lha .rar .tar.gz) file containing the applications files to your own desired location i.e. drawer/folder. Once extracted, launching it by double clicking on an icon (recommended) or using the shell (alternative). Generally, this is on a separate partition from your AROS system files, however in reality it can be any location - including RAM: if you don't want it staying around too long especially when you switch off. 

At some time in the future it may be desirable for AROS to have a package-manager like subsystem able to retrieve information online about packages available for AROS and whether they update anything you currently have installed, however at the moment no such ability exists.


===User Data files===

AmigaOS has no notion of a default location to store user data files, and presently neither does AROS - though it may be desirable at some time to provide a common start location.

For most people, extra small FAT32 NTFS partition(s) as well as the usual Sys: (DH0:) and Work: (DH1:) / Briefcase (DU1:) partitions to store data seems preferable.  Especially if a reinstall is ever needed.  


===User Environment configuration files===

AmigaOS/AROS stores persistent system configuration data in directory assigned to ENVARC:.  This, by default, points to SYS:Prefs/EnvArc.

During boot a copy is made to another assign, ENV:, which is for runtime usage.  Changes to the files here will not survive a reboot.

Setting the env variables is generally done by applications themselves, or when necessary by the user using the SetEnv command. SetEnv has a SAVE switch to force the persistent copy in ENVARC: to be written also for when you are sure the change should be permanent.

Under the standard installation of AmigaOS style OSs, ENVARC: is copied to ENV: upon startup, which, if you have a hard drive installation, is in RAM:, hence, ENV: ends up being RAM:Env.

ENVARC: is the Environment Archive, which is the permanent copy of ENV:, which is the Environment.  It's roughly like the Registry in Windoze. 

Most programs do (and all should) store their settings in ENVARC: somewhere, and load them from ENV:.  The effect of this can be seen in the Preference editors.  If you Save your preferences, they go in ENVARC: and ENV:.  If you click Use, they only go in ENV:.  If you reboot, normally, anything saved to ENV: is lost, and is replaced with a copy of what is in ENVARC:.

you can set the default public screen for any tool started from a cli with the PUBSCREEN variable. So open the pubscreen, set PUBSCREEN to the name and start newcli for example, then the new cli window (and all following windows opened from that window) will appear on that public screen.


===Drivers===

All hardware support is placed in the Devs drawer (folder/directory). The network drivers &lt;something.device&gt; go in the Networks sub-drawer. Audio drivers &lt;something.audio&gt; are put in the AHI sub-drawer. Graphics drivers &lt;something.hidd&gt; are put in the Drivers sub-drawer. 


==Configuring==

AROS has mainly decided on a MUI-like requester/menu/ clone so changing the background, icons, font, menus can be done with SYS:Prefs/Zune 

AROS has several desktop GUI front ends like 
* DOpus5 Magellan II, Wanderer and Scalos (medium) 
* AROS Workbench, Workbook (smaller) 

File / Directory managers like Dopus4, MCAmiga, 

App Launch Shortcuts like FKey, Amistart, BoingIconBar, right mouse click on magellan, wanderer desktop, etc. 

General usability decisions - Prefs/IControl, 


Most apps can be autostarted by copying into SYS:WBStartup directory folder 
e.g. WeatherBar.zip can be downloaded, unzip and the contents of the zip copied to wbstartup folder 
 ClicktoFront and .info to SYS:WBStartup so always be activated when turning on the computer 

or add a text line to user-startup is SYS:S (scripts version of wbstartup) 

e.g. standard Amiga / AROS does not allow clicking of background windows to come to the front to make it easy to get to the window you need but it has the ability if these apps are copied again to WBStartUp or are added to SYS:S/user-startup script 

 run QUIET sys:Tools/Commodities/ClickToFront &gt;Nil: 
 run QUIET sys:Tools/Commodities/DepthMenu &gt;Nil: 
 run QUIET sys:Tools/Commodities/Blanker seconds=300 &gt;Nil: 


Exchange controls Commodities and can be opened with alt, ctrl, h 

Although there are heaps of docks, menus and other launcher programs on the Amiga like OSs, FKey has got to be one of the quickest and less complicated ways to launch programs, and it comes with the OS. 

In SYS:Tools/Commodities, the FKey commodity (Ctrl Alt F) allows you to make actions assigned to some combinations of keys 

&lt;pre&gt;
ALT TAB       Cycle Windows
              Cycle Screens
              Enlarge Window
              Shrink Window
              Toggle Window Size
              Insert Text
              Run Program
              Run Arexx Script
&lt;/pre&gt;

e.g.
&lt;pre&gt;
LAmiga F1               = Avail Flush
LAmiga F2               = Open Prefs
LAmiga F3               = Finder
Alt Tab                 = Cycle Windows
LAmiga Tab or M         = Cycle Screens
Alt Up arrow            = Enlarge Window 
Alt Down arrow          = Shrink Window
Alt Home                = Toggle Window Size 
                        = Insert Text             
LAmiga e                = Run Program             
                        = Run Arexx Script        
&lt;/pre&gt;

If your FKey GUI pops up when you start your Workbench up and you don't want it to, click once on the icon, go to the Icons-Information in the menu and make sure it has the tooltype set &quot;CX_POPUP=NO&quot;. 

Now let's launch it and assign the locale switching. After you double-click on FKey icon, launch the Exchange, choose the FKey from list and click the Show button. This will invoke the FKey window. You can see the ALT TAB in list assigned to window switching. Now enter the first key combination, say, ALT Z and go to the right panel. Choose Launch the program from pulldown menu and enter SYS:Prefs/Input as an argument. Append the USE switch and english preset name to the string as shown:

SYS:Prefs/Input USE SYS:Prefs/Presets/english

Click on the New Button to add the another combination. Now set the combination for your locale as shown above, replacing English name with your preset name. Click New button again and then Save Settings. Now you can use defined combinations to switch the layouts.


Although not needed by most users, the system wide ARexx script capability can manage many file manipulation task(s) but this would work only with those program that support [https://en.wikibooks.org/wiki/Aros/Developer/Docs/Rexx ARexx] like 

*Desktop - DOpus5, Scalos 
*Dock - FKey, 
*Files - Multiview, DOpus4, 
*Internet Apps - Odyssey, WookieChat, 
*General Apps - 


the shell can be modified with escape strings but not needed in most cases 


 Common Keyboard Shortcuts

&lt;pre&gt;
RAlt Right Alt Key 
LAlt Left Alt Key 
RWinKey Right Windows Key 
LWinKey Left Windows Key 
RAmiga Right Amiga Key (if one)
LAmiga Left Amiga Key (if one)
&lt;/pre&gt;

;Bootup Options 
:Spacebar during boot, enters the bootmenu which allows a boot without startup sequence, etc  

;Left Click 
:LAmiga = LWinKey = F11 

;Right Click 
:RAmiga = RWinKey = F12 

;Mark 
:RAmiga and B 

;Cut 
:RAmiga and X 

;Copy 
:RAmiga and C 

;Paste 
:RAmiga and V 

;Search 
:RAmiga and S 

;Mouse Movement 
LAmiga and together with arrow keys - shift as well at the same time as well to move faster 

;Mouse Selection 
LAmiga and LAlt to select 

;Screen Switching 
LAmiga and M or N 

;HELP key 
Can sometimes be mapped to F11 but can be changed via FKey 


===DOpus 5 Directory Opus Magellan II===

Dopus 5.x is a whole desktop replacement on the Amiga Workbench (Desktop)
 
&lt;pre&gt;
Assign DOpus5: SYS:System/DOpus5 
DOpus5:DirectoryOpus 
;DOpus5:C/LoadDB
&lt;/pre&gt;

Left mouse button clicked twice on the desktop background brings up the Device List window. 
Green strip notifies SRCE (source) and if another is open it will be red for DEST (destination). clicking on the red strip changes to green 

Word list of actions with a left mouse click on the DOWN Arrow and directory stuff with &lt; button which mirrors the icons at the top of each lister 

single-key hotkeys? exactly the same as in dopus4, edit your functions (button bank, toolbar, menus etc.) and under the flags gadget is a key gadget, just click in it and press the key you want to use.

As for the extra text field... try turning off Extended lister key selection in environment / miscellaneous.

Shift and click on the icon - runs the icon 


DOpus5 Magellan 2 Directory folder drawer structure 
&lt;pre&gt;
ARexx      - Arexx scripts .rexx and .dopus5 to perform tasks 
Buttons    - 
Commands   - 
Desktop    - 
Filetypes  - 
Groups     - 
Icons      - 
Images     - 
Modules    - compiled tasks 
Settings   - 
Sounds     - 
Themes     - 
WBStartup  - Duplicate for 
&lt;/pre&gt;


Settings -&gt; Environment -&gt; Display -&gt; Workbench (Use) 


*Settings -&gt; Clock (add to title bar as well as the date) 

*Toolbar  -&gt; Editor (Right Win Key together with 1) for Copy, Move, Delete, etc above the Device List 
*Menu     -&gt;  (Right Win Key together with 2) 
*Buttons  -&gt; Editor (Right Win Key together with 3) 

*Settings         -&gt; Environment (Right Win key together with 4) for Backgrounds, etc 
*File Types       -&gt;  (Right Win key together with 5)
*User Menus       -&gt;  (Right Win key together with 6)
*Hotkeys          -&gt; Setup for quick shortcut keypresses (Right Win Key together with 7) 
*Scripts          -&gt;  (Right Win key together with 8)
*Icon Positioning -&gt;   (Right Win key together with 9)


Each Dopus5 theme are stored in a separate directory, named appropriately, which contains further sub directories 

* Font (amiga bitmap fonts)
* Screens (jpg or any picture supported by datatypes but not animations) 
* Sounds (wav but not iff 8svx ) 
* Icons (png newicons glowicons ) 
* Patterns (iff jpg png ) 


Just use wildcards in background filenames and you get a different picture every reboot 

For example, configure in Environment -&gt; Backgrounds -&gt; Desktop something like this:
&lt;pre&gt;
Work:Pictures/Backgrounds/#?
...or 
Work:Pictures/back#?.iff
...etc...
&lt;/pre&gt;


[https://aminet.net/util/dopus arcdir and themes]  


If you want to change the backdrop pic after a period of time, paste below into a text file called dopusrandbg.rexx and place in DOPus5:ARexx 

&lt;pre&gt;
/* Changes DOpus background image forever

   Start with:
   Run &gt;NIL: RX dopusrandbg.rexx 
*/

if ~show(&quot;L&quot;, &quot;rexxsupport.library&quot;) then do
	if ~addlib(&quot;rexxsupport.library&quot;, 0, -30,0) then exit 10
end

/* Configure these two lines for your needs: */
minutes=1
picpath=&quot;Work:Pics/#?.iff&quot;

address DOPUS.1

do forever
	call delay 3000*minutes
	dopus set background '&quot;'picpath'&quot;' desktop center custom
	dopus refresh background custom
end
&lt;/pre&gt;


If you don't want to use/open rexxsupport.library just for DELAY() then use the DOS Wait command

&lt;pre&gt;
/* random diropus backdrop changer */
/* by paul trauth, 1999 */
/* to do: non-repeatable randomness? */

options results

parse arg path

address DOPUS.1

/* get current backdrop pattern so it actually changes */

dopus query background desktop custom
currentpatt=result
lastslash=lastpos('/',currentpatt)
currentpatt=substr(currentpatt,lastslash+1,(pos('&quot;',currentpatt,2)-lastslash-1))

dir=showdir(path,'FILE','/')
num=0
do while dir~=''
    where=pos('/',dir)
    if where&gt;0 then do
        file=left(dir,where-1)
        dir=right(dir,length(dir)-where)
    end
    else do
        file=dir
        dir=''
    end

    if left(file,1) ~='.' &amp; file~=currentpatt then
        do
            pics.num=file
            num=num+1
        end
end

which=random(0,num-1,time(s))
newbg='&quot;'||path||'/'||pics.which||'&quot;'

dopus set background newbg desktop tile precision exact
dopus set background on
dopus refresh background
&lt;/pre&gt;


Clock format commands available are defined by locale. They are:
&lt;pre&gt;
 %a - abbreviated weekday name
 %A - weekday name
 %b - abbreviated month name
 %B - month name
 %c - same as &quot;%a %b %d %H:%M:%S %Y&quot;
 %d - day number with leading 0s
 %D - same as &quot;%m/%d/%y&quot;
 %e - day number with leading spaces
 %h - abbreviated month name
 %H - hour using 24-hour style with leading 0s
 %I - hour using 12-hour style with leading 0s
 %j - julian date
 %m - month number with leading 0s
 %M - the number of minutes with leading 0s
 %p - AM or PM strings
 %q - hour using 24-hour style
 %Q - hour using 12-hour style
 %r - same as &quot;%I:%M:%S %p&quot;
 %R - same as &quot;%H:%M&quot;
 %S - number of seconds with leadings 0s
 %T - same as &quot;%H:%M:%S&quot;
 %U - week number, taking Sunday as first day of week
 %w - weekday number
 %W - week number, taking Monday as first day of week
 %x - same as &quot;%m/%d/%y&quot;
 %X - same as &quot;%H:%M:%S&quot;
 %y - year using two digits with leading 0s
 %Y - year using four digits with leading 0s
&lt;/pre&gt;
like %a %d-%b-%y %H:%M or 


A WB ARexx interface, you could enter a cli command as a menu item to open a WB drawer like this...
 RX &quot;address WORKBENCH;WINDOW 'device:drawer' OPEN&quot;
Where device:drawer is replaced by the path of the drawer to open. 

The ARexx script would be capable to manage such a task but this would work only with those program that support ARexx 

&lt;pre&gt;
dopus addappicon
dopus addtrap
dopus back
dopus checkdesktop
dopus clear
dopus command
dopus desktoppopup
dopus error
dopus front
dopus getdesktop
dopus getfiletype
dopus getstring
dopus matchdesktop
dopus progress
dopus query background, font, palette, pens
dopus read
dopus refresh all, background, icons, lister
dopus remappicon
dopus remtrap
dopus request
dopus script
dopus screen
dopus send
dopus set background, font, palette, pens
dopus setappicon
dopus version
&lt;/pre&gt;

&lt;pre&gt;
lister add
lister addstem
lister copy
lister clear value
lister clearcaches
lister close
lister empty
lister findcache
lister getstring
lister iconify
lister new
lister query active all, dest source
lister query abort, busy, case, dirs, display, entries, entry, files, flags, handler, header, hide 
lister query label, lock, mode, namelength, numdirs, numentries, numfiles, numseldirs, numselfiles
lister query path, proc, position, seldirs, selentries, selfiles, separate, show, sort, 
lister query title, toolbar, value, visible, window
lister read
lister refresh
lister reload
lister remove
lister request
lister set busy, case, dest, display, field, flags, handler, header, hide, label, lock, mode
lister set namelength, newprogress, off, path, position, progress, separate, show, sort, source
lister set title, toolbar, value, variable
lister select
lister wait
&lt;/pre&gt;

The '''command''' allows you to call internal DOpus commands from an ARexx script

&lt;pre&gt;
command all
command wait copy
command read s:startup-sequence
command source 12345 makedir name noicon
&lt;/pre&gt;


*SFTP secure encrypted comms over internet using libssh2 and zlib (different protocol to the two below) on port 22 
*FTPS secured with https like security on port 21 
*FTP not secure and unencrypted protocol over internet on port 21 (should not be used today on the internet but for your own server) 


===Wanderer ===

Backgrounds icon text sizes, colors, etc. with wanderer prefs in the prefs drawer but cannot use #? or *.* in the backgrounds file entry to randomly choose pictures 

Enable the bar, you need to edit the text file ‘statusbar.prefs’. The change is simple: just change “False” to ‘True’.

Prefs/Env-Archive/SYS/Wanderer/statusbar.prefs

Provides a way to hide the old Workbench 3.1 style of windows and screens. 

Themes - SYS:Prefs -&gt; Appearance 
The default content of Prefs/Env-Archive/SYS/themes.var should be &quot;themes:ice&quot; but can be changed via the theme prefs, please do NOT click the Use button. Its useless. As you know, it will ask for the theme volume. Just pick the theme you want, click on Save, then reboot. 

* Decoration is on. Any time trying to change theme, you get: &quot;Please insert volume Theme: in any drive&quot;? 
You could check if you find SYS:System/Themes or if it is missing. Then you could open startup-sequence which you can find in drawer &quot;S&quot;. There should be a line: 
 Assign THEMES: SYS:SYSTEM/THEMES &gt;Nil: 
This does the trick. 
Open a shell and run: 
 Assign THEMES: SYS:SYSTEM/THEMES 
Than start the Theme prefs again... this should work 

* The theme is the only thing that could slow the system a bit, but it's not that performance impacting on most uses, and you can switch it of completely. Remove C:Decoration from the bottom of the file sys:s/startup-sequence. 

[http://archives.aros-exec.org/index.php?function=browse&amp;cat=graphics/theme ALua/Zulu script] built for faster Wanderer skin management. You can modify config files, install new (wdz format/zipped skin files) and delete skins via the Theme Manager. 


[http://sites.google.com/site/arosaspireone/download-1 Global.Prefs] 


===Scalos===

[https://web.archive.org/web/20180922220139/http://scalos.noname.fr/ Scalos] is not an OS replacement, it's a Workbench replacement. It replaces the desktop and graphical file management components. 

Scalos is 100% Workbench replacement with most functions working like the original Workbench ones. Undo and Redo available for most window and icon operations. Fully multitasking so every window has its own task. While loading icons, any window function (e.g. Drag&amp;Drop) is available. 

24bit color support with window patterns - Unlimited and easily configurable via tooltypes. Optimised backgroundpatterns routine so patterns can be tiled, centred or even scaled to fit into the windows. Live updating window scrolling - Supports middle mouse button panning and drawer (folder) windows can be iconified on the desktop. 

Icon imagetypes with all types are supported such as backfill or complement. Configurable surrounding iconborder. Icon support also visually highlights files which are soft-links in the file system. Icon dragging is more stable and far less flickery on graphics cards. Whilst dragging, icons are displayed with text and they can become transparent over anything where they can be dropped. 

Single-window lasso mode, with scrolling window contents invoked by dragging mouse with configurable qualifier key. Text icon lasso selection used to ignore &quot;Name column selects text icons&quot; flag. Support for backfilled thumbnail icons, with selectable color and transparency. Added option to always generate square thumbnail icons with preview icons for images - Thumbnails can be permanently saved in icons. 

Supports PNG icons with alpha channel and real transparency and displays OS3.5 GlowIcons and are all scalable. Iconborders with variations (normal, shadowed, outlined). 

Completely configurable, filetype-specific user-definable popup menus and tooltips. Plugin system to exchange or add features and can enhance the Workbench and make it more configurable. 

Filetype plugins to display filetype-specific information. - Currently, EXIF information viewer for JPEG images is included. Plugin included for 100% support of OS3.9 Workbench features. Plugin included for AREXX API compatible to OS3.9 Workbench. 

Online update with updater.module


Scalos works also as a Workbench replacement. In this case the 'emulation mode' has to be set by using Scalos' own version of LoadWB and offers 
* Scalos uses the Workbench Screen for its windows instead opening a new one 
* AppIcon, AppMenuItem, AppWindow functions are redirected to Scalos
* all Programs placed in &quot;WBStartup&quot; should start 
* The Screen will be reopened in case of changes in ScreenMode and Palette settings


&lt;pre&gt;
v1.0 (V39.201) - November 1999
v1.1 (V39.212) - December 1999
v1.2b (39.220) - June 6, 2000
v1.2d (39.222) - 2000 (latest public beta executable)
v1.3 (40.7) (beta) - August 2, 2001
v1.3 (40.22) - September 25, 2002
v1.4 (40.32) (beta) March 31, 2005
v1.6 (41.4) - March 27, 2007
v1.7 (41.5) - August 12, 2007
v1.8 (41.6) - March 12, 2009
v1.9 (41.7) (beta) - March 15, 2010
v1.9 (41.8) (RC1) - August 25, 2012 open source 
v1.9.2 (41.10) Deadwoods' AROS late 2022 32bit and 64bit build unifying the code base of ` for AROS x86 ABIv0, AROS x86_64 ABIv11 and AROS m68k  
&lt;/pre&gt;


Distros may have Scalos files under SYS:System/Scalos or Extras:Scalos. Known [https://github.com/deadwood2/AROS/issues/75 bug list], 


 Certain files like Menu13.prefs, Palette13.prefs, Pattern.prefs and scalos.prefs need to be in SYS:Prefs/Env-Archive/Scalos they can be found in Scalos:Storage/envarc and country drawer 

or run the &quot;Scalos Menu&quot; preferences program. Note if already setup with sub-menu entries and then re-save your menu prefs as it will now generate a new/overwrite prefs file called &quot;Menu13.prefs&quot; in &quot;envarc:scalos/&quot;. The same is also required for the new Palette prefs update, click 'Save' and a &quot;Palette13.prefs&quot; file will be saved in to &quot;envarc:scalos/&quot; directory. 


&lt;pre&gt;
ASSIGN Scalos:             SYS:xxx/xxx DEFER   
ASSIGN Libs:               Scalos:Libs add    
;ASSIGN SYS:Devs/Datatypes  Scalos:Devs/Datatypes   add  
Assign Theme:              Scalos:Themes/Default_Theme add 
Assign Locale:             Scalos:Locale add 

Protect Scalos:Tools/browse.script s add quiet 
Protect Scalos:Tools/OpenShell s add quiet 
Protect Scalos:Tools/run.script s add quiet 

run Scalos:Tools/LoadWB 
;Scalos:Scalos
&lt;/pre&gt;

Add the above to SYS:S/startup-sequence or SYS:S/user-startup '''before any Wanderer entries''' 


In the prefs drawer (folder) is the big prefs app Scalos_Prefs which covers these user setup areas 
&lt;pre&gt;
About Scalos
Paths               - should be preset 
Startup             - WBStartup drawer contents should auto run on each startup 
Desktop             - edit titlebar, icon layout and in misc, auto leave-out (drag icon to desktop) 
Icons               - 
Drag and Drop       - 
Windows             -
Text Windows        -   in misc, drawer sorting at start of listing if needed 
TrueType Fonts      - use Truetype fonts rather than system ones 
Miscellaneous       - 

Plugins             - after adding oop/title_clock.plugin %ti %da does not work, maybe needs ASCII .prefs added 
Modules             - ??
Menu                - setup for MainMenu and PopupsMenu with New Menu, RE Name, Key: shortcut, Command Properties 
FileTypes           - already added def_Project icons and def_Disk (hdd sdd cd dvd etc) support 
PopupMenu           - tweak how popups appear 
Pattern             - Wallpaper backgrounds with Type DE, each pattern in the list can be edited, Save as Pattern.pre 
Palette             - change the color of things , Save as Palette.pre 
&lt;/pre&gt;


Scalos_Prefs - Pattern - Minimum options to be changed are 
*DE Desktop/Background 
*SC Screen 
*TW Window/TextBackground ie Text listing showing if icon type not recognised 
*IW Window/Background ie Icons showing 

 Workflow - In &quot;Pattern List&quot; tab, select New - choose a picture, highlight in list, click in number box under New button and slide to another number, click on &quot;Defaults&quot; tab and adjust Pattern numbers slider to choose right picture for each of the above options - Click &quot;Pattern List&quot; tab to check eveything is OK and click Save 

Pattern List tab on Patterns Page - Allows you to compile a list of pictures (one at a time rather than a whole folder e.g. with #? or *.*), assigning a number Nr to one or more of them for easy reference. Using this number you will be able to assign the pictures to specific windows on the Defaults tab Page. If multiple pictures have the same number, one of the pictures will be chosen randomly. This will allow you to have random desktop pictures, random window backdrops etc. 

Defaults tab on Patterns Page - Here you can set the defaults for the background pictures for the Desktop, Screen, Window and/or Text Mode throughout Scalos. 
Randomize every time [check box] - Usually Pictures with the same number will be randomly selected as soon as the configuration loads. If this option is set, the picture will be selected as soon as a window with the same number assignment is opened. 

*Fit size: The picture will be resized to the dimension of the new window.You *MUST* have set GUIGfx on. asyncron layout: Pictures will be loaded and rendered while the windows opens (Like original Workbench). If this function is 'off', pictures will always be loaded before opening the windows. 
*Use friendbitmap : The picture is present twice in memory for best speed. This option has no effect if V43 picture.datatype or GUIGfx are used. Always relayout: If &quot;Fit size&quot; is set, the picture will be scaled everytime the window's dimensions change.
*Randomize everytime: Usually Pictures with the same number will be randomly selected as soon as the If more pictures have the same number, one of them will be chosen randomly. 

Patternlist New/Delete : Add a new picture. After that you should assign a number to it. The picture will be rendered as tiles. configuration loads. If this option is set, the picture

Asyncron-Task priority: You can set the CPU priority for the Task if &quot;asyncron layout&quot; is set. 
&lt;pre&gt;
Desktop: Number of the Picture for the main window.
Screen: Number of the picture for the Scalos-Screen.
Window: Number of the picture for the Scalos-windows.
TextMode: Number of the picture for the Scalos-windows in Text Mode.
&lt;/pre&gt;


Popup Menu preferences fully configurable menus (includes ToolsDaemon and ParM launch apps import), including support for context-sensitive Popup menus configs for top pull down menus for apps, etc. 

 Workflow - Scalos_Prefs then Menu, New Item, New Command add name at top then in Command Properties e.g. add Workbench and location e.g. DOpus:DOpus4 for apps  Command for c apps or Rexx for scripts or Plugin for  or AmigaDos for modules 

&lt;pre&gt;
DESCRIPTION	NAME/A      This is the title that is displayed in the top line of any popup menu  
INCLUDE NAME/A          Name of file to be included. Path can be relative to &quot;Scalos:FileTypes&quot; 

POPUPMENU      Starts the popup menu description section for this filetype.
&lt;/pre&gt;

The following Subcommands are allowed inside popup menus:
&lt;pre&gt;
SUBMENU &quot;NAME/A&quot;
ENDSUBMENU 


MENUENTRY &quot;NAME/A,KEY/K,DEFAULTACTION/S&quot;
ENDMENUENTRY 

INTERNALCMD	&quot;NAME/A&quot;
WBCMD &quot;NAME/A,STACK/K/N,WBARGS/S,PRI=PRIORITY/K/N&quot;
AREXXCMD &quot;NAME/A,STACK/K/N,WBARGS/S,P=PRIORITY/K/N&quot;
CLICMD &quot;NAME/A,STACK/K/N,WBARGS/S,P=PRIORITY/K/N&quot;

ICONWINDOWCMD &quot;NAME/A&quot;

PLUGINCMD
MENUSEPARATOR

ENDPOPUPMENU

TOOLTIP 
ENDTOOLTIP
&lt;/pre&gt;

&lt;pre&gt;
Starts the tooltip description section for this filetype. The following Subcommands are allowed inside popup menus:

GROUP &quot;ORIENTATION/K&quot;
ENDGROUP  
MEMBER &quot;HIDE/K&quot;
ENDMEMBER  

HBAR 
STRING &quot;ID/K,TEXT/K,SRC/K,TEXTPEN/K,HALIGN/K,STYLE/K,FONT/K,VALIGN/K&quot;
SPACE &quot;SIZE/N/A&quot;

DTIMAGE &quot;FILENAME/A&quot;
&lt;/pre&gt;


Each theme drawer (folder) has these further folders 
&lt;pre&gt;
About            - 
Desktop          - 
FileTrans        - 
FileType         - 
Icons            - 
Menu             - 
Modules          - 
PointerIcons     - 
Prefs            - 
Sound            - 
Window           - 
&lt;/pre&gt;


*Plugins
&lt;pre&gt;
devicefilter.plugin       
persist.plugin            should a crash or reboot occur - next time Scalos started, all windows re-opened 
title_clock.plugin        add digital clock to title see more below 
title_envvar.plugin       %ev, which can be used to display the value (a string) of the variable in the titlebar 
title_freepens.plugin     
volumegauge.plugin        
wb39.plugin               
wbrexx.plugin             plugin adds a Workbench 3.5+ compatible AREXX interface to Scalos internals 
xtwindows.plugin          left or right ALT or left or right SHIFT keys when open/close windows 
filetype.plugin           then run FileTypes-prefs and customize the filetypes (eg import from a DefIcons-brainfile) 
menu.plugin               
&lt;/pre&gt;


*Modules - delete, empty_trashcan, execute, find, format_disk, information, iconproperties, newdrawer, reboot, rename, systeminfo, windowproperties 


*Tools - scripts like LoadWB, quit.rexx, open_volume.rexx, 


In Scalos_Prefs-&gt;Filetype-&gt;Recognition  you can define the filetypes and on &quot;Action&quot; you define specific context menu for all filetypes defined in recognition (similar to magellan)
there is the same you must show all first (list is only limited) so you created a file type AAABBB, you need to have def_AAABBB icon 

Associating files with &quot;Scalos_FileTypes&quot; is very simple, practically it is very similar to Dopus4, first you create the Def_icons to assign to the file type (will be seen automatically ), then run &quot;Scalos_FileTypes&quot; you add the extension, fill in the descriptor (MATCH or PATTERN etc..) and save 

then you create a appropriate entry in the list and rename it, if def icon exists it is shown. Below you can define how files are identified. I use &quot;pattern&quot;, similar to magellan to identify file by ending. Then you click on the shown icon and define in it what program is used when you double-klick on it and save it. On the tab action you can define popup menu for it. 

defined all archive types from XAD in &quot;filetypes&quot;. If you change to &quot;action&quot; and click on &quot;archive&quot; you can define the context menu that is shown if you do not define a specific context menu for a filetype


Reset to Default in Scalos_Prefs resets all settings so BEWARE 


&lt;pre&gt;
The Scalos desktop screen titlebar may be configured using the main Scalos Preference program. This oop/time_clock plugin adds some additional placeholders:

    %ti, displays the current time in the default Locale format. e.g. &quot;10:43:37&quot;
    %da, displays the date in the default Locale format. e.g. &quot;Saturday 14 July 2001&quot;

Using the supplied prefs program for the plugin, or editing the ASCII file ENVARC:Scalos/title_clock.prefs you can use the following standard Amiga Locale values to change the formatting 

    %a - abbreviated weekday name
    %A - weekday name
    %b - abbreviated month name
    %B - month name
    %c - same as &quot;%a %b %d %H:%M:%S %Y&quot;
    %C - same as &quot;%a %b %e %T %Z %Y&quot;
    %d - day number with leading 0s
    %D - same as &quot;%m/%d/%y&quot;
    %e - day number with leading spaces
    %h - abbreviated month name
    %H - hour using 24-hour style with leading 0s
    %I - hour using 12-hour style with leading 0s
    %j - julian date
    %m - month number with leading 0s
    %M - the number of minutes with leading 0s
    %n - insert a linefeed
    %p - AM or PM strings
    %q - hour using 24-hour style
    %Q - hour using 12-hour style
    %r - same as &quot;%I:%M:%S %p&quot;
    %R - same as &quot;%H:%M&quot;
    %S - number of seconds with leadings 0s
    %t - insert a tab character
    %T - same as &quot;%H:%M:%S&quot;
    %U - week number, taking Sunday as first day of week
    %w - weekday number
    %W - week number, taking Monday as first day of week
    %x - same as &quot;%m/%d/%y&quot;
    %X - same as &quot;%H:%M:%S&quot;
    %y - year using two digits with leading 0s
    %Y - year using four digits with leading 0s

 like %d %m %y or %a %d %B %Y %p
&lt;/pre&gt;


Shutdown -&gt; right mouse button Scalos, About, Reboot, Shutdown 


ToolTypes can be added to the Scalos.info icon like 
*SCALOS_PATTERNNO=&lt;number&gt; : background image matching the number 
*SCALOS_NOTEXT : The Icon will be drawn without Text.
*SCALOS_NODRAG : The Icon will not be draggable. Its position will be fixed.
*Module iconproperties - Added SCALOS_BROWSERMODE tooltype support

runcommand parameters... in which case:
&lt;pre&gt;
%p = parameters
%w = directory path
%d = device-name
%% = literal percentage token
&lt;/pre&gt;


With the help of the wbrexx.plugin Scalos gains support for more of the compatible arexx API 

If an arexx command produces an error you will find the error code placed in the WORKBENCH.LASTERROR variable.

ACTIVATEWINDOW
&lt;pre&gt;
/* Activate the root window */
ADDRESS workbench
ACTIVATEWINDOW root

/* Activate the &quot;Work:&quot; partition's window if already open*/
ACTIVATEWINDOW &quot;Work:&quot;
&lt;/pre&gt;

CHANGEWINDOW
&lt;pre&gt;
/* Change the root window; move it to position 10,30. * and change its size to 200100 pixels */
ADDRESS workbench
CHANGEWINDOW root LEFTEDGE 10 TOPEDGE 30 WIDTH 200 HEIGHT 100

/* Change the currently active window */
CHANGEWINDOW active 20 40 200 100
&lt;/pre&gt;


Most of Scalos' issue are due to the flexibility of its' user configuring nature but if 


The sort menu plugin needs to be ported from ASM to C.

IIRC Scalos has a command line option to fully replace Workbench/Wanderer.

The Theme: assign is used by both Wanderer and Scalos but I didn't have any problems using both at the same time.


The Program will be started from the Shell.
If &quot;WB Args&quot; is set, with the Argument &quot;%p&quot; will be replaced by the path of the activated Icons. The Program will started with the specified Stack value.
IconWindow: Scalos opens the window of the specified path.


PlugIn: Starts a Scalos Menu-PlugIn.
If a Menu Item with empty name is specified, Scalos displays a separator line.
It's possible to Drag&amp;Drop an Icon in the Configuration Window. All values will be set accordingly. Entries may be dragged across the list.


Mac-like selection : This function activates a multiselection method used on MacOS or Win95. Don't have to hold down shift to drag them. Clicking on an already activated icon will
not deselect all other icons. 

MMB move: The window contents may be moved using the middle mouse button. 

WindowPopup title only: PopupMenu for windows can be opened only on window's title bars. 

FullBench: Screen-Titles removed and Main Window set Full Size. 
Scalos Prefs. Go to Settings-&gt;Scalos-&gt;Prefs and then the Misc section. Remove the tick against Full Bench. If you've enabled it, the titlebar will disappear when you select backdrop.


Default Icons saveable : The icons which Scalos generates if &quot;show all files&quot; is enabled, can now be saved
using &quot;snapshot&quot; menu option. load DefDisk first : Try to read the icons first from the DefIcons Path before using disk info. 


Hide hidden files : If this function is activated all files or directories where the &quot;hide&quot; flag is set will not be shown.

Many of my Icons display more than once on the screen, while on the workbench all seems ok.
The Workbench filters double displayed icons, Scalos does not. Solution: please edit the &quot;.backdrop&quot; file and clear double lines.

Background images not scaled. GUIGfx option not set or guigfx.library and/or render.library not installed.

If working with CD's causes crashs or Scalos doesn't work correctly.
Most Filesystems doesn't support the ExAll function correctly. Disable &quot;Use ExAll&quot; in Scalos prefs.

Scalos doesn't start any program in the WBStartup. WBStartup Path may be set wrongly or Scalos was not started in Emulation Mode (LoadWB etc) 
Some programs will not startup with error message &quot;has not returned, wait some more&quot;? and &quot;unable to open your tool&quot; 


need a def_icon with the same name predefined, then create an appropriate entry in the list and rename it, if def icon exists it is shown. Below this can define how files are identified. 
* either &quot;pattern&quot;, similar to magellan to identify file by ending
* or 
Then click on the shown icon and define in it what program is used when you double-click on it and save it. On the tab action you can define popup menu for it. All in all handling is of course different to magellan but can do similar 

For the RAM Icon, to obtain this you have only to copy the icon in the Icon Path as &quot;RAM.info&quot; or &quot;Ram Disk.info&quot;. All functions will automatically be performed 

sometimes cut into half or quarters when scrolled off screen or drawers moved - settings issue probably  

Sometimes leaves initial drawer window imprint on desktop when moved - settings issue 


Scalos AROS released a [https://github.com/deadwood2/contrib/tree/master/scalos new build V2022-07-21] with the following changes noted:
&lt;pre&gt;
Fixed:
    Numerous crashes when working on 64-bit with 64-bit heap
    Wrong background color of Scalos logo on Scalos splash window
    Backgroung image of Scalos splash window and Scalos About window is not visible
    Icon labels on desktop and in drawer windows are displayed using Topaz instead of Arial font
    Font.prefs are not being loaded on 64-bit
    Font.prefs are being wrongly saved on 64-bit
    scalos.prefs are not being loaded on x86 and x86_64, scalos is using always default preference
    scalos.prefs are being saved on x86 and x86_64 in format not compatible with m68k 
    NewPopupmenu.prefs is wrongly written
    Plugins are not loading at Scalos startup
    wbrexx.plugin is crashing at startup on 64-bit
    Multiple controls missing on Scalos Prefs/Icons page
    System crash when clicking on def icon image on FileTypes Prefs/Recognition page
    Status bar, control bar, buttons sometimes don't have images displayed
    Buttons in Scalos About window have white corners rendered where they should be transparent
    Crash when leaving out an icon
    Crash when adding a User-defined Button to Control bar without setting it's properties in Scalos Prefs
    Crash when removing any button from Control bar in Scalos Prefs
    Scalos Prefs allows editing TTEngine font properties when TTEngine is not present causing crash in Icons/Labels and Text Windows/Fonts pages
    deficons.prefs are not being loaded on x86 and x86_64
    Reset to default in FileType Prefs and Save does not save preferences

Won't fix:
    Scrollbars visible on titles of TrueType Fonts, PopupMenu, Menu, FileTypes, Pallette and Pattern pages of Scalos Preferences

Not fixed:
    Wrong rendering on DualPNG icons 
    Refreshing drawer windows is slow 
    Starting Prefs/Locale or Prefs/Input from Scalos causes other preferences to fail 
    Desktop wallpaper is damaged where Splay window was displayed 
    When started from Wanderer, after saving Scalos Prefs, reload does not re-open main Scalos window
    Difference in behavior between Cleanup from popup menu and Cleanup from top menu - possibly due to missing plugin, check Cleanup association in Menu Prefs
&lt;/pre&gt;


===DOpus 4 Directory Opus===

Copy DOpus4 app to WBStartup directory folder so it starts on boot up each time 

Another method is add the below to the bottom of the user-startup script in S: drawer/directory 
&lt;pre&gt;
run DOPUS:DirectoryOpus -i &gt;NIL
&lt;/pre&gt;
makes DOpus starts up in Iconified state at the top of Wanderer's screen. Left click on this to highlight and right mouse click to open. 


Just click on the sides of either outer edges of DOpus windows and it will display the parent device/volume list. 


DOpus saves it features in a CFG file which can be edited to suit anyones' needs by reading the [http://archives.aros-exec.org/index.php?function=browse&amp;cat=utility/filetool Dopus Manual] which is in Guide format. 


===AmiStart===

Auto generates the apps menu but scans the drive each time - AmiStart can choose apps you are not interested 

* how to disable annoying zune/mui 'bubbles'? 
try a right-click on AmiStart and release on Global settings. Then click on the bubbles gadget. Move the Show Bubbles slider all the way to the left.


===BoingIconBar===

User chooses the apps to add to the dock at the centre bottom of the screen but has to be done manually, please use Save afterwards 

Or easier edit the text file of SYS:Prefs/Env-Archive/iconbar.prefs and save 

&lt;pre&gt;
SYS:System/Shell 
SYS:Tools/DOpus4/DOpus4
SYS:Utilities/Editor
SYS:System/SysMon
SYS:System/Scout
Work:Extras/Internet/OWB/OWB
Work:Extras/Graphics/Lunapaint
Work:Extras/Graphics/ZunePaint
AROS:Tools/MPlayer/MPlayer
Extras:Internet/AmiFox/AmiFox
&lt;/pre&gt;

right mouse click on bottom edge of screen where boingiconbar shows - select settings which opens BoingIconBar Preferences to add apps 

If no dock showing Add, to add apps click Add Program and search for the executable 

another method is to drag icons to ends of the bar and move them on the Bar using the Prefs/BoingIconBar 


===Icons===

Icons are typically now .png pictures renamed as .info e.g. so Office application name would have a Office.png renamed as Office.info or MyApp.png as MyApp.info, etc.  

Leave Out menu option to leave app icon on desktop 

To select multiple icons and save their positions, click on the first icon and after while you hold the Shift key down select further icons and don't release it before SnapShot is finished.  You can also select a whole group of icons by pressing the LMB at the top left of the icons and while keeping the LMB down moving the power towards the bottom right. A expanding bounding box will appear and all the icons within it will be selected.  

Clean Up menu option (right mouse button -&gt; Icons) rearranges icons in a drawer or disk window into a neater condition. To use, open the window to rearrange and select Clean Up. To keep the icons in the new positions, select all the icons (shift key or mouse selection) and select 'Snapshot' and then Window and then again with All.  

In DOpus5, Scalos, wanderer, most files have an icon file associated with it. To change the default tool, select Icon menu, Information, and change the default tool string. For example, you could use Multiview, Editor and so on for most text, graphics and some sound files as long as the appropriate Datatype classes are installed. For scripts, set the tool to C:IconX 

C:Join Image1.png Image2.png TO MyFile.info
is enough to make a dual state icon from two png images. You can then use Wanderer's menu Icon/Information on it to edit its fields and tooltypes.

[http://www.amiga.org/forums/archive/index.php/t-46881.html Amiga OS 3.x AfA icons thread], [http://eab.abime.net/showthread.php?t=66213 Later DualPNG and OS4 icons thread] and [http://archives.aros-exec.org/share/graphics/icon/ Alternative Icons sets] like [http://www.amiga-look.org/artwork/classic-wb-png-iconset-l ClassicWB] 


[http://www.masonicons.info/6.html AISS toolbar images] unpack unarc them into RAM: and copy Images directory to SYS:Prefs/Presets/ 

AISS icons are looked for in PROGDIR:, PROGDIR:Images, SYS:Prefs/Presets/Images and then in TBImages: according to Open Amiga guidelines.  

there is Demos/iconscale which could be launched from S:User-Startup with two arguments, telling it the horizontal and vertical size. IE something like 
 Demos/iconscale 40 40

It will shrink icons... not sure if it will be very nice though. it doesn't work for the icons on the main desktop. 

there is an option to scale an icon to a bounding box afair, try iconsize followed by two numbers, like:
iconsize 32 32

Is there any way in AROS to change an icon type from Project to Tool or vice versa?
Either the SIT option of [http://archives.aros-exec.org/index.php?function=showfile&amp;file=utility/workbench/ ProcessIcon], or the TYPE option of HandleInfo (not sure if this one works at all, please test with care).
 processicon sys:pathoftheicon SIT=Project 

SIT Set type of ICON. Allowed types are: &quot;Disk&quot;, &quot;Drawer&quot;, &quot;Tool&quot;,  &quot;Project&quot;, &quot;Garbage&quot;, &quot;Device&quot;, &quot;Kick&quot; and &quot;AppIcon&quot;.

Btw, are your icons, the #?.info files, writable, is the W flag set ?


===Fonts===

Install the #?.ttf files to SYS:Fonts/TrueType. Use SYS:System/FTManager to &quot;Install Font&quot; each #?.ttf file which will generate associated #?.otag and #?.font in SYS:Fonts. Use SYS:Prefs/Fonts to change system fonts and SYS:Prefs/Zune to change others. 

To achieve our goal we will use the Setup Locale, Input, Zune and Fonts, as well as The FTManager.

Begin

The first step you should do is to get the system to know that we speak and write in another language. What you need to do is to open the setup program and choose Locale country, and list &quot;preferred languages&quot; to put it first and then English. If you want the tab &quot;Time Zone&quot; and select city of residence to set the clock correctly. Of course we save our changes and continue opening the setup program Input. This sets the keyboard language as our beginning. When the language layout was created there was no option to switch to Aros keyboard (layout switching), so to write in the language you had to hold down Alt, something you encounter in other functions. This time working with the team of Aros to create a new keyboard layout to replace the old so we can get rid of the button Alt. For now though let only selected this layout and do not turn the switch on the keyboard.


Custom Keyboard Layout

[http://repo.or.cz/w/AROS.git/tree/HEAD:/workbench/devs/keymaps keymaps are in place but unfortunately when they are not, then indeed things become a bit 'low-level' as it involves redefining some tables with values that match your keyboards] 

only need to add your compiled table as new keymap. 

So taking a little peek here shows that it should be possible to compile using
 gcc -opc105_tr pc_105.c -nostdlib
where the pc105_gr/pc_105.c needs to be replaced with your own adjusted keymapname/c-file

[https://en.wikiversity.org/wiki/Enabling_Greek_Characters_on_Your_Keyboard General overview of Greek letters on keyboards] 


Installing fonts

*[http://aminet.net/package/util/wb/EPAGrWb System jaggy] 
*Outline resizable .font .otag 
In this step you need to download some fonts that can support the encoding in our system. The easiest way is to run the script &quot;Download Fonts&quot; you'll find in the folder OWB. This script downloads from the Internet, and unpacks some fonts for OWB web browser, which is placed under the folder Fonts:TrueType. But as these can only be used by OWB and not the system, which unfortunately does not see. To make them available to the rest of the system, open the program FTManager, you will find the folder AROS: System /. From there select the field &quot;Codepage&quot; option &quot;ISO-8859-7&quot; and list the font &quot;Arial&quot; and &quot;Regular&quot; form in which you must double-click with the mouse. In the window that appears, select the bottom right the checkbox &quot;Anti-aliasing&quot; button and then &quot;Install&quot;. Immediately folder Fonts: created files &quot;arialregular.font&quot; and &quot;arialregular.otag&quot;, which are necessary in order to see the system font. Do the same steps if you wish for other fonts.


Final stages 

After completing the above, open the folder AROS: Prefs / and run the program settings Fonts. In the new window, select the fields &quot;Icons&quot; and &quot;Screen&quot; as the font &quot;ArialRegular&quot; to the size you want. In the field &quot;System&quot; to give &quot;s_courier&quot;, which, however, because it is not True Type Font support Antialising, and may seem a little broken. You can also use the CourierNew, if you have installed the above procedure. After you save the changes and open the Zune program settings. In this set the &quot;ArialRegular&quot; font fields in tabs &quot;Windows&quot; and &quot;Groups&quot;, and save the changes. Reboot the system. To make sure that the above worked properly run NoWinED, which you will find under the folder AROS: Tools /. If that everything is working correctly you will see the menu and the settings window with Greek letters. You can also write in the language using the button Alt. Second program that you can try, which is fully localized, is WookieChat, which you will find in the folder AROS: Extras / Networking. And in this place all the menu and settings window works. 


===Windows===

*Intuition
The window you position and resize, you right click on that windows title bar and in the dropdown menu you snapshot from there.  Right click to show menu -&gt; Window -&gt; Snapshot Windows or All but it will NOT work if that folder has no icon (e.g. Disk.nfo) attached to it. You need a folder icon. The window information gets saved in it.  

As for maximising the window using a shortcut key - Alt and up arrow key 

The AROS-Shell windows can be moved, resized by editing sys:s/icaros-sequence 

&lt;pre&gt;
; run shell
if ${Icaros/autoshell} EQ true
  run QUIET c:newshell &gt;NIL:
EndIF
&lt;/pre&gt;

; slimmer right aros the screen 
run QUIET c:newshell con:0/150//300/ &gt;NIL:

; top right corner scr-x scr-y win-x win-y
run QUIET c:newshell con:600/150//300/ &gt;NIL:


*Zune - AROS version of MUI
Magic Menu type functionality is implemented in IControl preferences editor: in the frame called Menus, switch type from Pull-Down to Pop-Up and/or iControl just tick the sticky menu option. 


Windows outside screens causing a problem either uncheck &quot;Offscreen move&quot; for windows in IControl prefs editor. Or use FKey commodity and define two key shortcuts: 

* the first using the command &quot;cycle windows&quot; (for example ALT TAB); 
* the second using the command &quot;rescue window&quot; (for example ALT F5). 

Now you can cycle windows until the one you want to rescue, and then &quot;rescue&quot; it: it will move back inside your screen. 


How to save the window size on wanderer (snapshot all, snapshot windows)

Same for icon position on wanderer, can't save the position. Icon position cannot be saved yet, but you should be able to save the window position and size. sys:prefs - wanderer icon has option to save window size on exit but just for dh0. To get saving working on (DH1: Extras:) partitions try deleting the dh1 disk.info file, then reboot. The system should create a new dh1 icon. 


* how to set up permanently 'view all files'?
As for viewing all files, removing disk.info for that disk did the job 

* how to list and kill processes (xkill would be useful) ? 
sys:Extras/System/Scout can kill apps 

sys:Tools/Commodities/Exchange can remove available commodities


* how to restore 'go up' button in wanderer window? (it doesn't show up anymore).
If you're using Icaros, go to the theme prefs and make sure that decoration is checked. Also, some themes do not use a parent button, so try another theme. You may have to restart Aros before the theme will change.

* Is it really safe to turn off (hardware button) computer at any time (worried about USB hard disk)
yes you can turn off the computer IF none of the drives are in progress (i.e. writing). Best to use Wanderer menu option Quit otherwise 


===Printing===

This is still work in progress 


print from my AROS box!
&lt;pre&gt;
1. installed printfile ( http://www.lerup.com/printfile/ ) on my Windows XP computer
2. set up the print spooler option, and used ghostscript filter for ps files
3. made the spool folder accessible from ftp (setting up ftp server on Windows)
4. send the ps file from my AROS box to the ftp server using curl (curl -T filename ftp://windows.box.adress --user username:password)
&lt;/pre&gt;
It's a bit complicated but it works!


*Postscript

Best to set Printer Prefs in the Prefs drawer to print-to-file or parallel/USB port 


Save document in postscript or convert picture/text to postscript 

Print using compatible [http://en.wikibooks.org/wiki/Aros/Platforms/AROS_USB_support#printer.class_-_PostScript_3_and_internal_ghostscript_drivers Ghostscript printer] or Postscript printer 


*GutenPrint

Some work has been done 

;There are no individual drivers yet for HP's Photosmart, EPSON's EPL, CANON's, Lexmark, CUPS PPD, etc. 


===Files===

====File endings and datatypes====

* Check if the file has his own .info icon file with a tool set to open it. IIRC this has higher priority over the def_XYZ.info file association. 
* In ENVARC:SYS/def_Text.info or whatever def_ file needs changing, use Wanderer's menu Icon -&gt; Information and change the def_XYZ.info there. If you're on ABIv0 and want it to be applied immediately, you might have to copy it to ENV:SYS/ (or to reboot). 
* Identifying file types by file ending is only a fallback. Far better it is to search for magic words, for flac files this would be &quot;flaC&quot; according to this [http://flac.sourceforge.net/documentation_format_overview.html documentation]. 

For instance, to open PDFs with arospdf not localised in the default drawer of Icaros (Work:Extras/Applications/arospdf) but localised in a custom drawer in AROS. The default tools are defined in the icons in sys:prefs/env-archive/sys e.g. def_PDF. 


File type identification is done by datatype descriptors which you can find in Devs/Datatypes. The AROS build system has a tool which creates such datatype descriptors. 


'''Changing of default tools of existing icons is easy as shown above. Adding of new file types is not hard, but needs knowledge of the AROS build system.'''


The enduser way would be to download the attached file, which contained two executables:
1) createdtdesc, to make a new datatype description
2) examinedtdesc, to read/show existing datatype descriptions

use 2 to get an idea on how it things are currently done in aros by providing this executable a file from the drawer sys:devs/datatypes/ (alternatively you can find the original .dtd files here).

use 1 to make your new datatype. Use the accompanied FORMAT file (also here) to read how to make your own datatype descriptor. use 2 to get hints from other datatype descriptors.

Note:
When creating a new descriptor would advise against using the pattern property, but instead use the default pattern of #? and create a Mask that matches your filetype. This requires some research in order to discover how your filetype can be recognized properly. Of course with making something like a descriptor for an ascii textfile, you would fallback to using the pattern (e.g. #?.text as the filetype cannot be determined easily otherwise). 

&lt;pre &gt;
# name - choose wisely and informative. also used for icon's name.
# version - choose as you like as long as it complies with version rules
# basename - the 'root' datatype class. be aware that e.g. it can influence behaviour. for example when choosing binary and using tool multiview in project icon, the file will be viewed as binary file (choosing sound would tell mulitview to view the file as a soundfile). So this can influence the underlying tool being used. Could become messy if users started to modify the tool manually. 
# pattern - This is the file pattern match e.g. #?.text
# Mask - A mask to identify the file. Requires knowledge of the actual file structure. For example 'M' 'Z' for an msdos executable.
# GroupdID - not supported (AROS native) files - use syst as that would be the least intrusive in case an AROS tool/program tries to load such datatyped file.
# ID - In your case, the first four characters of the name at subchapter 1 (in lower case) (or less if name is shorter).
# flags - How the mask needs to be interpreted. In your case would be mostly DTF_BINARY in combination with (wanted or not) DTF_CASE (to tell if mask used letters are case sensitive or not)
# priority - the priority of how the type is handled so that on datatype could have precedence over another? In any case, document tells it to be mostly 0. 
&lt;/pre &gt; 

Now that you know each field and what it does (more or less), you write this fields in a text file for your own invented datatype, save it and create the actual dt with the tool in 1. in the end the created dt must reside in sys:devs/datatypes/ drawer.

Then you would create a default icon in sys:prefs/Env-archive/SYS drawer. Don't forget to reboot or copy .info file to ram:env/sys in order to test. also don't forget to set which tool to start f.e. c:lx or dh4:emulators/mycoolemulator

To test, open Wanderer then show all files and doubleclick on a file of type you just created. Alternatively you could use the 'open' command from shell (with file of datatype you just created as parameter).

And as a last note. it would perhaps be welcome to have a program like xicon and/or runprglist for AROS (unfortunately both without source, but something similar could be created for AROS).

Sounds complicated ?

Perhaps... but OS like windows needs a complete registry to be able to do things like this. And yes, i am aware windows has gui tools that does it (more or less) for you (by manipulating the registry). Same could be done for AROS (without integrating a registry in AROS that is ).

Would that suffice ?

red1+2: typos, reformatting.

disclaimer: please note that using these tools can screw up your currently installed support for datatypes when used incorrectly. Do not use if you do not understand what you are doing. Use at own risk.


==Network Connection==

AROS currently only has one real choice for TCP/IP networking - AROSTCP.  This is a port of the AmiTCP package from AmigaOS (TM), with a number of enhancements/fixes from AROS developers. 


 Please use Prefs/Network to set up wired, wireless or USB networking 
 Non USB wifi is easier, USB wifi can be an annoyance - remember to save whilst in prefs 


===Wired===

=====IPv6=====

No support so far 


128bit IPv6 address packet 
&lt;pre&gt;
Local FD::/8
Global 2000::/3
64:ff9b::/96
&lt;/pre&gt;
NAT64 translates IPv6 to IPv4 
DNS64 


OS routing works with 
&lt;pre&gt;
MacOS Ventura 
Windows 11 with cloud account 
Ubuntu Jammy Jellyfish 
Android 10 (block google dns) 
&lt;/pre&gt;


====IPv4====

The top half of the IPv4 Configuration tab on the Network Prefs deals with the network card/USB and the lower half the router part. 

[[File:AROS Wanderer Network Prefs DHCP.png|thumb|DHCP Settings]]

'''Upper part of IPv4 tab''' 
* Click Add on the top right of the Prefs which opens a window called '''Interface''' 
* Enter Name as net0 (but can be anything as long as it is consistently used in other sections) 
* check mark on Active
* select device to be used using the '''right hand-side gadget''' of the box where the device name will go 
* set Unit to 0 
* IP Mode is default set to '''Get address from DHCP''' 


* IP Mode set to Manual if DHCP does not work automatically 

From the shell CLI,  ifconfig -a

Under net0: section, inet starting 192.168.x.xxx

* inet or '''Address''' of network card 
* netmask convert to decimal so 0x'''ffffff7f''' becomes 255.255.255.247 which is used to adjust the above '''Address''' into 
* broadcast 192.168.xxx.xxx

click OK


[[File:AROS Wanderer Network Prefs Manual.png|thumb|Manual Settings]]

'''Lower part of IPv4 tab''' 
* IP Mode Get address from DHCP (default) 


* or changing to Manual if automatic DHCP set up does not work 
* '''Gateway''' (Router Internal LAN-IP) (Default Route) = 192.168.0.1 (D-Link Netgear), 192.168.1.1 (Linksys 3com), 192.168.2.1 (SMC Microsoft), 192.168.1.254 (Belkin), 192.168.123.254 (USRobotics) else check with your router manual 
* first DNS = use 208.67.222.222 (opendns) or Gateway number above (to test web browser access to router) or 212.50.160.100 (google)  i.e. or whatever your ISP needs you to set 
* second DNS = use 208.67.220.220 (opendns) or Gateway number above (to test web browser access to router) or 213.249.130.100 (google) i.e. or whatever your ISP needs you to set 


* At the bottom of IPv4 tab, check mark the '''Start networking during system boot''' option 
* Save and reboot (sometimes Network restart fails, so reboot every time to be sure) 


'''an alternative way''' to AROS ifconfig -a, other OSs have similar for the same internet connection. Another connection will have different settings. 

e.g. From [http://www.ncsu.edu/resnet/windows/ipconfig/ Windows], '''ipconfig /all''' 
and note down the IP, subnet mask, default gateway, and DNS servers values and put these values in &quot;manually&quot; into AROS Network prefs. 

e.g. From Linux via dhcp router have a look at etc./dhcpc/dhcpcd-eth0.info 
* for manual input look at /etc/networks (IP or Gateway) and /etc/resolv.conf (DNS) 

 Please note that all in one routers (wired+wireless) or separate routers may need different settings 

IPv4 involves routing (192,168.x.x), firewall, NAT 


===Wireless===

[[File:MyArosWirelessSetup.png|thumb|Setting up]]

[[File:MyArosWirelessTCP.png|thumb|Shell commands to work out what is happening]]

We must first make certain you have a Atheros 5k chip inside acting as the wireless wifi option. Open PCITool in Tools directory. Down left hand side are a series of numbers 0.00.0 etc. Click on some at the bottom and hopefully one of them will say Atheros AR5??? or AR242?. 

or a Realtek RTL8187B, we can check using Prefs/Trident as this one is USB based 


There are many similarities with the above Wired set up so please read the above section as well 


* open Network/Prefs
* In '''IPv4 Configuration''' tab - click Add - enter net0 / active tick / #?.device / Unit 0 / IP Mode = manual (important if default DHCP does not work automatically) 

Make sure that any extra network names (e.g. eth1 or net1) should be deleted. If net0 already st previously, change net0 so that it shows associated with the appropriate device name like atheros5000.device or realtek8180.device. Having two entries here will cause sub-net problems. 

* Go to '''Wireless''' tab and click on &quot;Add&quot; button. 
* Insert network name (SSID your wireless network name use wirelessmanager to get it), select right &quot;encyption&quot; that is most likely &quot;WPA&quot;. 
* Key Type set as &quot;Passphrase&quot;. i.e. type in your password for your router (aka access key). 
* Unselect (no tick) &quot;hidden&quot; if it is selected, then apply. You may have to tick it if wireless does not work. 
* Finally, Save and '''reboot'''. 

For the best chance of success, set networking to start at boot, and then reboot with the USB adapter plugged in. 


===USB Ethernet===

Open SYS:Prefs/Network and in the IPv4 Configuration tag (top table covers your usb stick) 

* click Add button
* set Name as net0
* Tick Active box
* enter the usb-ethernet.device e.g. dm9601eth.device, usbpegasus.device or usbasixeth.device use SYS:c/devlist, '''Scout''' or trident prefs to get the correct spelling 
* set Unit to 0 (which is usual but check the messages from the bottom of the Trident prefs whilst plugging the device in to determine the unit number otherwise) 
* IP Mode is set to Get address from DHCP (make sure your router is set right for that) 
'''or manual'''
* IP Address of network card, i.e. 192.168.0.xx or 192.168.1.xx (xx being greater than 1) 
* Subnet netmask = 255.255.255.0 
* click OK

There can be sometimes be boot failures when using USB ethernet - plug the USB device in after boot and save the network prefs to make it work again. 


Lower part of IPv4 tab covers the router information 

* IP Mode Get address from DHCP 
'''or if manual settings'''
* Gateway (IP Address of router) = usually 192.168.0.1 or 192.168.1.1 but see router manual to make sure. 
* first DNS = use 8.8.8.8, 208.67.222.222 (opendns) or 212.50.160.100 
* second DNS = use 8.8.4.4, 208.67.220.220 (opendns) or 213.249.130.100 


===USB Tethering via Android smartphone===


Go to AROS Network Prefs (IPv4 configuration tab) and write type in &quot;usbrndis.device&quot; in the &quot;device&quot; textfield of &quot;Interface&quot; sub-window, which appears when you add a new device (or modify an existing one). Select &quot;Start Network during system boot&quot; and saved the configuration, the Connection is immediate no reboot is needed.&lt;br&gt;

usbrndis.device is a resident device (virtually always there) in fact, a driver is not present in DEVS:Networks &lt;br&gt;&lt;br&gt;

Plug in USB cable, go to Android settings and enable &quot;USB Tethering&quot; &lt;br&gt;

A reboot should not be necessary.

When restarting AROS, the Smartphone deactivates the connection and to access the network again have to reactivate it before starting the browser. 


===Solving Issues===

[[File:MyArosTCP.png|thumb|Aros network setup diagnostics - why does it not work?]]

* In Network Preferences, have '''only one''' item in the IPv4 Configuration tab 
* If using manual settings, make sure all numbers are correct, especially for IP address of the card/usb (changing the last number in chain of four) 
* For any USB based networking, it is often necessary to save in Prefs/Network, reboot AROS and network support can begin 


* For wired, make sure that the LAN-cable is plugged in before starting the computer 


* If wireless, try getting closer to the router. 
* Switch off the encryption option from your router then try wifi, if successful then your ip/dns is ok. If not then your ip/dns settings are most probably wrong or need to use one or more opendns numbers 
* Replace detachable wireless antenna (best wireless option to buy if you can) with a stronger antenna ie. 5&amp;nbsp;dBi or 7&amp;nbsp;dBi 
* Try with another computer/laptop/machine 

Program Error  C:WirelessManager 

* Test with another OS 
* Check that Wifi works before changeover (if possible) 
* Check that socket and card are working 
* Check if card is too new for laptop (date code on card MMYY blue askey date 2005-2007 etc)   


Are you connecting with the Router ? 

Check with protection off e.g. wps and wep to see if it makes a difference. 


For USB wireless - stopping and starting may be needed...

&lt;pre&gt;

; $VER: AROSTCP-startnet 1.0 (01/08/06)
; AROSTCP-startnet (c) The AROS Dev Team.
;
Run &lt;NIL: &gt;NIL: AROSTCP
WaitForPort AROSTCP
If NOT Warn
  ; echo &quot;Stack online&quot;
Else
  echo &quot;Wait for Stack Failed&quot;
EndIf

; stop and restart
execute &quot;sys:system/network/AROSTCP/s/stopnet&quot;

Run &lt;NIL: &gt;NIL: AROSTCP
WaitForPort AROSTCP
If NOT Warn
  ; echo &quot;Stack online&quot;
Else
  echo &quot;Wait for Stack Failed&quot;
EndIf

run &lt;NIL: &gt;NIL: wirelessmanager realtek8180.device

&lt;/pre&gt;


What IRQ number is assigned to the device? You can check with Tools/PCITool? 
It's possible the BIOS hasn't set the right IRQ number. If you have a Linux CD/DVD handy, could you check if it boots with the options &quot;acpi=off noapic nolapic&quot;? 


If the following does nothing, this will help us figure out why networking doesn't start automatically at boot

open a shell and run the following commands:

&lt;pre&gt;
echo ${AROSTCP/AutoRun}
echo ${AROSTCP/WirelessAutoRun}
echo ${AROSTCP/WirelessDevice}
&lt;/pre&gt;

Please report the output, typically it will look like this  

# True  (explanation this variable is related to the &quot;Start networking during system boot&quot; checkbox in network prefs) 
# True  ()
# Devs:networks/atheros5000.device unit 0


If there's a problem with the AROSTCP package. What's the output of this?

 ENV:sys/packages/AROSTCP 

should return a string = Sys:System/Network/AROSTCP


By the way, a quicker way to check networking is working would be to run some shell commands such as:


&lt;pre&gt;
ping www.google.com
ifconfig net0
&lt;/pre&gt;


The best way to list the available networks and diagnose / troubleshoot problems with connecting to a wireless network is to run WirelessManager manually. First uncheck the &quot;Start networking during system boot&quot; box in the Network prefs app, then save and reboot. Then run this in a shell:

 C:wirelessmanager atheros5000.device verbose 

or 

 C:wirelessmanager realtek8180.device verbose 

and capture the output 


If the above does not help, could you edit the file SYS:System/Network/AROSTCP/S/Package-Startup, and change &quot;&gt;NIL:&quot; to &quot;&gt;T:wifi.log&quot; on the WirelessManager line and add this as well Wait 5?

&lt;pre&gt;
if ${AROSTCP/WirelessAutoRun} eq &quot;True&quot;
Run QUIET &quot;C:WirelessManager ${AROSTCP/WirelessDevice} &gt;T:wifi.log&quot;
wait 5
EndIf
&lt;/pre&gt;

Then save, reboot and post the log file (T:wifi.log) here.


&lt;pre&gt;

c:wirelessmanager atheros5000.device verbose
Initializing interface 'atheros5000.device:0' conf 'ENV:Wireless.prefs' driver 'default' ctrl_interface 'N/A' bridge 'N/A'
Configuration file 'ENV:Wireless.prefs' -&gt; 'ENV:Wireless.prefs'
Reading configuration file 'ENV:Wireless.prefs'
Line: 1 - start of a new network block
ssid - hexdump_ascii(len=7)
65 63 68 65 6c 6f 6e echelon
PSK (ASCII passphrase) - hexdump_ascii(len=14): [REMOVED]
key_mgmt: 0x2
PSK (from passphrase) - hexdump(len=32): [REMOVED]
Priority group 0
id=0 ssid='echelon'


Then it just sits there. Not sure what a normal dump looks like, I don't see anything that looks wrong in the configuration.
&lt;/pre&gt;

looks like the driver isn't working with that card. Has anyone else successfully used that exact model number (AR2413)?


&lt;pre&gt;

Initializing interface 'atheros5000.device:0' conf 'ENV:Wireless.prefs' driver 'default' ctrl_interface 'N/A' bridge 'N/A'
Configuration file 'ENV:Wireless.prefs' -&gt; 'ENV:Wireless.prefs'
Line: 1 - start of a new network block
ssid - hexdump_ascii(len=7):
65 63 68 65 6c 6f 6e echelon
PSK (ASCII passphrase) - hexdump_ascii(len=14): [REMOVED]
key_mgmt: 0x2
PSK (from passphrase) - hexdump(len=32): [REMOVED]
Priority group 0
id=0 ssid='echelon'
*** [wpa_sm_init] sm-&gt;pmksa=02c66fd4 ***
Own MAC address: 00:01:36:15:ae:0c
RSN: flushing PMKID list in the driver
Setting scan request: 0 sec 100000 usec
EAPOL: SUPP_PAE entering state DISCONNECTED
EAPOL: Supplicant port status: Unauthorized
EAPOL: KEY_RX entering state NO_KEY_RECEIVE
EAPOL: SUPP_BE entering state INITIALIZE
EAP: EAP entering state DISABLED
EAPOL: Supplicant port status: Unauthorized
EAPOL: Supplicant port status: Unauthorized
Added interface atheros5000.device:0
State: DISCONNECTED -&gt; SCANNING
Started AP scan for wildcard SSID
MLME: starting scan
MLME: scan channel 1 (2412 MHz)
sana2: sending MLME frame


Then it stops. Does this mean the router is not authorizing this NIC?

IRQ 4 (A)

&lt;/pre&gt;

apparently locking up when the first frame is sent (a scan request).


&lt;pre&gt;

Devs/Networks/atheros5000.device:0
Initializing interface 'Devs/Networks/atheros5000.device:0' conf 'ENV:Wireless.prefs' driver 'default' ctrl_interface 'N/A' bridge 'N/A'
Configuration file 'ENV:Wireless.prefs' -&gt; 'ENV:Wireless.prefs'
Reading configuration file 'ENV:Wireless.prefs'
Line: 1 - start of a new network block
ssid - hexdump_ascii(len=12):
41 69 72 4c 69 6e 6b 35 39 33 30 30 AirLink59300
PSK (ASCII passphrase) - hexdump_ascii(len=8): [REMOVED]
key_mgmt: 0x2
PSK (from passphrase) - hexdump(len=32): [REMOVED]
Priority group 0
id=0 ssid='AirLink59300'
*** [wpa_sm_init] sm-&gt;pmksa=0224e444 ***
Own MAC address: 00:1f:e1:42:e3:7a
RSN: flushing PMKID list in the driver
Setting scan request: 0 sec 100000 usec
[eloop_reg_timeout] Timeout is at 1317686594.160000
EAPOL: SUPP_PAE entering state DISCONNECTED
EAPOL: Supplicant port status: Unauthorized
EAPOL: KEY_RX entering state NO_KEY_RECEIVE
EAPOL: SUPP_BE entering state INITIALIZE
EAP: EAP entering state DISABLED
EAPOL: Supplicant port status: Unauthorized
EAPOL: Supplicant port status: Unauthorized
[eloop_reg_timeout] Timeout is at 1317686595.060000
[eloop_reg_timeout] Timeout is at 1317686604.060000
Added interface Devs/Networks/atheros5000.device:0
[eloop_run] Starting
State: DISCONNECTED -&gt; SCANNING
Starting AP scan for wildcard SSID
MLME: starting scan
[eloop_reg_timeout] Timeout is at 1317686594.160001
MLME: scan channel 1 (2412 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.193000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.233000
MLME: scan channel 2 (2417 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.253000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.293000
MLME: scan channel 3 (2422 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.333000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.373000
MLME: scan channel 4 (2427 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.393000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.433000
MLME: scan channel 5 (2432 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.473000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.513000
MLME: scan channel 6 (2437 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.553000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.573000
MLME: scan channel 7 (2442 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.613000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.653000
MLME: scan channel 8 (2447 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.693000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.713000
MLME: scan channel 9 (2452 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.753000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.793000
MLME: scan channel 10 (2457 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.833000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.853000
MLME: scan channel 11 (2462 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.893000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686594.933000
MLME: scan channel 12 (2467 MHz)
[eloop_reg_timeout] Timeout is at 1317686594.973000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.013000
MLME: scan channel 13 (2472 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.033000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.073000
EAPOL: disable timer tick
EAPOL: Supplicant port status: Unauthorized
MLME: scan channel 14 (2484 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.113000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.153000
MLME: scan channel 1 (2412 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.193000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.213000
MLME: scan channel 2 (2417 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.253000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.293000
MLME: scan channel 3 (2422 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.333000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.353000
MLME: scan channel 4 (2427 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.393000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.433000
MLME: scan channel 5 (2432 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.473000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.493000
MLME: scan channel 6 (2437 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.533000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.573000
MLME: scan channel 7 (2442 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.613000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.653000
MLME: scan channel 8 (2447 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.673000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.713000
MLME: scan channel 9 (2452 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.753000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.793000
MLME: scan channel 10 (2457 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.833000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.853000
MLME: scan channel 11 (2462 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.893000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.933000
MLME: scan channel 12 (2467 MHz)
[eloop_reg_timeout] Timeout is at 1317686595.973000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686595.993000
MLME: scan channel 13 (2472 MHz)
[eloop_reg_timeout] Timeout is at 1317686596.033000
sana2: sending MLME frame
[eloop_reg_timeout] Timeout is at 1317686596.073000
MLME: scan completed

&lt;/pre&gt;

Is your network hidden? If so, did you enable the 'Hidden' checkbox in the network prefs? What distro version are you using? 


&lt;pre&gt;
&quot;ENV:sys/wireless.prefs&quot; looks like this:
network={
ssid=&quot;testadhoc&quot;
key_mgmt=NONE
wep_key0=&quot;12345&quot;
wep_tx_keyidx=0
}
&lt;/pre&gt; 


If your router doesn't broadcast its SSID (hidden), you need to add this option to the network block of the wpa_supplicant.conf on your aros machine and make changes after  # Example blocks: 

 scan_ssid=1

Here's a full description of all the [http://hostap.epitest.fi/gitweb/gitweb.cgi?p=hostap.git;a=blob_plain;f=wpa_supplicant/wpa_supplicant.conf config file options]. 

&lt;pre&gt;
ap_scan=1

network={
ssid=&quot;YOURESSID&quot;
scan_ssid=1
proto=RSN
key_mgmt=WPA-PSK
pairwise=CCMP
group=CCMP
psk=YOURPASSWORD
}
&lt;/pre&gt;

&lt;pre&gt;
filter_ssids=1
ap_scan=2

network={
ssid=&quot;REMOVED&quot;
scan_ssid=1
bssid=REMOVED
priority=100
mode=0
proto=RSN
key_mgmt=WPA-PSK
auth_alg=OPEN
pairwise=CCMP
group=CCMP
psk=REMOVED
}
&lt;/pre&gt;


Error 6: Couldn't resolve host name.

Check Scout -&gt; Devices and look at the device that you are using, in the OCnt column it should state 2 which means AROSTCP and Wirelessmanager are both accessing this driver. If 0 or 1, then uncheck the checkbox in Network prefs for starting networking at boot, save and reboot. Then run this is the shell:

C:WirelessManager realtek8180.device unit 0


some quirks setting up the wireless network as well 

1) it's far better setting up either the wired OR the wireless network adapter as net0:, or weird things happen

2) it's better using fixed IP on the local network instead of DHCP

3) network setting must be placed in network setting panel in /prefs, using the wirelessmanager helped me finding available SSIDs, but not actually connecting to them

once done, reboot.


If previous setup is proving problematic 

&lt;pre &gt;

SYS:Prefs/Env-Archive/Wireless.prefs
SYS:Prefs/Env-Archive/Zune/OWB.config
SYS:Prefs/Env-Archive/Zune/global.config
SYS:Prefs/Env-Archive/AROSTCP/WirelessDevice
SYS:Prefs/Env-Archive/AROSTCP/db/Interfaces
&lt;/pre &gt; 

Make a copy of these files and restore in case of problems. 


Please try this test to check if you can connect to your router, ie established that the WiFi layer is working 

̊̊̊̊Boot with networking disabled, by make sure that &quot;Start networking at boot&quot; in Network Prefs is unchecked (no tick).  
̊ Run this in a shell: C:WirelessManager atheros5000.device VERBOSE
̊If the output of that command is too long to summarise here, you can redirect it to a file by adding &gt;RAM:wifi.log to the end, then attach or paste that file here.


try running &quot;status&quot; in the shell and check that AROSTCP is listed/running
If AROStcp is not showing, then AROSTCP is not running. attempted to start it by clicking Use or Save in network prefs, or checking the &quot;start networking at boot&quot; box or typing into a shell. 

 Execute SYS:System/Network/AROSTCP/s/startnet

(run Status again afterwards).


The &quot;cannot resolve hostname&quot; will appear if you are blocked on the wifi network by the router as well as aros not being able to assign correct network address.

One way of testing this might be to disable the firewall in the router. you might also check the router how it sees the attempts aros do to speak to it. The easiest way to do that would be to manually give aros an IP number in the routers accepted range. and see if it shows up at all within the router.


Tests that can be undertaken to determine correct settings and functions 

 pciinfo
 sanautil -d broadcom4400.device status

&lt;pre &gt;
 ping &lt;router-address&gt; e.g. 192.168.0.1 (aka inet) or 80.237.146.33 (www.amiganews.de) 
 ifconfig net0
 ifconfig net0 up
 extras:networking/utils/sanautil/sanautil -d atheros5000.device status
 WirelessManager atheros5000.device verbose &gt;RAM:wifi.log
 ;to send the log to RAM disk to be read easier or if detected, 
 Run WirelessManager atheros5000.device &gt;NIL:
 Run WirelessManager atheros5000.device ssid=&quot;mynet1&quot; &gt;NIL: 
 C:WirelessManager realtek8180.device unit 0 
&lt;/pre &gt; 

Please look at the task list in Scout, and check if WirelessManager and AROSTCP are running. Also look at the device list in Scout to check if realtek8180.device is open. 


start tools/debug/sashimi, maybe it shows some debug messages when disconnection happens.


Firstly, let's take a look at what your setup most likely looks like, assuming you use a router. See diagram below: 

&lt;pre&gt;
Internet &lt;---------&gt; home router &lt;---------&gt; computer 
-----------external IP------------------internal IP-------------
&lt;/pre&gt;

Okay, so what am I trying to show you with that diagram. A few things. Firstly, the IP address that connects you to the Internet is not the same one that connects you to your router. What happens is that your computer doesn't have a direct connection to the Internet, instead your router connects to the Internet, and your computer connects to the router.

You can see the external and internal IP addresses in these example settings...

* Default Gateway : 76.91.64.1 (external IP for ISP/Internet host)
* IP Address : 76.91.71.184 (external IP for home router)

* IP Address : 192.168.0.1 (internal IP for home router)
* Address = 192.168.0.161 (internal IP for computer)

As you can see, there are two internal IP addresses and two external IP addresses. This is because there is a client/server relationship, effectively one address is for the service (server) and one address is for the device trying to access that service (client).

The server addresses in your case are 76.91.64.1 (your ISP's address, serving the Internet), and 192.168.0.1 (your home router's address, serving your home network). The term gateway applies here, they are your gateway to those services.

Subnet masks are used along with IP addresses to determine which IP addresses are allowed access to a network. I did learn the more in-depth rules about subnet masks once (watched a CCNA vid), but I've forgotten about it. The basic level of understanding you'll need is easy to remember though. A subnet mask value of 255 means that portion of the IP address must stay constant, whereas a subnet value of 0 means any unassigned value up to 255 is allowed in the IP address.

By far the most common subnet value is 255.255.255.0. What this means is that the first three parts of the IP address you use to connect to a service must stay the same as the server/gateway address, and only the last section can change.

So if your router's internal IP address is 192.168.0.1, and the subnet mask is 255.255.255.0, the only addresses that will be allowed to be used on that network are between 192.168.0.2 and 192.168.0.255 (I think 192.168.0.0 is reserved for other uses).

Final point to make is about DHCP (a.k.a. dynamic IP) vs static IP. A server/router using DHCP gives a device that connects to it an address within the acceptable range. It usually starts with the lowest numbered free address, so with your router it'll give the first device that connects to it 192.168.0.2, the next device 192.168.0.3, and so on. Static IP addresses are where you set the IP address you want to connect with in advance. 

When using static IP addresses on a router where DHCP is active, it's good to use a high number to avoid conflicts with other devices that are connected to your network, to reduce the risk that both devices will try using the same IP. That's why your current choice of 192.168.0.161 is good, unless you have over 159 devices connected on your current network!


Okay, so what's the next step. Well, if you can use ping, I'd suggest pinging 192.168.0.1. If you get a positive response it means you're connected to your router, if you don't get a response it means the connection between your router and your computer is at fault.

Documentation on configuring the AROSTCP environment further can be found [http://en.wikibooks.org/wiki/Aros/User/Networking here] 


===File Sharing===

As AROS knows only a few filesystems (FFS, OFS, SFS, PFS (amiga only), FAT12, 16, 32, Microsoft NTFS (windows), UDF (Blu-ray)). The remaining ones in regular use like MacOSX hfs+, Linux ext2/ext3 and ext4, Haiku BeFS provide a problem in transferring files between each other. 

Linux can access SFS partitions but it needs to be compiled. The latest full source are [http://home.elka.pw.edu.pl/~mszyprow/programy/asfs/ here]. It compiled fine with a 2.6.30 kernel in Puppy Linux 4.31. 

An alternative, is to use a FAT32 partition. AROS could be installed on to a 4GB USB-key, with 512MB FAT32 partition for sharing, and the rest SFS. It works very well. 

An hosted Linux or Windows install relieves some of the problems. 

Files could be transferred [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=2915&amp;viewmode=flat&amp;order=ASC Sending] via TCP network. 


====SMB2/3====

With Windows you can share one folder or all folders of the &quot;Public&quot; user.

On Windows what is important is to enable sharing (Network and Sharing Center).

AROS Mountlist should look lke this 
&lt;pre&gt;
Handler = L:smb2-handler
StackSize = 65536
Priority = 5
GlobVec = -1
ACTIVATE=1
Startup = &quot;smb://UserAcc:password@PCShare/Sharefolder&quot;
&lt;/pre&gt;

which could also be
&quot;smb://UserPC:password@192.168.x.x/Public&quot;
or
&quot;smb://UserPC:password@Name-PC/Public&quot;

so
&quot;smb://UserPC:password@192.168.1.158/Folder&quot;
or
&quot;smb://UserPC:password@Name-PC/Folder&quot;


After you have configured a share generates a DOSDrivers it is named &quot;SMB0&quot; which includes the setting, and at each reboot it is Mounted. You can still delete the DOSDriver by hand, is located in Storage/DOSDrivers, the file &quot;ServerAutoMounts&quot;, in ENV:AROSTCP which indicates the DOSDriver to be mounted, should also be deleted. 
The per-mount files are written to ENV:SMB or SYS:Storage/DOSDrivers. There is also additional file ENV:AROSTCP/ServerAutoMounts which states what will be presented to the end user. 


====Old SMBFS====

e.g. to connect to a NAS share such as \\NASBOX\Shared use -:

SMBFS WORKGROUP=&lt;YOUR WORKGROUP NAME&gt; VOLUME=&lt;AROS volume name to use&gt;: SERVICE=&lt;UNC Path to connect to&gt;

SMBFS WORKGROUP=MYNET VOLUME=Shared: SERVICE=//NASBOX/Shared

And you will then have an icon appear on your desktop for the volume name you have chosen. 


You can put the above script into wbstartup or  

give it an icon, change it to a 'project' and give it the default tool c:iconx 

Open a shell and type copy sys:script.info &quot;sys:wbstartup/YOURSCRIPTNAME.info&quot;

This should create an icon for your script file.

Now right-click on your script and select 'information'.

Change 'tool' to 'project', put 'c:iconx' into the 'default tool' box, click save 

The reason being that scripts need to be opened with 'execute SCRIPTNAME' (or 'iconx') whereas the programs started from wbstartup are opened using 'run PROGRAMNAME'. It's the same as trying to start a command-line tool from the workbench by double-clicking it.


====Setup ISO images within AROS====

Use [http://archives.aros-exec.org/index.php?function=browse&amp;cat=driver/storage DiskImage] which supports many cd image formats ISO, CCD, MDF/MDS, CUE/BIN, NRG and UIF. To mount CD or DVD images use below....

&lt;pre &gt;
# Rename your iso 'Unit0' (note no extension).
# Do 'View/All files' on you Aros partition. You should now see a folder called 'Diskimages'. Copy your renamed iso to there. 
(Alternatively, you could type at the shell 'assign FDSK: xxx', where xxx is the location of your iso.) 
# From the shell, type 'mount CD0:' and the iso should appear on the Wanderer desktop. You can now access it like a real disk.
&lt;/pre &gt; 

 assign devname: dismount 
 Assign DOSVOLUME: remove
 [http://aminet.net/package/disk/misc/unmount-0.1 unmount] most filesystems work but SFS lacks support for ACTION_DIE packet 

If you are using an IcAros install, the startup scripts are set up to wipe the Diskimages directory on boot, so its worth keeping a second copy of the iso somewhere else. Alternatively, you could set up extra mountlists for additional iso images. I've made a file called iso1 in the Aros:devs directory that contains the following text:

&lt;pre&gt;
/* Entry for ISO image */

ISO1:
FileSystem = cdrom.handler
Device = fdsk.device
Unit = 1
LowCyl = 0
HighCyl = 0
Surfaces = 1
BlocksPerTrack = 1
DOSType = 0x41434400
Activate = 1
#
&lt;/pre&gt;

Then I just need an iso called 'Unit1' (corresponding to the 'Unit = 1' entry in the mountlist) in Diskimages (or wherever I assign FDSK: to) and to mount I type in at the shell:

 Mount iso1: from devs:iso1

Of course, if you create mountlists for ISO2, ISO3:, etc. (with the corresponding change to the 'Unit = ' line) you can have as many isos mounted as you wish. I just call mine ISO1: etc. to distinguish them from the real CD drives 


==Video Guides==


Video demonstrations and tutorials covering:

:00. '''Introduction''' 
::[https://www.youtube.com/@jamesmattson6813/videos Various Aros Installs], 
::[https://www.youtube.com/embed/j8EmSEby0Rg AROS repo in gource, view of AROS dev commits from 1997 to 2025], [http://www.youtube.com/watch?v=Vx_zqlBow40&amp;feature=related Gource view of AROS 1997 up to 2009], 
::[http://www.youtube.com/watch?v=s1RsvEm7UrU Why an Amiga OS in 2011], 
::[https://www.youtube.com/watch?v=1W886mheV74&amp;pp=ygUPYW1pZ2EgYXJvcyAyMDI2 Johan Grip on early days of AROS x86], [], 

:01. '''Installation'''
::[https://www.youtube.com/watch?v=M7YjufrJqDs Aros One install], [https://www.youtube.com/watch?v=iIMguHTdC5E Aros One USB install], [https://www.youtube.com/watch?v=ZNXauy5m5Wc Aros One install], [http://vimeo.com/11013489 Modify Grub boot], 
::[http://www.youtube.com/watch?v=wyQVeyXIywc&amp;feature=channel iMica Silent Pt3], [http://www.youtube.com/watch?v=o2AnkoflY14 Wipe whole drive and Install - warning loss of data on drive], 
::[http://www.youtube.com/watch?v=OVXm6_-witQ VirtualBox install], [ VMware install], 
::[http://www.youtube.com/watch?v=0k2PEmT8I14 Broadway AROS Install], 
::[https://www.youtube.com/watch?v=PtDiXhjSIfs Is Aros Icaros a choice?], 
::[ driver install], 
::[http://www.vimeo.com/10491104 HDAudio install but needs account], [], 

:02. '''Amiga Basics'''
::[http://www.youtube.com/watch?v=TY8mWxwzH5o Screens tutorial], 
::[https://m.youtube.com/user/AMIGASYSTEM/videos General], [ Dos Scripts tutorial], [http://www.youtube.com/watch?v=hPT7SmVEpjc OS 1.2], [http://www.youtube.com/watch?v=n6kX3FqH8Ww&amp;feature=related OS 1.3], 

:03. '''Customisation demos'''
::[https://www.youtube.com/@AMIGASYSTEM/videos Prefs tutorial], [ Decoration tutorial], [http://www.youtube.com/watch?v=Dn5C8G3aDXU Scalos], 

:04. '''Setting up''' internet access and surfing the web, FTP, IRC and Mail apps 
::[ Network Prefs], [ AirCOS tutorial], [ jabberwocky tutorial], 

:05. '''Native bundled Games and Applications''' 
::[http://www.youtube.com/watch?v=aYlFv2B-VXc 3D Games], [http://www.youtube.com/watch?v=MXK7wwhd-R0 Latest Games], [http://www.youtube.com/watch?v=RUgiVThv23Q&amp;feature=mfu_in_order&amp;list=UL PrBoom GL], [http://www.youtube.com/watch?v=0s7u8TPy7V4 Assault Cubes], [http://www.youtube.com/watch?v=fih6aCXKeqs Cube 2], [http://www.youtube.com/watch?v=-X0ay0MGOms DosBox on Aros], [http://www.youtube.com/watch?v=7nKduDjf14k Oct 2010], 

::[http://www.youtube.com/watch?v=FziV2z_uxnQ Apps Pt 1], [http://www.youtube.com/watch?v=xs37_nfa5CI Apps Pt 2], [http://www.youtube.com/watch?v=Bn59_VvbQR0&amp;feature=related Apps Pt 3], 
::DOpus4 [http://www.youtube.com/watch?v=aSRybWjrrME DOpus 4], 
::Milkytracker [http://www.youtube.com/watch?v=VxBOEPzpdKg&amp;feature=related Laying Down Base Tracks], 
::[http://www.youtube.com/watch?v=k2uKQ0-ieOE Audio Evolution 4 in action], [http://www.youtube.com/watch?v=Zq4r9k0_jZI Quick Videos], 
::[http://www.youtube.com/watch?v=gGKCFZcIc0I&amp;feature=related ScreenRecorder], [http://www.youtube.com/watch?v=974c2e-Fqak&amp;feature=related TV out Tests], 
::[http://www.youtube.com/watch?v=fjq8ct5d5IY AmiFIG], [http://www.youtube.com/watch?v=h0rHvPhYJo4&amp;feature=youtu.be ZuneFIG], 
::[http://wiki.povray.org/content/Documentation:Tutorial_Section_1 POVray Tutorial 1], 
::[http://www.youtube.com/watch?v=Jk-ZNLfJsvQ pt 1, jan. 2008], [http://www.youtube.com/watch?v=nWRy33g1R7Y pt 2, feb. 2009], [http://www.youtube.com/watch?v=r5PbhCtm4vE pt 3, feb. 2010], 

::[https://www.youtube.com/watch?v=G7_FJUoQ89o Hollywood programming], [], [], [],

::[], [], [], 
::[], [], [], 
::[], [], [], 


:06. '''Commercial software available'''
::[http://www.youtube.com/watch?v=fKXY9B4R43s AntiryadGX 3D Game Editor], 
::[http://www.youtube.com/watch?v=TMS9NDzwm5U BOH indie Game], 

:07. '''Running classic amiga apps and games''' 
:: Amiberry [], [], 
::[http://vmwaros.blogspot.com/2008/11/introducing-amibridge.html Intro Amibridge], [http://www.youtube.com/watch?v=ee2PWvCZeLo Old Amiga Apps], [http://www.youtube.com/watch?v=ee2PWvCZeLo Why Janus UAE is good], 
::[https://www.youtube.com/watch?v=VhlsNSYSuDg DPaint tutorial]

::[http://vmwaros.blogspot.com/2009/11/can-icaros-play-my-amiga-games-and-why.html Play Amiga Games], [http://www.youtube.com/watch?v=XTaZCNOvCnE], 
::[http://www.youtube.com/watch?v=tMehS77LXQ4 Pagestream Introduction], [http://www.youtube.com/watch?v=284-w3hTzII Pagestream Tutorial 1], [http://www.youtube.com/watch?v=mlwEGwhZzl4 Pagestream Tutorial 2], 
::[http://www.youtube.com/watch?v=iIcrIjPOctc Catweasel Mk4 PCI Part 1] and [http://www.youtube.com/watch?v=BaitHeL6bEA Part 2], 

:08. '''Misc and History'''

::[http://www.youtube.com/watch?v=d6mDXKU29w0 Mum uses old AmigaOS Workbench 1.1 (1986)], [http://www.youtube.com/watch?v=DaRkacQ-YMg Why an Amiga 500 (1987)], [http://www.youtube.com/watch?v=k5CYsgVCzYY an Amiga 2000 (1987)], 

:09. '''Misc Shows and Events'''
::[http://www.youtube.com/watch?v=klgVSWKs4kE VCF 2010], [https://www.youtube.com/watch?v=eQ3d5qR-Hv8 24:06 Jason McMullan at amiwest 2012 about AROS], [https://www.youtube.com/watch?v=jpQO7XSfAv4 Aros SMP multi core amiwest 2013], [], [https://www.youtube.com/watch?v=gFRtAAmiFbE ], [https://www.youtube.com/watch?v=DjdUEyjx8GM ], [https://www.youtube.com/watch?v=ydYDqZQpim8 ], [], [https://www.youtube.com/@uminekoshouten/featured ], [https://www.youtube.com/shorts/NfoY023w-vE ], 

:10. 
::[https://www.youtube.com/shorts/6qJTNW4-6GY ]


===History===

The project was originally started by a small group of Amiga [http://www.amigahistory.co.uk/aros.html enthusiasts] in 1995. These individuals were mainly computer-based college university students at the start, though that student trend has diminished since. An interview with Aaron Digulla [http://arosshow.blogspot.com/2006/12/interview-with-aaron-digulla-who.html here] 

* 1992 Commodore folds 
* 1996-1998 much of the early years was concerned with exec, dos and intuition libraries. 
* Early 1999, Haage &amp; Partner used parts of the AROS code in AmigaOS 3.9. 
* March 2001, floppy disk images of AROS became available. 
* Early 2002, AROS changed its name from Amiga Replacement Operating System to Amiga Research Operating System 
* June 2002, AROS devs decided to use Zune (MUI 3.8 rewrite) as the GUI system. 
* November 2002, Eric Schwartz drew Kitty for AROS usage. 
* Early 2003, AROS.org underwent a graphics facelift. 
* Late 2003, GCC C compiler arrived. 
* Early 2004, Aros-Exec opened. 
* Early 2005, Aros Max bootable CD arrived. 
* Late 2005, SFS filesystem ported and allowed fast access to apps and network support arrived 
* Early 2007, AROS.org underwent another graphics facelift. 
* Mid-2007, AROS changed to AROS Research Operating System after A.Inc. sued Hyperion with a trademark violation. 
* Late 2007, the hard disk installer added and VmwAROS (later called Icaros Desktop) distro launched. 
* Early 2009, Our first usable web browser (OWB)
* September 2010, first wireless support appears and AspireOS started as a distro 


* Early 2012, the first paper-cut bugfix and Fab's Odyssey Web Browser ported 
* Early 2014, backport of most features of ABIv1 into mainstream everyday use (Icaros 2.0 and above) 
* 2015 work started on using the extra cores of the PI 2 
* Early 2017, work started on utilising the addition cores on modern CPUs starting with the 64bit x86 version  
* Mid-2017, m68k port optimized for the Vampire 2 / Apollo accelerators (68080 AMMX FPGA) 
* 2018 The old AROS Exec website closed and a new one opened 
* 2019 AROS One distribution started and now with USB install version 
* Early 2021, backport of more features of ABIv1 into mainstream everyday ABIv0 (Aros One 1.5 and above) 
* 2025 year of 64bit pc builds and porting 32bit applications to 64bit ABIv11


===Bounties===

To help inspire developers with both ideas and monetary incentives, rewards are offered for the successful completion of &quot;bounties&quot; (requests for missing/new functionality) chosen by the community and handled by [http://power2people.org power2people] (formerly done by TeamAROS). A monthly option is [http://www.power2people.org/funds/aros/ here].


Future goals for AROS include expanding its underlying retargetability to support even more diverse architectures, provide memory protection features and user level file security, SMP and many other wonderful features missing from AmigaOS &amp;mdash; while still providing as much source level compatibility as is possible (however it is accepted that to achieve some goals code certain things may require a little recoding).


[http://www.ohloh.net/p/aros/contributors Developers] come and go as with any open source effort and we would like to thank them for their efforts... 

;1996-2000:In DigullaA (coordinator), GripJ, TempletonI (BSD), SchulzM, RittauS, voordenDagL, HolmM, JohanssonT, VanIngelgomH, SteigerwaldM, BortasP, deJongK, AlfredssonJ, InnocentiB, 

;2001-2005:In [http://chodorowski.com/adam/aros.html ChodorowskiA], StegerG, BergerS, HeutlingS, AlemagnaF (gcc), VerhaegenS (rexx), KielH, MatheussenKS (CAMD), SzczygielskiP, ErikssonP, LeCorfecD (Zune), BauerS (Zune), FurlongW, GustafssonJ, AndrewsN, CafferkeyN, GierichM (jpeg), PattonJ, ParsonsM, DietrichJ, SeilerT, BischoffL, LorentzenNH, AdamO, BerglundH, SmithP, HolmenD, BlomM, 

;2006-2010:In FedinP, RusslerM, SzymczykS (owb), SmiechowiczK (openGL), WeissM, NorrisR, BrunnerO, WiszkowskiT, GreppinA, [http://www.fukt.bsnet.se/~bearsoft/ Bearsoft Björn Screwelius], ErbY, CharletF, HodgesC, [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4819&amp;forum=18&amp;post_id=43103#forumpost43103 HokstadV], McMullanJ (m68k), WilenT (m68k), 

;2011- :In MuijzenbergPHvanden, ALB42, JonesEM, weiju, DizzyofCRN, wawa, miker, 


* 1996 - The linux hosted version for i386 was the first to arrive 
* 1998 - i386, The native version for i386-based PC AT computers and compatibles.
* 2004 - x86/64, The native version for 64-bit (x86_64, amd64) PC computers.
* 2008 - sam440/ppc, The native version for Sam440EP, Sam440EP Flex and Sam460ex computers.
* 2009 - efika, The native version for PowerPC Efika computers.
* 2010 - m68k, The native version for m68k Amigas or WinUAE
* 2013 - raspi/armfh, early native version for ARMv6 based Raspberry Pi computers.
* 2017 - x86/64bit smp 


Debugging capture serial debug at all (especially with sysdebug=all or --sysdebug=all) to see it displayed on screen 

* yes, usb -&gt; rs232 adapters can work most of the time, some of the cheapest ones are not fully compatible with all rs232 devices to capture to another device 
* you will need a null modem cable (or a null modem adapter usually female to female) in addition to the usb -&gt; rs232 adapter (usb adapter is a normal modem ie. the pins are not crossed over) 

Normal modem cable - straight connection DCE 
&lt;pre&gt;
Pin 2 -&gt; Pin 2  RXD
Pin 3 -&gt; Pin 3  TXD 
Pin 5 -&gt; Pin 5  GND
&lt;/pre&gt;

Null modem cable connections DTE 
&lt;pre&gt;
Pin 2 -&gt; Pin 3
Pin 3 -&gt; Pin 2
Pin 5 -&gt; Pin 5
&lt;/pre&gt;
(9pole SUB-D)


&lt;pre&gt;
serial  ser: (amiga/aros)  tty2 tty1USB0 (linux)  COM1 (windows)  (depends on the os being used) 
speed baud transfer rate 9600 38400     lower baud might be more successful 
data bits 8
stop bits 1
parity none
handshaking flow control - none xon/xoff (most likely)  rts/cts  dsr/dtr (pins not connected so should not work) 
&lt;/pre&gt;


*You cannot use compiled aros X86-64 bit software (when ready) on aros X86 32bit. PPC compiled software on X86 and so on. 
*68k is tested with the UAE emulator (WinUAE) but some tests are done on native 68000 based Amigas and others. 
*PPC support is very limited to certain devices. 


If you use the WBStartup, you have to delete the other icons in the folder (readme etc..) and you have to add in the Icon Tooltype the parameter DONOTWAIT

If you use user-startup instead, you need to add the attached command &quot;after assignment to LUA&quot;
C:WBRun DH1:Extras/Utility/WeatherBar/WeatherBar &gt;NIL:
Change the command to match your WeatherBar path.

&lt;pre&gt;
PATH sys:Utilities/WeatherBar ADD
run &gt;nil: lua:amilua weatherforecast.lua
&lt;/pre&gt;

To enter data your Country or City, ist with city_id numbers can be found [http://bulk.openweathermap.org/sample/city.list.json.gz here] or you need to go to [https://www.bbc.com/weather BBC Weather], once you type the name of your city or town in the appropriate tab, and press enter, the 7 numbers to be added in the &quot;WeatherBar&quot; will appear on the Browser url address bar above 


Unicode v16.0 emojis are not supported but [https://github.com/jens-maus/libcodesets codesets.library] provides 

&lt;pre&gt;
internally supported (hardcoded) charsets/codesets are: (conversions are possible from and to each codeset):

    AmigaPL – Polish (Amiga)
    Amiga-1251 – Cyrillic (Amiga)
    ISO-8859-1 – Western European
    ISO-8859-1+Euro – West European (with EURO)
    ISO-8859-2 – Central/East European
    ISO-8859-3 – South European
    ISO-8859-4 – North European
    ISO-8859-5 – Slavic languages
    ISO-8859-9 – Turkish
    ISO-8859-15 – West European II
    ISO-8859-16 – South-Eastern European
    KOI8-R – Russian
    UTF-8 – Unicode

In addition, external charset table files can be stored in LIBS:Charsets or loaded by an application from PROGDIR:Charsets. The charset files included with this distributions are:

    IBM866 – Cyrillic (cp866)
    ISO-8859-7 – Greek (LatinGreek)
    ISO-8859-10 – Nordic (Latin 6)
    windows-1250 – Central/East Europe (Windows)
    windows-1251 – Cyrillic (Windows)
    windows-1252 – West European (Windows)
&lt;/pre&gt;


Icaros 2.3 USB image needs a header stripped so it can work correctly 
 dd bs=512 skip=1 status=progress if=icaros_light_2-3-0_pendrive.bin of=/dev/sdxy &amp;&amp; sync


Scalos 
&lt;pre&gt;
-------------------------------
{ &quot;STRING&quot;,		&quot;ID/K,TEXT/K,SRC/K,TEXTPEN/K,HALIGN/K,STYLE/K,FONT/K,VALIGN/K&quot;,

HALIGN		LEFT | CENTER | RIGHT

VALIGN		TOP | CENTER | BOTTOM

STYLE		NORMAL | BOLD | ITALIC | BOLDITALIC

FONT		// font specification - format: &quot;fontname.font/size&quot;

-------------------------------
arguments for STRING SRC

&quot;diskstate&quot;,		
&quot;diskusage&quot;,		
&quot;diskusagefree&quot;,	
&quot;diskusageinuse&quot;,	
&quot;diskusagepercent&quot;,	
&quot;fibfilename&quot;,	
&quot;filecomment&quot;,	
&quot;filedate&quot;,		
&quot;fileprotection&quot;,	
&quot;filesize&quot;,		
&quot;filetime&quot;,		
&quot;filetypestring&quot;,	
&quot;iconname&quot;,		
&quot;linktarget&quot;,		
&quot;plugin&quot;	pluginname &lt;optional plugin arguments&gt;
&quot;versionstring&quot;,	
&quot;volumecreateddate&quot;,	
&quot;volumecreatedtime&quot;,	
&quot;volumeordevicename&quot;,	

-------------------------------

arguments for HIDE

&quot;novolumenode&quot;,	
&quot;isempty&quot; (some STRING)	

-------------------------------

all internal commands:

&quot;about&quot;,		
&quot;backdrop&quot;,		
&quot;cleanup&quot;,		
&quot;cleanupbyname&quot;,	
&quot;cleanupbydate&quot;,	
&quot;cleanupbysize&quot;,	
&quot;cleanupbytype&quot;,	
&quot;clearselection&quot;,	
&quot;clone&quot;,		
&quot;close&quot;,		
&quot;copy&quot;,		
&quot;cut&quot;,		
&quot;delete&quot;,		
&quot;emptytrashcan&quot;,	
&quot;executecommand&quot;,	
&quot;formatdisk&quot;,		
&quot;iconify&quot;,		
&quot;iconinfo&quot;,		
&quot;lastmsg&quot;,		
&quot;leaveout&quot;,		
&quot;makedir&quot;,		
&quot;open&quot;,		
&quot;parent&quot;,		
&quot;paste&quot;,		
&quot;putaway&quot;,		
&quot;quit&quot;,		
&quot;redraw&quot;,		
&quot;redrawall&quot;,		
&quot;rename&quot;,		
&quot;reset&quot;,		
&quot;selectall&quot;,		
&quot;showallfiles&quot;,	
&quot;showonlyicons&quot;,	
&quot;shutdown&quot;,		
&quot;sizetofit&quot;,		
&quot;snapshot&quot;,		
&quot;snapshotall&quot;,	
&quot;snapshotwindow&quot;,	
&quot;unsnapshot&quot;,		
&quot;update&quot;,		
&quot;updateall&quot;,		
&quot;viewbydate&quot;,		
&quot;viewbyicon&quot;,		
&quot;viewbysize&quot;,		
&quot;viewbytype&quot;,		
&quot;viewbytext&quot;,		
&lt;/pre&gt;


{{status|50%}}
{{BookCat}}</text>
      <sha1>39pxws8xasqpeki12u21ngk01ljm1vs</sha1>
    </revision>
  </page>
  <page>
    <title>Spanish/The Wrong Way To Learn Spanish/Dictionary</title>
    <ns>0</ns>
    <id>39299</id>
    <revision>
      <id>4636881</id>
      <parentid>4068941</parentid>
      <timestamp>2026-05-21T13:54:21Z</timestamp>
      <contributor>
        <username>~2026-30494-24</username>
        <id>3591373</id>
      </contributor>
      <comment>/* M */ I added the 'Montar' entry</comment>
      <origin>4636881</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="11406" sha1="1oqyf8sad3g7bd9trbp8ibto1vt23pq" xml:space="preserve">This is a mnemonic dictionary. Every word has its pronunciation, meaning, and a little sentence to help you remember the word and its meaning.

A mnemonic phrase is worthless without the right connections for your memory, the BEST way to remember what an orange is in Spanish is to get an orange, feel it's peel, smell the skin, listen to the sound when you cut through the peel, feel the resistance give way as the knife penetrates, take in that bright, vibrant, orange color of the flesh, taste the sweet tangy juices, ''smell'' the juices, feel rippled, slippery skin all the while connecting the essence of an orange to how Spanish expresses it: ''naranja''

The WORST way is to memorize a rhyme connecting a pun on the color orange to the fruit orange.  Three unrelated steps: reading a rhyme (something processed in a totally different part of the brain,) the color orange, and then an actual orange.  It might work to get an &quot;A&quot; on a test, but you will have a stutter when you are in Mexico.

Used correctly, a mnemonic phrase is somewhere in between the two extremes of true understanding and rote memorization.  With enough practice, especially in an immersion environment, the brain will make the direct connection to ''naranja'' circumventing the mnemonic phrase, but [http://www.cnn.com/TECH/9801/23/t_t/bilingual.brain/ never] like our &quot;first&quot; language.

In the bullet points under word definitions, leading letters of the Spanish word are italicized, and the English definition is bolded.

== A ==

'''abajo''' (ah-ba-ho) - down, downstairs, below [something]

* Imagine throwing '''down''' ''a ba''d cup of ''jo''e.
* Baja California is the area &quot;below&quot; California en inglés.

'''acostarse''' (a-co-star-say) - ''v.'' to put oneself to bed.  ''(&lt;u&gt;Irregular&lt;/u&gt; verb: when conjugated the first &quot;o&quot; is replaced with &quot;ue.&quot;)''

* Imagine for ''a costar'' to say &quot;'''Put''' '''oneself''' (your ''arse)'' '''to''' '''bed'''.&quot;

'''alguno''' (al-goon-oh) - ''pron.'' some, someone

* By the ''alg''ebra of '''some, someone''' is ''uno.''

'''año''' (an-yo) - ''m.'' year

*''an''nual ''o''rganization

'''aquel''' (ah-kale) - that (over there)

* R''aquel'' is '''that''' lady '''over there'''.

'''azul''' (ah-sool) - blue 

*''Azu''re ''l''iterally means bright '''blue''' en inglés.

== B ==

'''bailar''' (bay-lar) - to dance 
* Imagine it is time '''to''' '''dance''' around a bale of hay.
* Lyrics of La Bamba start with &quot;Para ''bailar'' la bamba&quot;

'''baile''' (bī-lay) - ''m.'' dance
* A popular type of performance '''dance''' is the ballet.

'''bonito''' (boh-nee-toh) ''a.'' pretty (masculine)

* That guy ''Bo'' is so '''pretty''' and I think that's n''eato''.

== C ==

'''caballero''' (cah-bah-yer-oh) - Depending on the country, this means &quot;cowboy&quot; or (less common) &quot;gentleman&quot;.

* Imagine a well dressed '''gentleman''' '''cowboy''' in a ''cab''.

'''cada''' (ca-da) - each, every

* '''Each''' and '''every''' ''ca''se, ''d''irectly ''a''pproached, should be more than pro forma.

'''cartera''' (kahr-teh-rah) ''n.'' - wallet, purse

*You should get a ''cartier'' '''purse / wallet'''!

'''cepillarse''' (cep-ill-arse) - to brush oneself.  E.g., ''cepillarse los dientes'' means to brush your teeth.

* Imagine it takes a caterpillar '''to brush''' '''onself''', e.g., your teeth.

'''cerrar''' (seh-rrahr) - to close

* Someone needs to tell ''Sarah R.'' '''to close''' her mouth 😡

'''cierto''' (see-air-toe) - ''adj.'' certain, sure, true

* Of course I'm ''cierto'' of my spelling, señor!

'''correr''' (core-air) - ''v.'' to run, or go fast

* Imagine that ''to run, or go fast'' your core will not get enough air.

'''creer''' (cr-ear) - ''v.'' to think, to believe

* Picture a monk yelling &quot;Forget your ''c''a''reer!''  '''To''' '''think,''' '''to''' '''believe''' in the Lord is not optional!&quot;

*Being credulous means '''to believe''' too easily, en inglés.

'''cuaderno''' (Kwan-dare-no) - ''m.'' notebook

* A '''notebook''' is a quadrangle (four-sided figure).

'''cuando''' (cwan-do) - ''conj.'' when

*''C''onsider ''u''pdate ''and'' time ''o''f.

== D ==

'''daiquirí''' - ''m.'' [http://en.wikipedia.org/wiki/Daiquiri daiquiri], a cocktail of rum, lemon, and sugar
* Be sure to enjoy '''a cocktail of rum, lemon, and sugar''' when visiting namesake [http://en.wikipedia.org/wiki/Daiquirí ''Daiquirí''], a port city in eastern Cuba.

'''dar''' (dar) - ''v.'' to give

*''Dar''win may not have meant '''to give''' God a size down.

'''deber''' (day-ver) - ''v.'' should, ought to; to owe

*''Deb''t ''e''ncouraged by ''r''ighteousness.

'''decir''' (day-seer) - ''v.'' to tell, say

* &quot;''Dec''lare ''IR''A!&quot;, enthusiastic nest egg incubators may declaim.

'''dejar''' (day-har) - ''v.'' to let, leave (rhetorically).

*''D''o ''e''nough, ''j''ust, ''a''nd ''r''etire.

'''despertarse''' (dais-per-tar-say) - ''v.'' to wake up.  ''(&lt;u&gt;Irregular&lt;/u&gt; verb: when conjugated the first &quot;e&quot; is replaced with &quot;ie&quot;.)'' 

* Dreaming that pirates are killing you, you're ''desper''a''t''e '''to wake''' your ''arse'' '''up'''.

'''descansar''' (dees-cahn-sar) - ''v.'' to rest
*''Descansar'' ('''to rest''') your disconsolation, may be to disassociate and dissolve it in sleep's soothing salve.

'''dolor''' (doe-lor) - m. pain.

* The in''dol''ent ''or'' lazy avoid '''pain''' of exertion.

== E ==

'''echar''' (eh-char) - ''v.'' to throw, to pour

*''E''scucha!  I hear ''char''coal thrown.

'''encontrar''' (en-cone-trar) - ''v.'' to find

*'''To find''' something is to it encounter.

'''enseñar''' (ehn-seh-nyahr) - ''v.'' to teach

*When you are '''taught''', your knowledge a''scen''ds.

== F ==

'''fábrica''' (FAH-bree-kah) - factory 

* A '''factory''' ''fabrica''tes.

'''fácil''' (FAH-seel) - easy

* It'd be ''facil''e to suggest that this nonsense ''facil''itates Spanish.

== G ==

'''gana''' (gah-nah) - ''f.'' desire

* I'm gonna (''gana'') wish absence didn't multiply '''desire'''.

'''gato''' (gah-toe) - ''m.'' cat

* A stray '''cat''' struts with ''ga''ps betwixt ''to''es.

'''gente''' (hen-tay) - people

* ladies and ''gent''l''e''men

== H ==

'''haber''' (ah-ver) - ''v.'' to have

*'''to ''ha''ve''', ''be''a''r''.

'''hacer''' (ha-ser) - ''v.'' to do, make

*''Hac''k''er''s do, do, ... '''make'''.

'''habitación''' (ah-bee-tah-see-own) - living space

* A habitation is a '''living space''' en inglés.

'''hablar''' ('ah-blar) - ''v.'' to speak, to talk

* bla, bla: '''to speak''' or '''talk''' much while saying little.

'''hay''' (ay) - there is (are)

*Make ''hay'' while '''there is''' sunshine.

== I ==

'''idioma''' (Ee-dee-OH-ma) - language

* &quot;thousands of ''idiom''s, occurring frequently in ''a''ll '''language'''s.&quot; -- Wikipedia

'''ir''' (ear) - ''v.'' to go

* '''To go''' ''ir''retrievably off course to save round trip fare, of course.

== J ==

* 

== K ==

*  

== L ==

'''labios''' (LA-bee-ohs) - lips

*''Labi''a ''o''rnament''s'' English with Latin ('''lips''').

'''león''' (ley-own) - lion

*''Leo''&lt;nowiki/&gt;'s symbol is a '''lion'''.

'''levantar''' (leh-bahn-tahr) - ''v.'' to raise, to lift up

*When you ''lev''i''ta''te, you are '''raised''' up off the ground

'''llamar''' (ya-mar) - ''v.'' to call, name

*''L''isten, ''L''amar – ''m''anage ''a'' ''r''ing!

'''llegar''' (yay-gar) - ''v.'' to arrive

*''L''and ''l''ightly, ''eg''ress, ''a''nd ''r''ow.

'''llevar''' (yay-var) - ''v.'' to take, carry.

*''L''ift, ''l''eave, ''ev''ade ''ar''rest.

'''lugar''' (loo-gar) - ''n.'' place, position

*''L''ocation ''u''sing ''g''round-''a''ssisted ''r''adar.

== M ==
'''mayor''' (ma-your) - ''adj.'' larger, older, main

* The ''mayor'' may have won '''main'''ly by dint of being '''larger''' and '''older'''.

'''mariposa''' - butterfly

*''Mari''e inventively ''pos''es ''a'' '''butterfly''' pin.

'''mismo''' (mees-moe) - ''adj.'' same

She ''mis''ses ''Mo''e the '''same'''.

'''Montar''' (moen-tar) - ''verb'' to ride

* '''To ride''' a horse, you'd have to ''mount'' your saddle.

== N ==

'''nacer''' (nah-sair) - ''v.'' to be born

* A re''na''issance ''cer''tainly means '''to be''' re'''born'''.

'''nuestro''' (new-aye-stro) - our

* '''Our''' notre dame, their ''nuestr''a señora, are ''o''f dedications made.

== O ==

* 

== P ==

'''parecer''' (par-ay-ser) - ''v.'' to seem, look like

* Ap''pare''ntly, not ''cer''tainly, ''parecer'' means apparently.

'''pez''' (pais) - ''m.'' fish

* Pisces is symbolized by a '''fish'''.

'''poder''' (poe-dair) - ''v.'' to be able to, can

*'''To be able to''' self-fulfill prophecy is ''po''tent ''der''ivation.

'''poner''' (poe-nair) - ''v.'' to put on, get (+ adj.)

*''P''ut it ''on, Er''win. 

'''primavera''' (preem-a-ver-a) - ''f.'' spring

* ''Prim''er''a ver''de, &quot;first green&quot;, is ''a'' description of '''spring'''.

'''probar''' (proh-bahr) - ''v.'' to try, to try on, to test

* You have to '''try''' the new ''pro bar''!

== Q ==
'''quedar''' (kay-dar) - ''v.'' to stay, remain

*''Q''uiescence ''u''nder ''e''very ''d''irectional ''ar''rangement.

'''querer''' (kay-air) - ''v.'' to want, love

* You do '''want''' '''to''' '''love''' a ''que''e''rer'' one...''?''

== R ==

'''ratón''' (ra-tone) - ''m.'' mouse

* A '''mouse''' looks like an old ''rat'' ''on''ce did.

== S ==

'''saber''' (sah-bear) - ''v.'' to know 

*'''To know''' proper social conduct is to have savoir faire (&quot;know how to do&quot;), the savvy savant demonstrated with his ''saber''.

'''sacar''' (sa-car) - ''v.'' to take out
* The ''sac''ked ''a''nd newly ''r''etired were given more stuff: sacs, '''to take''' it all '''out'''.

'''seguir''' (say-goo-ear) - ''v.'' to follow

*''Segu''e is ''ir''reducibly both noun and verb meaning '''to follow''' in time, en inglés.

'''según''' (say-goon) - ''prep.'' as; according to

*'''according to''' ''se''veral ''g''r''un''ts [insert gif]

'''sentarse''' (sent-ar-say) - ''v.'' to seat yourself.  ''(&lt;u&gt;Irregular&lt;/u&gt; verb: when conjugated the first &quot;e&quot; is replaced with &quot;''ie''.&quot;)''

*'''To seat yourself''' be ''sent'', ''arse''-first, to seat.

'''ser''' (sair) - ''v.'' to be (permanent condition / essential character) 

* Song title &quot;Que ''Ser''á ''Ser''á&quot; literally means &quot;whatever will be, will be&quot;.
*''Ser''ves as

'''sobre''' (so-bray) - ''prep.'' on top of, over, about

*''S''uperimposed ''o''r ''b''ased ‘''r''ound, ''e''nveloping.

== T ==

'''tal''' (tal) - ''adj.'' such 

* '''Such''' ''tal''isman, much luck.

'''talla''' (tah-yah) - size

* Yes, a '''size''' ''tall'' is ''a'' lot larger than small.

'''tanto''' (tawn-toe) - ''adv.'' so much, so many

*''Tant''alizing ''o''h '''so many, so much'''.

'''tener''' (ten-air) - ''v.'' to have

* To be tenacious is '''to have''' drive and persistence.

'''trabajo''' (tra-ba-hoe) ''m.'' work, job, effort

*''Tra''vail ''b''orne ''a''t ''jo''b.

== U ==

'''último''' (OO-tea-mo) - last 

*Penultimate means next to '''last''' en inglés.

== V ==

'''vacío''' (bah-SEE-oh) - ''m.'' empty 

* Vacuum meaning '''empty''' of even gas.

'''ver''' (vair) - ''v.'' to see

* She a''ver''red '''to''' have '''see'''n it, verily.

'''vez''' (bais) - ''f.'', time (as in number of times), instance

*''V''isitations ''e''numerated ''z''ealously.

== W ==

== X ==

== Y ==
'''ya''' (ya) - ''adv.'' already; still

*''Y''esterday ''a''ccomplished.

== Z ==

'''zorro''' (zorro) - ''m.'' fox

* Imagine a '''fox''' in a ''Zorro'' mask.

{{BookCat}}</text>
      <sha1>1oqyf8sad3g7bd9trbp8ibto1vt23pq</sha1>
    </revision>
  </page>
  <page>
    <title>Muggles' Guide to Harry Potter/Characters/The Grey Lady</title>
    <ns>0</ns>
    <id>91953</id>
    <revision>
      <id>4636892</id>
      <parentid>4094708</parentid>
      <timestamp>2026-05-21T14:39:04Z</timestamp>
      <contributor>
        <username>Pookiyama</username>
        <id>1766461</id>
      </contributor>
      <comment>Filled it outǃ</comment>
      <origin>4636892</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="5718" sha1="mhtaprw7ulp1r73f0rm9ms52ceq286r" xml:space="preserve">{{Muggles' Guide to Harry Potter/Character|
name=The Grey Lady|
gender=Female|
hair=Translucent|
eyes=Translucent|
family=[[Muggles' Guide to Harry Potter/Characters/Rowena Ravenclaw|Rowena Ravenclaw]]|
loyalty=[[Muggles' Guide to Harry Potter/Places/Ravenclaw House|Ravenclaw House]]
}}

== Overview ==

The '''''Grey Lady''''' is the ghost of Ravenclaw Tower. In life she was known as known as '''''Helena Ravenclaw''''', daughter of the House's founder, [[Muggles' Guide to Harry Potter/Characters/Rowena Ravenclaw|Rowena]].

== Role in the Books ==

{{Muggles' Guide to Harry Potter/Beginner Spoiler}}

=== [[Muggles' Guide to Harry Potter/Books/Deathly Hallows|Deathly Hallows]] ===

Although initially reluctant to do so, the Grey Lady helps [[Muggles' Guide to Harry Potter/Characters/Harry Potter|Harry]] with information about the lost Ravenclaw diadem, which has been made into a [[Muggles' Guide to Harry Potter/Magic/Horcrux|Horcrux]] by [[Muggles' Guide to Harry Potter/Characters/Lord Voldemort|Lord Voldemort]]. 

We discover through their discourse that she was, in life, [[Muggles' Guide to Harry Potter/Characters/Rowena Ravenclaw|Rowena Ravenclaw]]'s daughter Helena, and had stolen the diadem through jealousy, later hiding it in Albania. Harry correctly determines that it had been retrieved by Voldemort, and stored in the Room of Hidden things (an aspect of the [[Muggles' Guide to Harry Potter/Places/Room of Requirement|Room of Requirement]]), most likely on the same day he asked for a job.

As part of her story, we learn that the character who became [[Muggles' Guide to Harry Potter/Characters/The Bloody Baron|the Bloody Baron]] went to Albania, where Helena was hiding, to ask her to return to see her mother before she died. When she refused, the Baron, angered, killed her.

== Strengths ==
As Rowena Ravenclaw's daughter, we can assume Helena would have been possessed of some intelligence. She certainly had the singleness of mind to travel to Albania to hide something, which must have taken some planning.
== Weaknesses ==
We will note that she carried some envy for her mother from her actions. 

She also appears to be slightly imperious and aloof, initially with her interactions with Harry. She was, like so many others, not immune to the charms of [[Muggles' Guide to Harry Potter/Characters/Tom Marvolo Riddle|Tom Riddle]], the only prior student she had confided in.

== Relationships with Other Characters ==


The Grey Lady apparently stole the Diadem from Rowena Ravenclaw out of jealousy. We are not told why she refused to return, though we can safely guess that it was either fear of retribution or remorse.

She indicates that [[Muggles' Guide to Harry Potter/Characters/The Bloody Baron|the Bloody Baron]] had been in love with her in life, but whose affection she had spurned. He was eventually her killer, and she feels he deserves his miserable ghosthood.

She is not above talking with other ghosts such as [[Muggles' Guide to Harry Potter/Characters/Nearly Headless Nick|Nearly Headless Nick]], but she is hesitant to divulge information to non-Ravenclaw students. She does eventually do so to [[Muggles' Guide to Harry Potter/Characters/Tom Marvolo Riddle|Riddle]], and, of course, [[Muggles' Guide to Harry Potter/Characters/Harry Potter|Harry]].

== Analysis ==
The Grey Lady's brief appearance in [[Muggles' Guide to Harry Potter/Books/Deathly Hallows|Deathly Hallows]] answers many questions, not least of all who the Ravenclaw ghost isǃ Through her conversation, we get information about her past, the history of the diadem, and a clue to where it might be. This is important, because as a Ravenclaw she is privy to such information, whereas somebody like [[Muggles' Guide to Harry Potter/Characters/Nearly Headless Nick|Nick]] would doubtless try to help, but be less qualified to do so.
 
Other characters get a mention tooː [[Muggles' Guide to Harry Potter/Characters/Tom Marvolo Riddle|Riddle]] comes back into the story, having charmed her into giving him the information. We even get some extra information about [[Muggles' Guide to Harry Potter/Characters/The Bloody Baron|the Bloody Baron]], not necessary to the plot, but certainly a welcome piece of trivia.

Throughout the saga we have not had a lot of information about [[Muggles' Guide to Harry Potter/Places/Ravenclaw House|Ravenclaw House]]. Helena's story here, and our visit to the Ravenclaw common room later on, put this House briefly into focus.
== Questions ==
{{Muggles' Guide to Harry Potter/Questions}}
# Why was Helena jealous of her mother?
# What was the significance of Albania? Who else later visited there?
# Would Helena have been intelligent, witty and beautiful like her mother?
# Why didn't Helena return to her mother before she died?
== Greater Picture ==

{{Muggles' Guide to Harry Potter/Intermediate Spoiler}}
The reader almost never encounters the Grey Lady - she does not even get the cursory mentions that ghosts like [[Muggles' Guide to Harry Potter/Characters/The Fat Friar|The Fat Friar]] do, nor is she even mentioned at [[Muggles' Guide to Harry Potter/Books/Chamber of Secrets/Chapter 8|Nick's Deathday Party]]. She does make an appearance in the film adaptation of the first book, but remains unnamed. That she is thrown into such sharp focus for a short time is surprising, but not unwelcome.

Our contact with the Grey Lady is brief, but significant. From what we can tell, she appears to be a typical Ravenclaw - educated, well-spoken, clever and even a bit imperious.

We will note that we learn of the circumstances of her death - a single stab from the Baron, and Harry sees the wound, too - which adds to our knowledge of the ghosts.

{{BookCat}}</text>
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  <page>
    <title>Adventist Youth Honors Answer Book/Recreation/Camping Skills I</title>
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      <contributor>
        <username>Bonfas Mumbo</username>
        <id>3591125</id>
      </contributor>
      <minor />
      <comment>For the benefit of my Conference</comment>
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      <text bytes="13270" sha1="lc43keyeuvye2i9sf6z9lwglpvwjmo4" xml:space="preserve">{{honor_header|1|1986|Recreation|General Conference
Central Nyanza Conference}}

==1. Be at least in the 5th grade. ==
{{ay camping grade level|I|5}}

==2. Understand and practice wilderness and camping etiquette, regarding preservation of the outdoors. ==
{{:Adventist Youth Honors Answer Book/Camping/Etiquette}}

Memorize the 7 Leave No Trace Principles:

* Plan ahead and prepare.                                       
* Travel and camp on durable surfaces.                 
* Dispose of waste properly.                                                                         
* Leave what you find.                                            
* Minimize campfire impacts (be careful with fire).
* Respect wildlife.  
* Be considerate of other visitors.

Note: If you ever plan to go camping in a location that allows hunting- such as a national forest, bright colors is an important safety consideration.  Camouflaged or dark color tents will not aid hunters in quickly identifying that there are people in the area.

==3. Know ten things to do when lost. ==
{{:Adventist Youth Honors Answer Book/Camping/Lost}}

==4. Be familiar with various types of sleeping equipment suitable to location and season.==
===Sleeping bags===
{{:Adventist Youth Honors Answer Book/Camping/Sleeping bags}}

===Sleeping Pads===
{{:Adventist Youth Honors Answer Book/Camping/Sleeping pads}}

==5. List personal items needed for a weekend campout. ==
{{:Adventist Youth Honors Answer Book/Camping/Clothing}}

{{:Adventist Youth Honors Answer Book/Camping/Personal gear}}

==6. Plan and participate in a weekend camping trip. ==
There are a lot of aspects to planning a camping trip, including selection of a campground, choosing the dates, the menu, equipment, and solving the problems of getting there.  Get your whole group involved in as much of the decision-making as possible.  Where do they want to camp?  When can you go?  What will you eat?  Who will go?  How many tents will you need?  Who will sleep in which tents?  Is all the gear in a good state of repair?

When all these decisions are made, someone needs to go out and buy the food, repair, replace, or buy any gear that's needed, etc.  Every camper under the age of 11 should also have a signed permission slip and an up-to-date medical release form.  The forms should be photocopied (reduce them if necessary and use two-sided copies - that way you can have four forms per sheet of paper) and every staff member should carry them at all times.

On the day of the camp out, everyone should meet to load the equipment, and finally, you are ready to go.  When you get back, everyone should help unload the equipment.  Some should be taken home and cleaned, and if the tents and tarps were even slightly damp, they will need to be pitched again and allowed to dry ''completely''.  Then they will need to be put away.

==7. Know how to properly pitch and strike a tent. Observe fire precautions when a tent is in use. ==
{{: Adventist Youth Honors Answer Book/Camping/Pitch and strike a tent}}
assmant poles
Keep any fire at least 20 feet (6 meters) from the tents.  Sparks sometimes fly out of a fire or are projected into the air (such as when an inexperienced camper throws dry leaves into it).  If these sparks land on your tent, at best they will burn a little pinhole in it, but at worst can cause a deadly tragedy.

'''Never''' light a fire of any kind inside a tent, be it a candle, lantern, or a stove unless you ''know for a fact'' that the tent has been designed for that purpose.


==8. Know and practice the proper principles for camp sanitation for both primitive and established campsites. ==
{{:Adventist Youth Honors Answer Book/Camping/Sanitation}}

==9. Properly use the knife and hatchet. Know ten safety rules for their use. ==
===Knife Safety===
{{:Adventist Youth Honors Answer Book/Camping/Knife safety}}
===Hatchet Safety===
{{:Adventist Youth Honors Answer Book/Camping/Axe safety|Repeat the Following=Have participants repeat the following to ensure they know the guidelines:

I will treat knives with the respect due a useful tool.
I will always close or sheath knives and put them away when not in use.
I will not use a knife when it might injure someone near me.
I will use all knives and cutting tools in a safe manner at all times.}}

==10. Fires ==
===a. Demonstrate ability to choose and prepare a fire site. ===

{{:Adventist Youth Honors Answer Book/Camping/Fire/Fire site selection}}

{{:Adventist Youth Honors Answer Book/Camping/Fire/Fire ring}}

===b. Know fire safety precautions. ===
{{:Adventist Youth Honors Answer Book/Camping/Fire/Fire safety}}

===c. Know how to properly strike a match. ===
Three things are needed for a fire to start: oxygen, fuel, and heat.  The match head is a fuel that can be ignited at about 360&amp;nbsp;°F (182&amp;nbsp;°C), which can be obtained through friction.  The oxygen is supplied by the air.  To strike a match, quickly and firmly drag the match head along the striker pad on the side of the box or outside of the package. Keep your fingers away from the match head.  Once the head ignites, the temperature will increase sharply and ignite the match stick.  Fire prefers to climb uphill, and you can control the size of the flame to a certain extent by tilting the head down (for a bigger flame) or up (for a smaller flame).  Carefully shield the flame from wind (which lowers the temperature) by cupping your other hand around the flame and move it to the tinder you wish to light.

===d. Practice building a fire with the use of one match, using only natural materials. ===
There are three factors that govern a fire: 
# Oxygen
# Fuel
# Heat

You need all three to get a fire going, and the way you lay the fire will determine how much of each of these are available.  To get a fire going, you will need to ignite some tinder.  The tinder will need to burn long enough to ignite kindling, and the kindling will need to burn long enough to ignite the fuel.  Before lighting a match, it is important to have all three types of fuel available.

Start by laying your tinder in the center of your fire ring.  Tinder consists of small, easily ignited material, such as pine needles, shreds of birch bark, thin twigs (whose diameter is about the same as a pencil lead), or even dryer lint.  Once the tinder is on place, lay some larger pieces over it (this is the kindling). Kindling is wood whose diameter ranges from pencil thickness to {{units|4 cm|1.5 inches}}.  It should be arranged with the smallest-diameter pieces nearest to the tinder.

An effective method of doing this is to get two small fuel logs - about 3&quot; in diameter, and lay them parallel to one another and {{units|15-20 cm|6-8 inches}} apart, with the tinder in between. Then lay a small, straight stick across them and over the tinder. Call this stick the &quot;ridge pole&quot;. Next lay more pencil-sized sticks with one end on the ridge pole and the other end on the ground. Lay them alternately on both sides of the ridge pole as if you were framing a roof. These can be called the &quot;rafters&quot;. Once this is done and the rafters make a &quot;roof&quot; that spans the distance between the two logs and covers the tinder, lay two more ridge poles, one on either side of the first ridge pole, and then lay more rafters from them to the ground (but leave a little space between the rafters). You can repeat this a third time if you like, but it's important to leave a gap somewhere so you can get a match inside to light the tinder. The sticks in each layer of rafters should be a little larger than the ones that came before.

''Do not light this pile'' until you have gathered sufficient fuel for the fire!  Fuel consists of wood that is greater than {{units|7 cm|3 inches}} in diameter.  The tender pile described above will burn for about five minutes or so, and that does not leave much time for you to scrounge around looking for something to pile onto the flames.  Therefore, you should have your fuel ready to go.

Once the tinder is lit, you can use the fuel to lay a hunter's fire, teepee, a log cabin or a council fire on top of the first two logs. It works well, because there is a great deal of kindling stacked close together, but not so close as to reduce oxygen flow.  The kindling is also laid close to the tinder so the tinder has no trouble igniting it (assuming it is dry and pencil-sized).

===e. Demonstrate how to protect firewood in wet weather. ===
Obviously, you will want to keep your firewood dry, and there are many ways to do that.  One effective method is to put a tarp on the ground, stack the wood on top of it, and fold the tarp over the top.  Place one or two heavier logs on top to hold the tarp down.  Those logs will get wet, but they will prevent the wind from blowing the tarp off and soaking the rest of your wood.
Having a tarp beneath the wood will keep water from running under the stack and soaking the bottom logs, but this not entirely necessary.

You can also keep firewood in an enclosed trailer, or the trunk of a car if those are available to you.  Another option is to keep it under a kitchen tent or canopy.

==11. Bake bread on a stick. ==
{{:Adventist Youth Honors Answer Book/Camping/Bread on a stick}}

==12. Describe the proper procedures for washing and keeping clean the cooking and eating utensils. ==

Make up a mess kit for each camper, consisting of a plate, cup, bowl, knife, fork, and spoon. Store each kit in a mesh hosiery bag. Every mess kit should have a number, and every item in the kit should be labeled with that number. Every camper should be assigned a number. After the meal, each camper will wash his or her own mess kit. If a dirty plate is found abandoned on a picnic table, a quick check for its number will reveal who is responsible for that item.

Use three large tubs for washing the dishes. One will be filled with soapy water (heated if possible), the second one will have rinse water and the third tub is for sanitizing.  Plates should be scraped clean or wiped with a paper towel before placing them in the soapy water. This will allow the soapy water to be used longer before the food debris and grease prevents plate from being cleaned thoroughly before rinsing. The sanitizng solution is made by adding one measured tablespoon of Bleach per gallon (do not use scented or high efficiency bleach; old fashioned cheap chlorine bleach is what you need).  This solution should have about 100 parts per million (PPM) of chlorine.  It can also be used to sanitize food contact surfaces such as cutting boards etc.  The key is that the chlorine solution needs to come in contact with the item being sanitized for 60 seconds. Using the third sanitizing tub to soak items for 60 seconds ensures that the plates are properly sanitized.
 
To conserve water on the camp-out you may rotate the water (and bleach) down the line from clean to dirty.  That is you dump out the soapy wash water, wipe out the tub and add fresh soap.  Now dump the rinse water into the wash tub and wipe the tub out.  Finally dump the sanitizing water into the rinse tub and refill the sanitizing tub with fresh water and bleach.

Each dish should be washed, rinsed, sanitized, and returned to its mesh bag for drying. The mesh bags will then be hung from a clothesline. If the clothespins used to hold them to the line are also numbered, it is a lot easier for each camper to find his or her own kit if they are hung in numeric order.
 
Whoever is on kitchen duty for that meal (and everyone should be assigned at least once) is responsible for washing the cooking gear. Again, they should wipe the pots, pans, and utensils as clean as possible before subjecting the wash water to them. They will need to be dried after rinsing and then put away. The kitchen crew should then take steps to properly dispose of the trash, lest the camp attract critters. Critters may be cute, but they sure do make big messes!

==13. Describe sleeping wear and how to stay warm at night. ==
{{:Adventist Youth Honors Answer Book/Camping/Sleepwear}}

==14. Draw a spiritual object lesson from nature on your camping trip. ==
There are many possibilities for meeting this requirement.  Jesus used nature to illustrate object lessons on many occasions:
;Birds: ''Are not two sparrows sold for a penny? Yet not one of them will fall to the ground apart from the will of your Father.'' Matthew 10:29 - NIV
;Flowers: ''And why are you worried about clothing? Observe how the lilies of the field grow; they do not toil nor do they spin, yet I say to you that not even (AL)Solomon in all his glory clothed himself like one of these.'' Matthew 6:28,29 - NIV
;Water: Jesus meets the Samaritan woman at Jacob's well, John 4:7-38

==15. Explain and practice the motto: &quot;Take only pictures and leave only footprints.&quot; ==
{{:Adventist Youth Honors Answer Book/Camping/Take pictures leave footprints}}

==Note: The tent color for Camping Skills #1 is blue. ==
{{:Adventist Youth Honors Answer Book/Camping/Colors}}

==References==

[[{{BOOKCATEGORY|Adventist Youth Honors Answer Book}}|{{SUBPAGENAME}}]]
[[{{BOOKCATEGORY|Adventist Youth Honors Answer Book}}/Completed Honors|{{SUBPAGENAME}}]]</text>
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  <page>
    <title>Wikibooks:Reading room/General</title>
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      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>/* Regarding the project's FlaggedRevs extension */ archive to [[Wikibooks:Reading room/Archives/2026/March#Regarding the project's FlaggedRevs extension]] ([[mw:c:Special:MyLanguage/User:JWBTH/CD|CD]])</comment>
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      <text bytes="12907" sha1="msnr5df6hw46xm4ez63kupcdd2n8v1k" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:CHAT|WB:RR/G|WB:GENERAL}} {{TOC left|limit=3}}
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Welcome to the '''General reading room'''. On this page, Wikibookians are free to talk about the Wikibooks project in general. For proposals for improving Wikibooks, see the [[../Proposals/]] reading room.
{{clear}}

[[Category:Reading room]]

== Upcoming Wikimedia Café meetup regarding the [[:meta:Wikimedia Foundation Annual Plan/2026-2027|the 2026-2027 Wikimedia Foundation Annual Plan]] ==

{{tmbox
| image = [[File:Wikimedia Café logo in plain SVG format.svg|45px]]
| type=notice
| text  = Hello! There will be a '''[[:meta:Wikimedia Café|Wikimedia Café]]''' meetup on '''Saturday, 11 April 2026 at 14:00 UTC''', focusing on the [[:meta:Wikimedia Foundation Annual Plan/2026-2027|the 2026-2027 Wikimedia Foundation Annual Plan]]. The featured guests will be {{Noping|KStineRowe (WMF)|label1=Kelsi Stine-Rowe}} (senior manager, [[:meta:Movement Communications|Movement Communications]], Wikimedia Foundation), and {{Noping|Samwalton9 (WMF)|label1=Sam Walton}} (senior product manager, [[:mw:Moderator Tools|Moderator Tools]], Wikimedia Foundation). &lt;br /&gt;

In addition to this Café session, [[:meta:Wikimedia Foundation Annual Plan/2026-2027/Collaboration|several additional meetings regarding the Annual Plan are listed on the Collaboration page]], and you may participate on the [[:meta:Talk:Wikimedia Foundation Annual Plan/2026-2027|talk page]]. &lt;br /&gt;

This Café meetup will be approximately two hours long. Attendees may choose to attend only for a part. Please see the Café page for more information, including [[:meta:Wikimedia Café#Signups for the April 2026 session|how to register]]. &lt;br /&gt;
[[File:Buntstifte Eberhard Faber crop 64h.jpg|860px|alt=cropped image of colored pencils]]
}}
&lt;span style=&quot;white-space:nowrap;&quot;&gt;[[User:Pine|&lt;span style=&quot;color:#01796f; text-shadow:#00BFFF 0 0 1.0em&quot;&gt;↠Pine&lt;/span&gt;]] [[User talk:Pine|&lt;span style=&quot;color:DeepSkyBlue&quot;&gt;(&lt;b style=&quot;color:#FFDF00;text-shadow:#FFDF00 0 0 1.0em&quot;&gt;✉&lt;/b&gt;)&lt;/span&gt;]]&lt;/span&gt; 05:23, 29 March 2026 (UTC)

== Regarding copyright of recipes found on online cooking forums ==

What is the copyright situation regarding cooking recipes found on online recipe books with recipes made by other people? I ask this because I want to add/translate recipes from 下厨房 (xià chúfáng) for Chinese recipes, and while I was intending to add the original writer of the recipe with the translation I still want to ask for clarification. 

[[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:06, 30 March 2026 (UTC)

:Recipes are in principle not copyright-able, as they are just facts. When someone includes descriptive text or anything that elaborates on the basic ingredients and steps, that is copyright-able. I am not a lawyer or legal scholar and cannot give legal advice. See (e.g.) https://www.copyrightlaws.com/copyright-protection-recipes/ —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 19:16, 30 March 2026 (UTC)
::In that case, would simplifying ingredients and methods to where they are simple yet can still be understood be sufficient for said recipes? [[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:23, 30 March 2026 (UTC)
:::Yes, you can add a recipe here as long as the instructions and text are not too overlapping with the copyrighted original. As the linked page says, the '''ideas''' behind the ingredient list and steps to prepare a given food item are not currently copyrightable, but the way you write the ideas may be copyrightable. You should also cite where you took the recipe from so we can trace its origins. I personally recommend only adding recipes that you have successfully made so we don't become a massive repository of potentially low-quality or untested recipes—I only add recipes once I have made them successfully. Let me know if you have any more questions about the Cookbook! Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:06, 30 March 2026 (UTC)
::::To build up on this, if you want to understand what is copyright-able and what is not, the &quot;[[:w:en:Idea–expression distinction|idea versus expression]]&quot; distinction. You cannot own the idea of &quot;Boy meets girl, boy loses girl, boy and girl commit suicide&quot; but you can copyright a specific version of ''Romeo and Juliet'' with your own innovative ideas. And, for that matter, this is context-specific, but if you can understand the distinction, it can help with future questions about &quot;could this be protected by copyright?&quot;, which can be a subtle one. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 22:50, 30 March 2026 (UTC)
:::::To further build up on this, there's something called the merger doctrine (see ''[[w:Baker v. Selden|Baker v. Selden]]''). This is why you can't copyright drawings of [[w:Structural formula|structural formulas]]. This doctrine means that if there's only one or a handful of ways to express an idea, then any such expression cannot be copyrighted, since copyrighting that expression would essentially be copyrighting the idea itself. This comes in a lot with recipes. I very likely can't copyright this list (from [[Cookbook:Cornmeal Pancakes (Arepa)]]:
:::::* 2.4 cups corn flour
:::::* 1.2 tsp salt
:::::* 0.6 cup grated white cheese
:::::* 2.4 cups cool water 
:::::Since there's essentially only one way to express the idea of that combination of ingredients. However, if I say:
:::::* 2.4 cups corn flour: for this, I strongly recommend Harina P.A.N., because my grandma always used to make me arepas from that stuff every day, and it was delicious.
:::::That is copyrightable. At that point, I cease to merely be expressing the idea of a food item with those four ingredients, and add a minimum degree of creativity. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 02:02, 31 March 2026 (UTC)
::::::And to build on all &lt;em&gt;that&lt;/em&gt;, even if individual pieces of information are in the public domain (or are fair use), the &lt;em&gt;arrangement&lt;/em&gt; of them can be copyrighted. This is why even if ''Bartlett's Quotations'' only had public domain material, the act of selectively editing and positioning them thematically for the user's benefit could constitute a sufficiently original work. So we could copy the material from a bunch of recipes, but could run a foul of copyright issues if we arranged and sorted them in some kind of manner that replicated someone else's original work. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:28, 31 March 2026 (UTC)


== Style Guidelines for Advanced Points ==

Is there a general style guideline to refer the reader to advanced information, while the main text gives the short-answer version?  For example, how would I specify that in practical applications, A is true, but if you use the theory you see that A is not quite true, or has caveats, or similar?--
[[User:Iain marcuson|Iain marcuson]] ([[User talk:Iain marcuson|discuss]] • [[Special:Contributions/Iain marcuson|contribs]]) 17:50, 22 April 2026 (UTC)

== Request: Help adding Objective Projection writing guide (filter blocked) ==

Hello,

I am Levent Bulut (ORCID: 0009-0007-7500-2261), author of the 
Objective Projection methodology. I am trying to contribute a 
practical writing guide to Wikibooks under CC BY-SA 4.0.

Book title: &quot;Objective Projection: Why the Brain Never Forgets 
Some Stories&quot;

The automated filter blocked my edits due to external links and 
content volume. I have already created the page with the 
introduction and contents, but could not add the chapters.

The Turkish version of the same book is already live on Wikibooks:
https://tr.wikibooks.org/wiki/Nesnel_%C4%B0zd%C3%BC%C5%9F%C3%BCm:_Beyin_Neden_Baz%C4%B1_Hikayeleri_Unutmuyor%3F

This is not a new theory — it is an instructional guide teaching 
a published methodology documented in DOI-registered publications:
https://doi.org/10.5281/zenodo.18689179

Open license declaration on my site:
https://leventbulut.com/acik-lisans-bildirimi-wikibooks/

All content is my own work, written for Wikibooks, under CC BY-SA 4.0.

Could an experienced editor help add the remaining chapters, or 
whitelist my account so the filter does not block future edits?

Thank you.
Levent Bulut | leventbulut.com [[User:LeventBulut|LeventBulut]] ([[User talk:LeventBulut|discuss]] • [[Special:Contributions/LeventBulut|contribs]]) 21:28, 24 April 2026 (UTC)
: @[[User:LeventBulut|LeventBulut]] This happened because you added too much content when creating the book. Also, when reporting false positives from an edit filter, please report on [[Wikibooks:Edit filter/False positives]]. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 01:03, 25 April 2026 (UTC)

== Request for comment (global AI policy) ==

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot; class=&quot;mw-content-ltr&quot;&gt; A [[:m:Requests for comment/Artificial intelligence policy|request for comment]] is currently being held to decide on a global AI policy. {{int:Feedback-thanks-title}} [[User:MediaWiki message delivery|MediaWiki message delivery]] ([[User talk:MediaWiki message delivery|discuss]] • [[Special:Contributions/MediaWiki message delivery|contribs]]) 00:57, 26 April 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Codename Noreste@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=Distribution_list/Global_message_delivery&amp;oldid=30424282 --&gt;

== After WikiNews shuts down....? ==

Can people try and write news articles here? Thank you! [[User:BigKrow|BigKrow]] ([[User talk:BigKrow|discuss]] • [[Special:Contributions/BigKrow|contribs]]) 22:30, 1 May 2026 (UTC)

:Thanks for asking. You have a similar thread at our sister project Wikiversity and I am the equivalent of an admin there (we have a &quot;curators&quot; and &quot;custodians&quot; that are similar to admins on other projects). I'm not an admin here, but speaking as someone who has generally contributed here, writing news articles would not be appropriate. It would be great to write a textbook on [[journalism]]: we could use a great guide for ethics, finding sources, asking questions, objectivity and neutrality, etc. Unlike on Wikiversity, where the learning materials can be virtually anything, this project is specifically for a textbook/guide/manual, so writing news articles and posting them here is not really appropriate, but you could have a few example articles that you write for the purpose of having a textbook. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 23:46, 1 May 2026 (UTC)
:: Heads up, a wiki was created: &lt;span class=&quot;plainlinks&quot;&gt;[https://news.wikioasis.org/wiki/Main_Page news.wikioasis.org]&lt;/span&gt;. @[[User:Koavf|Koavf]]; I was temporarily granted some user rights to  manage the wiki's setup and migration. I'll give you sysop rights since you are currently one on English Wikinews. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:11, 2 May 2026 (UTC)
:::Thanks. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:14, 2 May 2026 (UTC)

== Discussion at [[Wikibooks talk:Reviewers]] ==

I started a discussion on whether we should introduce an inactivity criteria for reviewers (and possibly autoreviewed users), at [[Wikibooks talk:Reviewers#Inactivity criteria]]. Any participation would be appreciated. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:17, 18 May 2026 (UTC)</text>
      <sha1>msnr5df6hw46xm4ez63kupcdd2n8v1k</sha1>
    </revision>
    <revision>
      <id>4636925</id>
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      <timestamp>2026-05-21T19:01:21Z</timestamp>
      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>/* Upcoming Wikimedia Café meetup regarding the the 2026-2027 Wikimedia Foundation Annual Plan */ archive to [[Wikibooks:Reading room/Archives/2026/March#Upcoming Wikimedia Café meetup regarding the the 2026-2027 Wikimedia Foundation Annual Plan]] ([[mw:c:Special:MyLanguage/User:JWBTH/CD|CD]])</comment>
      <origin>4636925</origin>
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      <text bytes="11162" sha1="rvfsmxoby621oe1l6tzvj4kw9c2m0k9" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:CHAT|WB:RR/G|WB:GENERAL}} {{TOC left|limit=3}}
{{User:MiszaBot/config
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Welcome to the '''General reading room'''. On this page, Wikibookians are free to talk about the Wikibooks project in general. For proposals for improving Wikibooks, see the [[../Proposals/]] reading room.
{{clear}}

[[Category:Reading room]]

== Regarding copyright of recipes found on online cooking forums ==

What is the copyright situation regarding cooking recipes found on online recipe books with recipes made by other people? I ask this because I want to add/translate recipes from 下厨房 (xià chúfáng) for Chinese recipes, and while I was intending to add the original writer of the recipe with the translation I still want to ask for clarification. 

[[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:06, 30 March 2026 (UTC)

:Recipes are in principle not copyright-able, as they are just facts. When someone includes descriptive text or anything that elaborates on the basic ingredients and steps, that is copyright-able. I am not a lawyer or legal scholar and cannot give legal advice. See (e.g.) https://www.copyrightlaws.com/copyright-protection-recipes/ —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 19:16, 30 March 2026 (UTC)
::In that case, would simplifying ingredients and methods to where they are simple yet can still be understood be sufficient for said recipes? [[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:23, 30 March 2026 (UTC)
:::Yes, you can add a recipe here as long as the instructions and text are not too overlapping with the copyrighted original. As the linked page says, the '''ideas''' behind the ingredient list and steps to prepare a given food item are not currently copyrightable, but the way you write the ideas may be copyrightable. You should also cite where you took the recipe from so we can trace its origins. I personally recommend only adding recipes that you have successfully made so we don't become a massive repository of potentially low-quality or untested recipes—I only add recipes once I have made them successfully. Let me know if you have any more questions about the Cookbook! Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:06, 30 March 2026 (UTC)
::::To build up on this, if you want to understand what is copyright-able and what is not, the &quot;[[:w:en:Idea–expression distinction|idea versus expression]]&quot; distinction. You cannot own the idea of &quot;Boy meets girl, boy loses girl, boy and girl commit suicide&quot; but you can copyright a specific version of ''Romeo and Juliet'' with your own innovative ideas. And, for that matter, this is context-specific, but if you can understand the distinction, it can help with future questions about &quot;could this be protected by copyright?&quot;, which can be a subtle one. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 22:50, 30 March 2026 (UTC)
:::::To further build up on this, there's something called the merger doctrine (see ''[[w:Baker v. Selden|Baker v. Selden]]''). This is why you can't copyright drawings of [[w:Structural formula|structural formulas]]. This doctrine means that if there's only one or a handful of ways to express an idea, then any such expression cannot be copyrighted, since copyrighting that expression would essentially be copyrighting the idea itself. This comes in a lot with recipes. I very likely can't copyright this list (from [[Cookbook:Cornmeal Pancakes (Arepa)]]:
:::::* 2.4 cups corn flour
:::::* 1.2 tsp salt
:::::* 0.6 cup grated white cheese
:::::* 2.4 cups cool water 
:::::Since there's essentially only one way to express the idea of that combination of ingredients. However, if I say:
:::::* 2.4 cups corn flour: for this, I strongly recommend Harina P.A.N., because my grandma always used to make me arepas from that stuff every day, and it was delicious.
:::::That is copyrightable. At that point, I cease to merely be expressing the idea of a food item with those four ingredients, and add a minimum degree of creativity. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 02:02, 31 March 2026 (UTC)
::::::And to build on all &lt;em&gt;that&lt;/em&gt;, even if individual pieces of information are in the public domain (or are fair use), the &lt;em&gt;arrangement&lt;/em&gt; of them can be copyrighted. This is why even if ''Bartlett's Quotations'' only had public domain material, the act of selectively editing and positioning them thematically for the user's benefit could constitute a sufficiently original work. So we could copy the material from a bunch of recipes, but could run a foul of copyright issues if we arranged and sorted them in some kind of manner that replicated someone else's original work. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:28, 31 March 2026 (UTC)


== Style Guidelines for Advanced Points ==

Is there a general style guideline to refer the reader to advanced information, while the main text gives the short-answer version?  For example, how would I specify that in practical applications, A is true, but if you use the theory you see that A is not quite true, or has caveats, or similar?--
[[User:Iain marcuson|Iain marcuson]] ([[User talk:Iain marcuson|discuss]] • [[Special:Contributions/Iain marcuson|contribs]]) 17:50, 22 April 2026 (UTC)

== Request: Help adding Objective Projection writing guide (filter blocked) ==

Hello,

I am Levent Bulut (ORCID: 0009-0007-7500-2261), author of the 
Objective Projection methodology. I am trying to contribute a 
practical writing guide to Wikibooks under CC BY-SA 4.0.

Book title: &quot;Objective Projection: Why the Brain Never Forgets 
Some Stories&quot;

The automated filter blocked my edits due to external links and 
content volume. I have already created the page with the 
introduction and contents, but could not add the chapters.

The Turkish version of the same book is already live on Wikibooks:
https://tr.wikibooks.org/wiki/Nesnel_%C4%B0zd%C3%BC%C5%9F%C3%BCm:_Beyin_Neden_Baz%C4%B1_Hikayeleri_Unutmuyor%3F

This is not a new theory — it is an instructional guide teaching 
a published methodology documented in DOI-registered publications:
https://doi.org/10.5281/zenodo.18689179

Open license declaration on my site:
https://leventbulut.com/acik-lisans-bildirimi-wikibooks/

All content is my own work, written for Wikibooks, under CC BY-SA 4.0.

Could an experienced editor help add the remaining chapters, or 
whitelist my account so the filter does not block future edits?

Thank you.
Levent Bulut | leventbulut.com [[User:LeventBulut|LeventBulut]] ([[User talk:LeventBulut|discuss]] • [[Special:Contributions/LeventBulut|contribs]]) 21:28, 24 April 2026 (UTC)
: @[[User:LeventBulut|LeventBulut]] This happened because you added too much content when creating the book. Also, when reporting false positives from an edit filter, please report on [[Wikibooks:Edit filter/False positives]]. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 01:03, 25 April 2026 (UTC)

== Request for comment (global AI policy) ==

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot; class=&quot;mw-content-ltr&quot;&gt; A [[:m:Requests for comment/Artificial intelligence policy|request for comment]] is currently being held to decide on a global AI policy. {{int:Feedback-thanks-title}} [[User:MediaWiki message delivery|MediaWiki message delivery]] ([[User talk:MediaWiki message delivery|discuss]] • [[Special:Contributions/MediaWiki message delivery|contribs]]) 00:57, 26 April 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Codename Noreste@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=Distribution_list/Global_message_delivery&amp;oldid=30424282 --&gt;

== After WikiNews shuts down....? ==

Can people try and write news articles here? Thank you! [[User:BigKrow|BigKrow]] ([[User talk:BigKrow|discuss]] • [[Special:Contributions/BigKrow|contribs]]) 22:30, 1 May 2026 (UTC)

:Thanks for asking. You have a similar thread at our sister project Wikiversity and I am the equivalent of an admin there (we have a &quot;curators&quot; and &quot;custodians&quot; that are similar to admins on other projects). I'm not an admin here, but speaking as someone who has generally contributed here, writing news articles would not be appropriate. It would be great to write a textbook on [[journalism]]: we could use a great guide for ethics, finding sources, asking questions, objectivity and neutrality, etc. Unlike on Wikiversity, where the learning materials can be virtually anything, this project is specifically for a textbook/guide/manual, so writing news articles and posting them here is not really appropriate, but you could have a few example articles that you write for the purpose of having a textbook. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 23:46, 1 May 2026 (UTC)
:: Heads up, a wiki was created: &lt;span class=&quot;plainlinks&quot;&gt;[https://news.wikioasis.org/wiki/Main_Page news.wikioasis.org]&lt;/span&gt;. @[[User:Koavf|Koavf]]; I was temporarily granted some user rights to  manage the wiki's setup and migration. I'll give you sysop rights since you are currently one on English Wikinews. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:11, 2 May 2026 (UTC)
:::Thanks. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:14, 2 May 2026 (UTC)

== Discussion at [[Wikibooks talk:Reviewers]] ==

I started a discussion on whether we should introduce an inactivity criteria for reviewers (and possibly autoreviewed users), at [[Wikibooks talk:Reviewers#Inactivity criteria]]. Any participation would be appreciated. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:17, 18 May 2026 (UTC)</text>
      <sha1>rvfsmxoby621oe1l6tzvj4kw9c2m0k9</sha1>
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      <id>4636927</id>
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      <timestamp>2026-05-21T19:44:02Z</timestamp>
      <contributor>
        <username>Pine</username>
        <id>504037</id>
      </contributor>
      <comment>May 2026 meetups</comment>
      <origin>4636927</origin>
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      <text bytes="13626" sha1="c911xjt8zdkl99gdzn45tl7643wc1xf" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:CHAT|WB:RR/G|WB:GENERAL}} {{TOC left|limit=3}}
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Welcome to the '''General reading room'''. On this page, Wikibookians are free to talk about the Wikibooks project in general. For proposals for improving Wikibooks, see the [[../Proposals/]] reading room.
{{clear}}

[[Category:Reading room]]

== Regarding copyright of recipes found on online cooking forums ==

What is the copyright situation regarding cooking recipes found on online recipe books with recipes made by other people? I ask this because I want to add/translate recipes from 下厨房 (xià chúfáng) for Chinese recipes, and while I was intending to add the original writer of the recipe with the translation I still want to ask for clarification. 

[[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:06, 30 March 2026 (UTC)

:Recipes are in principle not copyright-able, as they are just facts. When someone includes descriptive text or anything that elaborates on the basic ingredients and steps, that is copyright-able. I am not a lawyer or legal scholar and cannot give legal advice. See (e.g.) https://www.copyrightlaws.com/copyright-protection-recipes/ —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 19:16, 30 March 2026 (UTC)
::In that case, would simplifying ingredients and methods to where they are simple yet can still be understood be sufficient for said recipes? [[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:23, 30 March 2026 (UTC)
:::Yes, you can add a recipe here as long as the instructions and text are not too overlapping with the copyrighted original. As the linked page says, the '''ideas''' behind the ingredient list and steps to prepare a given food item are not currently copyrightable, but the way you write the ideas may be copyrightable. You should also cite where you took the recipe from so we can trace its origins. I personally recommend only adding recipes that you have successfully made so we don't become a massive repository of potentially low-quality or untested recipes—I only add recipes once I have made them successfully. Let me know if you have any more questions about the Cookbook! Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:06, 30 March 2026 (UTC)
::::To build up on this, if you want to understand what is copyright-able and what is not, the &quot;[[:w:en:Idea–expression distinction|idea versus expression]]&quot; distinction. You cannot own the idea of &quot;Boy meets girl, boy loses girl, boy and girl commit suicide&quot; but you can copyright a specific version of ''Romeo and Juliet'' with your own innovative ideas. And, for that matter, this is context-specific, but if you can understand the distinction, it can help with future questions about &quot;could this be protected by copyright?&quot;, which can be a subtle one. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 22:50, 30 March 2026 (UTC)
:::::To further build up on this, there's something called the merger doctrine (see ''[[w:Baker v. Selden|Baker v. Selden]]''). This is why you can't copyright drawings of [[w:Structural formula|structural formulas]]. This doctrine means that if there's only one or a handful of ways to express an idea, then any such expression cannot be copyrighted, since copyrighting that expression would essentially be copyrighting the idea itself. This comes in a lot with recipes. I very likely can't copyright this list (from [[Cookbook:Cornmeal Pancakes (Arepa)]]:
:::::* 2.4 cups corn flour
:::::* 1.2 tsp salt
:::::* 0.6 cup grated white cheese
:::::* 2.4 cups cool water 
:::::Since there's essentially only one way to express the idea of that combination of ingredients. However, if I say:
:::::* 2.4 cups corn flour: for this, I strongly recommend Harina P.A.N., because my grandma always used to make me arepas from that stuff every day, and it was delicious.
:::::That is copyrightable. At that point, I cease to merely be expressing the idea of a food item with those four ingredients, and add a minimum degree of creativity. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 02:02, 31 March 2026 (UTC)
::::::And to build on all &lt;em&gt;that&lt;/em&gt;, even if individual pieces of information are in the public domain (or are fair use), the &lt;em&gt;arrangement&lt;/em&gt; of them can be copyrighted. This is why even if ''Bartlett's Quotations'' only had public domain material, the act of selectively editing and positioning them thematically for the user's benefit could constitute a sufficiently original work. So we could copy the material from a bunch of recipes, but could run a foul of copyright issues if we arranged and sorted them in some kind of manner that replicated someone else's original work. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:28, 31 March 2026 (UTC)


== Style Guidelines for Advanced Points ==

Is there a general style guideline to refer the reader to advanced information, while the main text gives the short-answer version?  For example, how would I specify that in practical applications, A is true, but if you use the theory you see that A is not quite true, or has caveats, or similar?--
[[User:Iain marcuson|Iain marcuson]] ([[User talk:Iain marcuson|discuss]] • [[Special:Contributions/Iain marcuson|contribs]]) 17:50, 22 April 2026 (UTC)

== Request: Help adding Objective Projection writing guide (filter blocked) ==

Hello,

I am Levent Bulut (ORCID: 0009-0007-7500-2261), author of the 
Objective Projection methodology. I am trying to contribute a 
practical writing guide to Wikibooks under CC BY-SA 4.0.

Book title: &quot;Objective Projection: Why the Brain Never Forgets 
Some Stories&quot;

The automated filter blocked my edits due to external links and 
content volume. I have already created the page with the 
introduction and contents, but could not add the chapters.

The Turkish version of the same book is already live on Wikibooks:
https://tr.wikibooks.org/wiki/Nesnel_%C4%B0zd%C3%BC%C5%9F%C3%BCm:_Beyin_Neden_Baz%C4%B1_Hikayeleri_Unutmuyor%3F

This is not a new theory — it is an instructional guide teaching 
a published methodology documented in DOI-registered publications:
https://doi.org/10.5281/zenodo.18689179

Open license declaration on my site:
https://leventbulut.com/acik-lisans-bildirimi-wikibooks/

All content is my own work, written for Wikibooks, under CC BY-SA 4.0.

Could an experienced editor help add the remaining chapters, or 
whitelist my account so the filter does not block future edits?

Thank you.
Levent Bulut | leventbulut.com [[User:LeventBulut|LeventBulut]] ([[User talk:LeventBulut|discuss]] • [[Special:Contributions/LeventBulut|contribs]]) 21:28, 24 April 2026 (UTC)
: @[[User:LeventBulut|LeventBulut]] This happened because you added too much content when creating the book. Also, when reporting false positives from an edit filter, please report on [[Wikibooks:Edit filter/False positives]]. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 01:03, 25 April 2026 (UTC)

== Request for comment (global AI policy) ==

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot; class=&quot;mw-content-ltr&quot;&gt; A [[:m:Requests for comment/Artificial intelligence policy|request for comment]] is currently being held to decide on a global AI policy. {{int:Feedback-thanks-title}} [[User:MediaWiki message delivery|MediaWiki message delivery]] ([[User talk:MediaWiki message delivery|discuss]] • [[Special:Contributions/MediaWiki message delivery|contribs]]) 00:57, 26 April 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Codename Noreste@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=Distribution_list/Global_message_delivery&amp;oldid=30424282 --&gt;

== After WikiNews shuts down....? ==

Can people try and write news articles here? Thank you! [[User:BigKrow|BigKrow]] ([[User talk:BigKrow|discuss]] • [[Special:Contributions/BigKrow|contribs]]) 22:30, 1 May 2026 (UTC)

:Thanks for asking. You have a similar thread at our sister project Wikiversity and I am the equivalent of an admin there (we have a &quot;curators&quot; and &quot;custodians&quot; that are similar to admins on other projects). I'm not an admin here, but speaking as someone who has generally contributed here, writing news articles would not be appropriate. It would be great to write a textbook on [[journalism]]: we could use a great guide for ethics, finding sources, asking questions, objectivity and neutrality, etc. Unlike on Wikiversity, where the learning materials can be virtually anything, this project is specifically for a textbook/guide/manual, so writing news articles and posting them here is not really appropriate, but you could have a few example articles that you write for the purpose of having a textbook. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 23:46, 1 May 2026 (UTC)
:: Heads up, a wiki was created: &lt;span class=&quot;plainlinks&quot;&gt;[https://news.wikioasis.org/wiki/Main_Page news.wikioasis.org]&lt;/span&gt;. @[[User:Koavf|Koavf]]; I was temporarily granted some user rights to  manage the wiki's setup and migration. I'll give you sysop rights since you are currently one on English Wikinews. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:11, 2 May 2026 (UTC)
:::Thanks. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:14, 2 May 2026 (UTC)

== Discussion at [[Wikibooks talk:Reviewers]] ==

I started a discussion on whether we should introduce an inactivity criteria for reviewers (and possibly autoreviewed users), at [[Wikibooks talk:Reviewers#Inactivity criteria]]. Any participation would be appreciated. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:17, 18 May 2026 (UTC)

== May 2026 Wikimedia Café meetups regarding the the Wikimedia Foundation Annual Plan ==
&lt;div class=&quot;border-box&quot; style=&quot;background-color: var(--background-color-warning-subtle, #f8eaba); max-width: 875px; padding: 5px; border: 1px solid black; margin: 5px; color: var(--clr-dark)&quot;&gt;
&lt;div class=&quot;box&quot; style=&quot;float:left; padding-top: 15px; padding-right: 15px;&quot;&gt;[[File:Wikimedia Café logo in plain SVG format.svg|75px|alt=The logo for the Wikimedia Café]]&lt;/div&gt;
Hello! There will be two '''[https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9 Wikimedia Café]''' discussion opportunities during the last weekend of May. Both sessions will focus on the [https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_Plan/2026-2027 the 2026-2027 Wikimedia Foundation Annual Plan]. Participants may attend either or both sessions.

#'''Saturday, 30 May 2026 at 15:00 UTC''' ([https://zonestamp.toolforge.org/1780153200 timestamp converter]), at a time friendly to the Americas, Africa, and Europe
#'''Sunday, 31 May 2026 at 05:00 UTC''' ([https://zonestamp.toolforge.org/1780203600 timestamp converter]), at a time friendly to Asia and the Pacific

Café participants are highly encouraged to read in advance [https://en.wikipedia.org/wiki/User:Sohom_Datta/annual_plan_guide at least this summary of the plan]. Optionally,  Café participants are encouraged to read portions of the plan that interest them and [https://meta.wikimedia.org/wiki/Talk:Wikimedia_Foundation_Annual_Plan/2026-2027 ask questions or provide feedback on the Annual Plan talk page]. 

Please see the Café page for more information, including [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#May_2026_meetings_with_a_focus_on_Wikimedia_Foundation_Annual_Plan/2026-2027 tables of timestamp conversions for both sessions], [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#Agenda._This_will_be_an_approximately_1_hour_Caf%C3%A9_session,_and_is_extendible_for_an_additional_30_minutes_if_needed. the agenda], and [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#How_to_attend_the_session how to register]!
&lt;br /&gt;
[[File:Buntstifte Eberhard Faber crop 64h.jpg|860px|alt=cropped image of colored pencils]]&lt;/div&gt;
&lt;span style=&quot;white-space:nowrap;&quot;&gt;[[User:Pine|&lt;span style=&quot;color:#01796f; text-shadow:#00BFFF 0 0 1.0em&quot;&gt;↠Pine&lt;/span&gt;]] [[User talk:Pine|&lt;span style=&quot;color:DeepSkyBlue&quot;&gt;(&lt;b style=&quot;color:#FFDF00;text-shadow:#FFDF00 0 0 1.0em&quot;&gt;✉&lt;/b&gt;)&lt;/span&gt;]]&lt;/span&gt; 19:44, 21 May 2026 (UTC)</text>
      <sha1>c911xjt8zdkl99gdzn45tl7643wc1xf</sha1>
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      <comment>/* May 2026 Wikimedia Café meetups regarding the the Wikimedia Foundation Annual Plan */ ce</comment>
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      <text bytes="13622" sha1="5q0rwazqcno7f0dm2v4wy7m9xp8x0rq" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:CHAT|WB:RR/G|WB:GENERAL}} {{TOC left|limit=3}}
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Welcome to the '''General reading room'''. On this page, Wikibookians are free to talk about the Wikibooks project in general. For proposals for improving Wikibooks, see the [[../Proposals/]] reading room.
{{clear}}

[[Category:Reading room]]

== Regarding copyright of recipes found on online cooking forums ==

What is the copyright situation regarding cooking recipes found on online recipe books with recipes made by other people? I ask this because I want to add/translate recipes from 下厨房 (xià chúfáng) for Chinese recipes, and while I was intending to add the original writer of the recipe with the translation I still want to ask for clarification. 

[[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:06, 30 March 2026 (UTC)

:Recipes are in principle not copyright-able, as they are just facts. When someone includes descriptive text or anything that elaborates on the basic ingredients and steps, that is copyright-able. I am not a lawyer or legal scholar and cannot give legal advice. See (e.g.) https://www.copyrightlaws.com/copyright-protection-recipes/ —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 19:16, 30 March 2026 (UTC)
::In that case, would simplifying ingredients and methods to where they are simple yet can still be understood be sufficient for said recipes? [[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:23, 30 March 2026 (UTC)
:::Yes, you can add a recipe here as long as the instructions and text are not too overlapping with the copyrighted original. As the linked page says, the '''ideas''' behind the ingredient list and steps to prepare a given food item are not currently copyrightable, but the way you write the ideas may be copyrightable. You should also cite where you took the recipe from so we can trace its origins. I personally recommend only adding recipes that you have successfully made so we don't become a massive repository of potentially low-quality or untested recipes—I only add recipes once I have made them successfully. Let me know if you have any more questions about the Cookbook! Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:06, 30 March 2026 (UTC)
::::To build up on this, if you want to understand what is copyright-able and what is not, the &quot;[[:w:en:Idea–expression distinction|idea versus expression]]&quot; distinction. You cannot own the idea of &quot;Boy meets girl, boy loses girl, boy and girl commit suicide&quot; but you can copyright a specific version of ''Romeo and Juliet'' with your own innovative ideas. And, for that matter, this is context-specific, but if you can understand the distinction, it can help with future questions about &quot;could this be protected by copyright?&quot;, which can be a subtle one. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 22:50, 30 March 2026 (UTC)
:::::To further build up on this, there's something called the merger doctrine (see ''[[w:Baker v. Selden|Baker v. Selden]]''). This is why you can't copyright drawings of [[w:Structural formula|structural formulas]]. This doctrine means that if there's only one or a handful of ways to express an idea, then any such expression cannot be copyrighted, since copyrighting that expression would essentially be copyrighting the idea itself. This comes in a lot with recipes. I very likely can't copyright this list (from [[Cookbook:Cornmeal Pancakes (Arepa)]]:
:::::* 2.4 cups corn flour
:::::* 1.2 tsp salt
:::::* 0.6 cup grated white cheese
:::::* 2.4 cups cool water 
:::::Since there's essentially only one way to express the idea of that combination of ingredients. However, if I say:
:::::* 2.4 cups corn flour: for this, I strongly recommend Harina P.A.N., because my grandma always used to make me arepas from that stuff every day, and it was delicious.
:::::That is copyrightable. At that point, I cease to merely be expressing the idea of a food item with those four ingredients, and add a minimum degree of creativity. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 02:02, 31 March 2026 (UTC)
::::::And to build on all &lt;em&gt;that&lt;/em&gt;, even if individual pieces of information are in the public domain (or are fair use), the &lt;em&gt;arrangement&lt;/em&gt; of them can be copyrighted. This is why even if ''Bartlett's Quotations'' only had public domain material, the act of selectively editing and positioning them thematically for the user's benefit could constitute a sufficiently original work. So we could copy the material from a bunch of recipes, but could run a foul of copyright issues if we arranged and sorted them in some kind of manner that replicated someone else's original work. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:28, 31 March 2026 (UTC)


== Style Guidelines for Advanced Points ==

Is there a general style guideline to refer the reader to advanced information, while the main text gives the short-answer version?  For example, how would I specify that in practical applications, A is true, but if you use the theory you see that A is not quite true, or has caveats, or similar?--
[[User:Iain marcuson|Iain marcuson]] ([[User talk:Iain marcuson|discuss]] • [[Special:Contributions/Iain marcuson|contribs]]) 17:50, 22 April 2026 (UTC)

== Request: Help adding Objective Projection writing guide (filter blocked) ==

Hello,

I am Levent Bulut (ORCID: 0009-0007-7500-2261), author of the 
Objective Projection methodology. I am trying to contribute a 
practical writing guide to Wikibooks under CC BY-SA 4.0.

Book title: &quot;Objective Projection: Why the Brain Never Forgets 
Some Stories&quot;

The automated filter blocked my edits due to external links and 
content volume. I have already created the page with the 
introduction and contents, but could not add the chapters.

The Turkish version of the same book is already live on Wikibooks:
https://tr.wikibooks.org/wiki/Nesnel_%C4%B0zd%C3%BC%C5%9F%C3%BCm:_Beyin_Neden_Baz%C4%B1_Hikayeleri_Unutmuyor%3F

This is not a new theory — it is an instructional guide teaching 
a published methodology documented in DOI-registered publications:
https://doi.org/10.5281/zenodo.18689179

Open license declaration on my site:
https://leventbulut.com/acik-lisans-bildirimi-wikibooks/

All content is my own work, written for Wikibooks, under CC BY-SA 4.0.

Could an experienced editor help add the remaining chapters, or 
whitelist my account so the filter does not block future edits?

Thank you.
Levent Bulut | leventbulut.com [[User:LeventBulut|LeventBulut]] ([[User talk:LeventBulut|discuss]] • [[Special:Contributions/LeventBulut|contribs]]) 21:28, 24 April 2026 (UTC)
: @[[User:LeventBulut|LeventBulut]] This happened because you added too much content when creating the book. Also, when reporting false positives from an edit filter, please report on [[Wikibooks:Edit filter/False positives]]. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 01:03, 25 April 2026 (UTC)

== Request for comment (global AI policy) ==

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot; class=&quot;mw-content-ltr&quot;&gt; A [[:m:Requests for comment/Artificial intelligence policy|request for comment]] is currently being held to decide on a global AI policy. {{int:Feedback-thanks-title}} [[User:MediaWiki message delivery|MediaWiki message delivery]] ([[User talk:MediaWiki message delivery|discuss]] • [[Special:Contributions/MediaWiki message delivery|contribs]]) 00:57, 26 April 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Codename Noreste@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=Distribution_list/Global_message_delivery&amp;oldid=30424282 --&gt;

== After WikiNews shuts down....? ==

Can people try and write news articles here? Thank you! [[User:BigKrow|BigKrow]] ([[User talk:BigKrow|discuss]] • [[Special:Contributions/BigKrow|contribs]]) 22:30, 1 May 2026 (UTC)

:Thanks for asking. You have a similar thread at our sister project Wikiversity and I am the equivalent of an admin there (we have a &quot;curators&quot; and &quot;custodians&quot; that are similar to admins on other projects). I'm not an admin here, but speaking as someone who has generally contributed here, writing news articles would not be appropriate. It would be great to write a textbook on [[journalism]]: we could use a great guide for ethics, finding sources, asking questions, objectivity and neutrality, etc. Unlike on Wikiversity, where the learning materials can be virtually anything, this project is specifically for a textbook/guide/manual, so writing news articles and posting them here is not really appropriate, but you could have a few example articles that you write for the purpose of having a textbook. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 23:46, 1 May 2026 (UTC)
:: Heads up, a wiki was created: &lt;span class=&quot;plainlinks&quot;&gt;[https://news.wikioasis.org/wiki/Main_Page news.wikioasis.org]&lt;/span&gt;. @[[User:Koavf|Koavf]]; I was temporarily granted some user rights to  manage the wiki's setup and migration. I'll give you sysop rights since you are currently one on English Wikinews. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:11, 2 May 2026 (UTC)
:::Thanks. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:14, 2 May 2026 (UTC)

== Discussion at [[Wikibooks talk:Reviewers]] ==

I started a discussion on whether we should introduce an inactivity criteria for reviewers (and possibly autoreviewed users), at [[Wikibooks talk:Reviewers#Inactivity criteria]]. Any participation would be appreciated. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:17, 18 May 2026 (UTC)

== May 2026 Wikimedia Café meetups regarding the Wikimedia Foundation Annual Plan ==
&lt;div class=&quot;border-box&quot; style=&quot;background-color: var(--background-color-warning-subtle, #f8eaba); max-width: 875px; padding: 5px; border: 1px solid black; margin: 5px; color: var(--clr-dark)&quot;&gt;
&lt;div class=&quot;box&quot; style=&quot;float:left; padding-top: 15px; padding-right: 15px;&quot;&gt;[[File:Wikimedia Café logo in plain SVG format.svg|75px|alt=The logo for the Wikimedia Café]]&lt;/div&gt;
Hello! There will be two '''[https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9 Wikimedia Café]''' discussion opportunities during the last weekend of May. Both sessions will focus on the [https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_Plan/2026-2027 the 2026-2027 Wikimedia Foundation Annual Plan]. Participants may attend either or both sessions.

#'''Saturday, 30 May 2026 at 15:00 UTC''' ([https://zonestamp.toolforge.org/1780153200 timestamp converter]), at a time friendly to the Americas, Africa, and Europe
#'''Sunday, 31 May 2026 at 05:00 UTC''' ([https://zonestamp.toolforge.org/1780203600 timestamp converter]), at a time friendly to Asia and the Pacific

Café participants are highly encouraged to read in advance [https://en.wikipedia.org/wiki/User:Sohom_Datta/annual_plan_guide at least this summary of the plan]. Optionally,  Café participants are encouraged to read portions of the plan that interest them and [https://meta.wikimedia.org/wiki/Talk:Wikimedia_Foundation_Annual_Plan/2026-2027 ask questions or provide feedback on the Annual Plan talk page]. 

Please see the Café page for more information, including [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#May_2026_meetings_with_a_focus_on_Wikimedia_Foundation_Annual_Plan/2026-2027 tables of timestamp conversions for both sessions], [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#Agenda._This_will_be_an_approximately_1_hour_Caf%C3%A9_session,_and_is_extendible_for_an_additional_30_minutes_if_needed. the agenda], and [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#How_to_attend_the_session how to register]!
&lt;br /&gt;
[[File:Buntstifte Eberhard Faber crop 64h.jpg|860px|alt=cropped image of colored pencils]]&lt;/div&gt;
&lt;span style=&quot;white-space:nowrap;&quot;&gt;[[User:Pine|&lt;span style=&quot;color:#01796f; text-shadow:#00BFFF 0 0 1.0em&quot;&gt;↠Pine&lt;/span&gt;]] [[User talk:Pine|&lt;span style=&quot;color:DeepSkyBlue&quot;&gt;(&lt;b style=&quot;color:#FFDF00;text-shadow:#FFDF00 0 0 1.0em&quot;&gt;✉&lt;/b&gt;)&lt;/span&gt;]]&lt;/span&gt; 19:44, 21 May 2026 (UTC)</text>
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        <id>3592031</id>
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      <comment>/* Valve Spring Locator Market to Reach USD 1.48 Billion by 2032 with 8.3% CAGR Driven by High-Performance Engine Manufacturing Growth */ new section</comment>
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Welcome to the '''General reading room'''. On this page, Wikibookians are free to talk about the Wikibooks project in general. For proposals for improving Wikibooks, see the [[../Proposals/]] reading room.
{{clear}}

[[Category:Reading room]]

== Regarding copyright of recipes found on online cooking forums ==

What is the copyright situation regarding cooking recipes found on online recipe books with recipes made by other people? I ask this because I want to add/translate recipes from 下厨房 (xià chúfáng) for Chinese recipes, and while I was intending to add the original writer of the recipe with the translation I still want to ask for clarification. 

[[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:06, 30 March 2026 (UTC)

:Recipes are in principle not copyright-able, as they are just facts. When someone includes descriptive text or anything that elaborates on the basic ingredients and steps, that is copyright-able. I am not a lawyer or legal scholar and cannot give legal advice. See (e.g.) https://www.copyrightlaws.com/copyright-protection-recipes/ —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 19:16, 30 March 2026 (UTC)
::In that case, would simplifying ingredients and methods to where they are simple yet can still be understood be sufficient for said recipes? [[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:23, 30 March 2026 (UTC)
:::Yes, you can add a recipe here as long as the instructions and text are not too overlapping with the copyrighted original. As the linked page says, the '''ideas''' behind the ingredient list and steps to prepare a given food item are not currently copyrightable, but the way you write the ideas may be copyrightable. You should also cite where you took the recipe from so we can trace its origins. I personally recommend only adding recipes that you have successfully made so we don't become a massive repository of potentially low-quality or untested recipes—I only add recipes once I have made them successfully. Let me know if you have any more questions about the Cookbook! Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:06, 30 March 2026 (UTC)
::::To build up on this, if you want to understand what is copyright-able and what is not, the &quot;[[:w:en:Idea–expression distinction|idea versus expression]]&quot; distinction. You cannot own the idea of &quot;Boy meets girl, boy loses girl, boy and girl commit suicide&quot; but you can copyright a specific version of ''Romeo and Juliet'' with your own innovative ideas. And, for that matter, this is context-specific, but if you can understand the distinction, it can help with future questions about &quot;could this be protected by copyright?&quot;, which can be a subtle one. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 22:50, 30 March 2026 (UTC)
:::::To further build up on this, there's something called the merger doctrine (see ''[[w:Baker v. Selden|Baker v. Selden]]''). This is why you can't copyright drawings of [[w:Structural formula|structural formulas]]. This doctrine means that if there's only one or a handful of ways to express an idea, then any such expression cannot be copyrighted, since copyrighting that expression would essentially be copyrighting the idea itself. This comes in a lot with recipes. I very likely can't copyright this list (from [[Cookbook:Cornmeal Pancakes (Arepa)]]:
:::::* 2.4 cups corn flour
:::::* 1.2 tsp salt
:::::* 0.6 cup grated white cheese
:::::* 2.4 cups cool water 
:::::Since there's essentially only one way to express the idea of that combination of ingredients. However, if I say:
:::::* 2.4 cups corn flour: for this, I strongly recommend Harina P.A.N., because my grandma always used to make me arepas from that stuff every day, and it was delicious.
:::::That is copyrightable. At that point, I cease to merely be expressing the idea of a food item with those four ingredients, and add a minimum degree of creativity. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 02:02, 31 March 2026 (UTC)
::::::And to build on all &lt;em&gt;that&lt;/em&gt;, even if individual pieces of information are in the public domain (or are fair use), the &lt;em&gt;arrangement&lt;/em&gt; of them can be copyrighted. This is why even if ''Bartlett's Quotations'' only had public domain material, the act of selectively editing and positioning them thematically for the user's benefit could constitute a sufficiently original work. So we could copy the material from a bunch of recipes, but could run a foul of copyright issues if we arranged and sorted them in some kind of manner that replicated someone else's original work. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:28, 31 March 2026 (UTC)


== Style Guidelines for Advanced Points ==

Is there a general style guideline to refer the reader to advanced information, while the main text gives the short-answer version?  For example, how would I specify that in practical applications, A is true, but if you use the theory you see that A is not quite true, or has caveats, or similar?--
[[User:Iain marcuson|Iain marcuson]] ([[User talk:Iain marcuson|discuss]] • [[Special:Contributions/Iain marcuson|contribs]]) 17:50, 22 April 2026 (UTC)

== Request: Help adding Objective Projection writing guide (filter blocked) ==

Hello,

I am Levent Bulut (ORCID: 0009-0007-7500-2261), author of the 
Objective Projection methodology. I am trying to contribute a 
practical writing guide to Wikibooks under CC BY-SA 4.0.

Book title: &quot;Objective Projection: Why the Brain Never Forgets 
Some Stories&quot;

The automated filter blocked my edits due to external links and 
content volume. I have already created the page with the 
introduction and contents, but could not add the chapters.

The Turkish version of the same book is already live on Wikibooks:
https://tr.wikibooks.org/wiki/Nesnel_%C4%B0zd%C3%BC%C5%9F%C3%BCm:_Beyin_Neden_Baz%C4%B1_Hikayeleri_Unutmuyor%3F

This is not a new theory — it is an instructional guide teaching 
a published methodology documented in DOI-registered publications:
https://doi.org/10.5281/zenodo.18689179

Open license declaration on my site:
https://leventbulut.com/acik-lisans-bildirimi-wikibooks/

All content is my own work, written for Wikibooks, under CC BY-SA 4.0.

Could an experienced editor help add the remaining chapters, or 
whitelist my account so the filter does not block future edits?

Thank you.
Levent Bulut | leventbulut.com [[User:LeventBulut|LeventBulut]] ([[User talk:LeventBulut|discuss]] • [[Special:Contributions/LeventBulut|contribs]]) 21:28, 24 April 2026 (UTC)
: @[[User:LeventBulut|LeventBulut]] This happened because you added too much content when creating the book. Also, when reporting false positives from an edit filter, please report on [[Wikibooks:Edit filter/False positives]]. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 01:03, 25 April 2026 (UTC)

== Request for comment (global AI policy) ==

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot; class=&quot;mw-content-ltr&quot;&gt; A [[:m:Requests for comment/Artificial intelligence policy|request for comment]] is currently being held to decide on a global AI policy. {{int:Feedback-thanks-title}} [[User:MediaWiki message delivery|MediaWiki message delivery]] ([[User talk:MediaWiki message delivery|discuss]] • [[Special:Contributions/MediaWiki message delivery|contribs]]) 00:57, 26 April 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Codename Noreste@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=Distribution_list/Global_message_delivery&amp;oldid=30424282 --&gt;

== After WikiNews shuts down....? ==

Can people try and write news articles here? Thank you! [[User:BigKrow|BigKrow]] ([[User talk:BigKrow|discuss]] • [[Special:Contributions/BigKrow|contribs]]) 22:30, 1 May 2026 (UTC)

:Thanks for asking. You have a similar thread at our sister project Wikiversity and I am the equivalent of an admin there (we have a &quot;curators&quot; and &quot;custodians&quot; that are similar to admins on other projects). I'm not an admin here, but speaking as someone who has generally contributed here, writing news articles would not be appropriate. It would be great to write a textbook on [[journalism]]: we could use a great guide for ethics, finding sources, asking questions, objectivity and neutrality, etc. Unlike on Wikiversity, where the learning materials can be virtually anything, this project is specifically for a textbook/guide/manual, so writing news articles and posting them here is not really appropriate, but you could have a few example articles that you write for the purpose of having a textbook. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 23:46, 1 May 2026 (UTC)
:: Heads up, a wiki was created: &lt;span class=&quot;plainlinks&quot;&gt;[https://news.wikioasis.org/wiki/Main_Page news.wikioasis.org]&lt;/span&gt;. @[[User:Koavf|Koavf]]; I was temporarily granted some user rights to  manage the wiki's setup and migration. I'll give you sysop rights since you are currently one on English Wikinews. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:11, 2 May 2026 (UTC)
:::Thanks. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:14, 2 May 2026 (UTC)

== Discussion at [[Wikibooks talk:Reviewers]] ==

I started a discussion on whether we should introduce an inactivity criteria for reviewers (and possibly autoreviewed users), at [[Wikibooks talk:Reviewers#Inactivity criteria]]. Any participation would be appreciated. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:17, 18 May 2026 (UTC)

== May 2026 Wikimedia Café meetups regarding the Wikimedia Foundation Annual Plan ==
&lt;div class=&quot;border-box&quot; style=&quot;background-color: var(--background-color-warning-subtle, #f8eaba); max-width: 875px; padding: 5px; border: 1px solid black; margin: 5px; color: var(--clr-dark)&quot;&gt;
&lt;div class=&quot;box&quot; style=&quot;float:left; padding-top: 15px; padding-right: 15px;&quot;&gt;[[File:Wikimedia Café logo in plain SVG format.svg|75px|alt=The logo for the Wikimedia Café]]&lt;/div&gt;
Hello! There will be two '''[https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9 Wikimedia Café]''' discussion opportunities during the last weekend of May. Both sessions will focus on the [https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_Plan/2026-2027 the 2026-2027 Wikimedia Foundation Annual Plan]. Participants may attend either or both sessions.

#'''Saturday, 30 May 2026 at 15:00 UTC''' ([https://zonestamp.toolforge.org/1780153200 timestamp converter]), at a time friendly to the Americas, Africa, and Europe
#'''Sunday, 31 May 2026 at 05:00 UTC''' ([https://zonestamp.toolforge.org/1780203600 timestamp converter]), at a time friendly to Asia and the Pacific

Café participants are highly encouraged to read in advance [https://en.wikipedia.org/wiki/User:Sohom_Datta/annual_plan_guide at least this summary of the plan]. Optionally,  Café participants are encouraged to read portions of the plan that interest them and [https://meta.wikimedia.org/wiki/Talk:Wikimedia_Foundation_Annual_Plan/2026-2027 ask questions or provide feedback on the Annual Plan talk page]. 

Please see the Café page for more information, including [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#May_2026_meetings_with_a_focus_on_Wikimedia_Foundation_Annual_Plan/2026-2027 tables of timestamp conversions for both sessions], [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#Agenda._This_will_be_an_approximately_1_hour_Caf%C3%A9_session,_and_is_extendible_for_an_additional_30_minutes_if_needed. the agenda], and [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#How_to_attend_the_session how to register]!
&lt;br /&gt;
[[File:Buntstifte Eberhard Faber crop 64h.jpg|860px|alt=cropped image of colored pencils]]&lt;/div&gt;
&lt;span style=&quot;white-space:nowrap;&quot;&gt;[[User:Pine|&lt;span style=&quot;color:#01796f; text-shadow:#00BFFF 0 0 1.0em&quot;&gt;↠Pine&lt;/span&gt;]] [[User talk:Pine|&lt;span style=&quot;color:DeepSkyBlue&quot;&gt;(&lt;b style=&quot;color:#FFDF00;text-shadow:#FFDF00 0 0 1.0em&quot;&gt;✉&lt;/b&gt;)&lt;/span&gt;]]&lt;/span&gt; 19:44, 21 May 2026 (UTC)

== Valve Spring Locator Market to Reach USD 1.48 Billion by 2032 with 8.3% CAGR Driven by High-Performance Engine Manufacturing Growth ==

The global Valve Spring Locator market is expanding steadily due to rising demand for high-performance engines, precision automotive components, and advanced valve train stability systems. In 2024, the market was valued at approximately USD 780 million and is projected to surpass USD 1.48 billion by 2032, registering a CAGR of 8.3% during 2024–2032. Increasing engine efficiency requirements, high-RPM performance tuning adoption, and global automotive production growth are driving consistent demand for Valve Spring Locator systems.

The market recorded year-over-year growth of 7.6% in 2023 compared to 6.1% in 2022 and 5.4% in 2021. Between 2019 and 2024, global revenue increased by nearly USD 240 million. Global engine component production exceeded 1.9 billion units in 2024, compared to 1.3 billion units in 2018, reflecting a 46% increase over six years due to rising automotive and industrial engine demand.

Asia-Pacific dominated the Valve Spring Locator market in 2024 with 45% revenue share, followed by North America at 27% and Europe at 23%. China, Japan, India, and South Korea collectively accounted for over 68% of global engine component manufacturing output. Regional automotive and industrial manufacturing investments exceeded USD 420 billion between 2021 and 2024, supporting strong demand for precision valve train components.

Historically, the Valve Spring Locator market grew from USD 420 million in 2016 to USD 780 million in 2024, representing an 86% total increase. During this period, global internal combustion engine production remained above 110 million units annually despite electrification trends. Demand for performance-oriented ICE systems increased steadily, boosting adoption of advanced valve stabilization components.

Passenger vehicles accounted for 62% of total Valve Spring Locator revenue in 2024. Global passenger vehicle production exceeded 93 million units, with nearly 58% using multi-valve engine systems requiring precision valve stability. Engine performance improvements of 12%–18% over the past decade have increased dependence on high-accuracy valve positioning components.

Commercial vehicles contributed 21% of market revenue in 2024. Heavy-duty truck production exceeded 5.2 million units, while light commercial vehicles surpassed 28 million units globally. Fleet modernization programs improved engine durability requirements by 22%, increasing demand for stable valve spring positioning solutions.

The performance engine segment accounted for 34% of total demand in 2024. High-RPM engines operating above 6,000 RPM require enhanced valve control, reducing valve float incidents by up to 40% when equipped with precision Valve Spring Locators. Motorsports engine development increased by 17% year-over-year, further strengthening demand for high-performance components.

North America generated USD 230 million in 2024. The United States represented 85% of regional demand due to strong performance vehicle culture and motorsports participation. More than 45 million performance and modified vehicles operate in the U.S., driving high aftermarket consumption of engine precision components.

Europe reached USD 215 million in 2024. Germany, Italy, France, and the United Kingdom accounted for 72% of regional revenue. European OEMs increased engine refinement investments by 14% annually, focusing on precision valve timing systems and high-efficiency combustion designs.

China led global demand with USD 280 million in 2024. The country produced over 30 million vehicles and 38 million engines annually. Government support for advanced manufacturing exceeded USD 120 billion over five years, accelerating precision automotive component production.

India is emerging as a high-growth market with engine production rising 19% year-over-year. Vehicle output exceeded 5.9 million units in 2024, while stricter emission norms under Bharat Stage VI significantly increased demand for efficient valve train systems.

Aftermarket applications contributed 28% of total market revenue in 2024. Global automotive aftermarket spending exceeded USD 1.1 trillion, with engine modification and repair services accounting for 18% of total demand. Performance tuning workshops reported a 13% rise in valve train upgrades.

Aerospace and marine sectors contributed 9% of demand in 2024. Marine engine production exceeded 74,000 vessels annually, while aerospace maintenance spending surpassed USD 85 billion globally. Precision valve stabilization improved engine efficiency by 11%–15% in high-load applications.

Technological advancements improved manufacturing precision by 23% between 2020 and 2024. High-strength alloys increased fatigue resistance by 19%, while CNC machining reduced dimensional variation by 21%, improving valve stability in extreme RPM environments.

E-commerce channels accounted for 57% of aftermarket sales in 2024. Global online automotive parts sales exceeded USD 190 billion, with engine component purchases increasing 21% year-over-year due to rising DIY vehicle maintenance trends.

The market remains moderately consolidated, with the top 10 manufacturers controlling 54% of global revenue. R&amp;D investments increased 12% annually, focusing on lightweight alloys, thermal resistance, and high-performance engine compatibility.

Production costs increased 15% between 2021 and 2023 due to raw material inflation. However, automation in machining is expected to reduce costs by 7% by 2028, improving global supply chain efficiency.

Environmental regulations indirectly support demand, as automakers optimize engines for 25% higher efficiency targets, increasing reliance on precision valve systems.

Future projections show global engine component demand reaching 2.6 billion units by 2032. Performance engine applications are expected to exceed USD 620 million, while OEM applications will grow at a CAGR of 8.1%.

The Valve Spring Locator market will continue expanding due to rising performance vehicle demand, increasing automotive production, and advancements in precision engineering. With the market projected to reach USD 1.48 billion by 2032 and global automotive manufacturing investments surpassing USD 2 trillion, long-term growth remains strong across automotive, motorsport, aerospace, and industrial sectors.

[[User:Sharmasejal|Sharmasejal]] ([[User talk:Sharmasejal|discuss]] • [[Special:Contributions/Sharmasejal|contribs]]) 08:53, 22 May 2026 (UTC)</text>
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      <text bytes="13622" sha1="5q0rwazqcno7f0dm2v4wy7m9xp8x0rq" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:CHAT|WB:RR/G|WB:GENERAL}} {{TOC left|limit=3}}
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Welcome to the '''General reading room'''. On this page, Wikibookians are free to talk about the Wikibooks project in general. For proposals for improving Wikibooks, see the [[../Proposals/]] reading room.
{{clear}}

[[Category:Reading room]]

== Regarding copyright of recipes found on online cooking forums ==

What is the copyright situation regarding cooking recipes found on online recipe books with recipes made by other people? I ask this because I want to add/translate recipes from 下厨房 (xià chúfáng) for Chinese recipes, and while I was intending to add the original writer of the recipe with the translation I still want to ask for clarification. 

[[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:06, 30 March 2026 (UTC)

:Recipes are in principle not copyright-able, as they are just facts. When someone includes descriptive text or anything that elaborates on the basic ingredients and steps, that is copyright-able. I am not a lawyer or legal scholar and cannot give legal advice. See (e.g.) https://www.copyrightlaws.com/copyright-protection-recipes/ —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 19:16, 30 March 2026 (UTC)
::In that case, would simplifying ingredients and methods to where they are simple yet can still be understood be sufficient for said recipes? [[User:Fukukitaru|Fukukitaru]] ([[User talk:Fukukitaru|discuss]] • [[Special:Contributions/Fukukitaru|contribs]]) 19:23, 30 March 2026 (UTC)
:::Yes, you can add a recipe here as long as the instructions and text are not too overlapping with the copyrighted original. As the linked page says, the '''ideas''' behind the ingredient list and steps to prepare a given food item are not currently copyrightable, but the way you write the ideas may be copyrightable. You should also cite where you took the recipe from so we can trace its origins. I personally recommend only adding recipes that you have successfully made so we don't become a massive repository of potentially low-quality or untested recipes—I only add recipes once I have made them successfully. Let me know if you have any more questions about the Cookbook! Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:06, 30 March 2026 (UTC)
::::To build up on this, if you want to understand what is copyright-able and what is not, the &quot;[[:w:en:Idea–expression distinction|idea versus expression]]&quot; distinction. You cannot own the idea of &quot;Boy meets girl, boy loses girl, boy and girl commit suicide&quot; but you can copyright a specific version of ''Romeo and Juliet'' with your own innovative ideas. And, for that matter, this is context-specific, but if you can understand the distinction, it can help with future questions about &quot;could this be protected by copyright?&quot;, which can be a subtle one. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 22:50, 30 March 2026 (UTC)
:::::To further build up on this, there's something called the merger doctrine (see ''[[w:Baker v. Selden|Baker v. Selden]]''). This is why you can't copyright drawings of [[w:Structural formula|structural formulas]]. This doctrine means that if there's only one or a handful of ways to express an idea, then any such expression cannot be copyrighted, since copyrighting that expression would essentially be copyrighting the idea itself. This comes in a lot with recipes. I very likely can't copyright this list (from [[Cookbook:Cornmeal Pancakes (Arepa)]]:
:::::* 2.4 cups corn flour
:::::* 1.2 tsp salt
:::::* 0.6 cup grated white cheese
:::::* 2.4 cups cool water 
:::::Since there's essentially only one way to express the idea of that combination of ingredients. However, if I say:
:::::* 2.4 cups corn flour: for this, I strongly recommend Harina P.A.N., because my grandma always used to make me arepas from that stuff every day, and it was delicious.
:::::That is copyrightable. At that point, I cease to merely be expressing the idea of a food item with those four ingredients, and add a minimum degree of creativity. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 02:02, 31 March 2026 (UTC)
::::::And to build on all &lt;em&gt;that&lt;/em&gt;, even if individual pieces of information are in the public domain (or are fair use), the &lt;em&gt;arrangement&lt;/em&gt; of them can be copyrighted. This is why even if ''Bartlett's Quotations'' only had public domain material, the act of selectively editing and positioning them thematically for the user's benefit could constitute a sufficiently original work. So we could copy the material from a bunch of recipes, but could run a foul of copyright issues if we arranged and sorted them in some kind of manner that replicated someone else's original work. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:28, 31 March 2026 (UTC)


== Style Guidelines for Advanced Points ==

Is there a general style guideline to refer the reader to advanced information, while the main text gives the short-answer version?  For example, how would I specify that in practical applications, A is true, but if you use the theory you see that A is not quite true, or has caveats, or similar?--
[[User:Iain marcuson|Iain marcuson]] ([[User talk:Iain marcuson|discuss]] • [[Special:Contributions/Iain marcuson|contribs]]) 17:50, 22 April 2026 (UTC)

== Request: Help adding Objective Projection writing guide (filter blocked) ==

Hello,

I am Levent Bulut (ORCID: 0009-0007-7500-2261), author of the 
Objective Projection methodology. I am trying to contribute a 
practical writing guide to Wikibooks under CC BY-SA 4.0.

Book title: &quot;Objective Projection: Why the Brain Never Forgets 
Some Stories&quot;

The automated filter blocked my edits due to external links and 
content volume. I have already created the page with the 
introduction and contents, but could not add the chapters.

The Turkish version of the same book is already live on Wikibooks:
https://tr.wikibooks.org/wiki/Nesnel_%C4%B0zd%C3%BC%C5%9F%C3%BCm:_Beyin_Neden_Baz%C4%B1_Hikayeleri_Unutmuyor%3F

This is not a new theory — it is an instructional guide teaching 
a published methodology documented in DOI-registered publications:
https://doi.org/10.5281/zenodo.18689179

Open license declaration on my site:
https://leventbulut.com/acik-lisans-bildirimi-wikibooks/

All content is my own work, written for Wikibooks, under CC BY-SA 4.0.

Could an experienced editor help add the remaining chapters, or 
whitelist my account so the filter does not block future edits?

Thank you.
Levent Bulut | leventbulut.com [[User:LeventBulut|LeventBulut]] ([[User talk:LeventBulut|discuss]] • [[Special:Contributions/LeventBulut|contribs]]) 21:28, 24 April 2026 (UTC)
: @[[User:LeventBulut|LeventBulut]] This happened because you added too much content when creating the book. Also, when reporting false positives from an edit filter, please report on [[Wikibooks:Edit filter/False positives]]. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 01:03, 25 April 2026 (UTC)

== Request for comment (global AI policy) ==

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot; class=&quot;mw-content-ltr&quot;&gt; A [[:m:Requests for comment/Artificial intelligence policy|request for comment]] is currently being held to decide on a global AI policy. {{int:Feedback-thanks-title}} [[User:MediaWiki message delivery|MediaWiki message delivery]] ([[User talk:MediaWiki message delivery|discuss]] • [[Special:Contributions/MediaWiki message delivery|contribs]]) 00:57, 26 April 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Codename Noreste@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=Distribution_list/Global_message_delivery&amp;oldid=30424282 --&gt;

== After WikiNews shuts down....? ==

Can people try and write news articles here? Thank you! [[User:BigKrow|BigKrow]] ([[User talk:BigKrow|discuss]] • [[Special:Contributions/BigKrow|contribs]]) 22:30, 1 May 2026 (UTC)

:Thanks for asking. You have a similar thread at our sister project Wikiversity and I am the equivalent of an admin there (we have a &quot;curators&quot; and &quot;custodians&quot; that are similar to admins on other projects). I'm not an admin here, but speaking as someone who has generally contributed here, writing news articles would not be appropriate. It would be great to write a textbook on [[journalism]]: we could use a great guide for ethics, finding sources, asking questions, objectivity and neutrality, etc. Unlike on Wikiversity, where the learning materials can be virtually anything, this project is specifically for a textbook/guide/manual, so writing news articles and posting them here is not really appropriate, but you could have a few example articles that you write for the purpose of having a textbook. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 23:46, 1 May 2026 (UTC)
:: Heads up, a wiki was created: &lt;span class=&quot;plainlinks&quot;&gt;[https://news.wikioasis.org/wiki/Main_Page news.wikioasis.org]&lt;/span&gt;. @[[User:Koavf|Koavf]]; I was temporarily granted some user rights to  manage the wiki's setup and migration. I'll give you sysop rights since you are currently one on English Wikinews. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:11, 2 May 2026 (UTC)
:::Thanks. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 02:14, 2 May 2026 (UTC)

== Discussion at [[Wikibooks talk:Reviewers]] ==

I started a discussion on whether we should introduce an inactivity criteria for reviewers (and possibly autoreviewed users), at [[Wikibooks talk:Reviewers#Inactivity criteria]]. Any participation would be appreciated. Thank you. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:17, 18 May 2026 (UTC)

== May 2026 Wikimedia Café meetups regarding the Wikimedia Foundation Annual Plan ==
&lt;div class=&quot;border-box&quot; style=&quot;background-color: var(--background-color-warning-subtle, #f8eaba); max-width: 875px; padding: 5px; border: 1px solid black; margin: 5px; color: var(--clr-dark)&quot;&gt;
&lt;div class=&quot;box&quot; style=&quot;float:left; padding-top: 15px; padding-right: 15px;&quot;&gt;[[File:Wikimedia Café logo in plain SVG format.svg|75px|alt=The logo for the Wikimedia Café]]&lt;/div&gt;
Hello! There will be two '''[https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9 Wikimedia Café]''' discussion opportunities during the last weekend of May. Both sessions will focus on the [https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_Plan/2026-2027 the 2026-2027 Wikimedia Foundation Annual Plan]. Participants may attend either or both sessions.

#'''Saturday, 30 May 2026 at 15:00 UTC''' ([https://zonestamp.toolforge.org/1780153200 timestamp converter]), at a time friendly to the Americas, Africa, and Europe
#'''Sunday, 31 May 2026 at 05:00 UTC''' ([https://zonestamp.toolforge.org/1780203600 timestamp converter]), at a time friendly to Asia and the Pacific

Café participants are highly encouraged to read in advance [https://en.wikipedia.org/wiki/User:Sohom_Datta/annual_plan_guide at least this summary of the plan]. Optionally,  Café participants are encouraged to read portions of the plan that interest them and [https://meta.wikimedia.org/wiki/Talk:Wikimedia_Foundation_Annual_Plan/2026-2027 ask questions or provide feedback on the Annual Plan talk page]. 

Please see the Café page for more information, including [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#May_2026_meetings_with_a_focus_on_Wikimedia_Foundation_Annual_Plan/2026-2027 tables of timestamp conversions for both sessions], [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#Agenda._This_will_be_an_approximately_1_hour_Caf%C3%A9_session,_and_is_extendible_for_an_additional_30_minutes_if_needed. the agenda], and [https://meta.wikimedia.org/wiki/Wikimedia_Caf%C3%A9#How_to_attend_the_session how to register]!
&lt;br /&gt;
[[File:Buntstifte Eberhard Faber crop 64h.jpg|860px|alt=cropped image of colored pencils]]&lt;/div&gt;
&lt;span style=&quot;white-space:nowrap;&quot;&gt;[[User:Pine|&lt;span style=&quot;color:#01796f; text-shadow:#00BFFF 0 0 1.0em&quot;&gt;↠Pine&lt;/span&gt;]] [[User talk:Pine|&lt;span style=&quot;color:DeepSkyBlue&quot;&gt;(&lt;b style=&quot;color:#FFDF00;text-shadow:#FFDF00 0 0 1.0em&quot;&gt;✉&lt;/b&gt;)&lt;/span&gt;]]&lt;/span&gt; 19:44, 21 May 2026 (UTC)</text>
      <sha1>5q0rwazqcno7f0dm2v4wy7m9xp8x0rq</sha1>
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  <page>
    <title>Git/Submodules and Superprojects</title>
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      <text bytes="2520" sha1="f0nr3g60f7txflz8ygo8vt0ehs8qb5z" xml:space="preserve">'***A '''superproject''' is a new aspect of git which has been in development for a long while. It addresses the need for better control over numerous git repositories. The porcelain for the superproject functionality is fairly new and was only recently released with Git v1.5.3.

A Git '''project''' may consist of a set of ''git repositories'' and each of these &quot;git repositories&quot; is called a '''module'''.You can think of a '''module''' as a '''project,''' and the '''project''' as a '''module.''' It really doesn't make too much sense why either of these terms would have a ''sub-'' or ''super-'' prefix without their alternative; nonetheless, that's how the official Git documentation will refer to them.

The only git application specific to the submodule/superproject functionality is '''git-module'''.false'***

== Superprojects ==
A '''Superproject''', is simply a git repository. To create a superproject, simply ''git init'' any directory, and ''git submodule add'' all of the git archives you wish to include. A quick aside, you can not currently ''git submodule add'' git repositories that are direct children within the same directory.{{ref|lie_parent}}

The resulting structure will look similar to this:
 |- superproject
   |- submodule (git archive) [a]
   |- submodule [b]
   |- submodule [c]
   |- submodule [d]

When someone pulls down the superproject, they will see a series of empty folders for each submodule. They can then ''git submodule init'' all of those that they wish to utilize.

== Submodules ==
A ''git archive'' is said to become a ''submodule'' the second after you execute ''git submodule add'' in another git repository.


&lt;!--
&lt;syntaxhighlight lang=&quot;bash&quot;&gt;
atomic-example
&lt;/syntaxhighlight&gt;
--&gt;

== Work Flow ==

The work flow of superprojects, and submodules should generally adhere to the following:
# the repo has been initialized in path_to_working_directory
# Make change in submodule
# ''git commit'' change in submodule
# ''git commit'' change in superproject
# ''git submodule update'' to push change to the individual repositories that predate the superproject.

==Footnotes==
#{{note|lie_parent}} Well that isn't true at all, Git supports this as of v1.5.3, but the official porcelain doesn't. You can ''git init'' a parent directory, and create your own &quot;.gitmodules&quot;, then follow it up with a ''git submodule init''. Generally speaking though, what the porcelain doesn't cover is outside of the scope of this book.

{{BookCat}}

[[fr:Git/Sous-modules et Super-projets]]</text>
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      <minor />
      <comment>[[WB:REVERT|Reverted]] edit by [[Special:Contributions/~2026-30565-60|~2026-30565-60]] ([[User talk:~2026-30565-60|talk]]) to last version by MathXplore</comment>
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      <text bytes="2507" sha1="36w2bm8w7dxmp1l6bt052rj062150p8" xml:space="preserve">A '''superproject''' is a new aspect of git which has been in development for a long while. It addresses the need for better control over numerous git repositories. The porcelain for the superproject functionality is fairly new and was only recently released with Git v1.5.3.

A Git '''project''' may consist of a set of ''git repositories'' and each of these &quot;git repositories&quot; is called a '''module'''.You can think of a '''module''' as a '''project,''' and the '''project''' as a '''module.''' It really doesn't make too much sense why either of these terms would have a ''sub-'' or ''super-'' prefix without their alternative; nonetheless, that's how the official Git documentation will refer to them.

The only git application specific to the submodule/superproject functionality is '''git-module'''.

== Superprojects ==
A '''Superproject''', is simply a git repository. To create a superproject, simply ''git init'' any directory, and ''git submodule add'' all of the git archives you wish to include. A quick aside, you can not currently ''git submodule add'' git repositories that are direct children within the same directory.{{ref|lie_parent}}

The resulting structure will look similar to this:
 |- superproject
   |- submodule (git archive) [a]
   |- submodule [b]
   |- submodule [c]
   |- submodule [d]

When someone pulls down the superproject, they will see a series of empty folders for each submodule. They can then ''git submodule init'' all of those that they wish to utilize.

== Submodules ==
A ''git archive'' is said to become a ''submodule'' the second after you execute ''git submodule add'' in another git repository.


&lt;!--
&lt;syntaxhighlight lang=&quot;bash&quot;&gt;
atomic-example
&lt;/syntaxhighlight&gt;
--&gt;

== Work Flow ==

The work flow of superprojects, and submodules should generally adhere to the following:
# the repo has been initialized in path_to_working_directory
# Make change in submodule
# ''git commit'' change in submodule
# ''git commit'' change in superproject
# ''git submodule update'' to push change to the individual repositories that predate the superproject.

==Footnotes==
#{{note|lie_parent}} Well that isn't true at all, Git supports this as of v1.5.3, but the official porcelain doesn't. You can ''git init'' a parent directory, and create your own &quot;.gitmodules&quot;, then follow it up with a ''git submodule init''. Generally speaking though, what the porcelain doesn't cover is outside of the scope of this book.

{{BookCat}}

[[fr:Git/Sous-modules et Super-projets]]</text>
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    <title>Wikibooks:Reading room/Administrative Assistance</title>
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      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>Requesting protection on [[Template:Closed/sandbox]]</comment>
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      <text bytes="12303" sha1="3352xiaxyons4nuqnhbw3c3uzppukyt" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{shortcut|WB:AN|WB:AA}} {{TOC left}}
{{User:MiszaBot/config
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{{ombox|type=content|text='''To request a rename or usurpation''', go to the global request page at Meta [[meta:SRUC|here]].&lt;br /&gt;''Please do not post those requests here!''}}
{{Clear}}
Welcome to the '''Administrative Assistance reading room'''.  You can request assistance from [[WB:ADMIN|administrators]] for handling a variety of problems here and alert them about problems which may require special actions not normally used during regular content editing. Please be patient as administrators are often quite busy with either their own projects or trying to perform general maintenance and cleanup.

You can deal with most vandalism yourself: [[Wikibooks:Dealing with vandalism|fix it]], then [[Wikibooks:Templates/User_notices|warn the user]]. If there is repeated vandalism by one user, lots of vandalism on a single page, or vandalism from many users, tell an admin here, or in [irc://irc.freenode.net/wikibooks #wikibooks] (say &lt;code&gt;!admin&lt;/code&gt; to get attention).

For more general questions and assistance that doesn't require an administrator, please use the [[WB:HELP|Assistance Reading Room]].
{{clear}}

[[Category:Reading room]]

== No data in page linked to by Wikidata ==

The page, [https://en.wikibooks.org/wiki/OpenSSH/Third_Party_Utilities OpenSSH: Third Party Utilities] has no data and thus should not be linked to from [https://www.wikidata.org/wiki/Q139625509 Q139625509]  How can the link be deleted?  Thanks.  [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 05:06, 4 May 2026 (UTC)

:Same for Q139611668 and Q139611580.  All three links should be deleted / removed as the destination pages in the en.wikibook do not have any data but instead normal prose.  - [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 05:15, 4 May 2026 (UTC)
:Same for Q139806271, Q139806269, Q139806266, Q139806265, Q139806264, Q139806263, Q139806262, Q139806261, Q139806260, Q139806258, Q139806256, Q139806255, Q139625509, Q139611668, and Q139611580.  There seems to be some new kind of vandalism going on.  Perhaps there is a better page to report it on instead of this one? • [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 17:37, 17 May 2026 (UTC)
:: @[[User:Larsnooden|Larsnooden]] Given that this situation is happening on Wikidata, there is nothing that English Wikibooks admins can do. Please report this matter to the Wikidata administrators. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:13, 17 May 2026 (UTC)

== Pizzazilla1 reported by MathXplore ==

* {{userlinks|Pizzazilla1}}

Spam &lt;!-- USERREPORTED:/Pizzazilla1/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:20, 8 May 2026 (UTC)

:Done. //[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 00:31, 9 May 2026 (UTC)
== ~2026-28014-44 reported by MathXplore ==

* {{userlinks|~2026-28014-44}}

Vandalism &lt;!-- USERREPORTED:/~2026-28014-44/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 01:02, 9 May 2026 (UTC)
: I blocked the underlying range. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 16:40, 10 May 2026 (UTC)

== Omran Tokhi Nickname OT7 reported by MathXplore ==

* {{userlinks|Omran Tokhi Nickname OT7}}

Long-term abuse. Spam / spambot. [[Special:CentralAuth/OmranTokhi7]] &lt;!-- USERREPORTED:/Omran Tokhi Nickname OT7/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 03:25, 10 May 2026 (UTC)

:{{done}}. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 04:29, 10 May 2026 (UTC)

== Can't log in :( ==

Xania here. I am logged in on Wikipedia but can't log in here even though it has always been automatic when switching between the two. Wikibooks seems to want me to authenticate myself via my authenticator app which I have not done before. Allows me to also use a recovery code which I do not have. How do I log in guys? [[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 18:15, 10 May 2026 (UTC)
: I believe it might be the CheckUser permission requiring 2FA (on parity with interface administrators and oversighters) as that group has restrictions. You might need to temporarily request to the [[m:Stewards' noticeboard|stewards]] to remove CU access from your account to enable 2FA; however, since this project only has 2 CUs, [[User:MarcGarver|MarcGarver]]'s CU rights would be temporarily suspended. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:36, 10 May 2026 (UTC)
: Thanks, I've left a notice on the Steward's board.--[[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 18:59, 10 May 2026 (UTC)
::This happened before when your CU rights were removed because you hadn't enrolled in 2FA. I presume you must have enrolled to get the CU rights back. Are you really sure you've never used any authenticator here? [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 11:49, 11 May 2026 (UTC)
:::See [https://en.wikibooks.org/wiki/User_talk:MarcGarver#Check_User previous discussion] from last year [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 11:51, 11 May 2026 (UTC)
::::Thanks. Good to know. I had completely forgotten that discussion. I will have to install some old authenticators and see which works.--[[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 17:09, 16 May 2026 (UTC)
: Logged in finally. Seems I had recovery codes (totally forgotten about them) saved but no authenticator so each time I log in I'll need to use the codes.--[[User:Xania|Xania]] [[Image:Flag_of_Estonia.svg|15px]]  [[Image:Flag_of_Ukraine.svg|15px]] [[User talk:Xania|&lt;sup&gt;talk&lt;/sup&gt;]] 17:54, 16 May 2026 (UTC)

== Cs24jam2 reported by MathXplore ==

* {{userlinks|Cs24jam2}}

Vandalism &lt;!-- USERREPORTED:/Cs24jam2/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 11:54, 11 May 2026 (UTC)

:{{done}} by @[[User:Codename Noreste|Codename Noreste]] —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 16:58, 11 May 2026 (UTC)
== Mnckhagaul reported by MathXplore ==

* {{userlinks|Mnckhagaul}}

Spam &lt;!-- USERREPORTED:/Mnckhagaul/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 08:35, 16 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 03:28, 17 May 2026 (UTC)
== Vrindavanmathuratourpackages reported by MathXplore ==

* {{userlinks|Vrindavanmathuratourpackages}}

Spam &lt;!-- USERREPORTED:/Vrindavanmathuratourpackages/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:13, 18 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:28, 18 May 2026 (UTC)
== Shawndavidsonosp2 reported by MathXplore ==

* {{userlinks|Shawndavidsonosp2}}

Spam, [[Special:AbuseLog/312343]], [[Special:AbuseLog/312344]] &lt;!-- USERREPORTED:/Shawndavidsonosp2/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:10, 19 May 2026 (UTC)

:This is not a spam. Its a discussion topic on Healthcare Software Development [[User:Shawndavidsonosp2|Shawndavidsonosp2]] ([[User talk:Shawndavidsonosp2|discuss]] • [[Special:Contributions/Shawndavidsonosp2|contribs]]) 13:00, 19 May 2026 (UTC)
: {{ping|MarcGarver|Xania}} (CU request) User:Shawndavidsonosp2 &amp; User:Lunasora33 made link additions for osplabs.com ([https://en.wikibooks.org/w/index.php?title=Information_Technology_and_Ethics/IT_and_Healthcare&amp;diff=prev&amp;oldid=4636437], [https://spamcheck.toolforge.org/by-domain?q=osplabs.com])
: {{ping|MarcGarver|SHB2000}} [[Special:CentralAuth/Rachvictor05]] &amp; [[Special:CentralAuth/Emma_Joseph_Swift]] (Locked) also made link additions for osplabs.com ([https://spamcheck.toolforge.org/by-domain?q=osplabs.com]) [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 13:46, 19 May 2026 (UTC)
::Clearly promotional accounts, both blocked. [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 16:00, 19 May 2026 (UTC)
:::and their spam domain added to the blacklist [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 16:02, 19 May 2026 (UTC)

== Banibrotechnologies reported by MathXplore ==

* {{userlinks|Banibrotechnologies}}

Spam &lt;!-- USERREPORTED:/Banibrotechnologies/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:10, 19 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 16:51, 19 May 2026 (UTC)

== Texasanne12 reported by MathXplore ==

* {{userlinks|Texasanne12}}

Link spam, [[Special:AbuseLog/312336]] &lt;!-- USERREPORTED:/Texasanne12/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:18, 19 May 2026 (UTC)

:{{done}} —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 02:14, 20 May 2026 (UTC)

== [[User:Me Lendroz]] (CU request) ==

{{ping|MarcGarver|Xania}} (this is related to previous CU, [[Wikibooks:Reading_room/Administrative_Assistance/Archives/2024/February#Alert_about_possible_evasion_of_previous_1-week_block_at_English_Wikibooks_(CU_needed?)]], [[Wikibooks:Reading_room/Administrative_Assistance/Archives/2024/August#Another_user_editing_User:Jay_Bolero's_user_page]]) &lt;br&gt;
I found [[Special:Contributions/CarlessParking]] editing the user page of [[User:Me Lendroz]]. What do our CUs think about this? [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 14:00, 19 May 2026 (UTC)

:It's an obvious sock of Jay Bolero not least because the account has posted &quot;my name is Karl Basallote&quot; everywhere and &quot;Basallote&quot; matches the previous sock. I've blocked CarlessParking as this is an abusive use of multiple accounts. [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 15:57, 19 May 2026 (UTC)
== Request for protection of [[:Template:Closed/sandbox]] ==
'''Indefinite full&amp;nbsp;protection:''' Test report, disregard. 
 &lt;!-- PAGEREQUESTED:/Template:Closed/sandbox/ --&gt; [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 14:33, 21 May 2026 (UTC)</text>
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      <comment>[[WB:REVERT|Reverted]] edit by [[Special:Contributions/Codename Noreste|Codename Noreste]] ([[User talk:Codename Noreste|talk]]) to last version by ArchiverBot</comment>
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{{ombox|type=content|text='''To request a rename or usurpation''', go to the global request page at Meta [[meta:SRUC|here]].&lt;br /&gt;''Please do not post those requests here!''}}
{{Clear}}
Welcome to the '''Administrative Assistance reading room'''.  You can request assistance from [[WB:ADMIN|administrators]] for handling a variety of problems here and alert them about problems which may require special actions not normally used during regular content editing. Please be patient as administrators are often quite busy with either their own projects or trying to perform general maintenance and cleanup.

You can deal with most vandalism yourself: [[Wikibooks:Dealing with vandalism|fix it]], then [[Wikibooks:Templates/User_notices|warn the user]]. If there is repeated vandalism by one user, lots of vandalism on a single page, or vandalism from many users, tell an admin here, or in [irc://irc.freenode.net/wikibooks #wikibooks] (say &lt;code&gt;!admin&lt;/code&gt; to get attention).

For more general questions and assistance that doesn't require an administrator, please use the [[WB:HELP|Assistance Reading Room]].
{{clear}}

[[Category:Reading room]]

== No data in page linked to by Wikidata ==

The page, [https://en.wikibooks.org/wiki/OpenSSH/Third_Party_Utilities OpenSSH: Third Party Utilities] has no data and thus should not be linked to from [https://www.wikidata.org/wiki/Q139625509 Q139625509]  How can the link be deleted?  Thanks.  [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 05:06, 4 May 2026 (UTC)

:Same for Q139611668 and Q139611580.  All three links should be deleted / removed as the destination pages in the en.wikibook do not have any data but instead normal prose.  - [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 05:15, 4 May 2026 (UTC)
:Same for Q139806271, Q139806269, Q139806266, Q139806265, Q139806264, Q139806263, Q139806262, Q139806261, Q139806260, Q139806258, Q139806256, Q139806255, Q139625509, Q139611668, and Q139611580.  There seems to be some new kind of vandalism going on.  Perhaps there is a better page to report it on instead of this one? • [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 17:37, 17 May 2026 (UTC)
:: @[[User:Larsnooden|Larsnooden]] Given that this situation is happening on Wikidata, there is nothing that English Wikibooks admins can do. Please report this matter to the Wikidata administrators. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:13, 17 May 2026 (UTC)

== Pizzazilla1 reported by MathXplore ==

* {{userlinks|Pizzazilla1}}

Spam &lt;!-- USERREPORTED:/Pizzazilla1/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:20, 8 May 2026 (UTC)

:Done. //[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 00:31, 9 May 2026 (UTC)
== ~2026-28014-44 reported by MathXplore ==

* {{userlinks|~2026-28014-44}}

Vandalism &lt;!-- USERREPORTED:/~2026-28014-44/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 01:02, 9 May 2026 (UTC)
: I blocked the underlying range. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 16:40, 10 May 2026 (UTC)

== Omran Tokhi Nickname OT7 reported by MathXplore ==

* {{userlinks|Omran Tokhi Nickname OT7}}

Long-term abuse. Spam / spambot. [[Special:CentralAuth/OmranTokhi7]] &lt;!-- USERREPORTED:/Omran Tokhi Nickname OT7/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 03:25, 10 May 2026 (UTC)

:{{done}}. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 04:29, 10 May 2026 (UTC)

== Can't log in :( ==

Xania here. I am logged in on Wikipedia but can't log in here even though it has always been automatic when switching between the two. Wikibooks seems to want me to authenticate myself via my authenticator app which I have not done before. Allows me to also use a recovery code which I do not have. How do I log in guys? [[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 18:15, 10 May 2026 (UTC)
: I believe it might be the CheckUser permission requiring 2FA (on parity with interface administrators and oversighters) as that group has restrictions. You might need to temporarily request to the [[m:Stewards' noticeboard|stewards]] to remove CU access from your account to enable 2FA; however, since this project only has 2 CUs, [[User:MarcGarver|MarcGarver]]'s CU rights would be temporarily suspended. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:36, 10 May 2026 (UTC)
: Thanks, I've left a notice on the Steward's board.--[[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 18:59, 10 May 2026 (UTC)
::This happened before when your CU rights were removed because you hadn't enrolled in 2FA. I presume you must have enrolled to get the CU rights back. Are you really sure you've never used any authenticator here? [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 11:49, 11 May 2026 (UTC)
:::See [https://en.wikibooks.org/wiki/User_talk:MarcGarver#Check_User previous discussion] from last year [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 11:51, 11 May 2026 (UTC)
::::Thanks. Good to know. I had completely forgotten that discussion. I will have to install some old authenticators and see which works.--[[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 17:09, 16 May 2026 (UTC)
: Logged in finally. Seems I had recovery codes (totally forgotten about them) saved but no authenticator so each time I log in I'll need to use the codes.--[[User:Xania|Xania]] [[Image:Flag_of_Estonia.svg|15px]]  [[Image:Flag_of_Ukraine.svg|15px]] [[User talk:Xania|&lt;sup&gt;talk&lt;/sup&gt;]] 17:54, 16 May 2026 (UTC)

== Cs24jam2 reported by MathXplore ==

* {{userlinks|Cs24jam2}}

Vandalism &lt;!-- USERREPORTED:/Cs24jam2/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 11:54, 11 May 2026 (UTC)

:{{done}} by @[[User:Codename Noreste|Codename Noreste]] —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 16:58, 11 May 2026 (UTC)
== Mnckhagaul reported by MathXplore ==

* {{userlinks|Mnckhagaul}}

Spam &lt;!-- USERREPORTED:/Mnckhagaul/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 08:35, 16 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 03:28, 17 May 2026 (UTC)
== Vrindavanmathuratourpackages reported by MathXplore ==

* {{userlinks|Vrindavanmathuratourpackages}}

Spam &lt;!-- USERREPORTED:/Vrindavanmathuratourpackages/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:13, 18 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:28, 18 May 2026 (UTC)
== Shawndavidsonosp2 reported by MathXplore ==

* {{userlinks|Shawndavidsonosp2}}

Spam, [[Special:AbuseLog/312343]], [[Special:AbuseLog/312344]] &lt;!-- USERREPORTED:/Shawndavidsonosp2/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:10, 19 May 2026 (UTC)

:This is not a spam. Its a discussion topic on Healthcare Software Development [[User:Shawndavidsonosp2|Shawndavidsonosp2]] ([[User talk:Shawndavidsonosp2|discuss]] • [[Special:Contributions/Shawndavidsonosp2|contribs]]) 13:00, 19 May 2026 (UTC)
: {{ping|MarcGarver|Xania}} (CU request) User:Shawndavidsonosp2 &amp; User:Lunasora33 made link additions for osplabs.com ([https://en.wikibooks.org/w/index.php?title=Information_Technology_and_Ethics/IT_and_Healthcare&amp;diff=prev&amp;oldid=4636437], [https://spamcheck.toolforge.org/by-domain?q=osplabs.com])
: {{ping|MarcGarver|SHB2000}} [[Special:CentralAuth/Rachvictor05]] &amp; [[Special:CentralAuth/Emma_Joseph_Swift]] (Locked) also made link additions for osplabs.com ([https://spamcheck.toolforge.org/by-domain?q=osplabs.com]) [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 13:46, 19 May 2026 (UTC)
::Clearly promotional accounts, both blocked. [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 16:00, 19 May 2026 (UTC)
:::and their spam domain added to the blacklist [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 16:02, 19 May 2026 (UTC)

== Banibrotechnologies reported by MathXplore ==

* {{userlinks|Banibrotechnologies}}

Spam &lt;!-- USERREPORTED:/Banibrotechnologies/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:10, 19 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 16:51, 19 May 2026 (UTC)

== Texasanne12 reported by MathXplore ==

* {{userlinks|Texasanne12}}

Link spam, [[Special:AbuseLog/312336]] &lt;!-- USERREPORTED:/Texasanne12/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:18, 19 May 2026 (UTC)

:{{done}} —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 02:14, 20 May 2026 (UTC)

== [[User:Me Lendroz]] (CU request) ==

{{ping|MarcGarver|Xania}} (this is related to previous CU, [[Wikibooks:Reading_room/Administrative_Assistance/Archives/2024/February#Alert_about_possible_evasion_of_previous_1-week_block_at_English_Wikibooks_(CU_needed?)]], [[Wikibooks:Reading_room/Administrative_Assistance/Archives/2024/August#Another_user_editing_User:Jay_Bolero's_user_page]]) &lt;br&gt;
I found [[Special:Contributions/CarlessParking]] editing the user page of [[User:Me Lendroz]]. What do our CUs think about this? [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 14:00, 19 May 2026 (UTC)

:It's an obvious sock of Jay Bolero not least because the account has posted &quot;my name is Karl Basallote&quot; everywhere and &quot;Basallote&quot; matches the previous sock. I've blocked CarlessParking as this is an abusive use of multiple accounts. [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 15:57, 19 May 2026 (UTC)</text>
      <sha1>igyz9nvhwf76dznlv6t3385za6vdfkf</sha1>
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      <id>4637012</id>
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      <comment>Reporting Sharmasejal</comment>
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{{ombox|type=content|text='''To request a rename or usurpation''', go to the global request page at Meta [[meta:SRUC|here]].&lt;br /&gt;''Please do not post those requests here!''}}
{{Clear}}
Welcome to the '''Administrative Assistance reading room'''.  You can request assistance from [[WB:ADMIN|administrators]] for handling a variety of problems here and alert them about problems which may require special actions not normally used during regular content editing. Please be patient as administrators are often quite busy with either their own projects or trying to perform general maintenance and cleanup.

You can deal with most vandalism yourself: [[Wikibooks:Dealing with vandalism|fix it]], then [[Wikibooks:Templates/User_notices|warn the user]]. If there is repeated vandalism by one user, lots of vandalism on a single page, or vandalism from many users, tell an admin here, or in [irc://irc.freenode.net/wikibooks #wikibooks] (say &lt;code&gt;!admin&lt;/code&gt; to get attention).

For more general questions and assistance that doesn't require an administrator, please use the [[WB:HELP|Assistance Reading Room]].
{{clear}}

[[Category:Reading room]]

== No data in page linked to by Wikidata ==

The page, [https://en.wikibooks.org/wiki/OpenSSH/Third_Party_Utilities OpenSSH: Third Party Utilities] has no data and thus should not be linked to from [https://www.wikidata.org/wiki/Q139625509 Q139625509]  How can the link be deleted?  Thanks.  [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 05:06, 4 May 2026 (UTC)

:Same for Q139611668 and Q139611580.  All three links should be deleted / removed as the destination pages in the en.wikibook do not have any data but instead normal prose.  - [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 05:15, 4 May 2026 (UTC)
:Same for Q139806271, Q139806269, Q139806266, Q139806265, Q139806264, Q139806263, Q139806262, Q139806261, Q139806260, Q139806258, Q139806256, Q139806255, Q139625509, Q139611668, and Q139611580.  There seems to be some new kind of vandalism going on.  Perhaps there is a better page to report it on instead of this one? • [[User:Larsnooden|Larsnooden]] ([[User talk:Larsnooden|discuss]] • [[Special:Contributions/Larsnooden|contribs]]) 17:37, 17 May 2026 (UTC)
:: @[[User:Larsnooden|Larsnooden]] Given that this situation is happening on Wikidata, there is nothing that English Wikibooks admins can do. Please report this matter to the Wikidata administrators. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:13, 17 May 2026 (UTC)

== Pizzazilla1 reported by MathXplore ==

* {{userlinks|Pizzazilla1}}

Spam &lt;!-- USERREPORTED:/Pizzazilla1/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:20, 8 May 2026 (UTC)

:Done. //[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 00:31, 9 May 2026 (UTC)
== ~2026-28014-44 reported by MathXplore ==

* {{userlinks|~2026-28014-44}}

Vandalism &lt;!-- USERREPORTED:/~2026-28014-44/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 01:02, 9 May 2026 (UTC)
: I blocked the underlying range. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 16:40, 10 May 2026 (UTC)

== Omran Tokhi Nickname OT7 reported by MathXplore ==

* {{userlinks|Omran Tokhi Nickname OT7}}

Long-term abuse. Spam / spambot. [[Special:CentralAuth/OmranTokhi7]] &lt;!-- USERREPORTED:/Omran Tokhi Nickname OT7/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 03:25, 10 May 2026 (UTC)

:{{done}}. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 04:29, 10 May 2026 (UTC)

== Can't log in :( ==

Xania here. I am logged in on Wikipedia but can't log in here even though it has always been automatic when switching between the two. Wikibooks seems to want me to authenticate myself via my authenticator app which I have not done before. Allows me to also use a recovery code which I do not have. How do I log in guys? [[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 18:15, 10 May 2026 (UTC)
: I believe it might be the CheckUser permission requiring 2FA (on parity with interface administrators and oversighters) as that group has restrictions. You might need to temporarily request to the [[m:Stewards' noticeboard|stewards]] to remove CU access from your account to enable 2FA; however, since this project only has 2 CUs, [[User:MarcGarver|MarcGarver]]'s CU rights would be temporarily suspended. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:36, 10 May 2026 (UTC)
: Thanks, I've left a notice on the Steward's board.--[[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 18:59, 10 May 2026 (UTC)
::This happened before when your CU rights were removed because you hadn't enrolled in 2FA. I presume you must have enrolled to get the CU rights back. Are you really sure you've never used any authenticator here? [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 11:49, 11 May 2026 (UTC)
:::See [https://en.wikibooks.org/wiki/User_talk:MarcGarver#Check_User previous discussion] from last year [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 11:51, 11 May 2026 (UTC)
::::Thanks. Good to know. I had completely forgotten that discussion. I will have to install some old authenticators and see which works.--[[Special:Contributions/&amp;#126;2026-28255-89|&amp;#126;2026-28255-89]] ([[User talk:&amp;#126;2026-28255-89|talk]]) 17:09, 16 May 2026 (UTC)
: Logged in finally. Seems I had recovery codes (totally forgotten about them) saved but no authenticator so each time I log in I'll need to use the codes.--[[User:Xania|Xania]] [[Image:Flag_of_Estonia.svg|15px]]  [[Image:Flag_of_Ukraine.svg|15px]] [[User talk:Xania|&lt;sup&gt;talk&lt;/sup&gt;]] 17:54, 16 May 2026 (UTC)

== Cs24jam2 reported by MathXplore ==

* {{userlinks|Cs24jam2}}

Vandalism &lt;!-- USERREPORTED:/Cs24jam2/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 11:54, 11 May 2026 (UTC)

:{{done}} by @[[User:Codename Noreste|Codename Noreste]] —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 16:58, 11 May 2026 (UTC)
== Mnckhagaul reported by MathXplore ==

* {{userlinks|Mnckhagaul}}

Spam &lt;!-- USERREPORTED:/Mnckhagaul/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 08:35, 16 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 03:28, 17 May 2026 (UTC)
== Vrindavanmathuratourpackages reported by MathXplore ==

* {{userlinks|Vrindavanmathuratourpackages}}

Spam &lt;!-- USERREPORTED:/Vrindavanmathuratourpackages/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:13, 18 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:28, 18 May 2026 (UTC)
== Shawndavidsonosp2 reported by MathXplore ==

* {{userlinks|Shawndavidsonosp2}}

Spam, [[Special:AbuseLog/312343]], [[Special:AbuseLog/312344]] &lt;!-- USERREPORTED:/Shawndavidsonosp2/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:10, 19 May 2026 (UTC)

:This is not a spam. Its a discussion topic on Healthcare Software Development [[User:Shawndavidsonosp2|Shawndavidsonosp2]] ([[User talk:Shawndavidsonosp2|discuss]] • [[Special:Contributions/Shawndavidsonosp2|contribs]]) 13:00, 19 May 2026 (UTC)
: {{ping|MarcGarver|Xania}} (CU request) User:Shawndavidsonosp2 &amp; User:Lunasora33 made link additions for osplabs.com ([https://en.wikibooks.org/w/index.php?title=Information_Technology_and_Ethics/IT_and_Healthcare&amp;diff=prev&amp;oldid=4636437], [https://spamcheck.toolforge.org/by-domain?q=osplabs.com])
: {{ping|MarcGarver|SHB2000}} [[Special:CentralAuth/Rachvictor05]] &amp; [[Special:CentralAuth/Emma_Joseph_Swift]] (Locked) also made link additions for osplabs.com ([https://spamcheck.toolforge.org/by-domain?q=osplabs.com]) [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 13:46, 19 May 2026 (UTC)
::Clearly promotional accounts, both blocked. [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 16:00, 19 May 2026 (UTC)
:::and their spam domain added to the blacklist [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 16:02, 19 May 2026 (UTC)

== Banibrotechnologies reported by MathXplore ==

* {{userlinks|Banibrotechnologies}}

Spam &lt;!-- USERREPORTED:/Banibrotechnologies/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:10, 19 May 2026 (UTC)
: {{done}}. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 16:51, 19 May 2026 (UTC)

== Texasanne12 reported by MathXplore ==

* {{userlinks|Texasanne12}}

Link spam, [[Special:AbuseLog/312336]] &lt;!-- USERREPORTED:/Texasanne12/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:18, 19 May 2026 (UTC)

:{{done}} —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 02:14, 20 May 2026 (UTC)

== [[User:Me Lendroz]] (CU request) ==

{{ping|MarcGarver|Xania}} (this is related to previous CU, [[Wikibooks:Reading_room/Administrative_Assistance/Archives/2024/February#Alert_about_possible_evasion_of_previous_1-week_block_at_English_Wikibooks_(CU_needed?)]], [[Wikibooks:Reading_room/Administrative_Assistance/Archives/2024/August#Another_user_editing_User:Jay_Bolero's_user_page]]) &lt;br&gt;
I found [[Special:Contributions/CarlessParking]] editing the user page of [[User:Me Lendroz]]. What do our CUs think about this? [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 14:00, 19 May 2026 (UTC)

:It's an obvious sock of Jay Bolero not least because the account has posted &quot;my name is Karl Basallote&quot; everywhere and &quot;Basallote&quot; matches the previous sock. I've blocked CarlessParking as this is an abusive use of multiple accounts. [[User:MarcGarver|MarcGarver]] ([[User talk:MarcGarver|discuss]] • [[Special:Contributions/MarcGarver|contribs]]) 15:57, 19 May 2026 (UTC)
== Sharmasejal reported by MathXplore ==
* {{userlinks|Sharmasejal}}

Spam, [[Special:AbuseLog/312466]] &lt;!-- USERREPORTED:/Sharmasejal/ --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 11:12, 22 May 2026 (UTC)</text>
      <sha1>7oz66uh46nmzvdlxhvgw2o8oy1bpr4c</sha1>
    </revision>
  </page>
  <page>
    <title>Unicode/Character reference/1F000-1FFFF</title>
    <ns>0</ns>
    <id>155016</id>
    <revision>
      <id>4636905</id>
      <parentid>4636631</parentid>
      <timestamp>2026-05-21T17:45:56Z</timestamp>
      <contributor>
        <username>WeelkyWikiReader</username>
        <id>3474871</id>
      </contributor>
      <comment>NO MORE FONTS!!!!! &gt;:|</comment>
      <origin>4636905</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="206429" sha1="6efsxndjsffczbukndhdk5gmqy1szxi" xml:space="preserve">{{:Unicode/Character reference}}

{|border=&quot;1&quot; cellpadding=&quot;2&quot; cellspacing=&quot;0&quot; style=&quot;border-collapse:collapse;&quot;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Mahjong Tiles'''
|----- style=&quot;background:#ccccff&quot;
!width=&quot;4%&quot;|U+!!width=&quot;6%&quot;|0!!width=&quot;6%&quot;|1!!width=&quot;6%&quot;|2!!width=&quot;6%&quot;|3!!width=&quot;6%&quot;|4!!width=&quot;6%&quot;|5!!width=&quot;6%&quot;|6!!width=&quot;6%&quot;|7!!width=&quot;6%&quot;|8!!width=&quot;6%&quot;|9!!width=&quot;6%&quot;|A!!width=&quot;6%&quot;|B!!width=&quot;6%&quot;|C!!width=&quot;6%&quot;|D!!width=&quot;6%&quot;|E!!width=&quot;6%&quot;|F
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F00x
|{{H:title|dotted=no|MAHJONG TILE EAST WIND|&amp;#x1f000;}}||{{H:title|dotted=no|MAHJONG TILE SOUTH WIND|&amp;#x1f001;}}||{{H:title|dotted=no|MAHJONG TILE WEST WIND|&amp;#x1f002;}}||{{H:title|dotted=no|MAHJONG TILE NORTH WIND|&amp;#x1f003;}}||{{H:title|dotted=no|MAHJONG TILE RED DRAGON|&amp;#x1f004;}}||{{H:title|dotted=no|MAHJONG TILE GREEN DRAGON|&amp;#x1f005;}}||{{H:title|dotted=no|MAHJONG TILE WHITE DRAGON|&amp;#x1f006;}}||{{H:title|dotted=no|MAHJONG TILE ONE OF CHARACTERS|&amp;#x1f007;}}||{{H:title|dotted=no|MAHJONG TILE TWO OF CHARACTERS|&amp;#x1f008;}}||{{H:title|dotted=no|MAHJONG TILE THREE OF CHARACTERS|&amp;#x1f009;}}||{{H:title|dotted=no|MAHJONG TILE FOUR OF CHARACTERS|&amp;#x1f00a;}}||{{H:title|dotted=no|MAHJONG TILE FIVE OF CHARACTERS|&amp;#x1f00b;}}||{{H:title|dotted=no|MAHJONG TILE SIX OF CHARACTERS|&amp;#x1f00c;}}||{{H:title|dotted=no|MAHJONG TILE SEVEN OF CHARACTERS|&amp;#x1f00d;}}||{{H:title|dotted=no|MAHJONG TILE EIGHT OF CHARACTERS|&amp;#x1f00e;}}||{{H:title|dotted=no|MAHJONG TILE NINE OF CHARACTERS|&amp;#x1f00f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F01x
|{{H:title|dotted=no|MAHJONG TILE ONE OF BAMBOOS|&amp;#x1f010;}}||{{H:title|dotted=no|MAHJONG TILE TWO OF BAMBOOS|&amp;#x1f011;}}||{{H:title|dotted=no|MAHJONG TILE THREE OF BAMBOOS|&amp;#x1f012;}}||{{H:title|dotted=no|MAHJONG TILE FOUR OF BAMBOOS|&amp;#x1f013;}}||{{H:title|dotted=no|MAHJONG TILE FIVE OF BAMBOOS|&amp;#x1f014;}}||{{H:title|dotted=no|MAHJONG TILE SIX OF BAMBOOS|&amp;#x1f015;}}||{{H:title|dotted=no|MAHJONG TILE SEVEN OF BAMBOOS|&amp;#x1f016;}}||{{H:title|dotted=no|MAHJONG TILE EIGHT OF BAMBOOS|&amp;#x1f017;}}||{{H:title|dotted=no|MAHJONG TILE NINE OF BAMBOOS|&amp;#x1f018;}}||{{H:title|dotted=no|MAHJONG TILE ONE OF CIRCLES|&amp;#x1f019;}}||{{H:title|dotted=no|MAHJONG TILE TWO OF CIRCLES|&amp;#x1f01a;}}||{{H:title|dotted=no|MAHJONG TILE THREE OF CIRCLES|&amp;#x1f01b;}}||{{H:title|dotted=no|MAHJONG TILE FOUR OF CIRCLES|&amp;#x1f01c;}}||{{H:title|dotted=no|MAHJONG TILE FIVE OF CIRCLES|&amp;#x1f01d;}}||{{H:title|dotted=no|MAHJONG TILE SIX OF CIRCLES|&amp;#x1f01e;}}||{{H:title|dotted=no|MAHJONG TILE SEVEN OF CIRCLES|&amp;#x1f01f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F02x
|{{H:title|dotted=no|MAHJONG TILE EIGHT OF CIRCLES|&amp;#x1f020;}}||{{H:title|dotted=no|MAHJONG TILE NINE OF CIRCLES|&amp;#x1f021;}}||{{H:title|dotted=no|MAHJONG TILE PLUM|&amp;#x1f022;}}||{{H:title|dotted=no|MAHJONG TILE ORCHID|&amp;#x1f023;}}||{{H:title|dotted=no|MAHJONG TILE BAMBOO|&amp;#x1f024;}}||{{H:title|dotted=no|MAHJONG TILE CHRYSANTHEMUM|&amp;#x1f025;}}||{{H:title|dotted=no|MAHJONG TILE SPRING|&amp;#x1f026;}}||{{H:title|dotted=no|MAHJONG TILE SUMMER|&amp;#x1f027;}}||{{H:title|dotted=no|MAHJONG TILE AUTUMN|&amp;#x1f028;}}||{{H:title|dotted=no|MAHJONG TILE WINTER|&amp;#x1f029;}}||{{H:title|dotted=no|MAHJONG TILE JOKER|&amp;#x1f02a;}}||{{H:title|dotted=no|MAHJONG TILE BACK|&amp;#x1f02b;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Domino Tiles'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F03x
|{{H:title|dotted=no|DOMINO TILE HORIZONTAL BACK|&amp;#x1f030;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-00|&amp;#x1f031;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-01|&amp;#x1f032;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-02|&amp;#x1f033;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-03|&amp;#x1f034;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-04|&amp;#x1f035;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-05|&amp;#x1f036;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-00-06|&amp;#x1f037;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-00|&amp;#x1f038;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-01|&amp;#x1f039;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-02|&amp;#x1f03a;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-03|&amp;#x1f03b;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-04|&amp;#x1f03c;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-05|&amp;#x1f03d;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-01-06|&amp;#x1f03e;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-00|&amp;#x1f03f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F04x
|{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-01|&amp;#x1f040;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-02|&amp;#x1f041;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-03|&amp;#x1f042;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-04|&amp;#x1f043;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-05|&amp;#x1f044;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-02-06|&amp;#x1f045;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-00|&amp;#x1f046;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-01|&amp;#x1f047;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-02|&amp;#x1f048;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-03|&amp;#x1f049;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-04|&amp;#x1f04a;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-05|&amp;#x1f04b;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-03-06|&amp;#x1f04c;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-00|&amp;#x1f04d;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-01|&amp;#x1f04e;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-02|&amp;#x1f04f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F05x
|{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-03|&amp;#x1f050;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-04|&amp;#x1f051;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-05|&amp;#x1f052;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-04-06|&amp;#x1f053;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-00|&amp;#x1f054;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-01|&amp;#x1f055;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-02|&amp;#x1f056;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-03|&amp;#x1f057;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-04|&amp;#x1f058;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-05|&amp;#x1f059;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-05-06|&amp;#x1f05a;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-00|&amp;#x1f05b;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-01|&amp;#x1f05c;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-02|&amp;#x1f05d;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-03|&amp;#x1f05e;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-04|&amp;#x1f05f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F06x
|{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-05|&amp;#x1f060;}}||{{H:title|dotted=no|DOMINO TILE HORIZONTAL-06-06|&amp;#x1f061;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL BACK|&amp;#x1f062;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-00|&amp;#x1f063;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-01|&amp;#x1f064;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-02|&amp;#x1f065;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-03|&amp;#x1f066;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-04|&amp;#x1f067;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-05|&amp;#x1f068;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-00-06|&amp;#x1f069;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-01-00|&amp;#x1f06a;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-01-01|&amp;#x1f06b;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-01-02|&amp;#x1f06c;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-01-03|&amp;#x1f06d;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-01-04|&amp;#x1f06e;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-01-05|&amp;#x1f06f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F07x
|{{H:title|dotted=no|DOMINO TILE VERTICAL-01-06|&amp;#x1f070;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-00|&amp;#x1f071;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-01|&amp;#x1f072;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-02|&amp;#x1f073;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-03|&amp;#x1f074;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-04|&amp;#x1f075;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-05|&amp;#x1f076;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-02-06|&amp;#x1f077;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-00|&amp;#x1f078;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-01|&amp;#x1f079;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-02|&amp;#x1f07a;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-03|&amp;#x1f07b;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-04|&amp;#x1f07c;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-05|&amp;#x1f07d;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-03-06|&amp;#x1f07e;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-04-00|&amp;#x1f07f;}}
|----- align=&quot;center&quot; style=&quot;background:#75ffab&quot;
!style=&quot;background:#ffffff&quot;|1F08x
|{{H:title|dotted=no|DOMINO TILE VERTICAL-04-01|&amp;#x1f080;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-04-02|&amp;#x1f081;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-04-03|&amp;#x1f082;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-04-04|&amp;#x1f083;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-04-05|&amp;#x1f084;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-04-06|&amp;#x1f085;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-00|&amp;#x1f086;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-01|&amp;#x1f087;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-02|&amp;#x1f088;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-03|&amp;#x1f089;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-04|&amp;#x1f08a;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-05|&amp;#x1f08b;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-05-06|&amp;#x1f08c;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-06-00|&amp;#x1f08d;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-06-01|&amp;#x1f08e;}}||{{H:title|dotted=no|DOMINO TILE VERTICAL-06-02|&amp;#x1f08f;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F09x
|style=&quot;background:#75ffab&quot;|{{H:title|dotted=no|DOMINO TILE VERTICAL-06-03|&amp;#x1f090;}}||style=&quot;background:#75ffab&quot;|{{H:title|dotted=no|DOMINO TILE VERTICAL-06-04|&amp;#x1f091;}}||style=&quot;background:#75ffab&quot;|{{H:title|dotted=no|DOMINO TILE VERTICAL-06-05|&amp;#x1f092;}}||style=&quot;background:#75ffab&quot;|{{H:title|dotted=no|DOMINO TILE VERTICAL-06-06|&amp;#x1f093;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Playing Cards'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F0Ax
|{{H:title|dotted=no|PLAYING CARD BACK|&amp;#x1f0a0;}}||{{H:title|dotted=no|PLAYING CARD ACE OF SPADES|&amp;#x1f0a1;}}||{{H:title|dotted=no|PLAYING CARD TWO OF SPADES|&amp;#x1f0a2;}}||{{H:title|dotted=no|PLAYING CARD THREE OF SPADES|&amp;#x1f0a3;}}||{{H:title|dotted=no|PLAYING CARD FOUR OF SPADES|&amp;#x1f0a4;}}||{{H:title|dotted=no|PLAYING CARD FIVE OF SPADES|&amp;#x1f0a5;}}||{{H:title|dotted=no|PLAYING CARD SIX OF SPADES|&amp;#x1f0a6;}}||{{H:title|dotted=no|PLAYING CARD SEVEN OF SPADES|&amp;#x1f0a7;}}||{{H:title|dotted=no|PLAYING CARD EIGHT OF SPADES|&amp;#x1f0a8;}}||{{H:title|dotted=no|PLAYING CARD NINE OF SPADES|&amp;#x1f0a9;}}||{{H:title|dotted=no|PLAYING CARD TEN OF SPADES|&amp;#x1f0aa;}}||{{H:title|dotted=no|PLAYING CARD JACK OF SPADES|&amp;#x1f0ab;}}||{{H:title|dotted=no|PLAYING CARD KNIGHT OF SPADES|&amp;#x1f0ac;}}||{{H:title|dotted=no|PLAYING CARD QUEEN OF SPADES|&amp;#x1f0ad;}}||{{H:title|dotted=no|PLAYING CARD KING OF SPADES|&amp;#x1f0ae;}}||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F0Bx
|style=&quot;background:#777777&quot;|&amp;nbsp;||{{H:title|dotted=no|PLAYING CARD ACE OF HEARTS|&amp;#x1f0b1;}}||{{H:title|dotted=no|PLAYING CARD TWO OF HEARTS|&amp;#x1f0b2;}}||{{H:title|dotted=no|PLAYING CARD THREE OF HEARTS|&amp;#x1f0b3;}}||{{H:title|dotted=no|PLAYING CARD FOUR OF HEARTS|&amp;#x1f0b4;}}||{{H:title|dotted=no|PLAYING CARD FIVE OF HEARTS|&amp;#x1f0b5;}}||{{H:title|dotted=no|PLAYING CARD SIX OF HEARTS|&amp;#x1f0b6;}}||{{H:title|dotted=no|PLAYING CARD SEVEN OF HEARTS|&amp;#x1f0b7;}}||{{H:title|dotted=no|PLAYING CARD EIGHT OF HEARTS|&amp;#x1f0b8;}}||{{H:title|dotted=no|PLAYING CARD NINE OF HEARTS|&amp;#x1f0b9;}}||{{H:title|dotted=no|PLAYING CARD TEN OF HEARTS|&amp;#x1f0ba;}}||{{H:title|dotted=no|PLAYING CARD JACK OF HEARTS|&amp;#x1f0bb;}}||{{H:title|dotted=no|PLAYING CARD KNIGHT OF HEARTS|&amp;#x1f0bc;}}||{{H:title|dotted=no|PLAYING CARD QUEEN OF HEARTS|&amp;#x1f0bd;}}||{{H:title|dotted=no|PLAYING CARD KING OF HEARTS|&amp;#x1f0be;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD RED JOKER|&amp;#x1f0bf;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F0Cx
|style=&quot;background:#777777&quot;|&amp;nbsp;||{{H:title|dotted=no|PLAYING CARD ACE OF DIAMONDS|&amp;#x1f0c1;}}||{{H:title|dotted=no|PLAYING CARD TWO OF DIAMONDS|&amp;#x1f0c2;}}||{{H:title|dotted=no|PLAYING CARD THREE OF DIAMONDS|&amp;#x1f0c3;}}||{{H:title|dotted=no|PLAYING CARD FOUR OF DIAMONDS|&amp;#x1f0c4;}}||{{H:title|dotted=no|PLAYING CARD FIVE OF DIAMONDS|&amp;#x1f0c5;}}||{{H:title|dotted=no|PLAYING CARD SIX OF DIAMONDS|&amp;#x1f0c6;}}||{{H:title|dotted=no|PLAYING CARD SEVEN OF DIAMONDS|&amp;#x1f0c7;}}||{{H:title|dotted=no|PLAYING CARD EIGHT OF DIAMONDS|&amp;#x1f0c8;}}||{{H:title|dotted=no|PLAYING CARD NINE OF DIAMONDS|&amp;#x1f0c9;}}||{{H:title|dotted=no|PLAYING CARD TEN OF DIAMONDS|&amp;#x1f0ca;}}||{{H:title|dotted=no|PLAYING CARD JACK OF DIAMONDS|&amp;#x1f0cb;}}||{{H:title|dotted=no|PLAYING CARD KNIGHT OF DIAMONDS|&amp;#x1f0cc;}}||{{H:title|dotted=no|PLAYING CARD QUEEN OF DIAMONDS|&amp;#x1f0cd;}}||{{H:title|dotted=no|PLAYING CARD KING OF DIAMONDS|&amp;#x1f0ce;}}||{{H:title|dotted=no|PLAYING CARD BLACK JOKER|&amp;#x1f0cf;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F0Dx
|style=&quot;background:#777777&quot;|&amp;nbsp;||{{H:title|dotted=no|PLAYING CARD ACE OF CLUBS|&amp;#x1f0d1;}}||{{H:title|dotted=no|PLAYING CARD TWO OF CLUBS|&amp;#x1f0d2;}}||{{H:title|dotted=no|PLAYING CARD THREE OF CLUBS|&amp;#x1f0d3;}}||{{H:title|dotted=no|PLAYING CARD FOUR OF CLUBS|&amp;#x1f0d4;}}||{{H:title|dotted=no|PLAYING CARD FIVE OF CLUBS|&amp;#x1f0d5;}}||{{H:title|dotted=no|PLAYING CARD SIX OF CLUBS|&amp;#x1f0d6;}}||{{H:title|dotted=no|PLAYING CARD SEVEN OF CLUBS|&amp;#x1f0d7;}}||{{H:title|dotted=no|PLAYING CARD EIGHT OF CLUBS|&amp;#x1f0d8;}}||{{H:title|dotted=no|PLAYING CARD NINE OF CLUBS|&amp;#x1f0d9;}}||{{H:title|dotted=no|PLAYING CARD TEN OF CLUBS|&amp;#x1f0da;}}||{{H:title|dotted=no|PLAYING CARD JACK OF CLUBS|&amp;#x1f0db;}}||{{H:title|dotted=no|PLAYING CARD KNIGHT OF CLUBS|&amp;#x1f0dc;}}||{{H:title|dotted=no|PLAYING CARD QUEEN OF CLUBS|&amp;#x1f0dd;}}||{{H:title|dotted=no|PLAYING CARD KING OF CLUBS|&amp;#x1f0de;}}||{{H:title|dotted=no|PLAYING CARD WHITE JOKER|&amp;#x1f0df;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F0Ex
|{{H:title|dotted=no|PLAYING CARD FOOL|&amp;#x1f0e0;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-1|&amp;#x1f0e1;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-2|&amp;#x1f0e2;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-3|&amp;#x1f0e3;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-4|&amp;#x1f0e4;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-5|&amp;#x1f0e5;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-6|&amp;#x1f0e6;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-7|&amp;#x1f0e7;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-8|&amp;#x1f0e8;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-9|&amp;#x1f0e9;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-10|&amp;#x1f0ea;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-11|&amp;#x1f0eb;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-12|&amp;#x1f0ec;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-13|&amp;#x1f0ed;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-14|&amp;#x1f0ee;}}||{{H:title|dotted=no|PLAYING CARD TRUMP-15|&amp;#x1f0ef;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F0Fx
|style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD TRUMP-16|&amp;#x1f0f0;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD TRUMP-17|&amp;#x1f0f1;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD TRUMP-18|&amp;#x1f0f2;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD TRUMP-19|&amp;#x1f0f3;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD TRUMP-20|&amp;#x1f0f4;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PLAYING CARD TRUMP-21|&amp;#x1f0f5;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Enclosed Alphanumeric Supplement'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#78ffca&quot;
!style=&quot;background:#ffffff&quot;|1F10x
|{{H:title|dotted=no|DIGIT ZERO FULL STOP|&amp;#x1f100;}}||{{H:title|dotted=no|DIGIT ZERO COMMA|&amp;#x1f101;}}||{{H:title|dotted=no|DIGIT ONE COMMA|&amp;#x1f102;}}||{{H:title|dotted=no|DIGIT TWO COMMA|&amp;#x1f103;}}||{{H:title|dotted=no|DIGIT THREE COMMA|&amp;#x1f104;}}||{{H:title|dotted=no|DIGIT FOUR COMMA|&amp;#x1f105;}}||{{H:title|dotted=no|DIGIT FIVE COMMA|&amp;#x1f106;}}||{{H:title|dotted=no|DIGIT SIX COMMA|&amp;#x1f107;}}||{{H:title|dotted=no|DIGIT SEVEN COMMA|&amp;#x1f108;}}||{{H:title|dotted=no|DIGIT EIGHT COMMA|&amp;#x1f109;}}||{{H:title|dotted=no|DIGIT NINE COMMA|&amp;#x1f10a;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|DINGBAT CIRCLED SANS-SERIF DIGIT ZERO|&amp;#x1f10b;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|DINGBAT NEGATIVE CIRCLED SANS-SERIF DIGIT ZERO|&amp;#x1f10c;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|CIRCLED ZERO WITH SLASH|&amp;#x1f10d;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|CIRCLED ANTICLOCKWISE ARROW|&amp;#x1f10e;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|CIRCLED DOLLAR SIGN WITH OVERLAID BACKSLASH|&amp;#x1f10f;}}
|----- align=&quot;center&quot; style=&quot;background:#78ffca&quot;
!style=&quot;background:#ffffff&quot;|1F11x
|{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER A|&amp;#x1f110;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER B|&amp;#x1f111;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER C|&amp;#x1f112;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER D|&amp;#x1f113;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER E|&amp;#x1f114;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER F|&amp;#x1f115;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER G|&amp;#x1f116;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER H|&amp;#x1f117;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER I|&amp;#x1f118;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER J|&amp;#x1f119;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER K|&amp;#x1f11a;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER L|&amp;#x1f11b;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER M|&amp;#x1f11c;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER N|&amp;#x1f11d;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER O|&amp;#x1f11e;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER P|&amp;#x1f11f;}}
|----- align=&quot;center&quot; style=&quot;background:#78ffca&quot;
!style=&quot;background:#ffffff&quot;|1F12x
|{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER Q|&amp;#x1f120;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER R|&amp;#x1f121;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER S|&amp;#x1f122;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER T|&amp;#x1f123;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER U|&amp;#x1f124;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER V|&amp;#x1f125;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER W|&amp;#x1f126;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER X|&amp;#x1f127;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER Y|&amp;#x1f128;}}||{{H:title|dotted=no|PARENTHESIZED LATIN CAPITAL LETTER Z|&amp;#x1f129;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED LATIN CAPITAL LETTER S|&amp;#x1f12a;}}||{{H:title|dotted=no|CIRCLED ITALIC LATIN CAPITAL LETTER C|&amp;#x1f12b;}}||{{H:title|dotted=no|CIRCLED ITALIC LATIN CAPITAL LETTER R|&amp;#x1f12c;}}||{{H:title|dotted=no|CIRCLED CD|&amp;#x1f12d;}}||{{H:title|dotted=no|CIRCLED WZ|&amp;#x1f12e;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|COPYLEFT SYMBOL|&amp;#x1f12f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F13x
|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER A|&amp;#x1f130;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER B|&amp;#x1f131;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER C|&amp;#x1f132;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER D|&amp;#x1f133;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER E|&amp;#x1f134;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER F|&amp;#x1f135;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER G|&amp;#x1f136;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER H|&amp;#x1f137;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER I|&amp;#x1f138;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER J|&amp;#x1f139;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER K|&amp;#x1f13a;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER L|&amp;#x1f13b;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER M|&amp;#x1f13c;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER N|&amp;#x1f13d;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER O|&amp;#x1f13e;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER P|&amp;#x1f13f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F14x
|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER Q|&amp;#x1f140;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER R|&amp;#x1f141;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER S|&amp;#x1f142;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER T|&amp;#x1f143;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER U|&amp;#x1f144;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER V|&amp;#x1f145;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER W|&amp;#x1f146;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER X|&amp;#x1f147;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER Y|&amp;#x1f148;}}||{{H:title|dotted=no|SQUARED LATIN CAPITAL LETTER Z|&amp;#x1f149;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED HV|&amp;#x1f14a;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED MV|&amp;#x1f14b;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED SD|&amp;#x1f14c;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED SS|&amp;#x1f14d;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED PPV|&amp;#x1f14e;}}||{{H:title|dotted=no|SQUARED WC|&amp;#x1f14f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F15x
|{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER A|&amp;#x1f150;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER B|&amp;#x1f151;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER C|&amp;#x1f152;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER D|&amp;#x1f153;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER E|&amp;#x1f154;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER F|&amp;#x1f155;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER G|&amp;#x1f156;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER H|&amp;#x1f157;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER I|&amp;#x1f158;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER J|&amp;#x1f159;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER K|&amp;#x1f15a;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER L|&amp;#x1f15b;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER M|&amp;#x1f15c;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER N|&amp;#x1f15d;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER O|&amp;#x1f15e;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER P|&amp;#x1f15f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F16x
|{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER Q|&amp;#x1f160;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER R|&amp;#x1f161;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER S|&amp;#x1f162;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER T|&amp;#x1f163;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER U|&amp;#x1f164;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER V|&amp;#x1f165;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER W|&amp;#x1f166;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER X|&amp;#x1f167;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER Y|&amp;#x1f168;}}||{{H:title|dotted=no|NEGATIVE CIRCLED LATIN CAPITAL LETTER Z|&amp;#x1f169;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|RAISED MC SIGN|&amp;#x1f16a;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|RAISED MD SIGN|&amp;#x1f16b;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|RAISED MR SIGN|&amp;#x1f16c;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|CIRCLED CC|&amp;#x1f16d;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|CIRCLED C WITH OVERLAID BACKSLASH|&amp;#x1f16e;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|CIRCLED HUMAN FIGURE|&amp;#x1f16f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F17x
|{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER A|&amp;#x1f170;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER B|&amp;#x1f171;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER C|&amp;#x1f172;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER D|&amp;#x1f173;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER E|&amp;#x1f174;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER F|&amp;#x1f175;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER G|&amp;#x1f176;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER H|&amp;#x1f177;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER I|&amp;#x1f178;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER J|&amp;#x1f179;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER K|&amp;#x1f17a;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER L|&amp;#x1f17b;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER M|&amp;#x1f17c;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER N|&amp;#x1f17d;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER O|&amp;#x1f17e;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER P|&amp;#x1f17f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F18x
|{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER Q|&amp;#x1f180;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER R|&amp;#x1f181;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER S|&amp;#x1f182;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER T|&amp;#x1f183;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER U|&amp;#x1f184;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER V|&amp;#x1f185;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER W|&amp;#x1f186;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER X|&amp;#x1f187;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER Y|&amp;#x1f188;}}||{{H:title|dotted=no|NEGATIVE SQUARED LATIN CAPITAL LETTER Z|&amp;#x1f189;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|CROSSED NEGATIVE SQUARED LATIN CAPITAL LETTER P|&amp;#x1f18a;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED IC|&amp;#x1f18b;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED PA|&amp;#x1f18c;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|NEGATIVE SQUARED SA|&amp;#x1f18d;}}||{{H:title|dotted=no|NEGATIVE SQUARED AB|&amp;#x1f18e;}}||{{H:title|dotted=no|NEGATIVE SQUARED WC|&amp;#x1f18f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F19x
|style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARE DJ|&amp;#x1f190;}}||{{H:title|dotted=no|SQUARED CL|&amp;#x1f191;}}||{{H:title|dotted=no|SQUARED COOL|&amp;#x1f192;}}||{{H:title|dotted=no|SQUARED FREE|&amp;#x1f193;}}||{{H:title|dotted=no|SQUARED ID|&amp;#x1f194;}}||{{H:title|dotted=no|SQUARED NEW|&amp;#x1f195;}}||{{H:title|dotted=no|SQUARED NG|&amp;#x1f196;}}||{{H:title|dotted=no|SQUARED OK|&amp;#x1f197;}}||{{H:title|dotted=no|SQUARED SOS|&amp;#x1f198;}}||{{H:title|dotted=no|SQUARED UP WITH EXCLAMATION MARK|&amp;#x1f199;}}||{{H:title|dotted=no|SQUARED VS|&amp;#x1f19a;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUARED THREE D|&amp;#x1f19b;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUARED SECOND SCREEN|&amp;#x1f19c;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUARED TWO K|&amp;#x1f19d;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUARED FOUR K|&amp;#x1f19e;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUARED EIGHT K|&amp;#x1f19f;}}
|----- align=&quot;center&quot; style=&quot;background:#9c8dff&quot;
!style=&quot;background:#ffffff&quot;|1F1Ax
|{{H:title|dotted=no|SQUARED FIVE POINT ONE|&amp;#x1f1a0;}}||{{H:title|dotted=no|SQUARED SEVEN POINT ONE|&amp;#x1f1a1;}}||{{H:title|dotted=no|SQUARED TWENTY-TWO POINT TWO|&amp;#x1f1a2;}}||{{H:title|dotted=no|SQUARED SIXTY P|&amp;#x1f1a3;}}||{{H:title|dotted=no|SQUARED ONE HUNDRED TWENTY P|&amp;#x1f1a4;}}||{{H:title|dotted=no|SQUARED LATIN SMALL LETTER D|&amp;#x1f1a5;}}||{{H:title|dotted=no|SQUARED HC|&amp;#x1f1a6;}}||{{H:title|dotted=no|SQUARED HDR|&amp;#x1f1a7;}}||{{H:title|dotted=no|SQUARED HI-RES|&amp;#x1f1a8;}}||{{H:title|dotted=no|SQUARED LOSSLESS|&amp;#x1f1a9;}}||{{H:title|dotted=no|SQUARED SHV|&amp;#x1f1aa;}}||{{H:title|dotted=no|SQUARED UHD|&amp;#x1f1ab;}}||{{H:title|dotted=no|SQUARED VOD|&amp;#x1f1ac;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|MASK WORK SYMBOL|&amp;#x1f1ad;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|TOMOBIKI SYMBOL|&amp;#x1f1ae;}}||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F1Bx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F1Cx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F1Dx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F1Ex
|style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER A|&amp;#x1f1e6;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER B|&amp;#x1f1e7;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER C|&amp;#x1f1e8;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER D|&amp;#x1f1e9;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER E|&amp;#x1f1ea;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER F|&amp;#x1f1eb;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER G|&amp;#x1f1ec;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER H|&amp;#x1f1ed;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER I|&amp;#x1f1ee;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER J|&amp;#x1f1ef;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F1Fx
|{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER K|&amp;#x1f1f0;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER L|&amp;#x1f1f1;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER M|&amp;#x1f1f2;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER N|&amp;#x1f1f3;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER O|&amp;#x1f1f4;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER P|&amp;#x1f1f5;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER Q|&amp;#x1f1f6;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER R|&amp;#x1f1f7;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER S|&amp;#x1f1f8;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER T|&amp;#x1f1f9;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER U|&amp;#x1f1fa;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER V|&amp;#x1f1fb;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER W|&amp;#x1f1fc;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER X|&amp;#x1f1fd;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER Y|&amp;#x1f1fe;}}||{{H:title|dotted=no|REGIONAL INDICATOR SYMBOL LETTER Z|&amp;#x1f1ff;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Enclosed Ideographic Supplement'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F20x
|style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARE HIRAGANA HOKA|&amp;#x1f200;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|SQUARED KATAKANA KOKO|&amp;#x1f201;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|SQUARED KATAKANA SA|&amp;#x1f202;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#78ffca&quot;
!style=&quot;background:#ffffff&quot;|1F21x
|{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-624B|&amp;#x1f210;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5B57|&amp;#x1f211;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-53CC|&amp;#x1f212;}}||{{H:title|dotted=no|SQUARED KATAKANA DE|&amp;#x1f213;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-4E8C|&amp;#x1f214;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-591A|&amp;#x1f215;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-89E3|&amp;#x1f216;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5929|&amp;#x1f217;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-4EA4|&amp;#x1f218;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6620|&amp;#x1f219;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-7121|&amp;#x1f21a;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6599|&amp;#x1f21b;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-524D|&amp;#x1f21c;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5F8C|&amp;#x1f21d;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-518D|&amp;#x1f21e;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-65B0|&amp;#x1f21f;}}
|----- align=&quot;center&quot; style=&quot;background:#78ffca&quot;
!style=&quot;background:#ffffff&quot;|1F22x
|{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-521D|&amp;#x1f220;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-7D42|&amp;#x1f221;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-751F|&amp;#x1f222;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-8CA9|&amp;#x1f223;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-58F0|&amp;#x1f224;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5439|&amp;#x1f225;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6F14|&amp;#x1f226;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6295|&amp;#x1f227;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6355|&amp;#x1f228;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-4E00|&amp;#x1f229;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-4E09|&amp;#x1f22a;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-904A|&amp;#x1f22b;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5DE6|&amp;#x1f22c;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-4E2D|&amp;#x1f22d;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-53F3|&amp;#x1f22e;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6307|&amp;#x1f22f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F23x
|style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-8D70|&amp;#x1f230;}}||style=&quot;background:#78ffca&quot;|{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6253|&amp;#x1f231;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-7981|&amp;#x1f232;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-7A7A|&amp;#x1f233;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5408|&amp;#x1f234;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6E80|&amp;#x1f235;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6709|&amp;#x1f236;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-6708|&amp;#x1f237;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-7533|&amp;#x1f238;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-5272|&amp;#x1f239;}}||{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-55B6|&amp;#x1f23a;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUARED CJK UNIFIED IDEOGRAPH-914D|&amp;#x1f23b;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#78ffca&quot;
!style=&quot;background:#ffffff&quot;|1F24x
|{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-672C|&amp;#x1f240;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-4E09|&amp;#x1f241;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-4E8C|&amp;#x1f242;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-5B89|&amp;#x1f243;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-70B9|&amp;#x1f244;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-6253|&amp;#x1f245;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-76D7|&amp;#x1f246;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-52DD|&amp;#x1f247;}}||{{H:title|dotted=no|TORTOISE SHELL BRACKETED CJK UNIFIED IDEOGRAPH-6557|&amp;#x1f248;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F25x
|style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|CIRCLED IDEOGRAPH ADVANTAGE|&amp;#x1f250;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|CIRCLED IDEOGRAPH ACCEPT|&amp;#x1f251;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F26x
|style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ROUNDED SYMBOL FOR FU|&amp;#x1f260;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ROUNDED SYMBOL FOR LU|&amp;#x1f261;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ROUNDED SYMBOL FOR SHOU|&amp;#x1f262;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ROUNDED SYMBOL FOR XI|&amp;#x1f263;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ROUNDED SYMBOL FOR SHUANGXI|&amp;#x1f264;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ROUNDED SYMBOL FOR CAI|&amp;#x1f265;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F27x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F28x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F29x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F2Ax
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F2Bx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F2Cx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F2Dx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F2Ex
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F2Fx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Miscellaneous Symbols and Pictographs'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F30x
|{{H:title|dotted=no|CYCLONE|&amp;#x1f300;}}||{{H:title|dotted=no|FOGGY|&amp;#x1f301;}}||{{H:title|dotted=no|CLOSED UMBRELLA|&amp;#x1f302;}}||{{H:title|dotted=no|NIGHT WITH STARS|&amp;#x1f303;}}||{{H:title|dotted=no|SUNRISE OVER MOUNTAINS|&amp;#x1f304;}}||{{H:title|dotted=no|SUNRISE|&amp;#x1f305;}}||{{H:title|dotted=no|CITYSCAPE AT DUSK|&amp;#x1f306;}}||{{H:title|dotted=no|SUNSET OVER BUILDINGS|&amp;#x1f307;}}||{{H:title|dotted=no|RAINBOW|&amp;#x1f308;}}||{{H:title|dotted=no|BRIDGE AT NIGHT|&amp;#x1f309;}}||{{H:title|dotted=no|WATER WAVE|&amp;#x1f30a;}}||{{H:title|dotted=no|VOLCANO|&amp;#x1f30b;}}||{{H:title|dotted=no|MILKY WAY|&amp;#x1f30c;}}||{{H:title|dotted=no|EARTH GLOBE EUROPE-AFRICA|&amp;#x1f30d;}}||{{H:title|dotted=no|EARTH GLOBE AMERICAS|&amp;#x1f30e;}}||{{H:title|dotted=no|EARTH GLOBE ASIA-AUSTRALIA|&amp;#x1f30f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F31x
|{{H:title|dotted=no|GLOBE WITH MERIDIANS|&amp;#x1f310;}}||{{H:title|dotted=no|NEW MOON SYMBOL|&amp;#x1f311;}}||{{H:title|dotted=no|WAXING CRESCENT MOON SYMBOL|&amp;#x1f312;}}||{{H:title|dotted=no|FIRST QUARTER MOON SYMBOL|&amp;#x1f313;}}||{{H:title|dotted=no|WAXING GIBBOUS MOON SYMBOL|&amp;#x1f314;}}||{{H:title|dotted=no|FULL MOON SYMBOL|&amp;#x1f315;}}||{{H:title|dotted=no|WANING GIBBOUS MOON SYMBOL|&amp;#x1f316;}}||{{H:title|dotted=no|LAST QUARTER MOON SYMBOL|&amp;#x1f317;}}||{{H:title|dotted=no|WANING CRESCENT MOON SYMBOL|&amp;#x1f318;}}||{{H:title|dotted=no|CRESCENT MOON|&amp;#x1f319;}}||{{H:title|dotted=no|NEW MOON WITH FACE|&amp;#x1f31a;}}||{{H:title|dotted=no|FIRST QUARTER MOON WITH FACE|&amp;#x1f31b;}}||{{H:title|dotted=no|LAST QUARTER MOON WITH FACE|&amp;#x1f31c;}}||{{H:title|dotted=no|FULL MOON WITH FACE|&amp;#x1f31d;}}||{{H:title|dotted=no|SUN WITH FACE|&amp;#x1f31e;}}||{{H:title|dotted=no|GLOWING STAR|&amp;#x1f31f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F32x
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|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F42x
|{{H:title|dotted=no|TROPICAL FISH|&amp;#x1f420;}}||{{H:title|dotted=no|BLOWFISH|&amp;#x1f421;}}||{{H:title|dotted=no|TURTLE|&amp;#x1f422;}}||{{H:title|dotted=no|HATCHING CHICK|&amp;#x1f423;}}||{{H:title|dotted=no|BABY CHICK|&amp;#x1f424;}}||{{H:title|dotted=no|FRONT-FACING BABY CHICK|&amp;#x1f425;}}||{{H:title|dotted=no|BIRD|&amp;#x1f426;}}||{{H:title|dotted=no|PENGUIN|&amp;#x1f427;}}||{{H:title|dotted=no|KOALA|&amp;#x1f428;}}||{{H:title|dotted=no|POODLE|&amp;#x1f429;}}||{{H:title|dotted=no|DROMEDARY CAMEL|&amp;#x1f42a;}}||{{H:title|dotted=no|BACTRIAN CAMEL|&amp;#x1f42b;}}||{{H:title|dotted=no|DOLPHIN|&amp;#x1f42c;}}||{{H:title|dotted=no|MOUSE FACE|&amp;#x1f42d;}}||{{H:title|dotted=no|COW FACE|&amp;#x1f42e;}}||{{H:title|dotted=no|TIGER FACE|&amp;#x1f42f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F43x
|{{H:title|dotted=no|RABBIT FACE|&amp;#x1f430;}}||{{H:title|dotted=no|CAT FACE|&amp;#x1f431;}}||{{H:title|dotted=no|DRAGON FACE|&amp;#x1f432;}}||{{H:title|dotted=no|SPOUTING WHALE|&amp;#x1f433;}}||{{H:title|dotted=no|HORSE FACE|&amp;#x1f434;}}||{{H:title|dotted=no|MONKEY FACE|&amp;#x1f435;}}||{{H:title|dotted=no|DOG FACE|&amp;#x1f436;}}||{{H:title|dotted=no|PIG FACE|&amp;#x1f437;}}||{{H:title|dotted=no|FROG FACE|&amp;#x1f438;}}||{{H:title|dotted=no|HAMSTER FACE|&amp;#x1f439;}}||{{H:title|dotted=no|WOLF FACE|&amp;#x1f43a;}}||{{H:title|dotted=no|BEAR FACE|&amp;#x1f43b;}}||{{H:title|dotted=no|PANDA FACE|&amp;#x1f43c;}}||{{H:title|dotted=no|PIG NOSE|&amp;#x1f43d;}}||{{H:title|dotted=no|PAW PRINTS|&amp;#x1f43e;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|CHIPMUNK|&amp;#x1f43f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F44x
|{{H:title|dotted=no|EYES|&amp;#x1f440;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|EYE|&amp;#x1f441;}}||{{H:title|dotted=no|EAR|&amp;#x1f442;}}||{{H:title|dotted=no|NOSE|&amp;#x1f443;}}||{{H:title|dotted=no|MOUTH|&amp;#x1f444;}}||{{H:title|dotted=no|TONGUE|&amp;#x1f445;}}||{{H:title|dotted=no|WHITE UP POINTING BACKHAND INDEX|&amp;#x1f446;}}||{{H:title|dotted=no|WHITE DOWN POINTING BACKHAND INDEX|&amp;#x1f447;}}||{{H:title|dotted=no|WHITE LEFT POINTING BACKHAND INDEX|&amp;#x1f448;}}||{{H:title|dotted=no|WHITE RIGHT POINTING BACKHAND INDEX|&amp;#x1f449;}}||{{H:title|dotted=no|FISTED HAND SIGN|&amp;#x1f44a;}}||{{H:title|dotted=no|WAVING HAND SIGN|&amp;#x1f44b;}}||{{H:title|dotted=no|OK HAND SIGN|&amp;#x1f44c;}}||{{H:title|dotted=no|THUMBS UP SIGN|&amp;#x1f44d;}}||{{H:title|dotted=no|THUMBS DOWN SIGN|&amp;#x1f44e;}}||{{H:title|dotted=no|CLAPPING HANDS SIGN|&amp;#x1f44f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F45x
|{{H:title|dotted=no|OPEN HANDS SIGN|&amp;#x1f450;}}||{{H:title|dotted=no|CROWN|&amp;#x1f451;}}||{{H:title|dotted=no|WOMANS HAT|&amp;#x1f452;}}||{{H:title|dotted=no|EYEGLASSES|&amp;#x1f453;}}||{{H:title|dotted=no|NECKTIE|&amp;#x1f454;}}||{{H:title|dotted=no|T-SHIRT|&amp;#x1f455;}}||{{H:title|dotted=no|JEANS|&amp;#x1f456;}}||{{H:title|dotted=no|DRESS|&amp;#x1f457;}}||{{H:title|dotted=no|KIMONO|&amp;#x1f458;}}||{{H:title|dotted=no|BIKINI|&amp;#x1f459;}}||{{H:title|dotted=no|WOMANS CLOTHES|&amp;#x1f45a;}}||{{H:title|dotted=no|PURSE|&amp;#x1f45b;}}||{{H:title|dotted=no|HANDBAG|&amp;#x1f45c;}}||{{H:title|dotted=no|POUCH|&amp;#x1f45d;}}||{{H:title|dotted=no|MANS SHOE|&amp;#x1f45e;}}||{{H:title|dotted=no|ATHLETIC SHOE|&amp;#x1f45f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F46x
|{{H:title|dotted=no|HIGH-HEELED SHOE|&amp;#x1f460;}}||{{H:title|dotted=no|WOMANS SANDAL|&amp;#x1f461;}}||{{H:title|dotted=no|WOMANS BOOTS|&amp;#x1f462;}}||{{H:title|dotted=no|FOOTPRINTS|&amp;#x1f463;}}||{{H:title|dotted=no|BUST IN SILHOUETTE|&amp;#x1f464;}}||{{H:title|dotted=no|BUSTS IN SILHOUETTE|&amp;#x1f465;}}||{{H:title|dotted=no|BOY|&amp;#x1f466;}}||{{H:title|dotted=no|GIRL|&amp;#x1f467;}}||{{H:title|dotted=no|MAN|&amp;#x1f468;}}||{{H:title|dotted=no|WOMAN|&amp;#x1f469;}}||{{H:title|dotted=no|FAMILY|&amp;#x1f46a;}}||{{H:title|dotted=no|MAN AND WOMAN HOLDING HANDS|&amp;#x1f46b;}}||{{H:title|dotted=no|TWO MEN HOLDING HANDS|&amp;#x1f46c;}}||{{H:title|dotted=no|TWO WOMEN HOLDING HANDS|&amp;#x1f46d;}}||{{H:title|dotted=no|POLICE OFFICER|&amp;#x1f46e;}}||{{H:title|dotted=no|WOMAN WITH BUNNY EARS|&amp;#x1f46f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F47x
|{{H:title|dotted=no|BRIDE WITH VEIL|&amp;#x1f470;}}||{{H:title|dotted=no|PERSON WITH BLOND HAIR|&amp;#x1f471;}}||{{H:title|dotted=no|MAN WITH GUA PI MAO|&amp;#x1f472;}}||{{H:title|dotted=no|MAN WITH TURBAN|&amp;#x1f473;}}||{{H:title|dotted=no|OLDER MAN|&amp;#x1f474;}}||{{H:title|dotted=no|OLDER WOMAN|&amp;#x1f475;}}||{{H:title|dotted=no|BABY|&amp;#x1f476;}}||{{H:title|dotted=no|CONSTRUCTION WORKER|&amp;#x1f477;}}||{{H:title|dotted=no|PRINCESS|&amp;#x1f478;}}||{{H:title|dotted=no|JAPANESE OGRE|&amp;#x1f479;}}||{{H:title|dotted=no|JAPANESE GOBLIN|&amp;#x1f47a;}}||{{H:title|dotted=no|GHOST|&amp;#x1f47b;}}||{{H:title|dotted=no|BABY ANGEL|&amp;#x1f47c;}}||{{H:title|dotted=no|EXTRATERRESTRIAL ALIEN|&amp;#x1f47d;}}||{{H:title|dotted=no|ALIEN MONSTER|&amp;#x1f47e;}}||{{H:title|dotted=no|IMP|&amp;#x1f47f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F48x
|{{H:title|dotted=no|SKULL|&amp;#x1f480;}}||{{H:title|dotted=no|INFORMATION DESK PERSON|&amp;#x1f481;}}||{{H:title|dotted=no|GUARDSMAN|&amp;#x1f482;}}||{{H:title|dotted=no|DANCER|&amp;#x1f483;}}||{{H:title|dotted=no|LIPSTICK|&amp;#x1f484;}}||{{H:title|dotted=no|NAIL POLISH|&amp;#x1f485;}}||{{H:title|dotted=no|FACE MASSAGE|&amp;#x1f486;}}||{{H:title|dotted=no|HAIRCUT|&amp;#x1f487;}}||{{H:title|dotted=no|BARBER POLE|&amp;#x1f488;}}||{{H:title|dotted=no|SYRINGE|&amp;#x1f489;}}||{{H:title|dotted=no|PILL|&amp;#x1f48a;}}||{{H:title|dotted=no|KISS MARK|&amp;#x1f48b;}}||{{H:title|dotted=no|LOVE LETTER|&amp;#x1f48c;}}||{{H:title|dotted=no|RING|&amp;#x1f48d;}}||{{H:title|dotted=no|GEM STONE|&amp;#x1f48e;}}||{{H:title|dotted=no|KISS|&amp;#x1f48f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F49x
|{{H:title|dotted=no|BOUQUET|&amp;#x1f490;}}||{{H:title|dotted=no|COUPLE WITH HEART|&amp;#x1f491;}}||{{H:title|dotted=no|WEDDING|&amp;#x1f492;}}||{{H:title|dotted=no|BEATING HEART|&amp;#x1f493;}}||{{H:title|dotted=no|BROKEN HEART|&amp;#x1f494;}}||{{H:title|dotted=no|TWO HEARTS|&amp;#x1f495;}}||{{H:title|dotted=no|SPARKLING HEART|&amp;#x1f496;}}||{{H:title|dotted=no|GROWING HEART|&amp;#x1f497;}}||{{H:title|dotted=no|HEART WITH ARROW|&amp;#x1f498;}}||{{H:title|dotted=no|BLUE HEART|&amp;#x1f499;}}||{{H:title|dotted=no|GREEN HEART|&amp;#x1f49a;}}||{{H:title|dotted=no|YELLOW HEART|&amp;#x1f49b;}}||{{H:title|dotted=no|PURPLE HEART|&amp;#x1f49c;}}||{{H:title|dotted=no|HEART WITH RIBBON|&amp;#x1f49d;}}||{{H:title|dotted=no|REVOLVING HEARTS|&amp;#x1f49e;}}||{{H:title|dotted=no|HEART DECORATION|&amp;#x1f49f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F4Ax
|{{H:title|dotted=no|DIAMOND SHAPE WITH A DOT INSIDE|&amp;#x1f4a0;}}||{{H:title|dotted=no|ELECTRIC LIGHT BULB|&amp;#x1f4a1;}}||{{H:title|dotted=no|ANGER SYMBOL|&amp;#x1f4a2;}}||{{H:title|dotted=no|BOMB|&amp;#x1f4a3;}}||{{H:title|dotted=no|SLEEPING SYMBOL|&amp;#x1f4a4;}}||{{H:title|dotted=no|COLLISION SYMBOL|&amp;#x1f4a5;}}||{{H:title|dotted=no|SPLASHING SWEAT SYMBOL|&amp;#x1f4a6;}}||{{H:title|dotted=no|DROPLET|&amp;#x1f4a7;}}||{{H:title|dotted=no|DASH SYMBOL|&amp;#x1f4a8;}}||{{H:title|dotted=no|PILE OF POO|&amp;#x1f4a9;}}||{{H:title|dotted=no|FLEXED BICEPS|&amp;#x1f4aa;}}||{{H:title|dotted=no|DIZZY SYMBOL|&amp;#x1f4ab;}}||{{H:title|dotted=no|SPEECH BALLOON|&amp;#x1f4ac;}}||{{H:title|dotted=no|THOUGHT BALLOON|&amp;#x1f4ad;}}||{{H:title|dotted=no|WHITE FLOWER|&amp;#x1f4ae;}}||{{H:title|dotted=no|HUNDRED POINTS SYMBOL|&amp;#x1f4af;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F4Bx
|{{H:title|dotted=no|MONEY BAG|&amp;#x1f4b0;}}||{{H:title|dotted=no|CURRENCY EXCHANGE|&amp;#x1f4b1;}}||{{H:title|dotted=no|HEAVY DOLLAR SIGN|&amp;#x1f4b2;}}||{{H:title|dotted=no|CREDIT CARD|&amp;#x1f4b3;}}||{{H:title|dotted=no|BANKNOTE WITH YEN SIGN|&amp;#x1f4b4;}}||{{H:title|dotted=no|BANKNOTE WITH DOLLAR SIGN|&amp;#x1f4b5;}}||{{H:title|dotted=no|BANKNOTE WITH EURO SIGN|&amp;#x1f4b6;}}||{{H:title|dotted=no|BANKNOTE WITH POUND SIGN|&amp;#x1f4b7;}}||{{H:title|dotted=no|MONEY WITH WINGS|&amp;#x1f4b8;}}||{{H:title|dotted=no|CHART WITH UPWARDS TREND AND YEN SIGN|&amp;#x1f4b9;}}||{{H:title|dotted=no|SEAT|&amp;#x1f4ba;}}||{{H:title|dotted=no|PERSONAL COMPUTER|&amp;#x1f4bb;}}||{{H:title|dotted=no|BRIEFCASE|&amp;#x1f4bc;}}||{{H:title|dotted=no|MINIDISC|&amp;#x1f4bd;}}||{{H:title|dotted=no|FLOPPY DISK|&amp;#x1f4be;}}||{{H:title|dotted=no|OPTICAL DISC|&amp;#x1f4bf;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F4Cx
|{{H:title|dotted=no|DVD|&amp;#x1f4c0;}}||{{H:title|dotted=no|FILE FOLDER|&amp;#x1f4c1;}}||{{H:title|dotted=no|OPEN FILE FOLDER|&amp;#x1f4c2;}}||{{H:title|dotted=no|PAGE WITH CURL|&amp;#x1f4c3;}}||{{H:title|dotted=no|PAGE FACING UP|&amp;#x1f4c4;}}||{{H:title|dotted=no|CALENDAR|&amp;#x1f4c5;}}||{{H:title|dotted=no|TEAR-OFF CALENDAR|&amp;#x1f4c6;}}||{{H:title|dotted=no|CARD INDEX|&amp;#x1f4c7;}}||{{H:title|dotted=no|CHART WITH UPWARDS TREND|&amp;#x1f4c8;}}||{{H:title|dotted=no|CHART WITH DOWNWARDS TREND|&amp;#x1f4c9;}}||{{H:title|dotted=no|BAR CHART|&amp;#x1f4ca;}}||{{H:title|dotted=no|CLIPBOARD|&amp;#x1f4cb;}}||{{H:title|dotted=no|PUSHPIN|&amp;#x1f4cc;}}||{{H:title|dotted=no|ROUND PUSHPIN|&amp;#x1f4cd;}}||{{H:title|dotted=no|PAPERCLIP|&amp;#x1f4ce;}}||{{H:title|dotted=no|STRAIGHT RULER|&amp;#x1f4cf;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F4Dx
|{{H:title|dotted=no|TRIANGULAR RULER|&amp;#x1f4d0;}}||{{H:title|dotted=no|BOOKMARK TABS|&amp;#x1f4d1;}}||{{H:title|dotted=no|LEDGER|&amp;#x1f4d2;}}||{{H:title|dotted=no|NOTEBOOK|&amp;#x1f4d3;}}||{{H:title|dotted=no|NOTEBOOK WITH DECORATIVE COVER|&amp;#x1f4d4;}}||{{H:title|dotted=no|CLOSED BOOK|&amp;#x1f4d5;}}||{{H:title|dotted=no|OPEN BOOK|&amp;#x1f4d6;}}||{{H:title|dotted=no|GREEN BOOK|&amp;#x1f4d7;}}||{{H:title|dotted=no|BLUE BOOK|&amp;#x1f4d8;}}||{{H:title|dotted=no|ORANGE BOOK|&amp;#x1f4d9;}}||{{H:title|dotted=no|BOOKS|&amp;#x1f4da;}}||{{H:title|dotted=no|NAME BADGE|&amp;#x1f4db;}}||{{H:title|dotted=no|SCROLL|&amp;#x1f4dc;}}||{{H:title|dotted=no|MEMO|&amp;#x1f4dd;}}||{{H:title|dotted=no|TELEPHONE RECEIVER|&amp;#x1f4de;}}||{{H:title|dotted=no|PAGER|&amp;#x1f4df;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F4Ex
|{{H:title|dotted=no|FAX MACHINE|&amp;#x1f4e0;}}||{{H:title|dotted=no|SATELLITE ANTENNA|&amp;#x1f4e1;}}||{{H:title|dotted=no|PUBLIC ADDRESS LOUDSPEAKER|&amp;#x1f4e2;}}||{{H:title|dotted=no|CHEERING MEGAPHONE|&amp;#x1f4e3;}}||{{H:title|dotted=no|OUTBOX TRAY|&amp;#x1f4e4;}}||{{H:title|dotted=no|INBOX TRAY|&amp;#x1f4e5;}}||{{H:title|dotted=no|PACKAGE|&amp;#x1f4e6;}}||{{H:title|dotted=no|E-MAIL SYMBOL|&amp;#x1f4e7;}}||{{H:title|dotted=no|INCOMING ENVELOPE|&amp;#x1f4e8;}}||{{H:title|dotted=no|ENVELOPE WITH DOWNWARDS ARROW ABOVE|&amp;#x1f4e9;}}||{{H:title|dotted=no|CLOSED MAILBOX WITH LOWERED FLAG|&amp;#x1f4ea;}}||{{H:title|dotted=no|CLOSED MAILBOX WITH RAISED FLAG|&amp;#x1f4eb;}}||{{H:title|dotted=no|OPEN MAILBOX WITH RAISED FLAG|&amp;#x1f4ec;}}||{{H:title|dotted=no|OPEN MAILBOX WITH LOWERED FLAG|&amp;#x1f4ed;}}||{{H:title|dotted=no|POSTBOX|&amp;#x1f4ee;}}||{{H:title|dotted=no|POSTAL HORN|&amp;#x1f4ef;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F4Fx
|{{H:title|dotted=no|NEWSPAPER|&amp;#x1f4f0;}}||{{H:title|dotted=no|MOBILE PHONE|&amp;#x1f4f1;}}||{{H:title|dotted=no|MOBILE PHONE WITH RIGHTWARDS ARROW AT LEFT|&amp;#x1f4f2;}}||{{H:title|dotted=no|VIBRATION MODE|&amp;#x1f4f3;}}||{{H:title|dotted=no|MOBILE PHONE OFF|&amp;#x1f4f4;}}||{{H:title|dotted=no|NO MOBILE PHONES|&amp;#x1f4f5;}}||{{H:title|dotted=no|ANTENNA WITH BARS|&amp;#x1f4f6;}}||{{H:title|dotted=no|CAMERA|&amp;#x1f4f7;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|CAMERA WITH FLASH|&amp;#x1f4f8;}}||{{H:title|dotted=no|VIDEO CAMERA|&amp;#x1f4f9;}}||{{H:title|dotted=no|TELEVISION|&amp;#x1f4fa;}}||{{H:title|dotted=no|RADIO|&amp;#x1f4fb;}}||{{H:title|dotted=no|VIDEOCASSETTE|&amp;#x1f4fc;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|FILM PROJECTOR|&amp;#x1f4fd;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|PORTABLE STEREO|&amp;#x1f4fe;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|PRAYER BEADS|&amp;#x1f4ff;}}
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F50x
|{{H:title|dotted=no|TWISTED RIGHTWARDS ARROWS|&amp;#x1f500;}}||{{H:title|dotted=no|CLOCKWISE RIGHTWARDS AND LEFTWARDS OPEN CIRCLE ARROWS|&amp;#x1f501;}}||{{H:title|dotted=no|CLOCKWISE RIGHTWARDS AND LEFTWARDS OPEN CIRCLE ARROWS WITH CIRCLED ONE OVERLAY|&amp;#x1f502;}}||{{H:title|dotted=no|CLOCKWISE DOWNWARDS AND UPWARDS OPEN CIRCLE ARROWS|&amp;#x1f503;}}||{{H:title|dotted=no|ANTICLOCKWISE DOWNWARDS AND UPWARDS OPEN CIRCLE ARROWS|&amp;#x1f504;}}||{{H:title|dotted=no|LOW BRIGHTNESS SYMBOL|&amp;#x1f505;}}||{{H:title|dotted=no|HIGH BRIGHTNESS SYMBOL|&amp;#x1f506;}}||{{H:title|dotted=no|SPEAKER WITH CANCELLATION STROKE|&amp;#x1f507;}}||{{H:title|dotted=no|SPEAKER|&amp;#x1f508;}}||{{H:title|dotted=no|SPEAKER WITH ONE SOUND WAVE|&amp;#x1f509;}}||{{H:title|dotted=no|SPEAKER WITH THREE SOUND WAVES|&amp;#x1f50a;}}||{{H:title|dotted=no|BATTERY|&amp;#x1f50b;}}||{{H:title|dotted=no|ELECTRIC PLUG|&amp;#x1f50c;}}||{{H:title|dotted=no|LEFT-POINTING MAGNIFYING GLASS|&amp;#x1f50d;}}||{{H:title|dotted=no|RIGHT-POINTING MAGNIFYING GLASS|&amp;#x1f50e;}}||{{H:title|dotted=no|LOCK WITH INK PEN|&amp;#x1f50f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F51x
|{{H:title|dotted=no|CLOSED LOCK WITH KEY|&amp;#x1f510;}}||{{H:title|dotted=no|KEY|&amp;#x1f511;}}||{{H:title|dotted=no|LOCK|&amp;#x1f512;}}||{{H:title|dotted=no|OPEN LOCK|&amp;#x1f513;}}||{{H:title|dotted=no|BELL|&amp;#x1f514;}}||{{H:title|dotted=no|BELL WITH CANCELLATION STROKE|&amp;#x1f515;}}||{{H:title|dotted=no|BOOKMARK|&amp;#x1f516;}}||{{H:title|dotted=no|LINK SYMBOL|&amp;#x1f517;}}||{{H:title|dotted=no|RADIO BUTTON|&amp;#x1f518;}}||{{H:title|dotted=no|BACK WITH LEFTWARDS ARROW ABOVE|&amp;#x1f519;}}||{{H:title|dotted=no|END WITH LEFTWARDS ARROW ABOVE|&amp;#x1f51a;}}||{{H:title|dotted=no|ON WITH EXCLAMATION MARK WITH LEFT RIGHT ARROW ABOVE|&amp;#x1f51b;}}||{{H:title|dotted=no|SOON WITH RIGHTWARDS ARROW ABOVE|&amp;#x1f51c;}}||{{H:title|dotted=no|TOP WITH UPWARDS ARROW ABOVE|&amp;#x1f51d;}}||{{H:title|dotted=no|NO ONE UNDER EIGHTEEN SYMBOL|&amp;#x1f51e;}}||{{H:title|dotted=no|KEYCAP TEN|&amp;#x1f51f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F52x
|{{H:title|dotted=no|INPUT SYMBOL FOR LATIN CAPITAL LETTERS|&amp;#x1f520;}}||{{H:title|dotted=no|INPUT SYMBOL FOR LATIN SMALL LETTERS|&amp;#x1f521;}}||{{H:title|dotted=no|INPUT SYMBOL FOR NUMBERS|&amp;#x1f522;}}||{{H:title|dotted=no|INPUT SYMBOL FOR SYMBOLS|&amp;#x1f523;}}||{{H:title|dotted=no|INPUT SYMBOL FOR LATIN LETTERS|&amp;#x1f524;}}||{{H:title|dotted=no|FIRE|&amp;#x1f525;}}||{{H:title|dotted=no|ELECTRIC TORCH|&amp;#x1f526;}}||{{H:title|dotted=no|WRENCH|&amp;#x1f527;}}||{{H:title|dotted=no|HAMMER|&amp;#x1f528;}}||{{H:title|dotted=no|NUT AND BOLT|&amp;#x1f529;}}||{{H:title|dotted=no|HOCHO|&amp;#x1f52a;}}||{{H:title|dotted=no|PISTOL|&amp;#x1f52b;}}||{{H:title|dotted=no|MICROSCOPE|&amp;#x1f52c;}}||{{H:title|dotted=no|TELESCOPE|&amp;#x1f52d;}}||{{H:title|dotted=no|CRYSTAL BALL|&amp;#x1f52e;}}||{{H:title|dotted=no|SIX POINTED STAR WITH MIDDLE DOT|&amp;#x1f52f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F53x
|{{H:title|dotted=no|JAPANESE SYMBOL FOR BEGINNER|&amp;#x1f530;}}||{{H:title|dotted=no|TRIDENT EMBLEM|&amp;#x1f531;}}||{{H:title|dotted=no|BLACK SQUARE BUTTON|&amp;#x1f532;}}||{{H:title|dotted=no|WHITE SQUARE BUTTON|&amp;#x1f533;}}||{{H:title|dotted=no|LARGE RED CIRCLE|&amp;#x1f534;}}||{{H:title|dotted=no|LARGE BLUE CIRCLE|&amp;#x1f535;}}||{{H:title|dotted=no|LARGE ORANGE DIAMOND|&amp;#x1f536;}}||{{H:title|dotted=no|LARGE BLUE DIAMOND|&amp;#x1f537;}}||{{H:title|dotted=no|SMALL ORANGE DIAMOND|&amp;#x1f538;}}||{{H:title|dotted=no|SMALL BLUE DIAMOND|&amp;#x1f539;}}||{{H:title|dotted=no|UP-POINTING RED TRIANGLE|&amp;#x1f53a;}}||{{H:title|dotted=no|DOWN-POINTING RED TRIANGLE|&amp;#x1f53b;}}||{{H:title|dotted=no|UP-POINTING SMALL RED TRIANGLE|&amp;#x1f53c;}}||{{H:title|dotted=no|DOWN-POINTING SMALL RED TRIANGLE|&amp;#x1f53d;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|LOWER RIGHT SHADOWED WHITE CIRCLE|&amp;#x1f53e;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|UPPER RIGHT SHADOWED WHITE CIRCLE|&amp;#x1f53f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F54x
|style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|CIRCLED CROSS POMMEE|&amp;#x1f540;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|CROSS POMMEE WITH HALF-CIRCLE BELOW|&amp;#x1f541;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|CROSS POMMEE|&amp;#x1f542;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|NOTCHED LEFT SEMICIRCLE WITH THREE DOTS|&amp;#x1f543;}}||{{H:title|dotted=no|NOTCHED RIGHT SEMICIRCLE WITH THREE DOTS|&amp;#x1f544;}}||{{H:title|dotted=no|SYMBOL FOR MARKS CHAPTER|&amp;#x1f545;}}||{{H:title|dotted=no|WHITE LATIN CROSS|&amp;#x1f546;}}||{{H:title|dotted=no|HEAVY LATIN CROSS|&amp;#x1f547;}}||{{H:title|dotted=no|CELTIC CROSS|&amp;#x1f548;}}||{{H:title|dotted=no|OM SYMBOL|&amp;#x1f549;}}||{{H:title|dotted=no|DOVE OF PEACE|&amp;#x1f54a;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|KAABA|&amp;#x1f54b;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|MOSQUE|&amp;#x1f54c;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|SYNAGOGUE|&amp;#x1f54d;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|MENORAH WITH NINE BRANCHES|&amp;#x1f54e;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|BOWL OF HYGIEIA|&amp;#x1f54f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F55x
|{{H:title|dotted=no|CLOCK FACE ONE OCLOCK|&amp;#x1f550;}}||{{H:title|dotted=no|CLOCK FACE TWO OCLOCK|&amp;#x1f551;}}||{{H:title|dotted=no|CLOCK FACE THREE OCLOCK|&amp;#x1f552;}}||{{H:title|dotted=no|CLOCK FACE FOUR OCLOCK|&amp;#x1f553;}}||{{H:title|dotted=no|CLOCK FACE FIVE OCLOCK|&amp;#x1f554;}}||{{H:title|dotted=no|CLOCK FACE SIX OCLOCK|&amp;#x1f555;}}||{{H:title|dotted=no|CLOCK FACE SEVEN OCLOCK|&amp;#x1f556;}}||{{H:title|dotted=no|CLOCK FACE EIGHT OCLOCK|&amp;#x1f557;}}||{{H:title|dotted=no|CLOCK FACE NINE OCLOCK|&amp;#x1f558;}}||{{H:title|dotted=no|CLOCK FACE TEN OCLOCK|&amp;#x1f559;}}||{{H:title|dotted=no|CLOCK FACE ELEVEN OCLOCK|&amp;#x1f55a;}}||{{H:title|dotted=no|CLOCK FACE TWELVE OCLOCK|&amp;#x1f55b;}}||{{H:title|dotted=no|CLOCK FACE ONE-THIRTY|&amp;#x1f55c;}}||{{H:title|dotted=no|CLOCK FACE TWO-THIRTY|&amp;#x1f55d;}}||{{H:title|dotted=no|CLOCK FACE THREE-THIRTY|&amp;#x1f55e;}}||{{H:title|dotted=no|CLOCK FACE FOUR-THIRTY|&amp;#x1f55f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F56x
|{{H:title|dotted=no|CLOCK FACE FIVE-THIRTY|&amp;#x1f560;}}||{{H:title|dotted=no|CLOCK FACE SIX-THIRTY|&amp;#x1f561;}}||{{H:title|dotted=no|CLOCK FACE SEVEN-THIRTY|&amp;#x1f562;}}||{{H:title|dotted=no|CLOCK FACE EIGHT-THIRTY|&amp;#x1f563;}}||{{H:title|dotted=no|CLOCK FACE NINE-THIRTY|&amp;#x1f564;}}||{{H:title|dotted=no|CLOCK FACE TEN-THIRTY|&amp;#x1f565;}}||{{H:title|dotted=no|CLOCK FACE ELEVEN-THIRTY|&amp;#x1f566;}}||{{H:title|dotted=no|CLOCK FACE TWELVE-THIRTY|&amp;#x1f567;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|RIGHT SPEAKER|&amp;#x1f568;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|RIGHT SPEAKER WITH ONE SOUND WAVE|&amp;#x1f569;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|RIGHT SPEAKER WITH THREE SOUND WAVES|&amp;#x1f56a;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|BULLHORN|&amp;#x1f56b;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|BULLHORN WITH SOUND WAVES|&amp;#x1f56c;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|RINGING BELL|&amp;#x1f56d;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|BOOK|&amp;#x1f56e;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|CANDLE|&amp;#x1f56f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F57x
|{{H:title|dotted=no|MANTELPIECE CLOCK|&amp;#x1f570;}}||{{H:title|dotted=no|BLACK SKULL AND CROSSBONES|&amp;#x1f571;}}||{{H:title|dotted=no|NO PIRACY|&amp;#x1f572;}}||{{H:title|dotted=no|HOLE|&amp;#x1f573;}}||{{H:title|dotted=no|MAN IN BUSINESS SUIT LEVITATING|&amp;#x1f574;}}||{{H:title|dotted=no|SLEUTH OR SPY|&amp;#x1f575;}}||{{H:title|dotted=no|DARK SUNGLASSES|&amp;#x1f576;}}||{{H:title|dotted=no|SPIDER|&amp;#x1f577;}}||{{H:title|dotted=no|SPIDER WEB|&amp;#x1f578;}}||{{H:title|dotted=no|JOYSTICK|&amp;#x1f579;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|MAN DANCING|&amp;#x1f57a;}}||{{H:title|dotted=no|LEFT HAND TELEPHONE RECEIVER|&amp;#x1f57b;}}||{{H:title|dotted=no|TELEPHONE RECEIVER WITH PAGE|&amp;#x1f57c;}}||{{H:title|dotted=no|RIGHT HAND TELEPHONE RECEIVER|&amp;#x1f57d;}}||{{H:title|dotted=no|WHITE TOUCHTONE TELEPHONE|&amp;#x1f57e;}}||{{H:title|dotted=no|BLACK TOUCHTONE TELEPHONE|&amp;#x1f57f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F58x
|{{H:title|dotted=no|TELEPHONE ON TOP OF MODEM|&amp;#x1f580;}}||{{H:title|dotted=no|CLAMSHELL MOBILE PHONE|&amp;#x1f581;}}||{{H:title|dotted=no|BACK OF ENVELOPE|&amp;#x1f582;}}||{{H:title|dotted=no|STAMPED ENVELOPE|&amp;#x1f583;}}||{{H:title|dotted=no|ENVELOPE WITH LIGHTNING|&amp;#x1f584;}}||{{H:title|dotted=no|FLYING ENVELOPE|&amp;#x1f585;}}||{{H:title|dotted=no|PEN OVER STAMPED ENVELOPE|&amp;#x1f586;}}||{{H:title|dotted=no|LINKED PAPERCLIPS|&amp;#x1f587;}}||{{H:title|dotted=no|BLACK PUSHPIN|&amp;#x1f588;}}||{{H:title|dotted=no|LOWER LEFT PENCIL|&amp;#x1f589;}}||{{H:title|dotted=no|LOWER LEFT BALLPOINT PEN|&amp;#x1f58a;}}||{{H:title|dotted=no|LOWER LEFT FOUNTAIN PEN|&amp;#x1f58b;}}||{{H:title|dotted=no|LOWER LEFT PAINTBRUSH|&amp;#x1f58c;}}||{{H:title|dotted=no|LOWER LEFT CRAYON|&amp;#x1f58d;}}||{{H:title|dotted=no|LEFT WRITING HAND|&amp;#x1f58e;}}||{{H:title|dotted=no|TURNED OK HAND SIGN|&amp;#x1f58f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F59x
|{{H:title|dotted=no|RAISED HAND WITH FINGERS SPLAYED|&amp;#x1f590;}}||{{H:title|dotted=no|REVERSED RAISED HAND WITH FINGERS SPLAYED|&amp;#x1f591;}}||{{H:title|dotted=no|REVERSED THUMBS UP SIGN|&amp;#x1f592;}}||{{H:title|dotted=no|REVERSED THUMBS DOWN SIGN|&amp;#x1f593;}}||{{H:title|dotted=no|REVERSED VICTORY HAND|&amp;#x1f594;}}||{{H:title|dotted=no|REVERSED HAND WITH MIDDLE FINGER EXTENDED|&amp;#x1f595;}}||{{H:title|dotted=no|RAISED HAND WITH PART BETWEEN MIDDLE AND RING FINGERS|&amp;#x1f596;}}||{{H:title|dotted=no|WHITE DOWN POINTING LEFT HAND INDEX|&amp;#x1f597;}}||{{H:title|dotted=no|SIDEWAYS WHITE LEFT POINTING INDEX|&amp;#x1f598;}}||{{H:title|dotted=no|SIDEWAYS WHITE RIGHT POINTING INDEX|&amp;#x1f599;}}||{{H:title|dotted=no|SIDEWAYS BLACK LEFT POINTING INDEX|&amp;#x1f59a;}}||{{H:title|dotted=no|SIDEWAYS BLACK RIGHT POINTING INDEX|&amp;#x1f59b;}}||{{H:title|dotted=no|BLACK LEFT POINTING BACKHAND INDEX|&amp;#x1f59c;}}||{{H:title|dotted=no|BLACK RIGHT POINTING BACKHAND INDEX|&amp;#x1f59d;}}||{{H:title|dotted=no|SIDEWAYS WHITE UP POINTING INDEX|&amp;#x1f59e;}}||{{H:title|dotted=no|SIDEWAYS WHITE DOWN POINTING INDEX|&amp;#x1f59f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F5Ax
|{{H:title|dotted=no|SIDEWAYS BLACK UP POINTING INDEX|&amp;#x1f5a0;}}||{{H:title|dotted=no|SIDEWAYS BLACK DOWN POINTING INDEX|&amp;#x1f5a1;}}||{{H:title|dotted=no|BLACK UP POINTING BACKHAND INDEX|&amp;#x1f5a2;}}||{{H:title|dotted=no|BLACK DOWN POINTING BACKHAND INDEX|&amp;#x1f5a3;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|BLACK HEART|&amp;#x1f5a4;}}||{{H:title|dotted=no|DESKTOP COMPUTER|&amp;#x1f5a5;}}||{{H:title|dotted=no|KEYBOARD AND MOUSE|&amp;#x1f5a6;}}||{{H:title|dotted=no|THREE NETWORKED COMPUTERS|&amp;#x1f5a7;}}||{{H:title|dotted=no|PRINTER|&amp;#x1f5a8;}}||{{H:title|dotted=no|POCKET CALCULATOR|&amp;#x1f5a9;}}||{{H:title|dotted=no|BLACK HARD SHELL FLOPPY DISK|&amp;#x1f5aa;}}||{{H:title|dotted=no|WHITE HARD SHELL FLOPPY DISK|&amp;#x1f5ab;}}||{{H:title|dotted=no|SOFT SHELL FLOPPY DISK|&amp;#x1f5ac;}}||{{H:title|dotted=no|TAPE CARTRIDGE|&amp;#x1f5ad;}}||{{H:title|dotted=no|WIRED KEYBOARD|&amp;#x1f5ae;}}||{{H:title|dotted=no|ONE BUTTON MOUSE|&amp;#x1f5af;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F5Bx
|{{H:title|dotted=no|TWO BUTTON MOUSE|&amp;#x1f5b0;}}||{{H:title|dotted=no|THREE BUTTON MOUSE|&amp;#x1f5b1;}}||{{H:title|dotted=no|TRACKBALL|&amp;#x1f5b2;}}||{{H:title|dotted=no|OLD PERSONAL COMPUTER|&amp;#x1f5b3;}}||{{H:title|dotted=no|HARD DISK|&amp;#x1f5b4;}}||{{H:title|dotted=no|SCREEN|&amp;#x1f5b5;}}||{{H:title|dotted=no|PRINTER ICON|&amp;#x1f5b6;}}||{{H:title|dotted=no|FAX ICON|&amp;#x1f5b7;}}||{{H:title|dotted=no|OPTICAL DISC ICON|&amp;#x1f5b8;}}||{{H:title|dotted=no|DOCUMENT WITH TEXT|&amp;#x1f5b9;}}||{{H:title|dotted=no|DOCUMENT WITH TEXT AND PICTURE|&amp;#x1f5ba;}}||{{H:title|dotted=no|DOCUMENT WITH PICTURE|&amp;#x1f5bb;}}||{{H:title|dotted=no|FRAME WITH PICTURE|&amp;#x1f5bc;}}||{{H:title|dotted=no|FRAME WITH TILES|&amp;#x1f5bd;}}||{{H:title|dotted=no|FRAME WITH AN X|&amp;#x1f5be;}}||{{H:title|dotted=no|BLACK FOLDER|&amp;#x1f5bf;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F5Cx
|{{H:title|dotted=no|FOLDER|&amp;#x1f5c0;}}||{{H:title|dotted=no|OPEN FOLDER|&amp;#x1f5c1;}}||{{H:title|dotted=no|CARD INDEX DIVIDERS|&amp;#x1f5c2;}}||{{H:title|dotted=no|CARD FILE BOX|&amp;#x1f5c3;}}||{{H:title|dotted=no|FILE CABINET|&amp;#x1f5c4;}}||{{H:title|dotted=no|EMPTY NOTE|&amp;#x1f5c5;}}||{{H:title|dotted=no|EMPTY NOTE PAGE|&amp;#x1f5c6;}}||{{H:title|dotted=no|EMPTY NOTE PAD|&amp;#x1f5c7;}}||{{H:title|dotted=no|NOTE|&amp;#x1f5c8;}}||{{H:title|dotted=no|NOTE PAGE|&amp;#x1f5c9;}}||{{H:title|dotted=no|NOTE PAD|&amp;#x1f5ca;}}||{{H:title|dotted=no|EMPTY DOCUMENT|&amp;#x1f5cb;}}||{{H:title|dotted=no|EMPTY PAGE|&amp;#x1f5cc;}}||{{H:title|dotted=no|EMPTY PAGES|&amp;#x1f5cd;}}||{{H:title|dotted=no|DOCUMENT|&amp;#x1f5ce;}}||{{H:title|dotted=no|PAGE|&amp;#x1f5cf;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F5Dx
|{{H:title|dotted=no|PAGES|&amp;#x1f5d0;}}||{{H:title|dotted=no|WASTEBASKET|&amp;#x1f5d1;}}||{{H:title|dotted=no|SPIRAL NOTE PAD|&amp;#x1f5d2;}}||{{H:title|dotted=no|SPIRAL CALENDAR PAD|&amp;#x1f5d3;}}||{{H:title|dotted=no|DESKTOP WINDOW|&amp;#x1f5d4;}}||{{H:title|dotted=no|MINIMIZE|&amp;#x1f5d5;}}||{{H:title|dotted=no|MAXIMIZE|&amp;#x1f5d6;}}||{{H:title|dotted=no|OVERLAP|&amp;#x1f5d7;}}||{{H:title|dotted=no|CLOCKWISE RIGHT AND LEFT SEMICIRCLE ARROWS|&amp;#x1f5d8;}}||{{H:title|dotted=no|CANCELLATION X|&amp;#x1f5d9;}}||{{H:title|dotted=no|INCREASE FONT SIZE SYMBOL|&amp;#x1f5da;}}||{{H:title|dotted=no|DECREASE FONT SIZE SYMBOL|&amp;#x1f5db;}}||{{H:title|dotted=no|COMPRESSION|&amp;#x1f5dc;}}||{{H:title|dotted=no|OLD KEY|&amp;#x1f5dd;}}||{{H:title|dotted=no|ROLLED-UP NEWSPAPER|&amp;#x1f5de;}}||{{H:title|dotted=no|PAGE WITH CIRCLED TEXT|&amp;#x1f5df;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F5Ex
|{{H:title|dotted=no|STOCK CHART|&amp;#x1f5e0;}}||{{H:title|dotted=no|DAGGER KNIFE|&amp;#x1f5e1;}}||{{H:title|dotted=no|LIPS|&amp;#x1f5e2;}}||{{H:title|dotted=no|SPEAKING HEAD IN SILHOUETTE|&amp;#x1f5e3;}}||{{H:title|dotted=no|THREE RAYS ABOVE|&amp;#x1f5e4;}}||{{H:title|dotted=no|THREE RAYS BELOW|&amp;#x1f5e5;}}||{{H:title|dotted=no|THREE RAYS LEFT|&amp;#x1f5e6;}}||{{H:title|dotted=no|THREE RAYS RIGHT|&amp;#x1f5e7;}}||{{H:title|dotted=no|LEFT SPEECH BUBBLE|&amp;#x1f5e8;}}||{{H:title|dotted=no|RIGHT SPEECH BUBBLE|&amp;#x1f5e9;}}||{{H:title|dotted=no|TWO SPEECH BUBBLES|&amp;#x1f5ea;}}||{{H:title|dotted=no|THREE SPEECH BUBBLES|&amp;#x1f5eb;}}||{{H:title|dotted=no|LEFT THOUGHT BUBBLE|&amp;#x1f5ec;}}||{{H:title|dotted=no|RIGHT THOUGHT BUBBLE|&amp;#x1f5ed;}}||{{H:title|dotted=no|LEFT ANGER BUBBLE|&amp;#x1f5ee;}}||{{H:title|dotted=no|RIGHT ANGER BUBBLE|&amp;#x1f5ef;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F5Fx
|{{H:title|dotted=no|MOOD BUBBLE|&amp;#x1f5f0;}}||{{H:title|dotted=no|LIGHTNING MOOD BUBBLE|&amp;#x1f5f1;}}||{{H:title|dotted=no|LIGHTNING MOOD|&amp;#x1f5f2;}}||{{H:title|dotted=no|BALLOT BOX WITH BALLOT|&amp;#x1f5f3;}}||{{H:title|dotted=no|BALLOT SCRIPT X|&amp;#x1f5f4;}}||{{H:title|dotted=no|BALLOT BOX WITH SCRIPT X|&amp;#x1f5f5;}}||{{H:title|dotted=no|BALLOT BOLD SCRIPT X|&amp;#x1f5f6;}}||{{H:title|dotted=no|BALLOT BOX WITH BOLD SCRIPT X|&amp;#x1f5f7;}}||{{H:title|dotted=no|LIGHT CHECK MARK|&amp;#x1f5f8;}}||{{H:title|dotted=no|BALLOT BOX WITH BOLD CHECK|&amp;#x1f5f9;}}||{{H:title|dotted=no|WORLD MAP|&amp;#x1f5fa;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|MOUNT FUJI|&amp;#x1f5fb;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|TOKYO TOWER|&amp;#x1f5fc;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|STATUE OF LIBERTY|&amp;#x1f5fd;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|SILHOUETTE OF JAPAN|&amp;#x1f5fe;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|MOYAI|&amp;#x1f5ff;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Emoticons'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F60x
|style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|GRINNING FACE|&amp;#x1f600;}}||{{H:title|dotted=no|GRINNING FACE WITH SMILING EYES|&amp;#x1f601;}}||{{H:title|dotted=no|FACE WITH TEARS OF JOY|&amp;#x1f602;}}||{{H:title|dotted=no|SMILING FACE WITH OPEN MOUTH|&amp;#x1f603;}}||{{H:title|dotted=no|SMILING FACE WITH OPEN MOUTH AND SMILING EYES|&amp;#x1f604;}}||{{H:title|dotted=no|SMILING FACE WITH OPEN MOUTH AND COLD SWEAT|&amp;#x1f605;}}||{{H:title|dotted=no|SMILING FACE WITH OPEN MOUTH AND TIGHTLY-CLOSED EYES|&amp;#x1f606;}}||{{H:title|dotted=no|SMILING FACE WITH HALO|&amp;#x1f607;}}||{{H:title|dotted=no|SMILING FACE WITH HORNS|&amp;#x1f608;}}||{{H:title|dotted=no|WINKING FACE|&amp;#x1f609;}}||{{H:title|dotted=no|SMILING FACE WITH SMILING EYES|&amp;#x1f60a;}}||{{H:title|dotted=no|FACE SAVOURING DELICIOUS FOOD|&amp;#x1f60b;}}||{{H:title|dotted=no|RELIEVED FACE|&amp;#x1f60c;}}||{{H:title|dotted=no|SMILING FACE WITH HEART-SHAPED EYES|&amp;#x1f60d;}}||{{H:title|dotted=no|SMILING FACE WITH SUNGLASSES|&amp;#x1f60e;}}||{{H:title|dotted=no|SMIRKING FACE|&amp;#x1f60f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F61x
|{{H:title|dotted=no|NEUTRAL FACE|&amp;#x1f610;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|EXPRESSIONLESS FACE|&amp;#x1f611;}}||{{H:title|dotted=no|UNAMUSED FACE|&amp;#x1f612;}}||{{H:title|dotted=no|FACE WITH COLD SWEAT|&amp;#x1f613;}}||{{H:title|dotted=no|PENSIVE FACE|&amp;#x1f614;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|CONFUSED FACE|&amp;#x1f615;}}||{{H:title|dotted=no|CONFOUNDED FACE|&amp;#x1f616;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|KISSING FACE|&amp;#x1f617;}}||{{H:title|dotted=no|FACE THROWING A KISS|&amp;#x1f618;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|KISSING FACE WITH SMILING EYES|&amp;#x1f619;}}||{{H:title|dotted=no|KISSING FACE WITH CLOSED EYES|&amp;#x1f61a;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|FACE WITH STUCK-OUT TONGUE|&amp;#x1f61b;}}||{{H:title|dotted=no|FACE WITH STUCK-OUT TONGUE AND WINKING EYE|&amp;#x1f61c;}}||{{H:title|dotted=no|FACE WITH STUCK-OUT TONGUE AND TIGHTLY-CLOSED EYES|&amp;#x1f61d;}}||{{H:title|dotted=no|DISAPPOINTED FACE|&amp;#x1f61e;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|WORRIED FACE|&amp;#x1f61f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F62x
|{{H:title|dotted=no|ANGRY FACE|&amp;#x1f620;}}||{{H:title|dotted=no|POUTING FACE|&amp;#x1f621;}}||{{H:title|dotted=no|CRYING FACE|&amp;#x1f622;}}||{{H:title|dotted=no|PERSEVERING FACE|&amp;#x1f623;}}||{{H:title|dotted=no|FACE WITH LOOK OF TRIUMPH|&amp;#x1f624;}}||{{H:title|dotted=no|DISAPPOINTED BUT RELIEVED FACE|&amp;#x1f625;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|FROWNING FACE WITH OPEN MOUTH|&amp;#x1f626;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|ANGUISHED FACE|&amp;#x1f627;}}||{{H:title|dotted=no|FEARFUL FACE|&amp;#x1f628;}}||{{H:title|dotted=no|WEARY FACE|&amp;#x1f629;}}||{{H:title|dotted=no|SLEEPY FACE|&amp;#x1f62a;}}||{{H:title|dotted=no|TIRED FACE|&amp;#x1f62b;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|GRIMACING FACE|&amp;#x1f62c;}}||{{H:title|dotted=no|LOUDLY CRYING FACE|&amp;#x1f62d;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|FACE WITH OPEN MOUTH|&amp;#x1f62e;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|HUSHED FACE|&amp;#x1f62f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F63x
|{{H:title|dotted=no|FACE WITH OPEN MOUTH AND COLD SWEAT|&amp;#x1f630;}}||{{H:title|dotted=no|FACE SCREAMING IN FEAR|&amp;#x1f631;}}||{{H:title|dotted=no|ASTONISHED FACE|&amp;#x1f632;}}||{{H:title|dotted=no|FLUSHED FACE|&amp;#x1f633;}}||style=&quot;background:#7ef9ff&quot;|{{H:title|dotted=no|SLEEPING FACE|&amp;#x1f634;}}||{{H:title|dotted=no|DIZZY FACE|&amp;#x1f635;}}||{{H:title|dotted=no|FACE WITHOUT MOUTH|&amp;#x1f636;}}||{{H:title|dotted=no|FACE WITH MEDICAL MASK|&amp;#x1f637;}}||{{H:title|dotted=no|GRINNING CAT FACE WITH SMILING EYES|&amp;#x1f638;}}||{{H:title|dotted=no|CAT FACE WITH TEARS OF JOY|&amp;#x1f639;}}||{{H:title|dotted=no|SMILING CAT FACE WITH OPEN MOUTH|&amp;#x1f63a;}}||{{H:title|dotted=no|SMILING CAT FACE WITH HEART-SHAPED EYES|&amp;#x1f63b;}}||{{H:title|dotted=no|CAT FACE WITH WRY SMILE|&amp;#x1f63c;}}||{{H:title|dotted=no|KISSING CAT FACE WITH CLOSED EYES|&amp;#x1f63d;}}||{{H:title|dotted=no|POUTING CAT FACE|&amp;#x1f63e;}}||{{H:title|dotted=no|CRYING CAT FACE|&amp;#x1f63f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F64x
|{{H:title|dotted=no|WEARY CAT FACE|&amp;#x1f640;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|SLIGHTLY FROWNING FACE|&amp;#x1f641;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|SLIGHTLY SMILING FACE|&amp;#x1f642;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|UPSIDE-DOWN FACE|&amp;#x1f643;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|FACE WITH ROLLING EYES|&amp;#x1f644;}}||{{H:title|dotted=no|FACE WITH NO GOOD GESTURE|&amp;#x1f645;}}||{{H:title|dotted=no|FACE WITH OK GESTURE|&amp;#x1f646;}}||{{H:title|dotted=no|PERSON BOWING DEEPLY|&amp;#x1f647;}}||{{H:title|dotted=no|SEE-NO-EVIL MONKEY|&amp;#x1f648;}}||{{H:title|dotted=no|HEAR-NO-EVIL MONKEY|&amp;#x1f649;}}||{{H:title|dotted=no|SPEAK-NO-EVIL MONKEY|&amp;#x1f64a;}}||{{H:title|dotted=no|HAPPY PERSON RAISING ONE HAND|&amp;#x1f64b;}}||{{H:title|dotted=no|PERSON RAISING BOTH HANDS IN CELEBRATION|&amp;#x1f64c;}}||{{H:title|dotted=no|PERSON FROWNING|&amp;#x1f64d;}}||{{H:title|dotted=no|PERSON WITH POUTING FACE|&amp;#x1f64e;}}||{{H:title|dotted=no|PERSON WITH FOLDED HANDS|&amp;#x1f64f;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Ornamental Dingbats'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F65x
|{{H:title|dotted=no|NORTH WEST POINTING LEAF|&amp;#x1f650;}}||{{H:title|dotted=no|SOUTH WEST POINTING LEAF|&amp;#x1f651;}}||{{H:title|dotted=no|NORTH EAST POINTING LEAF|&amp;#x1f652;}}||{{H:title|dotted=no|SOUTH EAST POINTING LEAF|&amp;#x1f653;}}||{{H:title|dotted=no|TURNED NORTH WEST POINTING LEAF|&amp;#x1f654;}}||{{H:title|dotted=no|TURNED SOUTH WEST POINTING LEAF|&amp;#x1f655;}}||{{H:title|dotted=no|TURNED NORTH EAST POINTING LEAF|&amp;#x1f656;}}||{{H:title|dotted=no|TURNED SOUTH EAST POINTING LEAF|&amp;#x1f657;}}||{{H:title|dotted=no|NORTH WEST POINTING VINE LEAF|&amp;#x1f658;}}||{{H:title|dotted=no|SOUTH WEST POINTING VINE LEAF|&amp;#x1f659;}}||{{H:title|dotted=no|NORTH EAST POINTING VINE LEAF|&amp;#x1f65a;}}||{{H:title|dotted=no|SOUTH EAST POINTING VINE LEAF|&amp;#x1f65b;}}||{{H:title|dotted=no|HEAVY NORTH WEST POINTING VINE LEAF|&amp;#x1f65c;}}||{{H:title|dotted=no|HEAVY SOUTH WEST POINTING VINE LEAF|&amp;#x1f65d;}}||{{H:title|dotted=no|HEAVY NORTH EAST POINTING VINE LEAF|&amp;#x1f65e;}}||{{H:title|dotted=no|HEAVY SOUTH EAST POINTING VINE LEAF|&amp;#x1f65f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F66x
|{{H:title|dotted=no|NORTH WEST POINTING BUD|&amp;#x1f660;}}||{{H:title|dotted=no|SOUTH WEST POINTING BUD|&amp;#x1f661;}}||{{H:title|dotted=no|NORTH EAST POINTING BUD|&amp;#x1f662;}}||{{H:title|dotted=no|SOUTH EAST POINTING BUD|&amp;#x1f663;}}||{{H:title|dotted=no|HEAVY NORTH WEST POINTING BUD|&amp;#x1f664;}}||{{H:title|dotted=no|HEAVY SOUTH WEST POINTING BUD|&amp;#x1f665;}}||{{H:title|dotted=no|HEAVY NORTH EAST POINTING BUD|&amp;#x1f666;}}||{{H:title|dotted=no|HEAVY SOUTH EAST POINTING BUD|&amp;#x1f667;}}||{{H:title|dotted=no|HOLLOW QUILT SQUARE ORNAMENT|&amp;#x1f668;}}||{{H:title|dotted=no|HOLLOW QUILT SQUARE ORNAMENT IN BLACK SQUARE|&amp;#x1f669;}}||{{H:title|dotted=no|SOLID QUILT SQUARE ORNAMENT|&amp;#x1f66a;}}||{{H:title|dotted=no|SOLID QUILT SQUARE ORNAMENT IN BLACK SQUARE|&amp;#x1f66b;}}||{{H:title|dotted=no|LEFTWARDS ROCKET|&amp;#x1f66c;}}||{{H:title|dotted=no|UPWARDS ROCKET|&amp;#x1f66d;}}||{{H:title|dotted=no|RIGHTWARDS ROCKET|&amp;#x1f66e;}}||{{H:title|dotted=no|DOWNWARDS ROCKET|&amp;#x1f66f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F67x
|{{H:title|dotted=no|SCRIPT LIGATURE ET ORNAMENT|&amp;#x1f670;}}||{{H:title|dotted=no|HEAVY SCRIPT LIGATURE ET ORNAMENT|&amp;#x1f671;}}||{{H:title|dotted=no|LIGATURE OPEN ET ORNAMENT|&amp;#x1f672;}}||{{H:title|dotted=no|HEAVY LIGATURE OPEN ET ORNAMENT|&amp;#x1f673;}}||{{H:title|dotted=no|HEAVY AMPERSAND ORNAMENT|&amp;#x1f674;}}||{{H:title|dotted=no|SWASH AMPERSAND ORNAMENT|&amp;#x1f675;}}||{{H:title|dotted=no|SANS-SERIF HEAVY DOUBLE TURNED COMMA QUOTATION MARK ORNAMENT|&amp;#x1f676;}}||{{H:title|dotted=no|SANS-SERIF HEAVY DOUBLE COMMA QUOTATION MARK ORNAMENT|&amp;#x1f677;}}||{{H:title|dotted=no|SANS-SERIF HEAVY LOW DOUBLE COMMA QUOTATION MARK ORNAMENT|&amp;#x1f678;}}||{{H:title|dotted=no|HEAVY INTERROBANG ORNAMENT|&amp;#x1f679;}}||{{H:title|dotted=no|SANS-SERIF INTERROBANG ORNAMENT|&amp;#x1f67a;}}||{{H:title|dotted=no|HEAVY SANS-SERIF INTERROBANG ORNAMENT|&amp;#x1f67b;}}||{{H:title|dotted=no|VERY HEAVY SOLIDUS|&amp;#x1f67c;}}||{{H:title|dotted=no|VERY HEAVY REVERSE SOLIDUS|&amp;#x1f67d;}}||{{H:title|dotted=no|CHECKER BOARD|&amp;#x1f67e;}}||{{H:title|dotted=no|REVERSE CHECKER BOARD|&amp;#x1f67f;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Transport and Map Symbols'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F68x
|{{H:title|dotted=no|ROCKET|&amp;#x1f680;}}||{{H:title|dotted=no|HELICOPTER|&amp;#x1f681;}}||{{H:title|dotted=no|STEAM LOCOMOTIVE|&amp;#x1f682;}}||{{H:title|dotted=no|RAILWAY CAR|&amp;#x1f683;}}||{{H:title|dotted=no|HIGH-SPEED TRAIN|&amp;#x1f684;}}||{{H:title|dotted=no|HIGH-SPEED TRAIN WITH BULLET NOSE|&amp;#x1f685;}}||{{H:title|dotted=no|TRAIN|&amp;#x1f686;}}||{{H:title|dotted=no|METRO|&amp;#x1f687;}}||{{H:title|dotted=no|LIGHT RAIL|&amp;#x1f688;}}||{{H:title|dotted=no|STATION|&amp;#x1f689;}}||{{H:title|dotted=no|TRAM|&amp;#x1f68a;}}||{{H:title|dotted=no|TRAM CAR|&amp;#x1f68b;}}||{{H:title|dotted=no|BUS|&amp;#x1f68c;}}||{{H:title|dotted=no|ONCOMING BUS|&amp;#x1f68d;}}||{{H:title|dotted=no|TROLLEYBUS|&amp;#x1f68e;}}||{{H:title|dotted=no|BUS STOP|&amp;#x1f68f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F69x
|{{H:title|dotted=no|MINIBUS|&amp;#x1f690;}}||{{H:title|dotted=no|AMBULANCE|&amp;#x1f691;}}||{{H:title|dotted=no|FIRE ENGINE|&amp;#x1f692;}}||{{H:title|dotted=no|POLICE CAR|&amp;#x1f693;}}||{{H:title|dotted=no|ONCOMING POLICE CAR|&amp;#x1f694;}}||{{H:title|dotted=no|TAXI|&amp;#x1f695;}}||{{H:title|dotted=no|ONCOMING TAXI|&amp;#x1f696;}}||{{H:title|dotted=no|AUTOMOBILE|&amp;#x1f697;}}||{{H:title|dotted=no|ONCOMING AUTOMOBILE|&amp;#x1f698;}}||{{H:title|dotted=no|RECREATIONAL VEHICLE|&amp;#x1f699;}}||{{H:title|dotted=no|DELIVERY TRUCK|&amp;#x1f69a;}}||{{H:title|dotted=no|ARTICULATED LORRY|&amp;#x1f69b;}}||{{H:title|dotted=no|TRACTOR|&amp;#x1f69c;}}||{{H:title|dotted=no|MONORAIL|&amp;#x1f69d;}}||{{H:title|dotted=no|MOUNTAIN RAILWAY|&amp;#x1f69e;}}||{{H:title|dotted=no|SUSPENSION RAILWAY|&amp;#x1f69f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F6Ax
|{{H:title|dotted=no|MOUNTAIN CABLEWAY|&amp;#x1f6a0;}}||{{H:title|dotted=no|AERIAL TRAMWAY|&amp;#x1f6a1;}}||{{H:title|dotted=no|SHIP|&amp;#x1f6a2;}}||{{H:title|dotted=no|ROWBOAT|&amp;#x1f6a3;}}||{{H:title|dotted=no|SPEEDBOAT|&amp;#x1f6a4;}}||{{H:title|dotted=no|HORIZONTAL TRAFFIC LIGHT|&amp;#x1f6a5;}}||{{H:title|dotted=no|VERTICAL TRAFFIC LIGHT|&amp;#x1f6a6;}}||{{H:title|dotted=no|CONSTRUCTION SIGN|&amp;#x1f6a7;}}||{{H:title|dotted=no|POLICE CARS REVOLVING LIGHT|&amp;#x1f6a8;}}||{{H:title|dotted=no|TRIANGULAR FLAG ON POST|&amp;#x1f6a9;}}||{{H:title|dotted=no|DOOR|&amp;#x1f6aa;}}||{{H:title|dotted=no|NO ENTRY SIGN|&amp;#x1f6ab;}}||{{H:title|dotted=no|SMOKING SYMBOL|&amp;#x1f6ac;}}||{{H:title|dotted=no|NO SMOKING SYMBOL|&amp;#x1f6ad;}}||{{H:title|dotted=no|PUT LITTER IN ITS PLACE SYMBOL|&amp;#x1f6ae;}}||{{H:title|dotted=no|DO NOT LITTER SYMBOL|&amp;#x1f6af;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F6Bx
|{{H:title|dotted=no|POTABLE WATER SYMBOL|&amp;#x1f6b0;}}||{{H:title|dotted=no|NON-POTABLE WATER SYMBOL|&amp;#x1f6b1;}}||{{H:title|dotted=no|BICYCLE|&amp;#x1f6b2;}}||{{H:title|dotted=no|NO BICYCLES|&amp;#x1f6b3;}}||{{H:title|dotted=no|BICYCLIST|&amp;#x1f6b4;}}||{{H:title|dotted=no|MOUNTAIN BICYCLIST|&amp;#x1f6b5;}}||{{H:title|dotted=no|PEDESTRIAN|&amp;#x1f6b6;}}||{{H:title|dotted=no|NO PEDESTRIANS|&amp;#x1f6b7;}}||{{H:title|dotted=no|CHILDREN CROSSING|&amp;#x1f6b8;}}||{{H:title|dotted=no|MENS SYMBOL|&amp;#x1f6b9;}}||{{H:title|dotted=no|WOMENS SYMBOL|&amp;#x1f6ba;}}||{{H:title|dotted=no|RESTROOM|&amp;#x1f6bb;}}||{{H:title|dotted=no|BABY SYMBOL|&amp;#x1f6bc;}}||{{H:title|dotted=no|TOILET|&amp;#x1f6bd;}}||{{H:title|dotted=no|WATER CLOSET|&amp;#x1f6be;}}||{{H:title|dotted=no|SHOWER|&amp;#x1f6bf;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F6Cx
|style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|BATH|&amp;#x1f6c0;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|BATHTUB|&amp;#x1f6c1;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|PASSPORT CONTROL|&amp;#x1f6c2;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|CUSTOMS|&amp;#x1f6c3;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|BAGGAGE CLAIM|&amp;#x1f6c4;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|LEFT LUGGAGE|&amp;#x1f6c5;}}||{{H:title|dotted=no|TRIANGLE WITH ROUNDED CORNERS|&amp;#x1f6c6;}}||{{H:title|dotted=no|PROHIBITED SIGN|&amp;#x1f6c7;}}||{{H:title|dotted=no|CIRCLED INFORMATION SOURCE|&amp;#x1f6c8;}}||{{H:title|dotted=no|BOYS SYMBOL|&amp;#x1f6c9;}}||{{H:title|dotted=no|GIRLS SYMBOL|&amp;#x1f6ca;}}||{{H:title|dotted=no|COUCH AND LAMP|&amp;#x1f6cb;}}||{{H:title|dotted=no|SLEEPING ACCOMMODATION|&amp;#x1f6cc;}}||{{H:title|dotted=no|SHOPPING BAGS|&amp;#x1f6cd;}}||{{H:title|dotted=no|BELLHOP BELL|&amp;#x1f6ce;}}||{{H:title|dotted=no|BED|&amp;#x1f6cf;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F6Dx
|style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|PLACE OF WORSHIP|&amp;#x1f6d0;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|OCTAGONAL SIGN|&amp;#x1f6d1;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SHOPPING TROLLEY|&amp;#x1f6d2;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|STUPA|&amp;#x1f6d3;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|PAGODA|&amp;#x1f6d4;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|HINDU TEMPLE|&amp;#x1f6d5;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|HUT|&amp;#x1f6d6;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|ELEVATOR|&amp;#x1f6d7;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LANDSLIDE|&amp;#x1f6d8;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|LIGHTHOUSE|&amp;#x1f6d9;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|SEATBELT SIGN|&amp;#x1f6da;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|NO CARS|&amp;#x1f6db;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|WIRELESS|&amp;#x1f6dc;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|PLAYGROUND SLIDE|&amp;#x1f6dd;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|WHEEL|&amp;#x1f6de;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|RING BUOY|&amp;#x1f6df;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F6Ex
|{{H:title|dotted=no|HAMMER AND WRENCH|&amp;#x1f6e0;}}||{{H:title|dotted=no|SHIELD|&amp;#x1f6e1;}}||{{H:title|dotted=no|OIL DRUM|&amp;#x1f6e2;}}||{{H:title|dotted=no|MOTORWAY|&amp;#x1f6e3;}}||{{H:title|dotted=no|RAILWAY TRACK|&amp;#x1f6e4;}}||{{H:title|dotted=no|MOTOR BOAT|&amp;#x1f6e5;}}||{{H:title|dotted=no|UP-POINTING MILITARY AIRPLANE|&amp;#x1f6e6;}}||{{H:title|dotted=no|UP-POINTING AIRPLANE|&amp;#x1f6e7;}}||{{H:title|dotted=no|UP-POINTING SMALL AIRPLANE|&amp;#x1f6e8;}}||{{H:title|dotted=no|SMALL AIRPLANE|&amp;#x1f6e9;}}||{{H:title|dotted=no|NORTHEAST-POINTING AIRPLANE|&amp;#x1f6ea;}}||{{H:title|dotted=no|AIRPLANE DEPARTURE|&amp;#x1f6eb;}}||{{H:title|dotted=no|AIRPLANE ARRIVING|&amp;#x1f6ec;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|HOT AIR BALLOON|&amp;#x1f6ed;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|AIRSHIP|&amp;#x1f6ee;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|SEAPLANE|&amp;#x1f6ef;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F6Fx
|{{H:title|dotted=no|SATELLITE|&amp;#x1f6f0;}}||{{H:title|dotted=no|ONCOMING FIRE ENGINE|&amp;#x1f6f1;}}||{{H:title|dotted=no|DIESEL LOCOMOTIVE|&amp;#x1f6f2;}}||{{H:title|dotted=no|PASSENGER SHIP|&amp;#x1f6f3;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SCOOTER|&amp;#x1f6f4;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|MOTOR SCOOTER|&amp;#x1f6f5;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|CANOE|&amp;#x1f6f6;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SLED|&amp;#x1f6f7;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|FLYING SAUCER|&amp;#x1f6f8;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|SKATEBOARD|&amp;#x1f6f9;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|AUTO RICKSHAW|&amp;#x1f6fa;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|PICKUP TRUCK|&amp;#x1f6fb;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|ROLLER SKATE|&amp;#x1f6fc;}}||style=&quot;background:#768b4a&quot;|{{H:title|dotted=no|FORKLIFT|&amp;#x1f6fd;}}||style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|EXCAVATOR|&amp;#x1f6fe;}}||style=&quot;background:#457d8a&quot;|{{H:title|dotted=no|SUBMARINE|&amp;#x1f6ff;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Alchemical Symbols'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F70x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR QUINTESSENCE|&amp;#x1f700;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AIR|&amp;#x1f701;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR FIRE|&amp;#x1f702;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR EARTH|&amp;#x1f703;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR WATER|&amp;#x1f704;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AQUAFORTIS|&amp;#x1f705;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AQUA REGIA|&amp;#x1f706;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AQUA REGIA-2|&amp;#x1f707;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AQUA VITAE|&amp;#x1f708;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AQUA VITAE-2|&amp;#x1f709;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VINEGAR|&amp;#x1f70a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VINEGAR-2|&amp;#x1f70b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VINEGAR-3|&amp;#x1f70c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SULFUR|&amp;#x1f70d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR PHILOSOPHERS SULFUR|&amp;#x1f70e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BLACK SULFUR|&amp;#x1f70f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F71x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR MERCURY SUBLIMATE|&amp;#x1f710;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR MERCURY SUBLIMATE-2|&amp;#x1f711;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR MERCURY SUBLIMATE-3|&amp;#x1f712;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CINNABAR|&amp;#x1f713;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SALT|&amp;#x1f714;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR NITRE|&amp;#x1f715;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VITRIOL|&amp;#x1f716;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VITRIOL-2|&amp;#x1f717;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ROCK SALT|&amp;#x1f718;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ROCK SALT-2|&amp;#x1f719;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR GOLD|&amp;#x1f71a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SILVER|&amp;#x1f71b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR IRON ORE|&amp;#x1f71c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR IRON ORE-2|&amp;#x1f71d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CROCUS OF IRON|&amp;#x1f71e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS OF IRON|&amp;#x1f71f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F72x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR COPPER ORE|&amp;#x1f720;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR IRON-COPPER ORE|&amp;#x1f721;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SUBLIMATE OF COPPER|&amp;#x1f722;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CROCUS OF COPPER|&amp;#x1f723;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CROCUS OF COPPER-2|&amp;#x1f724;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR COPPER ANTIMONIATE|&amp;#x1f725;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SALT OF COPPER ANTIMONIATE|&amp;#x1f726;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SUBLIMATE OF SALT OF COPPER|&amp;#x1f727;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VERDIGRIS|&amp;#x1f728;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR TIN ORE|&amp;#x1f729;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR LEAD ORE|&amp;#x1f72a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ANTIMONY ORE|&amp;#x1f72b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SUBLIMATE OF ANTIMONY|&amp;#x1f72c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SALT OF ANTIMONY|&amp;#x1f72d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SUBLIMATE OF SALT OF ANTIMONY|&amp;#x1f72e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR VINEGAR OF ANTIMONY|&amp;#x1f72f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F73x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS OF ANTIMONY|&amp;#x1f730;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS OF ANTIMONY-2|&amp;#x1f731;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS|&amp;#x1f732;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS-2|&amp;#x1f733;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS-3|&amp;#x1f734;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REGULUS-4|&amp;#x1f735;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ALKALI|&amp;#x1f736;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ALKALI-2|&amp;#x1f737;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR MARCASITE|&amp;#x1f738;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SAL-AMMONIAC|&amp;#x1f739;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ARSENIC|&amp;#x1f73a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REALGAR|&amp;#x1f73b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR REALGAR-2|&amp;#x1f73c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AURIPIGMENT|&amp;#x1f73d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BISMUTH ORE|&amp;#x1f73e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR TARTAR|&amp;#x1f73f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F74x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR TARTAR-2|&amp;#x1f740;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR QUICK LIME|&amp;#x1f741;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BORAX|&amp;#x1f742;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BORAX-2|&amp;#x1f743;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BORAX-3|&amp;#x1f744;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ALUM|&amp;#x1f745;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR OIL|&amp;#x1f746;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SPIRIT|&amp;#x1f747;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR TINCTURE|&amp;#x1f748;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR GUM|&amp;#x1f749;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR WAX|&amp;#x1f74a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR POWDER|&amp;#x1f74b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CALX|&amp;#x1f74c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR TUTTY|&amp;#x1f74d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CAPUT MORTUUM|&amp;#x1f74e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SCEPTER OF JOVE|&amp;#x1f74f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F75x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CADUCEUS|&amp;#x1f750;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR TRIDENT|&amp;#x1f751;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR STARRED TRIDENT|&amp;#x1f752;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR LODESTONE|&amp;#x1f753;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SOAP|&amp;#x1f754;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR URINE|&amp;#x1f755;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR HORSE DUNG|&amp;#x1f756;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ASHES|&amp;#x1f757;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR POT ASHES|&amp;#x1f758;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BRICK|&amp;#x1f759;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR POWDERED BRICK|&amp;#x1f75a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR AMALGAM|&amp;#x1f75b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR STRATUM SUPER STRATUM|&amp;#x1f75c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR STRATUM SUPER STRATUM-2|&amp;#x1f75d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR SUBLIMATION|&amp;#x1f75e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR PRECIPITATE|&amp;#x1f75f;}}
|----- align=&quot;center&quot; style=&quot;background:#7bffe8&quot;
!style=&quot;background:#ffffff&quot;|1F76x
|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR DISTILL|&amp;#x1f760;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR DISSOLVE|&amp;#x1f761;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR DISSOLVE-2|&amp;#x1f762;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR PURIFY|&amp;#x1f763;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR PUTREFACTION|&amp;#x1f764;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CRUCIBLE|&amp;#x1f765;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CRUCIBLE-2|&amp;#x1f766;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CRUCIBLE-3|&amp;#x1f767;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CRUCIBLE-4|&amp;#x1f768;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR CRUCIBLE-5|&amp;#x1f769;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR ALEMBIC|&amp;#x1f76a;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BATH OF MARY|&amp;#x1f76b;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR BATH OF VAPOURS|&amp;#x1f76c;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR RETORT|&amp;#x1f76d;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR HOUR|&amp;#x1f76e;}}||{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR NIGHT|&amp;#x1f76f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffc0c0&quot;
!style=&quot;background:#ffffff&quot;|1F77x
|style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR DAY-NIGHT|&amp;#x1f770;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR MONTH|&amp;#x1f771;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR HALF DRAM|&amp;#x1f772;}}||style=&quot;background:#7bffe8&quot;|{{H:title|dotted=no|ALCHEMICAL SYMBOL FOR HALF OUNCE|&amp;#x1f773;}}||{{H:title|dotted=no|LOT OF FORTUNE|&amp;#x1f774;}}||{{H:title|dotted=no|OCCULTATION|&amp;#x1f775;}}||{{H:title|dotted=no|LUNAR ECLIPSE|&amp;#x1f776;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|VESTA FORM TWO|&amp;#x1f777;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|ASTRAEA FORM TWO|&amp;#x1f778;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|HYGIEA FORM TWO|&amp;#x1f779;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|PARTHENOPE FORM TWO|&amp;#x1f77a;}}||{{H:title|dotted=no|HAUMEA|&amp;#x1f77B;}}||{{H:title|dotted=no|MAKEMAKE|&amp;#x1f77C;}}||{{H:title|dotted=no|GONGGONG|&amp;#x1f77D;}}||{{H:title|dotted=no|QUAOAR|&amp;#x1f77E;}}||{{H:title|dotted=no|ORCUS|&amp;#x1f77F;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Geometric Shapes Extended'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F78x
|{{H:title|dotted=no|BLACK LEFT-POINTING ISOSCELES RIGHT TRIANGLE|&amp;#x1f780;}}||{{H:title|dotted=no|BLACK UP-POINTING ISOSCELES RIGHT TRIANGLE|&amp;#x1f781;}}||{{H:title|dotted=no|BLACK RIGHT-POINTING ISOSCELES RIGHT TRIANGLE|&amp;#x1f782;}}||{{H:title|dotted=no|BLACK DOWN-POINTING ISOSCELES RIGHT TRIANGLE|&amp;#x1f783;}}||{{H:title|dotted=no|BLACK SLIGHTLY SMALL CIRCLE|&amp;#x1f784;}}||{{H:title|dotted=no|MEDIUM BOLD WHITE CIRCLE|&amp;#x1f785;}}||{{H:title|dotted=no|BOLD WHITE CIRCLE|&amp;#x1f786;}}||{{H:title|dotted=no|HEAVY WHITE CIRCLE|&amp;#x1f787;}}||{{H:title|dotted=no|VERY HEAVY WHITE CIRCLE|&amp;#x1f788;}}||{{H:title|dotted=no|EXTREMELY HEAVY WHITE CIRCLE|&amp;#x1f789;}}||{{H:title|dotted=no|WHITE CIRCLE CONTAINING BLACK SMALL CIRCLE|&amp;#x1f78a;}}||{{H:title|dotted=no|ROUND TARGET|&amp;#x1f78b;}}||{{H:title|dotted=no|BLACK TINY SQUARE|&amp;#x1f78c;}}||{{H:title|dotted=no|BLACK SLIGHTLY SMALL SQUARE|&amp;#x1f78d;}}||{{H:title|dotted=no|LIGHT WHITE SQUARE|&amp;#x1f78e;}}||{{H:title|dotted=no|MEDIUM WHITE SQUARE|&amp;#x1f78f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F79x
|{{H:title|dotted=no|BOLD WHITE SQUARE|&amp;#x1f790;}}||{{H:title|dotted=no|HEAVY WHITE SQUARE|&amp;#x1f791;}}||{{H:title|dotted=no|VERY HEAVY WHITE SQUARE|&amp;#x1f792;}}||{{H:title|dotted=no|EXTREMELY HEAVY WHITE SQUARE|&amp;#x1f793;}}||{{H:title|dotted=no|WHITE SQUARE CONTAINING BLACK VERY SMALL SQUARE|&amp;#x1f794;}}||{{H:title|dotted=no|WHITE SQUARE CONTAINING BLACK MEDIUM SQUARE|&amp;#x1f795;}}||{{H:title|dotted=no|SQUARE TARGET|&amp;#x1f796;}}||{{H:title|dotted=no|BLACK TINY DIAMOND|&amp;#x1f797;}}||{{H:title|dotted=no|BLACK VERY SMALL DIAMOND|&amp;#x1f798;}}||{{H:title|dotted=no|BLACK MEDIUM SMALL DIAMOND|&amp;#x1f799;}}||{{H:title|dotted=no|WHITE DIAMOND CONTAINING BLACK VERY SMALL DIAMOND|&amp;#x1f79a;}}||{{H:title|dotted=no|WHITE DIAMOND CONTAINING BLACK MEDIUM DIAMOND|&amp;#x1f79b;}}||{{H:title|dotted=no|DIAMOND TARGET|&amp;#x1f79c;}}||{{H:title|dotted=no|BLACK TINY LOZENGE|&amp;#x1f79d;}}||{{H:title|dotted=no|BLACK VERY SMALL LOZENGE|&amp;#x1f79e;}}||{{H:title|dotted=no|BLACK MEDIUM SMALL LOZENGE|&amp;#x1f79f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F7Ax
|{{H:title|dotted=no|WHITE LOZENGE CONTAINING BLACK SMALL LOZENGE|&amp;#x1f7a0;}}||{{H:title|dotted=no|THIN GREEK CROSS|&amp;#x1f7a1;}}||{{H:title|dotted=no|LIGHT GREEK CROSS|&amp;#x1f7a2;}}||{{H:title|dotted=no|MEDIUM GREEK CROSS|&amp;#x1f7a3;}}||{{H:title|dotted=no|BOLD GREEK CROSS|&amp;#x1f7a4;}}||{{H:title|dotted=no|VERY BOLD GREEK CROSS|&amp;#x1f7a5;}}||{{H:title|dotted=no|VERY HEAVY GREEK CROSS|&amp;#x1f7a6;}}||{{H:title|dotted=no|EXTREMELY HEAVY GREEK CROSS|&amp;#x1f7a7;}}||{{H:title|dotted=no|THIN SALTIRE|&amp;#x1f7a8;}}||{{H:title|dotted=no|LIGHT SALTIRE|&amp;#x1f7a9;}}||{{H:title|dotted=no|MEDIUM SALTIRE|&amp;#x1f7aa;}}||{{H:title|dotted=no|BOLD SALTIRE|&amp;#x1f7ab;}}||{{H:title|dotted=no|HEAVY SALTIRE|&amp;#x1f7ac;}}||{{H:title|dotted=no|VERY HEAVY SALTIRE|&amp;#x1f7ad;}}||{{H:title|dotted=no|EXTREMELY HEAVY SALTIRE|&amp;#x1f7ae;}}||{{H:title|dotted=no|LIGHT FIVE SPOKED ASTERISK|&amp;#x1f7af;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F7Bx
|{{H:title|dotted=no|MEDIUM FIVE SPOKED ASTERISK|&amp;#x1f7b0;}}||{{H:title|dotted=no|BOLD FIVE SPOKED ASTERISK|&amp;#x1f7b1;}}||{{H:title|dotted=no|HEAVY FIVE SPOKED ASTERISK|&amp;#x1f7b2;}}||{{H:title|dotted=no|VERY HEAVY FIVE SPOKED ASTERISK|&amp;#x1f7b3;}}||{{H:title|dotted=no|EXTREMELY HEAVY FIVE SPOKED ASTERISK|&amp;#x1f7b4;}}||{{H:title|dotted=no|LIGHT SIX SPOKED ASTERISK|&amp;#x1f7b5;}}||{{H:title|dotted=no|MEDIUM SIX SPOKED ASTERISK|&amp;#x1f7b6;}}||{{H:title|dotted=no|BOLD SIX SPOKED ASTERISK|&amp;#x1f7b7;}}||{{H:title|dotted=no|HEAVY SIX SPOKED ASTERISK|&amp;#x1f7b8;}}||{{H:title|dotted=no|VERY HEAVY SIX SPOKED ASTERISK|&amp;#x1f7b9;}}||{{H:title|dotted=no|EXTREMELY HEAVY SIX SPOKED ASTERISK|&amp;#x1f7ba;}}||{{H:title|dotted=no|LIGHT EIGHT SPOKED ASTERISK|&amp;#x1f7bb;}}||{{H:title|dotted=no|MEDIUM EIGHT SPOKED ASTERISK|&amp;#x1f7bc;}}||{{H:title|dotted=no|BOLD EIGHT SPOKED ASTERISK|&amp;#x1f7bd;}}||{{H:title|dotted=no|HEAVY EIGHT SPOKED ASTERISK|&amp;#x1f7be;}}||{{H:title|dotted=no|VERY HEAVY EIGHT SPOKED ASTERISK|&amp;#x1f7bf;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F7Cx
|{{H:title|dotted=no|LIGHT THREE POINTED BLACK STAR|&amp;#x1f7c0;}}||{{H:title|dotted=no|MEDIUM THREE POINTED BLACK STAR|&amp;#x1f7c1;}}||{{H:title|dotted=no|THREE POINTED BLACK STAR|&amp;#x1f7c2;}}||{{H:title|dotted=no|MEDIUM THREE POINTED PINWHEEL STAR|&amp;#x1f7c3;}}||{{H:title|dotted=no|LIGHT FOUR POINTED BLACK STAR|&amp;#x1f7c4;}}||{{H:title|dotted=no|MEDIUM FOUR POINTED BLACK STAR|&amp;#x1f7c5;}}||{{H:title|dotted=no|FOUR POINTED BLACK STAR|&amp;#x1f7c6;}}||{{H:title|dotted=no|MEDIUM FOUR POINTED PINWHEEL STAR|&amp;#x1f7c7;}}||{{H:title|dotted=no|REVERSE LIGHT FOUR POINTED PINWHEEL STAR|&amp;#x1f7c8;}}||{{H:title|dotted=no|LIGHT FIVE POINTED BLACK STAR|&amp;#x1f7c9;}}||{{H:title|dotted=no|HEAVY FIVE POINTED BLACK STAR|&amp;#x1f7ca;}}||{{H:title|dotted=no|MEDIUM SIX POINTED BLACK STAR|&amp;#x1f7cb;}}||{{H:title|dotted=no|HEAVY SIX POINTED BLACK STAR|&amp;#x1f7cc;}}||{{H:title|dotted=no|SIX POINTED PINWHEEL STAR|&amp;#x1f7cd;}}||{{H:title|dotted=no|MEDIUM EIGHT POINTED BLACK STAR|&amp;#x1f7ce;}}||{{H:title|dotted=no|HEAVY EIGHT POINTED BLACK STAR|&amp;#x1f7cf;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F7Dx
|style=&quot;background:#87abff&quot;|{{H:title|dotted=no|VERY HEAVY EIGHT POINTED BLACK STAR|&amp;#x1f7d0;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|HEAVY EIGHT POINTED PINWHEEL STAR|&amp;#x1f7d1;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|LIGHT TWELVE POINTED BLACK STAR|&amp;#x1f7d2;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|HEAVY TWELVE POINTED BLACK STAR|&amp;#x1f7d3;}}||style=&quot;background:#87abff&quot;|{{H:title|dotted=no|HEAVY TWELVE POINTED PINWHEEL STAR|&amp;#x1f7d4;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|CIRCLED TRIANGLE|&amp;#x1f7d5;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|NEGATIVE CIRCLED TRIANGLE|&amp;#x1f7d6;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|CIRCLED SQUARE|&amp;#x1f7d7;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|NEGATIVE CIRCLED SQUARE|&amp;#x1f7d8;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|NINE POINTED WHITE STAR|&amp;#x1f7d9;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|BLACK CIRCLE WITH WHITE VERTICAL BAR|&amp;#x1f7da;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|BULLET IN DOUBLE CIRCLE|&amp;#x1f7db;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1F7Ex
|{{H:title|dotted=no|LARGE ORANGE CIRCLE|&amp;#x1f7e0;}}||{{H:title|dotted=no|LARGE YELLOW CIRCLE|&amp;#x1f7e1;}}||{{H:title|dotted=no|LARGE GREEN CIRCLE|&amp;#x1f7e2;}}||{{H:title|dotted=no|LARGE PURPLE CIRCLE|&amp;#x1f7e3;}}||{{H:title|dotted=no|LARGE BROWN CIRCLE|&amp;#x1f7e4;}}||{{H:title|dotted=no|LARGE RED SQUARE|&amp;#x1f7e5;}}||{{H:title|dotted=no|LARGE BLUE SQUARE|&amp;#x1f7e6;}}||{{H:title|dotted=no|LARGE ORANGE SQUARE|&amp;#x1f7e7;}}||{{H:title|dotted=no|LARGE YELLOW SQUARE|&amp;#x1f7e8;}}||{{H:title|dotted=no|LARGE GREEN SQUARE|&amp;#x1f7e9;}}||{{H:title|dotted=no|LARGE PURPLE SQUARE|&amp;#x1f7ea;}}||{{H:title|dotted=no|LARGE BROWN SQUARE|&amp;#x1f7eb;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|HEAVY NOT EQUALS SIGN|&amp;#x1f7ec;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|1F7Fx
|style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|HEAVY EQUALS SIGN|&amp;#x1f7f0;}}||{{H:title|dotted=no|CIRCLE WITH DOUBLE VERTICAL AND HORIZONTAL LINE|&amp;#x1f7f1;}}||{{H:title|dotted=no|DOUBLE CIRCLE WITH DOUBLE HORIZONTAL LINE|&amp;#x1f7f2;}}||{{H:title|dotted=no|CIRCLED BOTTOM RIGHT OBLIQUE HALF BLACK CIRCLE|&amp;#x1f7f3;}}||{{H:title|dotted=no|LEFT HALF WHITE CIRCLE|&amp;#x1f7f4;}}||{{H:title|dotted=no|RIGHT HALF WHITE CIRCLE|&amp;#x1f7f5;}}||{{H:title|dotted=no|TRANSPARENT CUBE|&amp;#x1f7f6;}}||{{H:title|dotted=no|WHITE CUBE|&amp;#x1f7f7;}}||{{H:title|dotted=no|HORIZONTAL DOUBLE WHITE SMALL SQUARE|&amp;#x1f7f8;}}||{{H:title|dotted=no|VERTICAL DOUBLE WHITE SMALL SQUARE|&amp;#x1f7f9;}}||{{H:title|dotted=no|WHITE SQUARE WITH BOTTOM HALF BISECTED|&amp;#x1f7fa;}}||{{H:title|dotted=no|WHITE SQUARE WITH TOP HALF BISECTED|&amp;#x1f7fb;}}||{{H:title|dotted=no|WHITE SQUARE WITH HORIZONTAL AND VERTICAL BISECTING LINES|&amp;#x1f7fc;}}||{{H:title|dotted=no|LOWER RIGHT FLATTENED RIGHT TRIANGLE|&amp;#x1f7fd;}}||{{H:title|dotted=no|LOWER LEFT FLATTENED RIGHT TRIANGLE|&amp;#x1f7fe;}}||{{H:title|dotted=no|RHOMBUS|&amp;#x1f7ff;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Supplemental Arrows-C'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F80x
|{{H:title|dotted=no|LEFTWARDS ARROW WITH SMALL TRIANGLE ARROWHEAD|&amp;#x1f800;}}||{{H:title|dotted=no|UPWARDS ARROW WITH SMALL TRIANGLE ARROWHEAD|&amp;#x1f801;}}||{{H:title|dotted=no|RIGHTWARDS ARROW WITH SMALL TRIANGLE ARROWHEAD|&amp;#x1f802;}}||{{H:title|dotted=no|DOWNWARDS ARROW WITH SMALL TRIANGLE ARROWHEAD|&amp;#x1f803;}}||{{H:title|dotted=no|LEFTWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEAD|&amp;#x1f804;}}||{{H:title|dotted=no|UPWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEAD|&amp;#x1f805;}}||{{H:title|dotted=no|RIGHTWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEAD|&amp;#x1f806;}}||{{H:title|dotted=no|DOWNWARDS ARROW WITH MEDIUM TRIANGLE ARROWHEAD|&amp;#x1f807;}}||{{H:title|dotted=no|LEFTWARDS ARROW WITH LARGE TRIANGLE ARROWHEAD|&amp;#x1f808;}}||{{H:title|dotted=no|UPWARDS ARROW WITH LARGE TRIANGLE ARROWHEAD|&amp;#x1f809;}}||{{H:title|dotted=no|RIGHTWARDS ARROW WITH LARGE TRIANGLE ARROWHEAD|&amp;#x1f80a;}}||{{H:title|dotted=no|DOWNWARDS ARROW WITH LARGE TRIANGLE ARROWHEAD|&amp;#x1f80b;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F81x
|{{H:title|dotted=no|LEFTWARDS ARROW WITH SMALL EQUILATERAL ARROWHEAD|&amp;#x1f810;}}||{{H:title|dotted=no|UPWARDS ARROW WITH SMALL EQUILATERAL ARROWHEAD|&amp;#x1f811;}}||{{H:title|dotted=no|RIGHTWARDS ARROW WITH SMALL EQUILATERAL ARROWHEAD|&amp;#x1f812;}}||{{H:title|dotted=no|DOWNWARDS ARROW WITH SMALL EQUILATERAL ARROWHEAD|&amp;#x1f813;}}||{{H:title|dotted=no|LEFTWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f814;}}||{{H:title|dotted=no|UPWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f815;}}||{{H:title|dotted=no|RIGHTWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f816;}}||{{H:title|dotted=no|DOWNWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f817;}}||{{H:title|dotted=no|HEAVY LEFTWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f818;}}||{{H:title|dotted=no|HEAVY UPWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f819;}}||{{H:title|dotted=no|HEAVY RIGHTWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f81a;}}||{{H:title|dotted=no|HEAVY DOWNWARDS ARROW WITH EQUILATERAL ARROWHEAD|&amp;#x1f81b;}}||{{H:title|dotted=no|HEAVY LEFTWARDS ARROW WITH LARGE EQUILATERAL ARROWHEAD|&amp;#x1f81c;}}||{{H:title|dotted=no|HEAVY UPWARDS ARROW WITH LARGE EQUILATERAL ARROWHEAD|&amp;#x1f81d;}}||{{H:title|dotted=no|HEAVY RIGHTWARDS ARROW WITH LARGE EQUILATERAL ARROWHEAD|&amp;#x1f81e;}}||{{H:title|dotted=no|HEAVY DOWNWARDS ARROW WITH LARGE EQUILATERAL ARROWHEAD|&amp;#x1f81f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F82x
|{{H:title|dotted=no|LEFTWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFT|&amp;#x1f820;}}||{{H:title|dotted=no|UPWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFT|&amp;#x1f821;}}||{{H:title|dotted=no|RIGHTWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFT|&amp;#x1f822;}}||{{H:title|dotted=no|DOWNWARDS TRIANGLE-HEADED ARROW WITH NARROW SHAFT|&amp;#x1f823;}}||{{H:title|dotted=no|LEFTWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFT|&amp;#x1f824;}}||{{H:title|dotted=no|UPWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFT|&amp;#x1f825;}}||{{H:title|dotted=no|RIGHTWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFT|&amp;#x1f826;}}||{{H:title|dotted=no|DOWNWARDS TRIANGLE-HEADED ARROW WITH MEDIUM SHAFT|&amp;#x1f827;}}||{{H:title|dotted=no|LEFTWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFT|&amp;#x1f828;}}||{{H:title|dotted=no|UPWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFT|&amp;#x1f829;}}||{{H:title|dotted=no|RIGHTWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFT|&amp;#x1f82a;}}||{{H:title|dotted=no|DOWNWARDS TRIANGLE-HEADED ARROW WITH BOLD SHAFT|&amp;#x1f82b;}}||{{H:title|dotted=no|LEFTWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFT|&amp;#x1f82c;}}||{{H:title|dotted=no|UPWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFT|&amp;#x1f82d;}}||{{H:title|dotted=no|RIGHTWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFT|&amp;#x1f82e;}}||{{H:title|dotted=no|DOWNWARDS TRIANGLE-HEADED ARROW WITH HEAVY SHAFT|&amp;#x1f82f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F83x
|{{H:title|dotted=no|LEFTWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFT|&amp;#x1f830;}}||{{H:title|dotted=no|UPWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFT|&amp;#x1f831;}}||{{H:title|dotted=no|RIGHTWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFT|&amp;#x1f832;}}||{{H:title|dotted=no|DOWNWARDS TRIANGLE-HEADED ARROW WITH VERY HEAVY SHAFT|&amp;#x1f833;}}||{{H:title|dotted=no|LEFTWARDS FINGER-POST ARROW|&amp;#x1f834;}}||{{H:title|dotted=no|UPWARDS FINGER-POST ARROW|&amp;#x1f835;}}||{{H:title|dotted=no|RIGHTWARDS FINGER-POST ARROW|&amp;#x1f836;}}||{{H:title|dotted=no|DOWNWARDS FINGER-POST ARROW|&amp;#x1f837;}}||{{H:title|dotted=no|LEFTWARDS SQUARED ARROW|&amp;#x1f838;}}||{{H:title|dotted=no|UPWARDS SQUARED ARROW|&amp;#x1f839;}}||{{H:title|dotted=no|RIGHTWARDS SQUARED ARROW|&amp;#x1f83a;}}||{{H:title|dotted=no|DOWNWARDS SQUARED ARROW|&amp;#x1f83b;}}||{{H:title|dotted=no|LEFTWARDS COMPRESSED ARROW|&amp;#x1f83c;}}||{{H:title|dotted=no|UPWARDS COMPRESSED ARROW|&amp;#x1f83d;}}||{{H:title|dotted=no|RIGHTWARDS COMPRESSED ARROW|&amp;#x1f83e;}}||{{H:title|dotted=no|DOWNWARDS COMPRESSED ARROW|&amp;#x1f83f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F84x
|{{H:title|dotted=no|LEFTWARDS HEAVY COMPRESSED ARROW|&amp;#x1f840;}}||{{H:title|dotted=no|UPWARDS HEAVY COMPRESSED ARROW|&amp;#x1f841;}}||{{H:title|dotted=no|RIGHTWARDS HEAVY COMPRESSED ARROW|&amp;#x1f842;}}||{{H:title|dotted=no|DOWNWARDS HEAVY COMPRESSED ARROW|&amp;#x1f843;}}||{{H:title|dotted=no|LEFTWARDS HEAVY ARROW|&amp;#x1f844;}}||{{H:title|dotted=no|UPWARDS HEAVY ARROW|&amp;#x1f845;}}||{{H:title|dotted=no|RIGHTWARDS HEAVY ARROW|&amp;#x1f846;}}||{{H:title|dotted=no|DOWNWARDS HEAVY ARROW|&amp;#x1f847;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F85x
|{{H:title|dotted=no|LEFTWARDS SANS-SERIF ARROW|&amp;#x1f850;}}||{{H:title|dotted=no|UPWARDS SANS-SERIF ARROW|&amp;#x1f851;}}||{{H:title|dotted=no|RIGHTWARDS SANS-SERIF ARROW|&amp;#x1f852;}}||{{H:title|dotted=no|DOWNWARDS SANS-SERIF ARROW|&amp;#x1f853;}}||{{H:title|dotted=no|NORTH WEST SANS-SERIF ARROW|&amp;#x1f854;}}||{{H:title|dotted=no|NORTH EAST SANS-SERIF ARROW|&amp;#x1f855;}}||{{H:title|dotted=no|SOUTH EAST SANS-SERIF ARROW|&amp;#x1f856;}}||{{H:title|dotted=no|SOUTH WEST SANS-SERIF ARROW|&amp;#x1f857;}}||{{H:title|dotted=no|LEFT RIGHT SANS-SERIF ARROW|&amp;#x1f858;}}||{{H:title|dotted=no|UP DOWN SANS-SERIF ARROW|&amp;#x1f859;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F86x
|{{H:title|dotted=no|WIDE-HEADED LEFTWARDS LIGHT BARB ARROW|&amp;#x1f860;}}||{{H:title|dotted=no|WIDE-HEADED UPWARDS LIGHT BARB ARROW|&amp;#x1f861;}}||{{H:title|dotted=no|WIDE-HEADED RIGHTWARDS LIGHT BARB ARROW|&amp;#x1f862;}}||{{H:title|dotted=no|WIDE-HEADED DOWNWARDS LIGHT BARB ARROW|&amp;#x1f863;}}||{{H:title|dotted=no|WIDE-HEADED NORTH WEST LIGHT BARB ARROW|&amp;#x1f864;}}||{{H:title|dotted=no|WIDE-HEADED NORTH EAST LIGHT BARB ARROW|&amp;#x1f865;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH EAST LIGHT BARB ARROW|&amp;#x1f866;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH WEST LIGHT BARB ARROW|&amp;#x1f867;}}||{{H:title|dotted=no|WIDE-HEADED LEFTWARDS BARB ARROW|&amp;#x1f868;}}||{{H:title|dotted=no|WIDE-HEADED UPWARDS BARB ARROW|&amp;#x1f869;}}||{{H:title|dotted=no|WIDE-HEADED RIGHTWARDS BARB ARROW|&amp;#x1f86a;}}||{{H:title|dotted=no|WIDE-HEADED DOWNWARDS BARB ARROW|&amp;#x1f86b;}}||{{H:title|dotted=no|WIDE-HEADED NORTH WEST BARB ARROW|&amp;#x1f86c;}}||{{H:title|dotted=no|WIDE-HEADED NORTH EAST BARB ARROW|&amp;#x1f86d;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH EAST BARB ARROW|&amp;#x1f86e;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH WEST BARB ARROW|&amp;#x1f86f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F87x
|{{H:title|dotted=no|WIDE-HEADED LEFTWARDS MEDIUM BARB ARROW|&amp;#x1f870;}}||{{H:title|dotted=no|WIDE-HEADED UPWARDS MEDIUM BARB ARROW|&amp;#x1f871;}}||{{H:title|dotted=no|WIDE-HEADED RIGHTWARDS MEDIUM BARB ARROW|&amp;#x1f872;}}||{{H:title|dotted=no|WIDE-HEADED DOWNWARDS MEDIUM BARB ARROW|&amp;#x1f873;}}||{{H:title|dotted=no|WIDE-HEADED NORTH WEST MEDIUM BARB ARROW|&amp;#x1f874;}}||{{H:title|dotted=no|WIDE-HEADED NORTH EAST MEDIUM BARB ARROW|&amp;#x1f875;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH EAST MEDIUM BARB ARROW|&amp;#x1f876;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH WEST MEDIUM BARB ARROW|&amp;#x1f877;}}||{{H:title|dotted=no|WIDE-HEADED LEFTWARDS HEAVY BARB ARROW|&amp;#x1f878;}}||{{H:title|dotted=no|WIDE-HEADED UPWARDS HEAVY BARB ARROW|&amp;#x1f879;}}||{{H:title|dotted=no|WIDE-HEADED RIGHTWARDS HEAVY BARB ARROW|&amp;#x1f87a;}}||{{H:title|dotted=no|WIDE-HEADED DOWNWARDS HEAVY BARB ARROW|&amp;#x1f87b;}}||{{H:title|dotted=no|WIDE-HEADED NORTH WEST HEAVY BARB ARROW|&amp;#x1f87c;}}||{{H:title|dotted=no|WIDE-HEADED NORTH EAST HEAVY BARB ARROW|&amp;#x1f87d;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH EAST HEAVY BARB ARROW|&amp;#x1f87e;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH WEST HEAVY BARB ARROW|&amp;#x1f87f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F88x
|{{H:title|dotted=no|WIDE-HEADED LEFTWARDS VERY HEAVY BARB ARROW|&amp;#x1f880;}}||{{H:title|dotted=no|WIDE-HEADED UPWARDS VERY HEAVY BARB ARROW|&amp;#x1f881;}}||{{H:title|dotted=no|WIDE-HEADED RIGHTWARDS VERY HEAVY BARB ARROW|&amp;#x1f882;}}||{{H:title|dotted=no|WIDE-HEADED DOWNWARDS VERY HEAVY BARB ARROW|&amp;#x1f883;}}||{{H:title|dotted=no|WIDE-HEADED NORTH WEST VERY HEAVY BARB ARROW|&amp;#x1f884;}}||{{H:title|dotted=no|WIDE-HEADED NORTH EAST VERY HEAVY BARB ARROW|&amp;#x1f885;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH EAST VERY HEAVY BARB ARROW|&amp;#x1f886;}}||{{H:title|dotted=no|WIDE-HEADED SOUTH WEST VERY HEAVY BARB ARROW|&amp;#x1f887;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F89x
|{{H:title|dotted=no|LEFTWARDS TRIANGLE ARROWHEAD|&amp;#x1f890;}}||{{H:title|dotted=no|UPWARDS TRIANGLE ARROWHEAD|&amp;#x1f891;}}||{{H:title|dotted=no|RIGHTWARDS TRIANGLE ARROWHEAD|&amp;#x1f892;}}||{{H:title|dotted=no|DOWNWARDS TRIANGLE ARROWHEAD|&amp;#x1f893;}}||{{H:title|dotted=no|LEFTWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEAD|&amp;#x1f894;}}||{{H:title|dotted=no|UPWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEAD|&amp;#x1f895;}}||{{H:title|dotted=no|RIGHTWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEAD|&amp;#x1f896;}}||{{H:title|dotted=no|DOWNWARDS WHITE ARROW WITHIN TRIANGLE ARROWHEAD|&amp;#x1f897;}}||{{H:title|dotted=no|LEFTWARDS ARROW WITH NOTCHED TAIL|&amp;#x1f898;}}||{{H:title|dotted=no|UPWARDS ARROW WITH NOTCHED TAIL|&amp;#x1f899;}}||{{H:title|dotted=no|RIGHTWARDS ARROW WITH NOTCHED TAIL|&amp;#x1f89a;}}||{{H:title|dotted=no|DOWNWARDS ARROW WITH NOTCHED TAIL|&amp;#x1f89b;}}||{{H:title|dotted=no|HEAVY ARROW SHAFT WIDTH ONE|&amp;#x1f89c;}}||{{H:title|dotted=no|HEAVY ARROW SHAFT WIDTH TWO THIRDS|&amp;#x1f89d;}}||{{H:title|dotted=no|HEAVY ARROW SHAFT WIDTH ONE HALF|&amp;#x1f89e;}}||{{H:title|dotted=no|HEAVY ARROW SHAFT WIDTH ONE THIRD|&amp;#x1f89f;}}
|----- align=&quot;center&quot; style=&quot;background:#87abff&quot;
!style=&quot;background:#ffffff&quot;|1F8Ax
|{{H:title|dotted=no|LEFTWARDS BOTTOM-SHADED WHITE ARROW|&amp;#x1f8a0;}}||{{H:title|dotted=no|RIGHTWARDS BOTTOM SHADED WHITE ARROW|&amp;#x1f8a1;}}||{{H:title|dotted=no|LEFTWARDS TOP SHADED WHITE ARROW|&amp;#x1f8a2;}}||{{H:title|dotted=no|RIGHTWARDS TOP SHADED WHITE ARROW|&amp;#x1f8a3;}}||{{H:title|dotted=no|LEFTWARDS LEFT-SHADED WHITE ARROW|&amp;#x1f8a4;}}||{{H:title|dotted=no|RIGHTWARDS RIGHT-SHADED WHITE ARROW|&amp;#x1f8a5;}}||{{H:title|dotted=no|LEFTWARDS RIGHT-SHADED WHITE ARROW|&amp;#x1f8a6;}}||{{H:title|dotted=no|RIGHTWARDS LEFT-SHADED WHITE ARROW|&amp;#x1f8a7;}}||{{H:title|dotted=no|LEFTWARDS BACK-TILTED SHADOWED WHITE ARROW|&amp;#x1f8a8;}}||{{H:title|dotted=no|RIGHTWARDS BACK-TILTED SHADOWED WHITE ARROW|&amp;#x1f8a9;}}||{{H:title|dotted=no|LEFTWARDS FRONT-TILTED SHADOWED WHITE ARROW|&amp;#x1f8aa;}}||{{H:title|dotted=no|RIGHTWARDS FRONT-TILTED SHADOWED WHITE ARROW|&amp;#x1f8ab;}}||{{H:title|dotted=no|WHITE ARROW SHAFT WIDTH ONE|&amp;#x1f8ac;}}||{{H:title|dotted=no|WHITE ARROW SHAFT WIDTH TWO THIRDS|&amp;#x1f8ad;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F8Bx
|style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|ARROW POINTING UPWARDS THEN NORTH WEST|&amp;#x1f8b0;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|ARROW POINTING RIGHTWARDS THEN CURVING SOUTH WEST|&amp;#x1f8b1;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|RIGHTWARDS ARROW WITH LOWER HOOK|&amp;#x1f8b2;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|DOWNWARDS BLACK ARROW TO BAR|&amp;#x1f8b3;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|NEGATIVE SQUARED LEFTWARDS ARROW|&amp;#x1f8b4;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|NEGATIVE SQUARED UPWARDS ARROW|&amp;#x1f8b5;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|NEGATIVE SQUARED RIGHTWARDS ARROW|&amp;#x1f8b6;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|NEGATIVE SQUARED DOWNWARDS ARROW|&amp;#x1f8b7;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|NORTH WEST ARROW FROM BAR|&amp;#x1f8b8;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|NORTH EAST ARROW FROM BAR|&amp;#x1f8b9;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|SOUTH EAST ARROW FROM BAR|&amp;#x1f8ba;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|SOUTH WEST ARROW FROM BAR|&amp;#x1f8bb;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F8Cx
|style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|LEFTWARDS ARROW FROM DOWNWARDS ARROW|&amp;#x1f8c0;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|RIGHTWARDS ARROW FROM DOWNWARDS ARROW|&amp;#x1f8c1;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F8Dx
|style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG RIGHTWARDS ARROW OVER LONG LEFTWARDS ARROW|&amp;#x1f8d0;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG RIGHTWARDS HARPOON OVER LONG LEFTWARDS HARPOON|&amp;#x1f8d1;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG RIGHTWARDS HARPOON ABOVE SHORT LEFTWARDS HARPOON|&amp;#x1f8d2;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|SHORT RIGHTWARDS HARPOON ABOVE LONG LEFTWARDS HARPOON|&amp;#x1f8d3;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG RIGHTWARDS HARPOON ABOVE SHORT LEFTWARDS HARPOON|&amp;#x1f8d4;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|SHORT RIGHTWARDS HARPOON ABOVE LONG LEFTWARDS HARPOON|&amp;#x1f8d5;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG RIGHTWARDS ARROW THROUGH X|&amp;#x1f8d6;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG RIGHTWARDS ARROW WITH DOUBLE SLASH|&amp;#x1f8d7;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|LONG LEFT RIGHT ARROW WITH DEPENDENT LOBE|&amp;#x1f8d8;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F8Ex
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1F8Fx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Supplemental Symbols and Pictographs'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#b690ff&quot;
!style=&quot;background:#ffffff&quot;|1F90x
|{{H:title|dotted=no|CIRCLED CROSS FORMEE WITH FOUR DOTS|&amp;#x1f900;}}||{{H:title|dotted=no|CIRCLED CROSS FORMEE WITH TWO DOTS|&amp;#x1f901;}}||{{H:title|dotted=no|CIRCLED CROSS FORMEE|&amp;#x1f902;}}||{{H:title|dotted=no|LEFT HALF CIRCLE WITH FOUR DOTS|&amp;#x1f903;}}||{{H:title|dotted=no|LEFT HALF CIRCLE WITH THREE DOTS|&amp;#x1f904;}}||{{H:title|dotted=no|LEFT HALF CIRCLE WITH TWO DOTS|&amp;#x1f905;}}||{{H:title|dotted=no|LEFT HALF CIRCLE WITH DOT|&amp;#x1f906;}}||{{H:title|dotted=no|LEFT HALF CIRCLE|&amp;#x1f907;}}||{{H:title|dotted=no|DOWNWARD FACING HOOK|&amp;#x1f908;}}||{{H:title|dotted=no|DOWNWARD FACING NOTCHED HOOK|&amp;#x1f909;}}||{{H:title|dotted=no|DOWNWARD FACING HOOK WITH DOT|&amp;#x1f90a;}}||{{H:title|dotted=no|DOWNWARD FACING NOTCHED HOOK WITH DOT|&amp;#x1f90b;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|PINCHED FINGERS|&amp;#x1f90c;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|WHITE HEART|&amp;#x1f90d;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BROWN HEART|&amp;#x1f90e;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|PINCHING HAND|&amp;#x1f90f;}}
|----- align=&quot;center&quot; style=&quot;background:#8a94ff&quot;
!style=&quot;background:#ffffff&quot;|1F91x
|{{H:title|dotted=no|ZIPPER-MOUTH FACE|&amp;#x1f910;}}||{{H:title|dotted=no|MONEY-MOUTH FACE|&amp;#x1f911;}}||{{H:title|dotted=no|FACE WITH THERMOMETER|&amp;#x1f912;}}||{{H:title|dotted=no|NERD FACE|&amp;#x1f913;}}||{{H:title|dotted=no|THINKING FACE|&amp;#x1f914;}}||{{H:title|dotted=no|FACE WITH HEAD-BANDAGE|&amp;#x1f915;}}||{{H:title|dotted=no|ROBOT FACE|&amp;#x1f916;}}||{{H:title|dotted=no|HUGGING FACE|&amp;#x1f917;}}||{{H:title|dotted=no|SIGN OF THE HORNS|&amp;#x1f918;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|CALL ME HAND|&amp;#x1f919;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|RAISED BACK OF HAND|&amp;#x1f91a;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|LEFT-FACING FIST|&amp;#x1f91b;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|RIGHT-FACING FIST|&amp;#x1f91c;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|HANDSHAKE|&amp;#x1f91d;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|HAND WITH INDEX AND MIDDLE FINGERS CROSSED|&amp;#x1f91e;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|I LOVE YOU HAND SIGN|&amp;#x1f91f;}}
|----- align=&quot;center&quot; style=&quot;background:#9c8dff&quot;
!style=&quot;background:#ffffff&quot;|1F92x
|{{H:title|dotted=no|FACE WITH COWBOY HAT|&amp;#x1f920;}}||{{H:title|dotted=no|CLOWN FACE|&amp;#x1f921;}}||{{H:title|dotted=no|NAUSEATED FACE|&amp;#x1f922;}}||{{H:title|dotted=no|ROLLING ON THE FLOOR LAUGHING|&amp;#x1f923;}}||{{H:title|dotted=no|DROOLING FACE|&amp;#x1f924;}}||{{H:title|dotted=no|LYING FACE|&amp;#x1f925;}}||{{H:title|dotted=no|FACE PALM|&amp;#x1f926;}}||{{H:title|dotted=no|SNEEZING FACE|&amp;#x1f927;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|FACE WITH ONE EYEBROW RAISED|&amp;#x1f928;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|GRINNING FACE WITH STAR EYES|&amp;#x1f929;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|GRINNING FACE WITH ONE LARGE AND ONE SMALL EYE|&amp;#x1f92a;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|FACE WITH FINGER COVERING CLOSED LIPS|&amp;#x1f92b;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SERIOUS FACE WITH SYMBOLS COVERING MOUTH|&amp;#x1f92c;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SMILING FACE WITH SMILING EYES AND HAND COVERING MOUTH|&amp;#x1f92d;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|FACE WITH OPEN MOUTH VOMITING|&amp;#x1f92e;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SHOCKED FACE WITH EXPLODING HEAD|&amp;#x1f92f;}}
|----- align=&quot;center&quot; style=&quot;background:#9c8dff&quot;
!style=&quot;background:#ffffff&quot;|1F93x
|{{H:title|dotted=no|PREGNANT WOMAN|&amp;#x1f930;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|BREAST-FEEDING|&amp;#x1f931;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|PALMS UP TOGETHER|&amp;#x1f932;}}||{{H:title|dotted=no|SELFIE|&amp;#x1f933;}}||{{H:title|dotted=no|PRINCE|&amp;#x1f934;}}||{{H:title|dotted=no|MAN IN TUXEDO|&amp;#x1f935;}}||{{H:title|dotted=no|MOTHER CHRISTMAS|&amp;#x1f936;}}||{{H:title|dotted=no|SHRUG|&amp;#x1f937;}}||{{H:title|dotted=no|PERSON DOING CARTWHEEL|&amp;#x1f938;}}||{{H:title|dotted=no|JUGGLING|&amp;#x1f939;}}||{{H:title|dotted=no|FENCER|&amp;#x1f93a;}}||{{H:title|dotted=no|MODERN PENTATHLON|&amp;#x1f93b;}}||{{H:title|dotted=no|WRESTLERS|&amp;#x1f93c;}}||{{H:title|dotted=no|WATER POLO|&amp;#x1f93d;}}||{{H:title|dotted=no|HANDBALL|&amp;#x1f93e;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|DIVING MASK|&amp;#x1f93f;}}
|----- align=&quot;center&quot; style=&quot;background:#9c8dff&quot;
!style=&quot;background:#ffffff&quot;|1F94x
|{{H:title|dotted=no|WILTED FLOWER|&amp;#x1f940;}}||{{H:title|dotted=no|DRUM WITH DRUMSTICKS|&amp;#x1f941;}}||{{H:title|dotted=no|CLINKING GLASSES|&amp;#x1f942;}}||{{H:title|dotted=no|TUMBLER GLASS|&amp;#x1f943;}}||{{H:title|dotted=no|SPOON|&amp;#x1f944;}}||{{H:title|dotted=no|GOAL NET|&amp;#x1f945;}}||{{H:title|dotted=no|RIFLE|&amp;#x1f946;}}||{{H:title|dotted=no|FIRST PLACE MEDAL|&amp;#x1f947;}}||{{H:title|dotted=no|SECOND PLACE MEDAL|&amp;#x1f948;}}||{{H:title|dotted=no|THIRD PLACE MEDAL|&amp;#x1f949;}}||{{H:title|dotted=no|BOXING GLOVE|&amp;#x1f94a;}}||{{H:title|dotted=no|MARTIAL ARTS UNIFORM|&amp;#x1f94b;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|CURLING STONE|&amp;#x1f94c;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|LACROSSE STICK AND BALL|&amp;#x1f94d;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|SOFTBALL|&amp;#x1f94e;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|FLYING DISC|&amp;#x1f94f;}}
|----- align=&quot;center&quot; style=&quot;background:#9c8dff&quot;
!style=&quot;background:#ffffff&quot;|1F95x
|{{H:title|dotted=no|CROISSANT|&amp;#x1f950;}}||{{H:title|dotted=no|AVOCADO|&amp;#x1f951;}}||{{H:title|dotted=no|CUCUMBER|&amp;#x1f952;}}||{{H:title|dotted=no|BACON|&amp;#x1f953;}}||{{H:title|dotted=no|POTATO|&amp;#x1f954;}}||{{H:title|dotted=no|CARROT|&amp;#x1f955;}}||{{H:title|dotted=no|BAGUETTE BREAD|&amp;#x1f956;}}||{{H:title|dotted=no|GREEN SALAD|&amp;#x1f957;}}||{{H:title|dotted=no|SHALLOW PAN OF FOOD|&amp;#x1f958;}}||{{H:title|dotted=no|STUFFED FLATBREAD|&amp;#x1f959;}}||{{H:title|dotted=no|EGG|&amp;#x1f95a;}}||{{H:title|dotted=no|GLASS OF MILK|&amp;#x1f95b;}}||{{H:title|dotted=no|PEANUTS|&amp;#x1f95c;}}||{{H:title|dotted=no|KIWIFRUIT|&amp;#x1f95d;}}||{{H:title|dotted=no|PANCAKES|&amp;#x1f95e;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|DUMPLING|&amp;#x1f95f;}}
|----- align=&quot;center&quot; style=&quot;background:#b690ff&quot;
!style=&quot;background:#ffffff&quot;|1F96x
|{{H:title|dotted=no|FORTUNE COOKIE|&amp;#x1f960;}}||{{H:title|dotted=no|TAKEOUT BOX|&amp;#x1f961;}}||{{H:title|dotted=no|CHOPSTICKS|&amp;#x1f962;}}||{{H:title|dotted=no|BOWL WITH SPOON|&amp;#x1f963;}}||{{H:title|dotted=no|CUP WITH STRAW|&amp;#x1f964;}}||{{H:title|dotted=no|COCONUT|&amp;#x1f965;}}||{{H:title|dotted=no|BROCCOLI|&amp;#x1f966;}}||{{H:title|dotted=no|PIE|&amp;#x1f967;}}||{{H:title|dotted=no|PRETZEL|&amp;#x1f968;}}||{{H:title|dotted=no|CUT OF MEAT|&amp;#x1f969;}}||{{H:title|dotted=no|SANDWICH|&amp;#x1f96a;}}||{{H:title|dotted=no|CANNED FOOD|&amp;#x1f96b;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|LEAFY GREEN|&amp;#x1f96c;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|MANGO|&amp;#x1f96d;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|MOON CAKE|&amp;#x1f96e;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|BAGEL|&amp;#x1f96f;}}
|----- align=&quot;center&quot; style=&quot;background:#d093ff&quot;
!style=&quot;background:#ffffff&quot;|1F97x
|{{H:title|dotted=no|SMILING FACE WITH SMILING EYES AND THREE HEARTS|&amp;#x1f970;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|YAWNING FACE|&amp;#x1f971;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|SMILING FACE WITH TEAR|&amp;#x1f972;}}||{{H:title|dotted=no|FACE WITH PARTY HORN AND PARTY HAT|&amp;#x1f973;}}||{{H:title|dotted=no|FACE WITH UNEVEN EYES AND WAVY MOUTH|&amp;#x1f974;}}||{{H:title|dotted=no|OVERHEATED FACE|&amp;#x1f975;}}||{{H:title|dotted=no|FREEZING FACE|&amp;#x1f976;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|NINJA|&amp;#x1f977;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|DISGUISED FACE|&amp;#x1f978;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|FACE HOLDING BACK TEARS|&amp;#x1f979;}}||{{H:title|dotted=no|FACE WITH PLEADING EYES|&amp;#x1f97a;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|SARI|&amp;#x1f97b;}}||{{H:title|dotted=no|LAB COAT|&amp;#x1f97c;}}||{{H:title|dotted=no|GOGGLES|&amp;#x1f97d;}}||{{H:title|dotted=no|HIKING BOOT|&amp;#x1f97e;}}||{{H:title|dotted=no|FLAT SHOE|&amp;#x1f97f;}}
|----- align=&quot;center&quot; style=&quot;background:#9c8dff&quot;
!style=&quot;background:#ffffff&quot;|1F98x
|style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|CRAB|&amp;#x1f980;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|LION FACE|&amp;#x1f981;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|SCORPION|&amp;#x1f982;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|TURKEY|&amp;#x1f983;}}||style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|UNICORN FACE|&amp;#x1f984;}}||{{H:title|dotted=no|EAGLE|&amp;#x1f985;}}||{{H:title|dotted=no|DUCK|&amp;#x1f986;}}||{{H:title|dotted=no|BAT|&amp;#x1f987;}}||{{H:title|dotted=no|SHARK|&amp;#x1f988;}}||{{H:title|dotted=no|OWL|&amp;#x1f989;}}||{{H:title|dotted=no|FOX FACE|&amp;#x1f98a;}}||{{H:title|dotted=no|BUTTERFLY|&amp;#x1f98b;}}||{{H:title|dotted=no|DEER|&amp;#x1f98c;}}||{{H:title|dotted=no|GORILLA|&amp;#x1f98d;}}||{{H:title|dotted=no|LIZARD|&amp;#x1f98e;}}||{{H:title|dotted=no|RHINOCEROS|&amp;#x1f98f;}}
|----- align=&quot;center&quot; style=&quot;background:#d093ff&quot;
!style=&quot;background:#ffffff&quot;|1F99x
|style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SHRIMP|&amp;#x1f990;}}||style=&quot;background:#9c8dff&quot;|{{H:title|dotted=no|SQUID|&amp;#x1f991;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|GIRAFFE FACE|&amp;#x1f992;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ZEBRA FACE|&amp;#x1f993;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|HEDGEHOG|&amp;#x1f994;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SAUROPOD|&amp;#x1f995;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|T-REX|&amp;#x1f996;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|CRICKET|&amp;#x1f997;}}||{{H:title|dotted=no|KANGAROO|&amp;#x1f998;}}||{{H:title|dotted=no|LLAMA|&amp;#x1f999;}}||{{H:title|dotted=no|PEACOCK|&amp;#x1f99a;}}||{{H:title|dotted=no|HIPPOPOTAMUS|&amp;#x1f99b;}}||{{H:title|dotted=no|PARROT|&amp;#x1f99c;}}||{{H:title|dotted=no|RACCOON|&amp;#x1f99d;}}||{{H:title|dotted=no|LOBSTER|&amp;#x1f99e;}}||{{H:title|dotted=no|MOSQUITO|&amp;#x1f99f;}}
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1F9Ax
|style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|MICROBE|&amp;#x1f9a0;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|BADGER|&amp;#x1f9a1;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|SWAN|&amp;#x1f9a2;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|MAMMOTH|&amp;#x1f9a3;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|DODO|&amp;#x1f9a4;}}||{{H:title|dotted=no|SLOTH|&amp;#x1f9a5;}}||{{H:title|dotted=no|OTTER|&amp;#x1f9a6;}}||{{H:title|dotted=no|ORANGUTAN|&amp;#x1f9a7;}}||{{H:title|dotted=no|SKUNK|&amp;#x1f9a8;}}||{{H:title|dotted=no|FLAMINGO|&amp;#x1f9a9;}}||{{H:title|dotted=no|OYSTER|&amp;#x1f9aa;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BEAVER|&amp;#x1f9ab;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BISON|&amp;#x1f9ac;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|SEAL|&amp;#x1f9ad;}}||{{H:title|dotted=no|GUIDE DOG|&amp;#x1f9ae;}}||{{H:title|dotted=no|PROBING CANE|&amp;#x1f9af;}}
|----- align=&quot;center&quot; style=&quot;background:#d093ff&quot;
!style=&quot;background:#ffffff&quot;|1F9Bx
|{{H:title|dotted=no|EMOJI COMPONENT RED HAIR|&amp;#x1f9b0;}}||{{H:title|dotted=no|EMOJI COMPONENT CURLY HAIR|&amp;#x1f9b1;}}||{{H:title|dotted=no|EMOJI COMPONENT BALD|&amp;#x1f9b2;}}||{{H:title|dotted=no|EMOJI COMPONENT WHITE HAIR|&amp;#x1f9b3;}}||{{H:title|dotted=no|BONE|&amp;#x1f9b4;}}||{{H:title|dotted=no|LEG|&amp;#x1f9b5;}}||{{H:title|dotted=no|FOOT|&amp;#x1f9b6;}}||{{H:title|dotted=no|TOOTH|&amp;#x1f9b7;}}||{{H:title|dotted=no|SUPERHERO|&amp;#x1f9b8;}}||{{H:title|dotted=no|SUPERVILLAIN|&amp;#x1f9b9;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|SAFETY VEST|&amp;#x1f9ba;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|EAR WITH HEARING AID|&amp;#x1f9bb;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|MOTORIZED WHEELCHAIR|&amp;#x1f9bc;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|MANUAL WHEELCHAIR|&amp;#x1f9bd;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|MECHANICAL ARM|&amp;#x1f9be;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|MECHANICAL LEG|&amp;#x1f9bf;}}
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1F9Cx
|style=&quot;background:#8a94ff&quot;|{{H:title|dotted=no|CHEESE WEDGE|&amp;#x1f9c0;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|CUPCAKE|&amp;#x1f9c1;}}||style=&quot;background:#d093ff&quot;|{{H:title|dotted=no|SALT SHAKER|&amp;#x1f9c2;}}||{{H:title|dotted=no|BEVERAGE BOX|&amp;#x1f9c3;}}||{{H:title|dotted=no|GARLIC|&amp;#x1f9c4;}}||{{H:title|dotted=no|ONION|&amp;#x1f9c5;}}||{{H:title|dotted=no|FALAFEL|&amp;#x1f9c6;}}||{{H:title|dotted=no|WAFFLE|&amp;#x1f9c7;}}||{{H:title|dotted=no|BUTTER|&amp;#x1f9c8;}}||{{H:title|dotted=no|MATE DRINK|&amp;#x1f9c9;}}||{{H:title|dotted=no|ICE CUBE|&amp;#x1f9ca;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BUBBLE TEA|&amp;#x1f9cb;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|TROLL|&amp;#x1f9cc;}}||{{H:title|dotted=no|STANDING PERSON|&amp;#x1f9cd;}}||{{H:title|dotted=no|KNEELING PERSON|&amp;#x1f9ce;}}||{{H:title|dotted=no|DEAF PERSON|&amp;#x1f9cf;}}
|----- align=&quot;center&quot; style=&quot;background:#b690ff&quot;
!style=&quot;background:#ffffff&quot;|1F9Dx
|{{H:title|dotted=no|FACE WITH MONOCLE|&amp;#x1f9d0;}}||{{H:title|dotted=no|ADULT|&amp;#x1f9d1;}}||{{H:title|dotted=no|CHILD|&amp;#x1f9d2;}}||{{H:title|dotted=no|OLDER ADULT|&amp;#x1f9d3;}}||{{H:title|dotted=no|BEARDED PERSON|&amp;#x1f9d4;}}||{{H:title|dotted=no|PERSON WITH HEADSCARF|&amp;#x1f9d5;}}||{{H:title|dotted=no|PERSON IN STEAMY ROOM|&amp;#x1f9d6;}}||{{H:title|dotted=no|PERSON CLIMBING|&amp;#x1f9d7;}}||{{H:title|dotted=no|PERSON IN LOTUS POSITION|&amp;#x1f9d8;}}||{{H:title|dotted=no|MAGE|&amp;#x1f9d9;}}||{{H:title|dotted=no|FAIRY|&amp;#x1f9da;}}||{{H:title|dotted=no|VAMPIRE|&amp;#x1f9db;}}||{{H:title|dotted=no|MERPERSON|&amp;#x1f9dc;}}||{{H:title|dotted=no|ELF|&amp;#x1f9dd;}}||{{H:title|dotted=no|GENIE|&amp;#x1f9de;}}||{{H:title|dotted=no|ZOMBIE|&amp;#x1f9df;}}
|----- align=&quot;center&quot; style=&quot;background:#d093ff&quot;
!style=&quot;background:#ffffff&quot;|1F9Ex
|style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|BRAIN|&amp;#x1f9e0;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|ORANGE HEART|&amp;#x1f9e1;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|BILLED CAP|&amp;#x1f9e2;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SCARF|&amp;#x1f9e3;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|GLOVES|&amp;#x1f9e4;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|COAT|&amp;#x1f9e5;}}||style=&quot;background:#b690ff&quot;|{{H:title|dotted=no|SOCKS|&amp;#x1f9e6;}}||{{H:title|dotted=no|RED GIFT ENVELOPE|&amp;#x1f9e7;}}||{{H:title|dotted=no|FIRECRACKER|&amp;#x1f9e8;}}||{{H:title|dotted=no|JIGSAW PUZZLE PIECE|&amp;#x1f9e9;}}||{{H:title|dotted=no|TEST TUBE|&amp;#x1f9ea;}}||{{H:title|dotted=no|PETRI DISH|&amp;#x1f9eb;}}||{{H:title|dotted=no|DNA DOUBLE HELIX|&amp;#x1f9ec;}}||{{H:title|dotted=no|COMPASS|&amp;#x1f9ed;}}||{{H:title|dotted=no|ABACUS|&amp;#x1f9ee;}}||{{H:title|dotted=no|FIRE EXTINGUISHER|&amp;#x1f9ef;}}
|----- align=&quot;center&quot; style=&quot;background:#d093ff&quot;
!style=&quot;background:#ffffff&quot;|1F9Fx
|{{H:title|dotted=no|TOOLBOX|&amp;#x1f9f0;}}||{{H:title|dotted=no|BRICK|&amp;#x1f9f1;}}||{{H:title|dotted=no|MAGNET|&amp;#x1f9f2;}}||{{H:title|dotted=no|LUGGAGE|&amp;#x1f9f3;}}||{{H:title|dotted=no|LOTION BOTTLE|&amp;#x1f9f4;}}||{{H:title|dotted=no|SPOOL OF THREAD|&amp;#x1f9f5;}}||{{H:title|dotted=no|BALL OF YARN|&amp;#x1f9f6;}}||{{H:title|dotted=no|SAFETY PIN|&amp;#x1f9f7;}}||{{H:title|dotted=no|TEDDY BEAR|&amp;#x1f9f8;}}||{{H:title|dotted=no|BROOM|&amp;#x1f9f9;}}||{{H:title|dotted=no|BASKET|&amp;#x1f9fa;}}||{{H:title|dotted=no|ROLL OF PAPER|&amp;#x1f9fb;}}||{{H:title|dotted=no|BAR OF SOAP|&amp;#x1f9fc;}}||{{H:title|dotted=no|SPONGE|&amp;#x1f9fd;}}||{{H:title|dotted=no|RECEIPT|&amp;#x1f9fe;}}||{{H:title|dotted=no|NAZAR AMULET|&amp;#x1f9ff;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Chess Symbols'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1FA0x
|{{H:title|dotted=no|NEUTRAL CHESS KING|&amp;#x1fa00;}}||{{H:title|dotted=no|NEUTRAL CHESS QUEEN|&amp;#x1fa01;}}||{{H:title|dotted=no|NEUTRAL CHESS ROOK|&amp;#x1fa02;}}||{{H:title|dotted=no|NEUTRAL CHESS BISHOP|&amp;#x1fa03;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT|&amp;#x1fa04;}}||{{H:title|dotted=no|NEUTRAL CHESS PAWN|&amp;#x1fa05;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT ROTATED FORTY-FIVE DEGREE|&amp;#x1fa06;}}||{{H:title|dotted=no|BLACK CHESS KNIGHT ROTATED FORTY-FIVE DEGREES|&amp;#x1fa07;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT ROTATED FORTY-FIVE DEGREES|&amp;#x1fa08;}}||{{H:title|dotted=no|WHITE CHESS KING ROTATED NINETY DEGREES|&amp;#x1fa09;}}||{{H:title|dotted=no|WHITE CHESS QUEEN ROTATED NINETY DEGREES|&amp;#x1fa0a;}}||{{H:title|dotted=no|WHITE CHESS ROOK ROTATED NINETY DEGREES|&amp;#x1fa0b;}}||{{H:title|dotted=no|WHITE CHESS BISHOP ROTATED NINETY DEGREES|&amp;#x1fa0c;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT ROTATED NINETY DEGREES|&amp;#x1fa0d;}}||{{H:title|dotted=no|WHITE CHESS PAWN ROTATED NINETY DEGREES|&amp;#x1fa0e;}}||{{H:title|dotted=no|BLACK CHESS KING ROTATED NINETY DEGREES|&amp;#x1fa0f;}}
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1FA1x
|{{H:title|dotted=no|BLACK CHESS QUEEN ROTATED NINETY DEGREES|&amp;#x1fa10;}}||{{H:title|dotted=no|BLACK CHESS ROOK ROTATED NINETY DEGREES|&amp;#x1fa11;}}||{{H:title|dotted=no|BLACK CHESS BISHOP ROTATED NINETY DEGREES|&amp;#x1fa12;}}||{{H:title|dotted=no|BLACK CHESS KNIGHT ROTATED NINETY DEGREES|&amp;#x1fa13;}}||{{H:title|dotted=no|BLACK CHESS PAWN ROTATED NINETY DEGREES|&amp;#x1fa14;}}||{{H:title|dotted=no|NEUTRAL CHESS KING ROTATED NINETY DEGREES|&amp;#x1fa15;}}||{{H:title|dotted=no|NEUTRAL CHESS QUEEN ROTATED NINETY DEGREES|&amp;#x1fa16;}}||{{H:title|dotted=no|NEUTRAL CHESS ROOK ROTATED NINETY DEGREES|&amp;#x1fa17;}}||{{H:title|dotted=no|NEUTRAL CHESS BISHOP ROTATED NINETY DEGREES|&amp;#x1fa18;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT ROTATED NINETY DEGREES|&amp;#x1fa19;}}||{{H:title|dotted=no|NEUTRAL CHESS PAWN ROTATED NINETY DEGREES|&amp;#x1fa1a;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT ROTATED ONE HUNDRED THIRTY-FIVE DEGREES|&amp;#x1fa1b;}}||{{H:title|dotted=no|BLACK CHESS KNIGHT ROTATED ONE HUNDRED THIRTY-FIVE DEGREES|&amp;#x1fa1c;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT ROTATED ONE HUNDRED THIRTY-FIVE DEGREES|&amp;#x1fa1d;}}||{{H:title|dotted=no|WHITE CHESS TURNED KING|&amp;#x1fa1e;}}||{{H:title|dotted=no|WHITE CHESS TURNED QUEEN|&amp;#x1fa1f;}}
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1FA2x
|{{H:title|dotted=no|WHITE CHESS TURNED ROOK|&amp;#x1fa20;}}||{{H:title|dotted=no|WHITE CHESS TURNED BISHOP|&amp;#x1fa21;}}||{{H:title|dotted=no|WHITE CHESS TURNED KNIGHT|&amp;#x1fa22;}}||{{H:title|dotted=no|WHITE CHESS TURNED PAWN|&amp;#x1fa23;}}||{{H:title|dotted=no|BLACK CHESS TURNED KING|&amp;#x1fa24;}}||{{H:title|dotted=no|BLACK CHESS TURNED QUEEN|&amp;#x1fa25;}}||{{H:title|dotted=no|BLACK CHESS TURNED ROOK|&amp;#x1fa26;}}||{{H:title|dotted=no|BLACK CHESS TURNED BISHOP|&amp;#x1fa27;}}||{{H:title|dotted=no|BLACK CHESS TURNED KNIGHT|&amp;#x1fa28;}}||{{H:title|dotted=no|BLACK CHESS TURNED PAWN|&amp;#x1fa29;}}||{{H:title|dotted=no|NEUTRAL CHESS TURNED KING|&amp;#x1fa2a;}}||{{H:title|dotted=no|NEUTRAL CHESS TURNED QUEEN|&amp;#x1fa2b;}}||{{H:title|dotted=no|NEUTRAL CHESS TURNED ROOK|&amp;#x1fa2c;}}||{{H:title|dotted=no|NEUTRAL CHESS TURNED BISHOP|&amp;#x1fa2d;}}||{{H:title|dotted=no|NEUTRAL CHESS TURNED KNIGHT|&amp;#x1fa2e;}}||{{H:title|dotted=no|NEUTRAL CHESS TURNED PAWN|&amp;#x1fa2f;}}
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1FA3x
|{{H:title|dotted=no|WHITE CHESS KNIGHT ROTATED TWO HUNDRED TWENTY-FIVE DEGREES|&amp;#x1fa30;}}||{{H:title|dotted=no|BLACK CHESS KNIGHT ROTATED TWO HUNDRED TWENTY-FIVE DEGREES|&amp;#x1fa31;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT ROTATED TWO HUNDRED TWENTY-FIVE DEGREES|&amp;#x1fa32;}}||{{H:title|dotted=no|WHITE CHESS KING ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa33;}}||{{H:title|dotted=no|WHITE CHESS QUEEN ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa34;}}||{{H:title|dotted=no|WHITE CHESS ROOK ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa35;}}||{{H:title|dotted=no|WHITE CHESS BISHOP ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa36;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa37;}}||{{H:title|dotted=no|WHITE CHESS PAWN ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa38;}}||{{H:title|dotted=no|BLACK CHESS KING ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa39;}}||{{H:title|dotted=no|BLACK CHESS QUEEN ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa3a;}}||{{H:title|dotted=no|BLACK CHESS ROOK ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa3b;}}||{{H:title|dotted=no|BLACK CHESS BISHOP ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa3c;}}||{{H:title|dotted=no|BLACK CHESS KNIGHT ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa3d;}}||{{H:title|dotted=no|BLACK CHESS PAWN ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa3e;}}||{{H:title|dotted=no|NEUTRAL CHESS KING ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa3f;}}
|----- align=&quot;center&quot; style=&quot;background:#e896ff&quot;
!style=&quot;background:#ffffff&quot;|1FA4x
|{{H:title|dotted=no|NEUTRAL CHESS QUEEN ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa40;}}||{{H:title|dotted=no|NEUTRAL CHESS ROOK ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa41;}}||{{H:title|dotted=no|NEUTRAL CHESS BISHOP ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa42;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa43;}}||{{H:title|dotted=no|NEUTRAL CHESS PAWN ROTATED TWO HUNDRED SEVENTY DEGREES|&amp;#x1fa44;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT ROTATED THREE HUNDRED FIFTEEN DEGREES|&amp;#x1fa45;}}||{{H:title|dotted=no|BLACK CHESS KNIGHT ROTATED THREE HUNDRED FIFTEEN DEGREES|&amp;#x1fa46;}}||{{H:title|dotted=no|NEUTRAL CHESS KNIGHT ROTATED THREE HUNDRED FIFTEEN DEGREES|&amp;#x1fa47;}}||{{H:title|dotted=no|WHITE CHESS EQUIHOPPER|&amp;#x1fa48;}}||{{H:title|dotted=no|BLACK CHESS EQUIHOPPER|&amp;#x1fa49;}}||{{H:title|dotted=no|NEUTRAL CHESS EQUIHOPPER|&amp;#x1fa4a;}}||{{H:title|dotted=no|WHITE CHESS EQUIHOPPER ROTATED NINETY DEGREES|&amp;#x1fa4b;}}||{{H:title|dotted=no|BLACK CHESS EQUIHOPPER ROTATED NINETY DEGREES|&amp;#x1fa4c;}}||{{H:title|dotted=no|NEUTRAL CHESS EQUIHOPPER ROTATED NINETY DEGREES|&amp;#x1fa4d;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT-QUEEN|&amp;#x1fa4e;}}||{{H:title|dotted=no|WHITE CHESS KNIGHT-ROOK|&amp;#x1fa4f;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FA5x
|style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|WHITE CHESS KNIGHT-BISHOP|&amp;#x1fa50;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BLACK CHESS KNIGHT-QUEEN|&amp;#x1fa51;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BLACK CHESS KNIGHT-ROOK|&amp;#x1fa52;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BLACK CHESS KNIGHT-BISHOP|&amp;#x1fa53;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|WHITE CHESS FERZ|&amp;#x1fa54;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|WHITE CHESS ALFIL|&amp;#x1fa55;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|BLACK CHESS FERZ|&amp;#x1fa56;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|BLACK CHESS ALFIL|&amp;#x1fa57;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|WHITE CHESS WAZIR|&amp;#x1fa58;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|BLACK CHESS WAZIR|&amp;#x1fa59;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|WHITE CHESS CAMEL|&amp;#x1fa5a;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|BLACK CHESS CAMEL|&amp;#x1fa5b;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|WHITE CHESS GIRAFFE|&amp;#x1fa5c;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|BLACK CHESS GIRAFFE|&amp;#x1fa5d;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|WHITE CHESS DABBABA|&amp;#x1fa5e;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|BLACK CHESS DABBABA|&amp;#x1fa5f;}}
|----- align=&quot;center&quot; style=&quot;background:#d093ff&quot;
!style=&quot;background:#ffffff&quot;|1FA6x
|{{H:title|dotted=no|XIANGQI RED GENERAL|&amp;#x1fa60;}}||{{H:title|dotted=no|XIANGQI RED MANDARIN|&amp;#x1fa61;}}||{{H:title|dotted=no|XIANGQI RED ELEPHANT|&amp;#x1fa62;}}||{{H:title|dotted=no|XIANGQI RED HORSE|&amp;#x1fa63;}}||{{H:title|dotted=no|XIANGQI RED CHARIOT|&amp;#x1fa64;}}||{{H:title|dotted=no|XIANGQI RED CANNON|&amp;#x1fa65;}}||{{H:title|dotted=no|XIANGQI RED SOLDIER|&amp;#x1fa66;}}||{{H:title|dotted=no|XIANGQI BLACK GENERAL|&amp;#x1fa67;}}||{{H:title|dotted=no|XIANGQI BLACK MANDARIN|&amp;#x1fa68;}}||{{H:title|dotted=no|XIANGQI BLACK ELEPHANT|&amp;#x1fa69;}}||{{H:title|dotted=no|XIANGQI BLACK HORSE|&amp;#x1fa6a;}}||{{H:title|dotted=no|XIANGQI BLACK CHARIOT|&amp;#x1fa6b;}}||{{H:title|dotted=no|XIANGQI BLACK CANNON|&amp;#x1fa6c;}}||{{H:title|dotted=no|XIANGQI BLACK SOLDIER|&amp;#x1fa6d;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Symbols and Pictographs Extended-A'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FA7x
|style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BALLET SHOES|&amp;#x1fa70;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|ONE-PIECE SWIMSUIT|&amp;#x1fa71;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BRIEFS|&amp;#x1fa72;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|SHORTS|&amp;#x1fa73;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|THONG SANDAL|&amp;#x1fa74;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|LIGHT BLUE HEART|&amp;#x1fa75;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|GREY HEART|&amp;#x1fa76;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|PINK HEART|&amp;#x1fa77;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|DROP OF BLOOD|&amp;#x1fa78;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|ADHESIVE BANDAGE|&amp;#x1fa79;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|STETHOSCOPE|&amp;#x1fa7a;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|X-RAY|&amp;#x1fa7b;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|CRUTCH|&amp;#x1fa7c;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|BLOOD BAG|&amp;#x1fa7d;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|INHALER|&amp;#x1fa7e;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|BOX OF PILLS|&amp;#x1fa7f;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FA8x
|style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|YO-YO|&amp;#x1fa80;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|KITE|&amp;#x1fa81;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|PARACHUTE|&amp;#x1fa82;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BOOMERANG|&amp;#x1fa83;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|MAGIC WAND|&amp;#x1fa84;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|PINATA|&amp;#x1fa85;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|NESTING DOLLS|&amp;#x1fa86;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|MARACAS|&amp;#x1fa87;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|FLUTE|&amp;#x1fa88;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|HARP|&amp;#x1fa89;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|TROMBONE|&amp;#x1fa8a;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|METEOR|&amp;#x1fa8b;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|ERASER|&amp;#x1fa8c;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|NET WITH HANDLE|&amp;#x1fa8d;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|TREASURE CHEST|&amp;#x1fa8e;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|SHOVEL|&amp;#x1fa8f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FA9x
|style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|RINGED PLANET|&amp;#x1fa90;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|CHAIR|&amp;#x1fa91;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|RAZOR|&amp;#x1fa92;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|AXE|&amp;#x1fa93;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|DIYA LAMP|&amp;#x1fa94;}}||style=&quot;background:#e896ff&quot;|{{H:title|dotted=no|BANJO|&amp;#x1fa95;}}||{{H:title|dotted=no|MILITARY HELMET|&amp;#x1fa96;}}||{{H:title|dotted=no|ACCORDION|&amp;#x1fa97;}}||{{H:title|dotted=no|LONG DRUM|&amp;#x1fa98;}}||{{H:title|dotted=no|COIN|&amp;#x1fa99;}}||{{H:title|dotted=no|CARPENTRY SAW|&amp;#x1fa9a;}}||{{H:title|dotted=no|SCREWDRIVER|&amp;#x1fa9b;}}||{{H:title|dotted=no|LADDER|&amp;#x1fa9c;}}||{{H:title|dotted=no|HOOK|&amp;#x1fa9d;}}||{{H:title|dotted=no|MIRROR|&amp;#x1fa9e;}}||{{H:title|dotted=no|WINDOW|&amp;#x1fa9f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FAAx
|{{H:title|dotted=no|PLUNGER|&amp;#x1faa0;}}||{{H:title|dotted=no|SEWING NEEDLE|&amp;#x1faa1;}}||{{H:title|dotted=no|KNOT|&amp;#x1faa2;}}||{{H:title|dotted=no|BUCKET|&amp;#x1faa3;}}||{{H:title|dotted=no|MOUSE TRAP|&amp;#x1faa4;}}||{{H:title|dotted=no|TOOTHBRUSH|&amp;#x1faa5;}}||{{H:title|dotted=no|HEADSTONE|&amp;#x1faa6;}}||{{H:title|dotted=no|PLACARD|&amp;#x1faa7;}}||{{H:title|dotted=no|ROCK|&amp;#x1faa8;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|MIRROR BALL|&amp;#x1faa9;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|IDENTIFICATION CARD|&amp;#x1faaa;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|LOW BATTERY|&amp;#x1faab;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|HAMSA|&amp;#x1faac;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|FOLDING HAND FAN|&amp;#x1faad;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|HAIR PICK|&amp;#x1faae;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|KHANDA|&amp;#x1faaf;}}
|----- align=&quot;center&quot; style=&quot;background:#edc3b4&quot;
!style=&quot;background:#ffffff&quot;|1FABx
|style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|FLY|&amp;#x1fab0;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|WORM|&amp;#x1fab1;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BEETLE|&amp;#x1fab2;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|COCKROACH|&amp;#x1fab3;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|POTTED PLANT|&amp;#x1fab4;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|WOOD|&amp;#x1fab5;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|FEATHER|&amp;#x1fab6;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|LOTUS|&amp;#x1fab7;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|CORAL|&amp;#x1fab8;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|EMPTY NEST|&amp;#x1fab9;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|NEST WITH EGGS|&amp;#x1faba;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|HYACINTH|&amp;#x1fabb;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|JELLYFISH|&amp;#x1fabc;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|WING|&amp;#x1fabd;}}||{{H:title|dotted=no|LEAFLESS TREE|&amp;#x1fabe;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|GOOSE|&amp;#x1fabf;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FACx
|style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|ANATOMICAL HEART|&amp;#x1fac0;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|LUNGS|&amp;#x1fac1;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|PEOPLE HUGGING|&amp;#x1fac2;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|PREGNANT MAN|&amp;#x1fac3;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|PREGNANT PERSON|&amp;#x1fac4;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|PERSON WITH CROWN|&amp;#x1fac5;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|FINGERPRINT|&amp;#x1fac6;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|LIVER|&amp;#x1fac7;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|HAIRY CREATURE|&amp;#x1fac8;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|CENTAUR|&amp;#x1fac9;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|DRAGONFLY|&amp;#x1faca;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|KIWI BIRD|&amp;#x1facb;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|MONARCH BUTTERFLY|&amp;#x1facc;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|ORCA|&amp;#x1facd;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|MOOSE|&amp;#x1face;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|DONKEY|&amp;#x1facf;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FADx
|style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BLUEBERRIES|&amp;#x1fad0;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|BELL PEPPER|&amp;#x1fad1;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|OLIVE|&amp;#x1fad2;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|FLATBREAD|&amp;#x1fad3;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|TAMALE|&amp;#x1fad4;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|FONDUE|&amp;#x1fad5;}}||style=&quot;background:#ffb0ff&quot;|{{H:title|dotted=no|TEAPOT|&amp;#x1fad6;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|POURING LIQUID|&amp;#x1fad7;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|BEANS|&amp;#x1fad8;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|JAR|&amp;#x1fad9;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|GINGER ROOT|&amp;#x1fada;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|PEA POD|&amp;#x1fadb;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|ROOT VEGETABLE|&amp;#x1fadc;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|PICKLE|&amp;#x1fadd;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|RASPBERRY|&amp;#x1fade;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|SPLATTER|&amp;#x1fadf;}}
|----- align=&quot;center&quot; style=&quot;background:#ffc0e0&quot;
!style=&quot;background:#ffffff&quot;|1FAEx
|{{H:title|dotted=no|MELTING FACE|&amp;#x1fae0;}}||{{H:title|dotted=no|SALUTING FACE|&amp;#x1fae1;}}||{{H:title|dotted=no|FACE WITH OPEN EYES AND HAND OVER MOUTH|&amp;#x1fae2;}}||{{H:title|dotted=no|FACE WITH PEEKING EYE|&amp;#x1fae3;}}||{{H:title|dotted=no|FACE WITH DIAGONAL MOUTH|&amp;#x1fae4;}}||{{H:title|dotted=no|DOTTED LINE FACE|&amp;#x1fae5;}}||{{H:title|dotted=no|BITING LIP|&amp;#x1fae6;}}||{{H:title|dotted=no|BUBBLES|&amp;#x1fae7;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|SHAKING FACE|&amp;#x1fae8;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|FACE WITH BAGS UNDER EYES|&amp;#x1fae9;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|DISTORTED FACE|&amp;#x1faea;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|CRACKING FACE|&amp;#x1faeb;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|FACE WITH SQUINTING EYES|&amp;#x1faec;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|CLEVER FACE|&amp;#x1faed;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|FACE WITH PALM ON CHEEK|&amp;#x1faee;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|FIGHT CLOUD|&amp;#x1faef;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FAFx
|style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|HAND WITH INDEX FINGER AND THUMB CROSSED|&amp;#x1faf0;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|RIGHTWARDS HAND|&amp;#x1faf1;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|LEFTWARDS HAND|&amp;#x1faf2;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|PALM DOWN HAND|&amp;#x1faf3;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|PALM UP HAND|&amp;#x1faf4;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|INDEX POINTING AT THE VIEWER|&amp;#x1faf5;}}||style=&quot;background:#ffc0e0&quot;|{{H:title|dotted=no|HEART HANDS|&amp;#x1faf6;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|LEFTWARDS PUSHING HAND|&amp;#x1faf7;}}||style=&quot;background:#ffc0c0&quot;|{{H:title|dotted=no|RIGHTWARDS PUSHING HAND|&amp;#x1faf8;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|LEFTWARDS THUMB SIGN|&amp;#x1faf9;}}||style=&quot;background:#c8a36f&quot;|{{H:title|dotted=no|RIGHTWARDS THUMB SIGN|&amp;#x1fafa;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|THREE FINGER SALUTE|&amp;#x1fafb;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|HAND SNAPPING FINGERS|&amp;#x1fafc;}}||style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|HAND WITH INDEX FINGER AND THUMB FORMING CIRCLE|&amp;#x1fafd;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|LEG KICKING|&amp;#x1fafe;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|STOMP|&amp;#x1faff;}}
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Symbols for Legacy Computing'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB0x
|{{H:title|dotted=no|BLOCK SEXTANT-1|&amp;#x1fb00;}}||{{H:title|dotted=no|BLOCK SEXTANT-2|&amp;#x1fb01;}}||{{H:title|dotted=no|BLOCK SEXTANT-12|&amp;#x1fb02;}}||{{H:title|dotted=no|BLOCK SEXTANT-3|&amp;#x1fb03;}}||{{H:title|dotted=no|BLOCK SEXTANT-13|&amp;#x1fb04;}}||{{H:title|dotted=no|BLOCK SEXTANT-23|&amp;#x1fb05;}}||{{H:title|dotted=no|BLOCK SEXTANT-123|&amp;#x1fb06;}}||{{H:title|dotted=no|BLOCK SEXTANT-4|&amp;#x1fb07;}}||{{H:title|dotted=no|BLOCK SEXTANT-14|&amp;#x1fb08;}}||{{H:title|dotted=no|BLOCK SEXTANT-24|&amp;#x1fb09;}}||{{H:title|dotted=no|BLOCK SEXTANT-124|&amp;#x1fb0a;}}||{{H:title|dotted=no|BLOCK SEXTANT-34|&amp;#x1fb0b;}}||{{H:title|dotted=no|BLOCK SEXTANT-134|&amp;#x1fb0c;}}||{{H:title|dotted=no|BLOCK SEXTANT-234|&amp;#x1fb0d;}}||{{H:title|dotted=no|BLOCK SEXTANT-1234|&amp;#x1fb0e;}}||{{H:title|dotted=no|BLOCK SEXTANT-5|&amp;#x1fb0f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB1x
|{{H:title|dotted=no|BLOCK SEXTANT-15|&amp;#x1fb10;}}||{{H:title|dotted=no|BLOCK SEXTANT-25|&amp;#x1fb11;}}||{{H:title|dotted=no|BLOCK SEXTANT-125|&amp;#x1fb12;}}||{{H:title|dotted=no|BLOCK SEXTANT-35|&amp;#x1fb13;}}||{{H:title|dotted=no|BLOCK SEXTANT-235|&amp;#x1fb14;}}||{{H:title|dotted=no|BLOCK SEXTANT-1235|&amp;#x1fb15;}}||{{H:title|dotted=no|BLOCK SEXTANT-45|&amp;#x1fb16;}}||{{H:title|dotted=no|BLOCK SEXTANT-145|&amp;#x1fb17;}}||{{H:title|dotted=no|BLOCK SEXTANT-245|&amp;#x1fb18;}}||{{H:title|dotted=no|BLOCK SEXTANT-1245|&amp;#x1fb19;}}||{{H:title|dotted=no|BLOCK SEXTANT-345|&amp;#x1fb1a;}}||{{H:title|dotted=no|BLOCK SEXTANT-1345|&amp;#x1fb1b;}}||{{H:title|dotted=no|BLOCK SEXTANT-2345|&amp;#x1fb1c;}}||{{H:title|dotted=no|BLOCK SEXTANT-12345|&amp;#x1fb1d;}}||{{H:title|dotted=no|BLOCK SEXTANT-6|&amp;#x1fb1e;}}||{{H:title|dotted=no|BLOCK SEXTANT-16|&amp;#x1fb1f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB2x
|{{H:title|dotted=no|BLOCK SEXTANT-26|&amp;#x1fb20;}}||{{H:title|dotted=no|BLOCK SEXTANT-126|&amp;#x1fb21;}}||{{H:title|dotted=no|BLOCK SEXTANT-36|&amp;#x1fb22;}}||{{H:title|dotted=no|BLOCK SEXTANT-136|&amp;#x1fb23;}}||{{H:title|dotted=no|BLOCK SEXTANT-236|&amp;#x1fb24;}}||{{H:title|dotted=no|BLOCK SEXTANT-1236|&amp;#x1fb25;}}||{{H:title|dotted=no|BLOCK SEXTANT-46|&amp;#x1fb26;}}||{{H:title|dotted=no|BLOCK SEXTANT-146|&amp;#x1fb27;}}||{{H:title|dotted=no|BLOCK SEXTANT-1246|&amp;#x1fb28;}}||{{H:title|dotted=no|BLOCK SEXTANT-346|&amp;#x1fb29;}}||{{H:title|dotted=no|BLOCK SEXTANT-1346|&amp;#x1fb2a;}}||{{H:title|dotted=no|BLOCK SEXTANT-2346|&amp;#x1fb2b;}}||{{H:title|dotted=no|BLOCK SEXTANT-12346|&amp;#x1fb2c;}}||{{H:title|dotted=no|BLOCK SEXTANT-56|&amp;#x1fb2d;}}||{{H:title|dotted=no|BLOCK SEXTANT-156|&amp;#x1fb2e;}}||{{H:title|dotted=no|BLOCK SEXTANT-256|&amp;#x1fb2f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB3x
|{{H:title|dotted=no|BLOCK SEXTANT-1256|&amp;#x1fb30;}}||{{H:title|dotted=no|BLOCK SEXTANT-356|&amp;#x1fb31;}}||{{H:title|dotted=no|BLOCK SEXTANT-1356|&amp;#x1fb32;}}||{{H:title|dotted=no|BLOCK SEXTANT-2356|&amp;#x1fb33;}}||{{H:title|dotted=no|BLOCK SEXTANT-12356|&amp;#x1fb34;}}||{{H:title|dotted=no|BLOCK SEXTANT-456|&amp;#x1fb35;}}||{{H:title|dotted=no|BLOCK SEXTANT-1456|&amp;#x1fb36;}}||{{H:title|dotted=no|BLOCK SEXTANT-2456|&amp;#x1fb37;}}||{{H:title|dotted=no|BLOCK SEXTANT-12456|&amp;#x1fb38;}}||{{H:title|dotted=no|BLOCK SEXTANT-3456|&amp;#x1fb39;}}||{{H:title|dotted=no|BLOCK SEXTANT-13456|&amp;#x1fb3a;}}||{{H:title|dotted=no|BLOCK SEXTANT-23456|&amp;#x1fb3b;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL LOWER MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fb3c;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL LOWER MIDDLE LEFT TO LOWER RIGHT|&amp;#x1fb3d;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fb3e;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER RIGHT|&amp;#x1fb3f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB4x
|{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER LEFT TO LOWER CENTRE|&amp;#x1fb40;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL UPPER MIDDLE LEFT TO UPPER CENTRE|&amp;#x1fb41;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL UPPER MIDDLE LEFT TO UPPER RIGHT|&amp;#x1fb42;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER MIDDLE LEFT TO UPPER CENTRE|&amp;#x1fb43;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER MIDDLE LEFT TO UPPER RIGHT|&amp;#x1fb44;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER LEFT TO UPPER CENTRE|&amp;#x1fb45;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER MIDDLE LEFT TO UPPER MIDDLE RIGHT|&amp;#x1fb46;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER CENTRE TO LOWER MIDDLE RIGHT|&amp;#x1fb47;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER LEFT TO LOWER MIDDLE RIGHT|&amp;#x1fb48;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER CENTRE TO UPPER MIDDLE RIGHT|&amp;#x1fb49;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER LEFT TO UPPER MIDDLE RIGHT|&amp;#x1fb4a;}}||{{H:title|dotted=no|LOWER RIGHT BLOCK DIAGONAL LOWER CENTRE TO UPPER RIGHT|&amp;#x1fb4b;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER CENTRE TO UPPER MIDDLE RIGHT|&amp;#x1fb4c;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER LEFT TO UPPER MIDDLE RIGHT|&amp;#x1fb4d;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER CENTRE TO LOWER MIDDLE RIGHT|&amp;#x1fb4e;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER LEFT TO LOWER MIDDLE RIGHT|&amp;#x1fb4f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB5x
|{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER CENTRE TO LOWER RIGHT|&amp;#x1fb50;}}||{{H:title|dotted=no|LOWER LEFT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER MIDDLE RIGHT|&amp;#x1fb51;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL LOWER MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fb52;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL LOWER MIDDLE LEFT TO LOWER RIGHT|&amp;#x1fb53;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fb54;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER RIGHT|&amp;#x1fb55;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER LEFT TO LOWER CENTRE|&amp;#x1fb56;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL UPPER MIDDLE LEFT TO UPPER CENTRE|&amp;#x1fb57;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL UPPER MIDDLE LEFT TO UPPER RIGHT|&amp;#x1fb58;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER MIDDLE LEFT TO UPPER CENTRE|&amp;#x1fb59;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER MIDDLE LEFT TO UPPER RIGHT|&amp;#x1fb5a;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER LEFT TO UPPER CENTRE|&amp;#x1fb5b;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER MIDDLE LEFT TO UPPER MIDDLE RIGHT|&amp;#x1fb5c;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER CENTRE TO LOWER MIDDLE RIGHT|&amp;#x1fb5d;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER LEFT TO LOWER MIDDLE RIGHT|&amp;#x1fb5e;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER CENTRE TO UPPER MIDDLE RIGHT|&amp;#x1fb5f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB6x
|{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER LEFT TO UPPER MIDDLE RIGHT|&amp;#x1fb60;}}||{{H:title|dotted=no|UPPER LEFT BLOCK DIAGONAL LOWER CENTRE TO UPPER RIGHT|&amp;#x1fb61;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER CENTRE TO UPPER MIDDLE RIGHT|&amp;#x1fb62;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER LEFT TO UPPER MIDDLE RIGHT|&amp;#x1fb63;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER CENTRE TO LOWER MIDDLE RIGHT|&amp;#x1fb64;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER LEFT TO LOWER MIDDLE RIGHT|&amp;#x1fb65;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER CENTRE TO LOWER RIGHT|&amp;#x1fb66;}}||{{H:title|dotted=no|UPPER RIGHT BLOCK DIAGONAL UPPER MIDDLE LEFT TO LOWER MIDDLE RIGHT|&amp;#x1fb67;}}||{{H:title|dotted=no|UPPER AND RIGHT AND LOWER TRIANGULAR THREE QUARTERS BLOCK|&amp;#x1fb68;}}||{{H:title|dotted=no|LEFT AND LOWER AND RIGHT TRIANGULAR THREE QUARTERS BLOCK|&amp;#x1fb69;}}||{{H:title|dotted=no|UPPER AND LEFT AND LOWER TRIANGULAR THREE QUARTERS BLOCK|&amp;#x1fb6a;}}||{{H:title|dotted=no|LEFT AND UPPER AND RIGHT TRIANGULAR THREE QUARTERS BLOCK|&amp;#x1fb6b;}}||{{H:title|dotted=no|LEFT TRIANGULAR ONE QUARTER BLOCK|&amp;#x1fb6c;}}||{{H:title|dotted=no|UPPER TRIANGULAR ONE QUARTER BLOCK|&amp;#x1fb6d;}}||{{H:title|dotted=no|RIGHT TRIANGULAR ONE QUARTER BLOCK|&amp;#x1fb6e;}}||{{H:title|dotted=no|LOWER TRIANGULAR ONE QUARTER BLOCK|&amp;#x1fb6f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB7x
|{{H:title|dotted=no|VERTICAL ONE EIGHTH BLOCK-2|&amp;#x1fb70;}}||{{H:title|dotted=no|VERTICAL ONE EIGHTH BLOCK-3|&amp;#x1fb71;}}||{{H:title|dotted=no|VERTICAL ONE EIGHTH BLOCK-4|&amp;#x1fb72;}}||{{H:title|dotted=no|VERTICAL ONE EIGHTH BLOCK-5|&amp;#x1fb73;}}||{{H:title|dotted=no|VERTICAL ONE EIGHTH BLOCK-6|&amp;#x1fb74;}}||{{H:title|dotted=no|VERTICAL ONE EIGHTH BLOCK-7|&amp;#x1fb75;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-2|&amp;#x1fb76;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-3|&amp;#x1fb77;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-4|&amp;#x1fb78;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-5|&amp;#x1fb79;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-6|&amp;#x1fb7a;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-7|&amp;#x1fb7b;}}||{{H:title|dotted=no|LEFT AND LOWER ONE EIGHTH BLOCK|&amp;#x1fb7c;}}||{{H:title|dotted=no|LEFT AND UPPER ONE EIGHTH BLOCK|&amp;#x1fb7d;}}||{{H:title|dotted=no|RIGHT AND UPPER ONE EIGHTH BLOCK|&amp;#x1fb7e;}}||{{H:title|dotted=no|RIGHT AND LOWER ONE EIGHTH BLOCK|&amp;#x1fb7f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB8x
|{{H:title|dotted=no|UPPER AND LOWER ONE EIGHTH BLOCK|&amp;#x1fb80;}}||{{H:title|dotted=no|HORIZONTAL ONE EIGHTH BLOCK-1358|&amp;#x1fb81;}}||{{H:title|dotted=no|UPPER ONE QUARTER BLOCK|&amp;#x1fb82;}}||{{H:title|dotted=no|UPPER THREE EIGHTHS BLOCK|&amp;#x1fb83;}}||{{H:title|dotted=no|UPPER FIVE EIGHTHS BLOCK|&amp;#x1fb84;}}||{{H:title|dotted=no|UPPER THREE QUARTERS BLOCK|&amp;#x1fb85;}}||{{H:title|dotted=no|UPPER SEVEN EIGHTHS BLOCK|&amp;#x1fb86;}}||{{H:title|dotted=no|RIGHT ONE QUARTER BLOCK|&amp;#x1fb87;}}||{{H:title|dotted=no|RIGHT THREE EIGHTHS BLOCK|&amp;#x1fb88;}}||{{H:title|dotted=no|RIGHT FIVE EIGHTHS BLOCK|&amp;#x1fb89;}}||{{H:title|dotted=no|RIGHT THREE QUARTERS BLOCK|&amp;#x1fb8a;}}||{{H:title|dotted=no|RIGHT SEVEN EIGHTHS BLOCK|&amp;#x1fb8b;}}||{{H:title|dotted=no|LEFT HALF MEDIUM SHADE|&amp;#x1fb8c;}}||{{H:title|dotted=no|RIGHT HALF MEDIUM SHADE|&amp;#x1fb8d;}}||{{H:title|dotted=no|UPPER HALF MEDIUM SHADE|&amp;#x1fb8e;}}||{{H:title|dotted=no|LOWER HALF MEDIUM SHADE|&amp;#x1fb8f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FB9x
|{{H:title|dotted=no|INVERSE MEDIUM SHADE|&amp;#x1fb90;}}||{{H:title|dotted=no|UPPER HALF BLOCK AND LOWER HALF INVERSE MEDIUM SHADE|&amp;#x1fb91;}}||{{H:title|dotted=no|UPPER HALF INVERSE MEDIUM SHADE AND LOWER HALF BLOCK|&amp;#x1fb92;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||{{H:title|dotted=no|LEFT HALF INVERSE MEDIUM SHADE AND RIGHT HALF BLOCK|&amp;#x1fb94;}}||{{H:title|dotted=no|CHECKER BOARD FILL|&amp;#x1fb95;}}||{{H:title|dotted=no|INVERSE CHECKER BOARD FILL|&amp;#x1fb96;}}||{{H:title|dotted=no|HEAVY HORIZONTAL FILL|&amp;#x1fb97;}}||{{H:title|dotted=no|UPPER LEFT TO LOWER RIGHT FILL|&amp;#x1fb98;}}||{{H:title|dotted=no|UPPER RIGHT TO LOWER LEFT FILL|&amp;#x1fb99;}}||{{H:title|dotted=no|UPPER AND LOWER TRIANGULAR HALF BLOCK|&amp;#x1fb9a;}}||{{H:title|dotted=no|LEFT AND RIGHT TRIANGULAR HALF BLOCK|&amp;#x1fb9b;}}||{{H:title|dotted=no|UPPER LEFT TRIANGULAR MEDIUM SHADE|&amp;#x1fb9c;}}||{{H:title|dotted=no|UPPER RIGHT TRIANGULAR MEDIUM SHADE|&amp;#x1fb9d;}}||{{H:title|dotted=no|LOWER RIGHT TRIANGULAR MEDIUM SHADE|&amp;#x1fb9e;}}||{{H:title|dotted=no|LOWER LEFT TRIANGULAR MEDIUM SHADE|&amp;#x1fb9f;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FBAx
|{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE LEFT|&amp;#x1fba0;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE RIGHT|&amp;#x1fba1;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fba2;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE RIGHT TO LOWER CENTRE|&amp;#x1fba3;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fba4;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE RIGHT TO LOWER CENTRE|&amp;#x1fba5;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE LEFT TO LOWER CENTRE TO MIDDLE RIGHT|&amp;#x1fba6;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE LEFT TO UPPER CENTRE TO MIDDLE RIGHT|&amp;#x1fba7;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE LEFT AND MIDDLE RIGHT TO LOWER CENTRE|&amp;#x1fba8;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE RIGHT AND MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fba9;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE RIGHT TO LOWER CENTRE TO MIDDLE LEFT|&amp;#x1fbaa;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO MIDDLE LEFT TO LOWER CENTRE TO MIDDLE RIGHT|&amp;#x1fbab;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE LEFT TO UPPER CENTRE TO MIDDLE RIGHT TO LOWER CENTRE|&amp;#x1fbac;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE RIGHT TO UPPER CENTRE TO MIDDLE LEFT TO LOWER CENTRE|&amp;#x1fbad;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL DIAMOND|&amp;#x1fbae;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT HORIZONTAL WITH VERTICAL STROKE|&amp;#x1fbaf;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FBBx
|{{H:title|dotted=no|ARROWHEAD-SHAPED POINTER|&amp;#x1fbb0;}}||{{H:title|dotted=no|INVERSE CHECK MARK|&amp;#x1fbb1;}}||{{H:title|dotted=no|LEFT HALF RUNNING MAN|&amp;#x1fbb2;}}||{{H:title|dotted=no|RIGHT HALF RUNNING MAN|&amp;#x1fbb3;}}||{{H:title|dotted=no|INVERSE DOWNWARDS ARROW WITH TIP LEFTWARDS|&amp;#x1fbb4;}}||{{H:title|dotted=no|LEFTWARDS ARROW AND UPPER AND LOWER ONE EIGHTH BLOCK|&amp;#x1fbb5;}}||{{H:title|dotted=no|RIGHTWARDS ARROW AND UPPER AND LOWER ONE EIGHTH BLOCK|&amp;#x1fbb6;}}||{{H:title|dotted=no|DOWNWARDS ARROW AND RIGHT ONE EIGHTH BLOCK|&amp;#x1fbb7;}}||{{H:title|dotted=no|UPWARDS ARROW AND RIGHT ONE EIGHTH BLOCK|&amp;#x1fbb8;}}||{{H:title|dotted=no|LEFT HALF FOLDER|&amp;#x1fbb9;}}||{{H:title|dotted=no|RIGHT HALF FOLDER|&amp;#x1fbba;}}||{{H:title|dotted=no|VOIDED GREEK CROSS|&amp;#x1fbbb;}}||{{H:title|dotted=no|RIGHT OPEN SQUARED DOT|&amp;#x1fbbc;}}||{{H:title|dotted=no|NEGATIVE DIAGONAL CROSS|&amp;#x1fbbd;}}||{{H:title|dotted=no|NEGATIVE DIAGONAL MIDDLE RIGHT TO LOWER CENTRE|&amp;#x1fbbe;}}||{{H:title|dotted=no|NEGATIVE DIAGONAL DIAMOND|&amp;#x1fbbf;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FBCx
|{{H:title|dotted=no|WHITE HEAVY SALTIRE WITH ROUNDED CORNERS|&amp;#x1fbc0;}}||{{H:title|dotted=no|LEFT THIRD WHITE RIGHT POINTING INDEX|&amp;#x1fbc1;}}||{{H:title|dotted=no|MIDDLE THIRD WHITE RIGHT POINTING INDEX|&amp;#x1fbc2;}}||{{H:title|dotted=no|RIGHT THIRD WHITE RIGHT POINTING INDEX|&amp;#x1fbc3;}}||{{H:title|dotted=no|NEGATIVE SQUARED QUESTION MARK|&amp;#x1fbc4;}}||{{H:title|dotted=no|STICK FIGURE|&amp;#x1fbc5;}}||{{H:title|dotted=no|STICK FIGURE WITH ARMS RAISED|&amp;#x1fbc6;}}||{{H:title|dotted=no|STICK FIGURE LEANING LEFT|&amp;#x1fbc7;}}||{{H:title|dotted=no|STICK FIGURE LEANING RIGHT|&amp;#x1fbc8;}}||{{H:title|dotted=no|STICK FIGURE WITH DRESS|&amp;#x1fbc9;}}||{{H:title|dotted=no|WHITE UP-POINTING CHEVRON|&amp;#x1fbca;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|WHITE CROSS MARK|&amp;#x1fbcb;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|RAISED SMALL LEFT SQUARE BRACKET|&amp;#x1fbcc;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|BLACK SMALL UP-POINTING CHEVRON|&amp;#x1fbcd;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|LEFT TWO THIRDS BLOCK|&amp;#x1fbce;}}||style=&quot;background:#edc3b4&quot;|{{H:title|dotted=no|LEFT ONE THIRD BLOCK|&amp;#x1fbcf;}}
|----- align=&quot;center&quot; style=&quot;background:#edc3b4&quot;
!style=&quot;background:#ffffff&quot;|1FBDx
|{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE RIGHT TO LOWER LEFT|&amp;#x1fbd0;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER RIGHT TO MIDDLE LEFT|&amp;#x1fbd1;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO MIDDLE RIGHT|&amp;#x1fbd2;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL MIDDLE LEFT TO LOWER RIGHT|&amp;#x1fbd3;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO LOWER CENTRE|&amp;#x1fbd4;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO LOWER RIGHT|&amp;#x1fbd5;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER RIGHT TO LOWER CENTRE|&amp;#x1fbd6;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER CENTRE TO LOWER LEFT|&amp;#x1fbd7;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO MIDDLE CENTRE TO UPPER RIGHT|&amp;#x1fbd8;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER RIGHT TO MIDDLE CENTRE TO LOWER RIGHT|&amp;#x1fbd9;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL LOWER LEFT TO MIDDLE CENTRE TO LOWER RIGHT|&amp;#x1fbda;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO MIDDLE CENTRE TO LOWER LEFT|&amp;#x1fbdb;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO LOWER CENTRE TO UPPER RIGHT|&amp;#x1fbdc;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER RIGHT TO MIDDLE LEFT TO LOWER RIGHT|&amp;#x1fbdd;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL LOWER LEFT TO UPPER CENTRE TO LOWER RIGHT|&amp;#x1fbde;}}||{{H:title|dotted=no|BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO MIDDLE RIGHT TO LOWER LEFT|&amp;#x1fbdf;}}
|----- align=&quot;center&quot; style=&quot;background:#edc3b4&quot;
!style=&quot;background:#ffffff&quot;|1FBEx
|{{H:title|dotted=no|TOP JUSTIFIED LOWER HALF WHITE CIRCLE|&amp;#x1fbe0;}}||{{H:title|dotted=no|RIGHT JUSTIFIED LEFT HALF WHITE CIRCLE|&amp;#x1fbe1;}}||{{H:title|dotted=no|BOTTOM JUSTIFIED UPPER HALF WHITE CIRCLE|&amp;#x1fbe2;}}||{{H:title|dotted=no|LEFT JUSTIFIED RIGHT HALF WHITE CIRCLE|&amp;#x1fbe3;}}||{{H:title|dotted=no|UPPER CENTRE ONE QUARTER BLOCK|&amp;#x1fbe4;}}||{{H:title|dotted=no|LOWER CENTRE ONE QUARTER BLOCK|&amp;#x1fbe5;}}||{{H:title|dotted=no|MIDDLE LEFT ONE QUARTER BLOCK|&amp;#x1fbe6;}}||{{H:title|dotted=no|MIDDLE RIGHT ONE QUARTER BLOCK|&amp;#x1fbe7;}}||{{H:title|dotted=no|TOP JUSTIFIED LOWER HALF BLACK CIRCLE|&amp;#x1fbe8;}}||{{H:title|dotted=no|RIGHT JUSTIFIED LEFT HALF BLACK CIRCLE|&amp;#x1fbe9;}}||{{H:title|dotted=no|BOTTOM JUSTIFIED UPPER HALF BLACK CIRCLE|&amp;#x1fbea;}}||{{H:title|dotted=no|LEFT JUSTIFIED RIGHT HALF BLACK CIRCLE|&amp;#x1fbeb;}}||{{H:title|dotted=no|TOP RIGHT JUSTIFIED LOWER LEFT QUARTER BLACK CIRCLE|&amp;#x1fbec;}}||{{H:title|dotted=no|BOTTOM LEFT JUSTIFIED UPPER RIGHT QUARTER BLACK CIRCLE|&amp;#x1fbed;}}||{{H:title|dotted=no|BOTTOM RIGHT JUSTIFIED UPPER LEFT QUARTER BLACK CIRCLE|&amp;#x1fbee;}}||{{H:title|dotted=no|TOP LEFT JUSTIFIED LOWER RIGHT QUARTER BLACK CIRCLE|&amp;#x1fbef;}}
|----- align=&quot;center&quot; style=&quot;background:#ffb0ff&quot;
!style=&quot;background:#ffffff&quot;|1FBFx
|{{H:title|dotted=no|SEGMENTED DIGIT ZERO|&amp;#x1fbf0;}}||{{H:title|dotted=no|SEGMENTED DIGIT ONE|&amp;#x1fbf1;}}||{{H:title|dotted=no|SEGMENTED DIGIT TWO|&amp;#x1fbf2;}}||{{H:title|dotted=no|SEGMENTED DIGIT THREE|&amp;#x1fbf3;}}||{{H:title|dotted=no|SEGMENTED DIGIT FOUR|&amp;#x1fbf4;}}||{{H:title|dotted=no|SEGMENTED DIGIT FIVE|&amp;#x1fbf5;}}||{{H:title|dotted=no|SEGMENTED DIGIT SIX|&amp;#x1fbf6;}}||{{H:title|dotted=no|SEGMENTED DIGIT SEVEN|&amp;#x1fbf7;}}||{{H:title|dotted=no|SEGMENTED DIGIT EIGHT|&amp;#x1fbf8;}}||{{H:title|dotted=no|SEGMENTED DIGIT NINE|&amp;#x1fbf9;}}||style=&quot;background:#ddb495&quot;|{{H:title|dotted=no|ALARM BELL SYMBOL|&amp;#x1fbfa;}}||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;||style=&quot;background:#777777&quot;|&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | ''Unassigned''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FC9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FCAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FCBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FCCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FCDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FCEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FCFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Symbols and Pictographs Extended-B'''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD0x
|style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|RECTANGULAR TABLE|&amp;#x1fd00;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|ESCALATOR|&amp;#x1fd01;}}||style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|BULLDOZER|&amp;#x1fd02;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|FLAT TYRE|&amp;#x1fd03;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|EARTHQUAKE|&amp;#x1fd04;}}||style=&quot;background:#457d8a&quot;|{{H:title|dotted=no|TRICYCLE|&amp;#x1fd05;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD1x
|style=&quot;background:#bba757&quot;|{{H:title|dotted=no|NAIL CLIPPER|&amp;#x1fd10;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|TOOTHPASTE|&amp;#x1fd11;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|PLIER|&amp;#x1fd12;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|KNIFE WITH CUTTING BOARD|&amp;#x1fd13;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|RAKE|&amp;#x1fd14;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|TISSUE BOX|&amp;#x1fd15;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|CLOTHES HANGER|&amp;#x1fd16;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|DRILL|&amp;#x1fd17;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|SEWING BUTTON|&amp;#x1fd18;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|COOKING POT|&amp;#x1fd19;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|APRON|&amp;#x1fd1a;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|BINOCULARS|&amp;#x1fd1b;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|INCENSE|&amp;#x1fd1c;}}||style=&quot;background:#768b4a&quot;|{{H:title|dotted=no|PIGGY BANK|&amp;#x1fd1d;}}||style=&quot;background:#768b4a&quot;|{{H:title|dotted=no|SPRAY CAN|&amp;#x1fd1e;}}||style=&quot;background:#768b4a&quot;|{{H:title|dotted=no|PERFUME GLASS BOTTLE|&amp;#x1fd1f;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD2x
|style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|GOLD BAR|&amp;#x1fd20;}}||style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|CYMBALS|&amp;#x1fd21;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|XYLOPHONE|&amp;#x1fd22;}}||style=&quot;background:#457d8a&quot;|{{H:title|dotted=no|CONCRETE BLOCK|&amp;#x1fd23;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD4x
|style=&quot;background:#bba757&quot;|{{H:title|dotted=no|LEEK|&amp;#x1fd40;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|GRAPEFRUIT|&amp;#x1fd41;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|ICE POP|&amp;#x1fd42;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|CINNAMON STICKS|&amp;#x1fd43;}}||style=&quot;background:#768b4a&quot;|{{H:title|dotted=no|SUGAR CUBES|&amp;#x1fd44;}}||style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|POMEGRANATE|&amp;#x1fd45;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|DRAGON FRUIT|&amp;#x1fd46;}}||style=&quot;background:#457d8a&quot;|{{H:title|dotted=no|TOFFEE|&amp;#x1fd47;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD5x
|style=&quot;background:#bba757&quot;|{{H:title|dotted=no|ORCHID|&amp;#x1fd50;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|CHAMELEON|&amp;#x1fd51;}}||style=&quot;background:#aeaf4a&quot;|{{H:title|dotted=no|OSTRICH|&amp;#x1fd52;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|MOLE|&amp;#x1fd53;}}||style=&quot;background:#97a24a&quot;|{{H:title|dotted=no|MARIGOLD|&amp;#x1fd54;}}||style=&quot;background:#5d7e4a&quot;|{{H:title|dotted=no|WOMBAT|&amp;#x1fd55;}}||style=&quot;background:#457d6d&quot;|{{H:title|dotted=no|SEAHORSE|&amp;#x1fd56;}}||style=&quot;background:#457d8a&quot;|{{H:title|dotted=no|TOUCAN|&amp;#x1fd57;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD7x
|style=&quot;background:#bba757&quot;|{{H:title|dotted=no|STOMACH|&amp;#x1fd70;}}||style=&quot;background:#bba757&quot;|{{H:title|dotted=no|INTESTINE|&amp;#x1fd71;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD8x
|style=&quot;background:#768b4a&quot;|{{H:title|dotted=no|FACE REVEALING FACE|&amp;#x1fd80;}}||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FD9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FDAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FDBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FDCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FDDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FDEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FDFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | ''Unassigned''
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FE9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FEAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FEBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FECx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FEDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|1FEEx
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  <page>
    <title>Wikibooks:Reading room/Proposals</title>
    <ns>4</ns>
    <id>155682</id>
    <revision>
      <id>4636922</id>
      <parentid>4636401</parentid>
      <timestamp>2026-05-21T18:51:46Z</timestamp>
      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>/* Allow all users (registered and unregistered) to view edit filters and their logs? */ reply: I filed [[phab:T426992]]. (-) ([[mw:c:Special:MyLanguage/User:JWBTH/CD|CD]])</comment>
      <origin>4636922</origin>
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      <text bytes="26021" sha1="50n5fwerz5oam6dw960xbu8c39oc9an" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:RFC|WB:PROPOSALS}} {{TOC left&lt;!--|limit=2--&gt;}}

Welcome to the '''Proposals reading room'''. On this page, Wikibookians are free to talk about suggestions for improving Wikibooks.

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== Create a &quot;file&quot; that is an Example Book structured to be copied/used to quickly start a new book? ==

I am new to Wikibooks, if this already exists let me know.... 

If there was a Wikibook &quot;file&quot; that contained all the templates and &quot;parts&quot; that are used to create a properly structured book, it might be easier and quicker to create and contribute books here. This would have to include text that would explain the purpose of each of the sections and templates and offer advice for making changes that customize the example.  

One might copy it to their sandbox, follow the directions and make the updates that create the framework for their book. Then the work would be to fill in the text. I suppose the downside is that books would be categorized and shelved that are in progress. Abandoned books would need to be deleted or some template might need to be developed that might indicate that the book is incomplete. This would be removed when the book is ready for prime-time.
{{unsigned|Rchaswms01|01:32, 3 February 2026}}

== Allow all users (registered and unregistered) to view edit filters and their logs? ==

Hello, everyone. I would like to propose allowing all users to view not just edit filters and [[Special:AbuseLog|their log]], but also detailed edit filter log entries. In addition to that, I am also proposing that we set &lt;code&gt;$wgAbuseFilterNotifications&lt;/code&gt; to &lt;code&gt;true&lt;/code&gt; by removing &lt;code&gt;$wgAbuseFilterNotifications = false;&lt;/code&gt;.

{{collapse top|This proposal aims to reverse a part of [[phab:T26304]] for the AbuseFilter extension:}}
&lt;syntaxhighlight lang=&quot;wikitext&quot;&gt;
We would like to enable the AbuseFilter extension (see below) with custom permissions. Please *add*:

$wgGroupPermissions['*']['abusefilter-view'] = false;
$wgGroupPermissions['*']['abusefilter-log'] = false;
$wgGroupPermissions['autoconfirmed']['abusefilter-view'] = true;
$wgGroupPermissions['autoconfirmed']['abusefilter-log'] = true;
&lt;/syntaxhighlight&gt;
&lt;syntaxhighlight lang=&quot;wikitext&quot;&gt;
I'm sorry for yet another reply, but the user rights for the abuse filter need to be tweaked to match the request.

abusefilter-view should be for autoconfirmed/confirmed only and not for all users.

abusefilter-log should be for autoconfirmed/confirmed only and not for all users.

The logic behind this was to prevent casual vandals from gaming the system.

Thank you for your efforts.
&lt;/syntaxhighlight&gt;
{{collapse bottom}}
{{collapse top|Current configuration}}
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
case 'enwikibooks':
	$wgGroupPermissions['*']['abusefilter-view'] = false;
	$wgGroupPermissions['*']['abusefilter-log'] = false;
	$wgAbuseFilterNotifications = false;
	$wgGroupPermissions['autoconfirmed']['abusefilter-view'] = true;
	$wgGroupPermissions['autoconfirmed']['abusefilter-log'] = true;
	$wgGroupPermissions['autoconfirmed']['abusefilter-log-detail'] = true; // T383332
	$wgGroupPermissions['sysop']['abusefilter-revert'] = true; // T411828
	$wgAbuseFilterActions['block'] = true; // T273864
	break;
&lt;/syntaxhighlight&gt;
{{collapse bottom}}

{{collapse top|Proposed configuration}}
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
case 'enwikibooks':
	$wgGroupPermissions['*']['abusefilter-log-detail'] = true;
	$wgGroupPermissions['sysop']['abusefilter-revert'] = true; // T411828
	$wgAbuseFilterActions['block'] = true; // T273864
	break;
&lt;/syntaxhighlight&gt;
{{collapse bottom}}
Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:55, 2 April 2026 (UTC)

:See also: {{section link|Wikibooks:Reading room/Proposals/2025/January#Reforming the edit filter}}. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 22:50, 2 April 2026 (UTC)
:I would support. It's worth noting that filters can be marked as private if it's a necessity to keep the logs not visible to everyone on the internet (if, for example, one is targeting a long-term abuser). The usual anti-vandalism filters are almost certainly never going to be looked through by the average opportunistic vandal, and it's an unnecessary hinderance to non-admins to have filters hidden without much of a reason. [[User:EggRoll97|EggRoll97]] ([[User talk:EggRoll97|discuss]] • [[Special:Contributions/EggRoll97|contribs]]) 06:30, 19 May 2026 (UTC)
: I filed [[phab:T426992]]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:51, 21 May 2026 (UTC)

== Introduce speedy deletion criteria? ==

I would like to propose that we introduce speedy deletion criteria to Wikibooks, such as {{tq|G1: [reason]}}. I suggest that we adapt from the English Wikipedia's CSD criteria ([[:w:Wikipedia:Speedy deletion]]) but utilize our existing deletion reasons, and even include '''G''' for general, '''R''' for redirects, and so on.

Speedy deletion reasons are already included in the [[Wikibooks:Deletion policy|deletion policy]], but should this proposal pass, the new speedy deletion criteria can be split out to a separate policy page, if needed (e.g. [[Wikibooks:Speedy deletion]]).

Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 14:39, 7 April 2026 (UTC)

:On the whole, that seems like it could be useful to expand out our CSD in a more detailed way. Why don't you go ahead and create [[Wikibooks:Speedy deletion]] as a draft, write out your initial proposal, and then we can workshop it together? —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 15:33, 10 April 2026 (UTC)
:@[[User:Codename Noreste|Codename Noreste]]: How can this proposal avoid accusations of [[m:Instruction creep|instruction creep]]? [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 23:21, 14 April 2026 (UTC)
:: How does instruction creep have anything to do with this? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 23:31, 14 April 2026 (UTC)
::: Well, in that case, we might keep the descriptions simple, not overly detailed. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:30, 17 April 2026 (UTC)
::::In that case, we may need to introduce that motion. – [[User:RestoreAccess111|RestoreAccess111]] &lt;sup style=&quot;font-family:Arimo, Arial;&quot;&gt;[[User talk:RestoreAccess111|Talk!]]&lt;/sup&gt; &lt;sup style=&quot;font-family:Times New Roman, Tinos;&quot;&gt;[[Special:Contributions/RestoreAccess111|Watch!]]&lt;/sup&gt; 04:38, 17 April 2026 (UTC)
:We already have speedy deletion though so I don't understand this proposal. [[User:Leaderboard|Leaderboard]] ([[User talk:Leaderboard|discuss]] • [[Special:Contributions/Leaderboard|contribs]]) 15:56, 24 April 2026 (UTC)
:@[[User:Codename Noreste|Codename Noreste]] I created a very early draft in [[User:Kingofnuthin/sandbox|my sandbox]] by merging content from [[w:Wikipedia:Speedy deletion]] and [[Wikibooks:Deletion policy]]. I added most of the criteria from English Wikipedia's page but I left some that can't be in Wikibooks (such as notability criteria). As I said, the draft is currently very undetailed and only provides simple explanations for criteria except for a few of them.  You can add this draft to [[Wikibooks:Speedy deletion]] to clarify the details of the proposal. I am also open to any feedback regarding the draft. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:11, 26 April 2026 (UTC)
:: I moved your draft to [[Wikibooks:Speedy deletion]]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:15, 26 April 2026 (UTC)
::This generally looks good; I've got a couple comments on specific criteria:
::* &quot;G5. Pages dependent on a non-existent or deleted page&quot; includes subpages with no parent page. Given the extent to which Wikibooks uses page nesting, this seems risky - at a minimum, the criterion should be revised to &quot;subpages with no parent '''book'''&quot;, and existing pages which meet this criterion should be grandfathered in or otherwise addressed.
::* &quot;B4. Books that duplicate an existing topic&quot; should probably be removed. Unlike Wikipedia, Wikibooks has historically allowed multiple books to address the same topic, e.g. [[Mandarin Chinese]] and [[Chinese (Mandarin)]], or [[C++ Language]] and [[C++ Programming]]. Whether a book &quot;expands upon, details or improves information&quot; in another book is very subjective; determining whether this is the case should be handled in a deletion discussion, not by an admin processing speedy deletions.
::Additionally, I'd suggest that three criteria be added:
::* Books which are over a week old and which contain no instructional content (e.g. books which are nothing but a table of contents). These books are already routinely deleted under [[WB:NMC]]; adopting this as a CSD streamlines the process.
::* Pages in any namespace which are unambiguously advertisements or promotional in nature (akin to [[:w:WP:CSD#G11]]).
::* Pages in any namespace which infringe upon copyright, akin to [[:w:WP:CSD#G12]]. F6/F7 address ''files'' which are copyvios, but not text.
::[[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 05:54, 29 April 2026 (UTC)
::: [[User:Omphalographer|Omphalographer]], feel free to make those changes to [[Wikibooks:Speedy deletion]], from your comments. It's a draft proposal. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 14:21, 29 April 2026 (UTC)
:::@[[User:Omphalographer|Omphalographer]]: I agree on your thoughts for the removal of B4 and the addition of a new general criterion for copyvios, so I did those. However, I think that G5 is fine in its current state. I don't understand what situation would be &quot;risky&quot; in this case, so please provide some example for that. Additionally, I don't think we need an advertisement criterion right now, as Wikibooks does not seem to have a promotion problem, as it is a collection of textbooks. Also, you mentioned [[Wikibooks:NMC]] as a new criterion even though I copy-pasted criterion G1 from the exact part you mentioned. Such pages could be deleted under G1. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:06, 29 April 2026 (UTC)
::::With regards to G5, I've seen some situations where a book was incorrectly renamed in such a way that some of the subpages remained under the original title of the book, or pages of a book are inadvertently created under an incorrect title. Given the proposed wording for G5, those pages would be eligible for speedy deletion, even though they are in use as part of the book.
::::With regards to advertisements, Wikibooks does get some spam page creations; you'll see some if you scroll through [https://en.wikibooks.org/wiki/Special:Log?type=delete the deletion log]. It's typically deleted quickly by admins, but if we're codifying criteria for speedy deletion, this should be included as an allowable reason.
::::As far as G1 / NMC is concerned, I initially read G1 as applying only to pages which contain no meaningful content at all, like pages which are empty, nonsense, or vandalism, and which should be deleted promptly. I see this as distinct from books which are superficially well-formed, but which fail to develop, e.g. a user who creates an ambitious-sounding table of contents for a book, but never returns to write any of the text. These shouldn't be deleted immediately (since it takes time to write content!), but are routinely speedily deleted once it's clear that no further content is forthcoming. Since this is a bit of a different process, it should probably be treated as a separate criterion. [[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 17:28, 29 April 2026 (UTC)
:::::I added &quot;Editors should be careful when nominating such pages, as they might be incorrectly named instead. In such cases, editors should move the page to its correctly-titled version.&quot; to G5. For advertising you said &quot;Wikibooks does get some spam page creations&quot;, but we already have &quot;Spam and vandalism&quot; for G1. In G1, I removed &quot;abandoned content&quot; and made it a new criterion B5 under the book section. (As this would only apply to books.) [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 17:43, 29 April 2026 (UTC)
:Quite frankly I don't see the need for a wiki of this size, in addition to what {{u|Leaderboard}} has mentioned. The current reasonings are perfectly fine, and subtly discourage the use of using abbreviations meaningless to new users. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 05:51, 4 May 2026 (UTC)
::Maybe we could do it without abbreviations, whilst keeping the categories. Our current speedy deletion policy is too short, and only includes main and userspace pages. We need more criteria for the Cookbook and Wikijunior for example. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 12:21, 4 May 2026 (UTC)
:::But why? [[:w:Wikipedia:If it ain't broke, don't fix it|If it ain't broke, don't fix it]]. Cookbook and Wikijunior for all purposes of policy can generally be implied to be mainspace pages. I find this really overkill for a wiki of this size. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 07:55, 5 May 2026 (UTC)
::::I have to agree with SHB2000 here. One perk of a wiki like this is that we have rules when needed, but we don't put a rule for the sake for it. I haven't had anyone tell that they can't perform their tasks, and it's not like there's a lot of pages to delete. [[User:Leaderboard|Leaderboard]] ([[User talk:Leaderboard|discuss]] • [[Special:Contributions/Leaderboard|contribs]]) 12:44, 7 May 2026 (UTC)
::My other worry with this change is that it removes a ''lot'' of flexibility when it comes to page deletions. That's especially crucial on a wiki like this where there is a lot of abandoned content lying around; I thus {{oppose}} this proposal in any form. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 10:11, 6 May 2026 (UTC)
::: In my [[User:Codename Noreste/sandbox|sandbox]], I changed from criterion number to {{tq|Speedy deletion:}} in accordance with kingofnuthin. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 20:43, 17 May 2026 (UTC)

== Questions about [[Wikibooks:Annotated texts]] ==

I was recently reading over the policy on annotated texts and had a few questions aimed at reforming that policy. (The talk page for the policy has been inactive for eleven years, so I figured a post there would be unlikely to attract attention.)

# First and foremost - how many annotated texts of the type described by this policy are actually hosted on Wikibooks? I am only aware of one, [[Annotations to James Joyce's Ulysses]], which is quite incomplete. Are there a significant number more that I am unable to find? If not, might it be appropriate to revise this policy and related documents to reflect that annotated texts are, at best, an experimental part of the project?
# The policy on annotated texts currently permits '''unannotated''' source texts to be hosted on Wikibooks provided that either the text is not on Wikisource, or that it is &quot;widely used in classrooms&quot;. This seems like a rather large unintended loophole in the policy - there are innumerable texts which have not been transcribed on Wikisource, but which it would not make sense for Wikibooks to house either. Similarly, there are many texts which are &quot;widely used in classrooms&quot;, but which have never been annotated on Wikibooks and are unlikely to ever be. The policy also notes the possibility that a multilingual project could create annotated texts with parallel page names across all language editions; I am certainly unaware of any such. Are there any texts on Wikibooks which rely on this policy, or would it be appropriate to strike this section?
[[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 18:54, 28 April 2026 (UTC)

:The policy seems to be contradicting [[Wikibooks:SOURCE]], which states that annotated texts are the only exception to published texts being on Wikibooks. This means that we have a policy that says unannotated source texts are permitted, and another one that says they aren't allowed. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 19:02, 28 April 2026 (UTC)
:There is also [[Annotations of The Complete Peanuts]]. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 14:26, 29 April 2026 (UTC)
::That isn't an annotated text of the type described by this policy, as it doesn't include the original text that's being commented on. (Which it can't, because ''Peanuts'' is still under copyright.) [[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 16:29, 29 April 2026 (UTC)
:::Correct, it is not an inline annotation: I was just pointing it out as another kind of annotated text here.
:::For what it's worth, our sister project Wikisource [[:s:en:Category:Wikisource annotations|also hosts inline annotations]], such as [[:s:en:What to the Slave Is the Fourth of July?/Annotated]], which I made. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 16:33, 29 April 2026 (UTC)
:::The main problem here is that the policy permits &quot;unannotated texts&quot; even though we don't host them here. I think that the first thing you mentioned can stay but we might need to strike out the second part from the policy as it is contradictory. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:38, 29 April 2026 (UTC)
::::Yeah - I certainly don't mean to suggest that the ''Ulysses'' annotations need to go away; I'm mostly curious if this policy has any wider applicability, or if its only function is to allow this one text. [[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 17:37, 29 April 2026 (UTC)

== Proposal related to FlaggedRevs ==

As said per [[Wikibooks:Reading room/General#Page patrolling]], I would like to propose the following:
# &lt;code&gt;$wgUseNPPatrol&lt;/code&gt; and &lt;code&gt;$wgUseFilePatrol&lt;/code&gt; are both to be set to &lt;code&gt;false&lt;/code&gt;.
# &lt;code&gt;autopatrol&lt;/code&gt; and &lt;code&gt;patrol&lt;/code&gt; are to be removed from some user groups on this wiki.
This is because FlaggedRevs is used to review new pages and edits, so I don't think MediaWiki's native patrol function is needed here. It's similar to [[phab:T423461]] (completely turning off the new page patrol function on Ukrainian Wikipedia).

In addition, I would like to propose we move the following interface pages once after the below configuration has been implemented:
* [[MediaWiki:Revreview-value]] to [[MediaWiki:Revreview-accuracy]]
* [[MediaWiki:Revreview-value-1]] to [[MediaWiki:Revreview-accuracy-1]]
* [[MediaWiki:Revreview-value-2]] to [[MediaWiki:Revreview-accuracy-2]]
* [[MediaWiki:Revreview-value-3]] to [[MediaWiki:Revreview-accuracy-3]]
I don't really see a reason why we should use {{tq|value}} instead of {{tq|accuracy}} to stand out, when some other projects use {{tq|accuracy}}.
{{collapse top|Proposed configuration}}
=== core-Permissions.php ===
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
'+enwikibooks' =&gt; [
	'bot' =&gt; [ 'autopatrol' =&gt; false, ],
	'editor' =&gt; [
		'rollback' =&gt; true,
		'suppressredirect' =&gt; true,
	],
	'flood' =&gt; [ 'bot' =&gt; true ],
	'sysop' =&gt; [
		'autopatrol' =&gt; false,
		'patrol' =&gt; false,
		'importupload' =&gt; true, // T278683
	],
	'uploader' =&gt; [
		'upload' =&gt; true,
		'reupload' =&gt; true,
	],
	'import' =&gt; [ 'mergehistory' =&gt; true ], // T382785
	'transwiki' =&gt; [ 'mergehistory' =&gt; true ], // T382785
],
&lt;/syntaxhighlight&gt;

=== flaggedrevs.php ===
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
elseif ( $wgDBname == 'enwikibooks' ) {
	// Limited to the main, Cookbook, and Wikijunior namespaces (T408110)
	$wgFlaggedRevsNamespaces = [ NS_MAIN, 102, 110 ];
	$wgFlaggedRevsTags = [ 'accuracy' =&gt; [ 'levels' =&gt; 3 ] ];
	$wgGroupPermissions['sysop']['stablesettings'] = true;
	unset( $wgGroupPermissions['reviewer'] );
}
&lt;/syntaxhighlight&gt;

{{collapse bottom}}

Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:05, 3 May 2026 (UTC)

:{{support}}, patrolling is obsolete since we have FlaggedRevs extension here. Additionally, we should also consider renaming &lt;code&gt;editor&lt;/code&gt; to &lt;code&gt;reviewer&lt;/code&gt; to avoid confusion. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 15:19, 3 May 2026 (UTC)
:: I agree, but about the &lt;code&gt;validate&lt;/code&gt; user right, is this still needed? &lt;code&gt;reviewer&lt;/code&gt; has it by default, and administrators already have that user right; we might need to consider whether to remove &lt;code&gt;validate&lt;/code&gt; completely from this wiki.
:: Also, &lt;code&gt;reviewer&lt;/code&gt; is ''not'' under autopromotion, so this means an administrator will have to manually grant and remove that user group, unlike &lt;code&gt;editor&lt;/code&gt;. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:45, 3 May 2026 (UTC)
::: {{courtesy ping}} to @[[User:Kingofnuthin|Kingofnuthin]] to my response. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 20:59, 17 May 2026 (UTC)
::::If renaming the group would result in the autopromotion breaking, couldn't we edit the autopromotion as well? If this would break current reviewers' permissions I don't think we really need it right now as it is just known as &lt;code&gt;editor&lt;/code&gt; to the software. For the validate right, I don't have much technical knowledge so I don't know what it does, I can't give an opinion on that. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 12:07, 18 May 2026 (UTC)
::::: @[[User:Kingofnuthin|Kingofnuthin]] Regarding &lt;code&gt;validate&lt;/code&gt;, if we use this line of code...&lt;syntaxhighlight lang=&quot;php&quot;&gt;
$wgFlaggedRevsTagsRestrictions = [
		'accuracy' =&gt; [ 'review' =&gt; 2, 'validate' =&gt; 3 ],
	];
&lt;/syntaxhighlight&gt;... it means that reviewers will only be able to flag revisions either as minimal or average, while &lt;code&gt;validate&lt;/code&gt; is required to flag revisions as good quality (in which using the current configuration, only administrators can do; therefore, &lt;code&gt;validate&lt;/code&gt; is not needed at all here). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:03, 18 May 2026 (UTC)
:{{support}} I'd be inclined toward standard patrolling rather than FlaggedRevs, but I agree that having both seems clearly redundant and just introduces an administrative burden. ―[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''&lt;span style=&quot;color:black&quot;&gt;v&lt;/span&gt;f&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 15:21, 18 May 2026 (UTC)</text>
      <sha1>50n5fwerz5oam6dw960xbu8c39oc9an</sha1>
    </revision>
    <revision>
      <id>4636923</id>
      <parentid>4636922</parentid>
      <timestamp>2026-05-21T18:52:23Z</timestamp>
      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>/* Proposal related to FlaggedRevs */ +</comment>
      <origin>4636923</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="26040" sha1="2fv113xk35r9pezf0f57tqb73cj8qig" xml:space="preserve">__NEWSECTIONLINK__ {{Discussion Rooms}} {{Shortcut|WB:RFC|WB:PROPOSALS}} {{TOC left&lt;!--|limit=2--&gt;}}

Welcome to the '''Proposals reading room'''. On this page, Wikibookians are free to talk about suggestions for improving Wikibooks.

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== Create a &quot;file&quot; that is an Example Book structured to be copied/used to quickly start a new book? ==

I am new to Wikibooks, if this already exists let me know.... 

If there was a Wikibook &quot;file&quot; that contained all the templates and &quot;parts&quot; that are used to create a properly structured book, it might be easier and quicker to create and contribute books here. This would have to include text that would explain the purpose of each of the sections and templates and offer advice for making changes that customize the example.  

One might copy it to their sandbox, follow the directions and make the updates that create the framework for their book. Then the work would be to fill in the text. I suppose the downside is that books would be categorized and shelved that are in progress. Abandoned books would need to be deleted or some template might need to be developed that might indicate that the book is incomplete. This would be removed when the book is ready for prime-time.
{{unsigned|Rchaswms01|01:32, 3 February 2026}}

== Allow all users (registered and unregistered) to view edit filters and their logs? ==

Hello, everyone. I would like to propose allowing all users to view not just edit filters and [[Special:AbuseLog|their log]], but also detailed edit filter log entries. In addition to that, I am also proposing that we set &lt;code&gt;$wgAbuseFilterNotifications&lt;/code&gt; to &lt;code&gt;true&lt;/code&gt; by removing &lt;code&gt;$wgAbuseFilterNotifications = false;&lt;/code&gt;.

{{collapse top|This proposal aims to reverse a part of [[phab:T26304]] for the AbuseFilter extension:}}
&lt;syntaxhighlight lang=&quot;wikitext&quot;&gt;
We would like to enable the AbuseFilter extension (see below) with custom permissions. Please *add*:

$wgGroupPermissions['*']['abusefilter-view'] = false;
$wgGroupPermissions['*']['abusefilter-log'] = false;
$wgGroupPermissions['autoconfirmed']['abusefilter-view'] = true;
$wgGroupPermissions['autoconfirmed']['abusefilter-log'] = true;
&lt;/syntaxhighlight&gt;
&lt;syntaxhighlight lang=&quot;wikitext&quot;&gt;
I'm sorry for yet another reply, but the user rights for the abuse filter need to be tweaked to match the request.

abusefilter-view should be for autoconfirmed/confirmed only and not for all users.

abusefilter-log should be for autoconfirmed/confirmed only and not for all users.

The logic behind this was to prevent casual vandals from gaming the system.

Thank you for your efforts.
&lt;/syntaxhighlight&gt;
{{collapse bottom}}
{{collapse top|Current configuration}}
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
case 'enwikibooks':
	$wgGroupPermissions['*']['abusefilter-view'] = false;
	$wgGroupPermissions['*']['abusefilter-log'] = false;
	$wgAbuseFilterNotifications = false;
	$wgGroupPermissions['autoconfirmed']['abusefilter-view'] = true;
	$wgGroupPermissions['autoconfirmed']['abusefilter-log'] = true;
	$wgGroupPermissions['autoconfirmed']['abusefilter-log-detail'] = true; // T383332
	$wgGroupPermissions['sysop']['abusefilter-revert'] = true; // T411828
	$wgAbuseFilterActions['block'] = true; // T273864
	break;
&lt;/syntaxhighlight&gt;
{{collapse bottom}}

{{collapse top|Proposed configuration}}
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
case 'enwikibooks':
	$wgGroupPermissions['*']['abusefilter-log-detail'] = true;
	$wgGroupPermissions['sysop']['abusefilter-revert'] = true; // T411828
	$wgAbuseFilterActions['block'] = true; // T273864
	break;
&lt;/syntaxhighlight&gt;
{{collapse bottom}}
Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:55, 2 April 2026 (UTC)

:See also: {{section link|Wikibooks:Reading room/Proposals/2025/January#Reforming the edit filter}}. [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 22:50, 2 April 2026 (UTC)
:I would support. It's worth noting that filters can be marked as private if it's a necessity to keep the logs not visible to everyone on the internet (if, for example, one is targeting a long-term abuser). The usual anti-vandalism filters are almost certainly never going to be looked through by the average opportunistic vandal, and it's an unnecessary hinderance to non-admins to have filters hidden without much of a reason. [[User:EggRoll97|EggRoll97]] ([[User talk:EggRoll97|discuss]] • [[Special:Contributions/EggRoll97|contribs]]) 06:30, 19 May 2026 (UTC)
: I filed [[phab:T426992]]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:51, 21 May 2026 (UTC)

== Introduce speedy deletion criteria? ==

I would like to propose that we introduce speedy deletion criteria to Wikibooks, such as {{tq|G1: [reason]}}. I suggest that we adapt from the English Wikipedia's CSD criteria ([[:w:Wikipedia:Speedy deletion]]) but utilize our existing deletion reasons, and even include '''G''' for general, '''R''' for redirects, and so on.

Speedy deletion reasons are already included in the [[Wikibooks:Deletion policy|deletion policy]], but should this proposal pass, the new speedy deletion criteria can be split out to a separate policy page, if needed (e.g. [[Wikibooks:Speedy deletion]]).

Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 14:39, 7 April 2026 (UTC)

:On the whole, that seems like it could be useful to expand out our CSD in a more detailed way. Why don't you go ahead and create [[Wikibooks:Speedy deletion]] as a draft, write out your initial proposal, and then we can workshop it together? —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 15:33, 10 April 2026 (UTC)
:@[[User:Codename Noreste|Codename Noreste]]: How can this proposal avoid accusations of [[m:Instruction creep|instruction creep]]? [[User:JJPMaster|JJP]]&lt;sub&gt;[[User talk:JJPMaster|Mas]]&lt;sub&gt;[[Special:Contributions/JJPMaster|ter]]&lt;/sub&gt;&lt;/sub&gt; ([[wikt:she|she]]/[[wikt:they|they]]) 23:21, 14 April 2026 (UTC)
:: How does instruction creep have anything to do with this? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 23:31, 14 April 2026 (UTC)
::: Well, in that case, we might keep the descriptions simple, not overly detailed. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 02:30, 17 April 2026 (UTC)
::::In that case, we may need to introduce that motion. – [[User:RestoreAccess111|RestoreAccess111]] &lt;sup style=&quot;font-family:Arimo, Arial;&quot;&gt;[[User talk:RestoreAccess111|Talk!]]&lt;/sup&gt; &lt;sup style=&quot;font-family:Times New Roman, Tinos;&quot;&gt;[[Special:Contributions/RestoreAccess111|Watch!]]&lt;/sup&gt; 04:38, 17 April 2026 (UTC)
:We already have speedy deletion though so I don't understand this proposal. [[User:Leaderboard|Leaderboard]] ([[User talk:Leaderboard|discuss]] • [[Special:Contributions/Leaderboard|contribs]]) 15:56, 24 April 2026 (UTC)
:@[[User:Codename Noreste|Codename Noreste]] I created a very early draft in [[User:Kingofnuthin/sandbox|my sandbox]] by merging content from [[w:Wikipedia:Speedy deletion]] and [[Wikibooks:Deletion policy]]. I added most of the criteria from English Wikipedia's page but I left some that can't be in Wikibooks (such as notability criteria). As I said, the draft is currently very undetailed and only provides simple explanations for criteria except for a few of them.  You can add this draft to [[Wikibooks:Speedy deletion]] to clarify the details of the proposal. I am also open to any feedback regarding the draft. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:11, 26 April 2026 (UTC)
:: I moved your draft to [[Wikibooks:Speedy deletion]]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:15, 26 April 2026 (UTC)
::This generally looks good; I've got a couple comments on specific criteria:
::* &quot;G5. Pages dependent on a non-existent or deleted page&quot; includes subpages with no parent page. Given the extent to which Wikibooks uses page nesting, this seems risky - at a minimum, the criterion should be revised to &quot;subpages with no parent '''book'''&quot;, and existing pages which meet this criterion should be grandfathered in or otherwise addressed.
::* &quot;B4. Books that duplicate an existing topic&quot; should probably be removed. Unlike Wikipedia, Wikibooks has historically allowed multiple books to address the same topic, e.g. [[Mandarin Chinese]] and [[Chinese (Mandarin)]], or [[C++ Language]] and [[C++ Programming]]. Whether a book &quot;expands upon, details or improves information&quot; in another book is very subjective; determining whether this is the case should be handled in a deletion discussion, not by an admin processing speedy deletions.
::Additionally, I'd suggest that three criteria be added:
::* Books which are over a week old and which contain no instructional content (e.g. books which are nothing but a table of contents). These books are already routinely deleted under [[WB:NMC]]; adopting this as a CSD streamlines the process.
::* Pages in any namespace which are unambiguously advertisements or promotional in nature (akin to [[:w:WP:CSD#G11]]).
::* Pages in any namespace which infringe upon copyright, akin to [[:w:WP:CSD#G12]]. F6/F7 address ''files'' which are copyvios, but not text.
::[[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 05:54, 29 April 2026 (UTC)
::: [[User:Omphalographer|Omphalographer]], feel free to make those changes to [[Wikibooks:Speedy deletion]], from your comments. It's a draft proposal. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 14:21, 29 April 2026 (UTC)
:::@[[User:Omphalographer|Omphalographer]]: I agree on your thoughts for the removal of B4 and the addition of a new general criterion for copyvios, so I did those. However, I think that G5 is fine in its current state. I don't understand what situation would be &quot;risky&quot; in this case, so please provide some example for that. Additionally, I don't think we need an advertisement criterion right now, as Wikibooks does not seem to have a promotion problem, as it is a collection of textbooks. Also, you mentioned [[Wikibooks:NMC]] as a new criterion even though I copy-pasted criterion G1 from the exact part you mentioned. Such pages could be deleted under G1. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:06, 29 April 2026 (UTC)
::::With regards to G5, I've seen some situations where a book was incorrectly renamed in such a way that some of the subpages remained under the original title of the book, or pages of a book are inadvertently created under an incorrect title. Given the proposed wording for G5, those pages would be eligible for speedy deletion, even though they are in use as part of the book.
::::With regards to advertisements, Wikibooks does get some spam page creations; you'll see some if you scroll through [https://en.wikibooks.org/wiki/Special:Log?type=delete the deletion log]. It's typically deleted quickly by admins, but if we're codifying criteria for speedy deletion, this should be included as an allowable reason.
::::As far as G1 / NMC is concerned, I initially read G1 as applying only to pages which contain no meaningful content at all, like pages which are empty, nonsense, or vandalism, and which should be deleted promptly. I see this as distinct from books which are superficially well-formed, but which fail to develop, e.g. a user who creates an ambitious-sounding table of contents for a book, but never returns to write any of the text. These shouldn't be deleted immediately (since it takes time to write content!), but are routinely speedily deleted once it's clear that no further content is forthcoming. Since this is a bit of a different process, it should probably be treated as a separate criterion. [[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 17:28, 29 April 2026 (UTC)
:::::I added &quot;Editors should be careful when nominating such pages, as they might be incorrectly named instead. In such cases, editors should move the page to its correctly-titled version.&quot; to G5. For advertising you said &quot;Wikibooks does get some spam page creations&quot;, but we already have &quot;Spam and vandalism&quot; for G1. In G1, I removed &quot;abandoned content&quot; and made it a new criterion B5 under the book section. (As this would only apply to books.) [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 17:43, 29 April 2026 (UTC)
:Quite frankly I don't see the need for a wiki of this size, in addition to what {{u|Leaderboard}} has mentioned. The current reasonings are perfectly fine, and subtly discourage the use of using abbreviations meaningless to new users. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 05:51, 4 May 2026 (UTC)
::Maybe we could do it without abbreviations, whilst keeping the categories. Our current speedy deletion policy is too short, and only includes main and userspace pages. We need more criteria for the Cookbook and Wikijunior for example. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 12:21, 4 May 2026 (UTC)
:::But why? [[:w:Wikipedia:If it ain't broke, don't fix it|If it ain't broke, don't fix it]]. Cookbook and Wikijunior for all purposes of policy can generally be implied to be mainspace pages. I find this really overkill for a wiki of this size. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 07:55, 5 May 2026 (UTC)
::::I have to agree with SHB2000 here. One perk of a wiki like this is that we have rules when needed, but we don't put a rule for the sake for it. I haven't had anyone tell that they can't perform their tasks, and it's not like there's a lot of pages to delete. [[User:Leaderboard|Leaderboard]] ([[User talk:Leaderboard|discuss]] • [[Special:Contributions/Leaderboard|contribs]]) 12:44, 7 May 2026 (UTC)
::My other worry with this change is that it removes a ''lot'' of flexibility when it comes to page deletions. That's especially crucial on a wiki like this where there is a lot of abandoned content lying around; I thus {{oppose}} this proposal in any form. --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 10:11, 6 May 2026 (UTC)
::: In my [[User:Codename Noreste/sandbox|sandbox]], I changed from criterion number to {{tq|Speedy deletion:}} in accordance with kingofnuthin. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 20:43, 17 May 2026 (UTC)

== Questions about [[Wikibooks:Annotated texts]] ==

I was recently reading over the policy on annotated texts and had a few questions aimed at reforming that policy. (The talk page for the policy has been inactive for eleven years, so I figured a post there would be unlikely to attract attention.)

# First and foremost - how many annotated texts of the type described by this policy are actually hosted on Wikibooks? I am only aware of one, [[Annotations to James Joyce's Ulysses]], which is quite incomplete. Are there a significant number more that I am unable to find? If not, might it be appropriate to revise this policy and related documents to reflect that annotated texts are, at best, an experimental part of the project?
# The policy on annotated texts currently permits '''unannotated''' source texts to be hosted on Wikibooks provided that either the text is not on Wikisource, or that it is &quot;widely used in classrooms&quot;. This seems like a rather large unintended loophole in the policy - there are innumerable texts which have not been transcribed on Wikisource, but which it would not make sense for Wikibooks to house either. Similarly, there are many texts which are &quot;widely used in classrooms&quot;, but which have never been annotated on Wikibooks and are unlikely to ever be. The policy also notes the possibility that a multilingual project could create annotated texts with parallel page names across all language editions; I am certainly unaware of any such. Are there any texts on Wikibooks which rely on this policy, or would it be appropriate to strike this section?
[[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 18:54, 28 April 2026 (UTC)

:The policy seems to be contradicting [[Wikibooks:SOURCE]], which states that annotated texts are the only exception to published texts being on Wikibooks. This means that we have a policy that says unannotated source texts are permitted, and another one that says they aren't allowed. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 19:02, 28 April 2026 (UTC)
:There is also [[Annotations of The Complete Peanuts]]. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 14:26, 29 April 2026 (UTC)
::That isn't an annotated text of the type described by this policy, as it doesn't include the original text that's being commented on. (Which it can't, because ''Peanuts'' is still under copyright.) [[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 16:29, 29 April 2026 (UTC)
:::Correct, it is not an inline annotation: I was just pointing it out as another kind of annotated text here.
:::For what it's worth, our sister project Wikisource [[:s:en:Category:Wikisource annotations|also hosts inline annotations]], such as [[:s:en:What to the Slave Is the Fourth of July?/Annotated]], which I made. —[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''vf&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 16:33, 29 April 2026 (UTC)
:::The main problem here is that the policy permits &quot;unannotated texts&quot; even though we don't host them here. I think that the first thing you mentioned can stay but we might need to strike out the second part from the policy as it is contradictory. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:38, 29 April 2026 (UTC)
::::Yeah - I certainly don't mean to suggest that the ''Ulysses'' annotations need to go away; I'm mostly curious if this policy has any wider applicability, or if its only function is to allow this one text. [[User:Omphalographer|Omphalographer]] ([[User talk:Omphalographer|discuss]] • [[Special:Contributions/Omphalographer|contribs]]) 17:37, 29 April 2026 (UTC)

== Proposal related to FlaggedRevs ==
{{tracked|T426992}}
As said per [[Wikibooks:Reading room/General#Page patrolling]], I would like to propose the following:
# &lt;code&gt;$wgUseNPPatrol&lt;/code&gt; and &lt;code&gt;$wgUseFilePatrol&lt;/code&gt; are both to be set to &lt;code&gt;false&lt;/code&gt;.
# &lt;code&gt;autopatrol&lt;/code&gt; and &lt;code&gt;patrol&lt;/code&gt; are to be removed from some user groups on this wiki.
This is because FlaggedRevs is used to review new pages and edits, so I don't think MediaWiki's native patrol function is needed here. It's similar to [[phab:T423461]] (completely turning off the new page patrol function on Ukrainian Wikipedia).

In addition, I would like to propose we move the following interface pages once after the below configuration has been implemented:
* [[MediaWiki:Revreview-value]] to [[MediaWiki:Revreview-accuracy]]
* [[MediaWiki:Revreview-value-1]] to [[MediaWiki:Revreview-accuracy-1]]
* [[MediaWiki:Revreview-value-2]] to [[MediaWiki:Revreview-accuracy-2]]
* [[MediaWiki:Revreview-value-3]] to [[MediaWiki:Revreview-accuracy-3]]
I don't really see a reason why we should use {{tq|value}} instead of {{tq|accuracy}} to stand out, when some other projects use {{tq|accuracy}}.
{{collapse top|Proposed configuration}}
=== core-Permissions.php ===
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
'+enwikibooks' =&gt; [
	'bot' =&gt; [ 'autopatrol' =&gt; false, ],
	'editor' =&gt; [
		'rollback' =&gt; true,
		'suppressredirect' =&gt; true,
	],
	'flood' =&gt; [ 'bot' =&gt; true ],
	'sysop' =&gt; [
		'autopatrol' =&gt; false,
		'patrol' =&gt; false,
		'importupload' =&gt; true, // T278683
	],
	'uploader' =&gt; [
		'upload' =&gt; true,
		'reupload' =&gt; true,
	],
	'import' =&gt; [ 'mergehistory' =&gt; true ], // T382785
	'transwiki' =&gt; [ 'mergehistory' =&gt; true ], // T382785
],
&lt;/syntaxhighlight&gt;

=== flaggedrevs.php ===
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
elseif ( $wgDBname == 'enwikibooks' ) {
	// Limited to the main, Cookbook, and Wikijunior namespaces (T408110)
	$wgFlaggedRevsNamespaces = [ NS_MAIN, 102, 110 ];
	$wgFlaggedRevsTags = [ 'accuracy' =&gt; [ 'levels' =&gt; 3 ] ];
	$wgGroupPermissions['sysop']['stablesettings'] = true;
	unset( $wgGroupPermissions['reviewer'] );
}
&lt;/syntaxhighlight&gt;

{{collapse bottom}}

Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:05, 3 May 2026 (UTC)

:{{support}}, patrolling is obsolete since we have FlaggedRevs extension here. Additionally, we should also consider renaming &lt;code&gt;editor&lt;/code&gt; to &lt;code&gt;reviewer&lt;/code&gt; to avoid confusion. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 15:19, 3 May 2026 (UTC)
:: I agree, but about the &lt;code&gt;validate&lt;/code&gt; user right, is this still needed? &lt;code&gt;reviewer&lt;/code&gt; has it by default, and administrators already have that user right; we might need to consider whether to remove &lt;code&gt;validate&lt;/code&gt; completely from this wiki.
:: Also, &lt;code&gt;reviewer&lt;/code&gt; is ''not'' under autopromotion, so this means an administrator will have to manually grant and remove that user group, unlike &lt;code&gt;editor&lt;/code&gt;. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:45, 3 May 2026 (UTC)
::: {{courtesy ping}} to @[[User:Kingofnuthin|Kingofnuthin]] to my response. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 20:59, 17 May 2026 (UTC)
::::If renaming the group would result in the autopromotion breaking, couldn't we edit the autopromotion as well? If this would break current reviewers' permissions I don't think we really need it right now as it is just known as &lt;code&gt;editor&lt;/code&gt; to the software. For the validate right, I don't have much technical knowledge so I don't know what it does, I can't give an opinion on that. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 12:07, 18 May 2026 (UTC)
::::: @[[User:Kingofnuthin|Kingofnuthin]] Regarding &lt;code&gt;validate&lt;/code&gt;, if we use this line of code...&lt;syntaxhighlight lang=&quot;php&quot;&gt;
$wgFlaggedRevsTagsRestrictions = [
		'accuracy' =&gt; [ 'review' =&gt; 2, 'validate' =&gt; 3 ],
	];
&lt;/syntaxhighlight&gt;... it means that reviewers will only be able to flag revisions either as minimal or average, while &lt;code&gt;validate&lt;/code&gt; is required to flag revisions as good quality (in which using the current configuration, only administrators can do; therefore, &lt;code&gt;validate&lt;/code&gt; is not needed at all here). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 15:03, 18 May 2026 (UTC)
:{{support}} I'd be inclined toward standard patrolling rather than FlaggedRevs, but I agree that having both seems clearly redundant and just introduces an administrative burden. ―[[User:Koavf|Justin (&lt;span style=&quot;color:grey&quot;&gt;ko'''a'''&lt;span style=&quot;color:black&quot;&gt;v&lt;/span&gt;f&lt;/span&gt;)]]&lt;span style=&quot;color:red&quot;&gt;❤[[User talk:Koavf|T]]☮[[Special:Contributions/Koavf|C]]☺[[Special:Emailuser/Koavf|M]]☯&lt;/span&gt; 15:21, 18 May 2026 (UTC)</text>
      <sha1>2fv113xk35r9pezf0f57tqb73cj8qig</sha1>
    </revision>
  </page>
  <page>
    <title>Chess Opening Theory/1. e4/1...c5/2. f4</title>
    <ns>0</ns>
    <id>157364</id>
    <revision>
      <id>4636929</id>
      <parentid>4490283</parentid>
      <timestamp>2026-05-21T20:37:43Z</timestamp>
      <contributor>
        <username>~2026-30373-51</username>
        <id>3591647</id>
      </contributor>
      <comment>/* 2. f4 · McDonnell attack */  typo 2...Nc3 was an illegal move</comment>
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      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="3022" sha1="2rex5obi7n8glqfjzsd2o93g08hvapu" xml:space="preserve">{{Chess Opening Theory/Position|=
|McDonnell attack|
   |rd|nd|bd|qd|kd|bd|nd|rd|=
   |pd|pd|  |pd|pd|pd|pd|pd|=
   |  |  |  |  |  |  |  |  |=
   |  |  |pd|  |  |  |  |  |=
   |  |  |  |  |pl|pl|  |  |=
   |  |  |  |  |  |  |  |  |=
   |pl|pl|pl|pl|  |  |pl|pl|=
   |rl|nl|bl|ql|kl|bl|nl|rl|=
||
|eco=[[Chess/ECOB|B21]]
|parent=[[../|Sicilian defence]]
|responses=[[/2...d5|2...d5 · Tal gambit]]
}}

== 2. f4 · McDonnell attack ==

With '''2. f4''' White begins an aggressive attack against Black's kingside. This is the McDonnell attack, aka  a(n accelerated) Grand Prix. 

[[/2...d5|'''2...d5''']], the Tal gambit, lets Black thwart the attack before it gets started. If White declines with 3. e5, Black can play Bf5 and e6, achieving a superior [[Chess/French Defence|French defence]] structure without the lousy French bishop. If White accepts, 3. exd5, Black can recover the pawn and get a development lead: 3...Nf6 4. Nc3 Nxd5 5. Nxd5 Qxd5.  

For this reason the attack is often played in the move order [[../2. Nc3|2. Nc3]] followed by 3. f4, the (conventional) Grand Prix, where if e.g. 2. Nc3 Nc6 3. f4 e5 can be met with Nxe5. 

Quieter second moves for Black, continuing however they would against an Open or Closed Sicilian--2...Nc6, 2...e6, so on--are also very playable, but don't capitalise on the position as much as the Tal Gambit. 

=== History ===

2. f4 was played many times by Alexander McDonnell as White against La Bourdonnais in their [[Wikipedia:La Bourdonnais–McDonnell chess matches|1834 match series]]. La Bourdonnais was considered the strongest player of his generation, and their confrontation a precursor to the modern world chess championship. His success with the Sicilian defence in these matches was later credited with reviving the interest in the opening. 

==Theory table==
{{Chess Opening Theory/Table}}.

'''1.e4 c5 2.f4'''
&lt;table border=&quot;0&quot; cellspacing=&quot;0&quot; cellpadding=&quot;4&quot;&gt;
	&lt;tr&gt;
		&lt;th&gt;&lt;/th&gt;
		&lt;th align=&quot;left&quot;&gt;2&lt;/th&gt;
		&lt;th align=&quot;left&quot;&gt;3&lt;/th&gt;
		&lt;th align=&quot;left&quot;&gt;4&lt;/th&gt;
		&lt;th align=&quot;left&quot;&gt;5&lt;/th&gt;
	&lt;/tr&gt;
	&lt;tr&gt;
		&lt;th align=&quot;right&quot;&gt;&lt;/th&gt;
		&lt;td&gt;f4&lt;br&gt;[[/2...d5|d5]]&lt;/td&gt;
		&lt;td&gt;Nc3&lt;br&gt;d4&lt;/td&gt;
		&lt;td&gt;Nce2&lt;br&gt;Nc6&lt;/td&gt;
		&lt;td&gt;=&lt;/td&gt;
	&lt;/tr&gt;
	&lt;tr&gt;
		&lt;th align=&quot;right&quot;&gt;&lt;/th&gt;
		&lt;td&gt;...&lt;br&gt;[[/2...Nc6|Nc6]]&lt;/td&gt;
		&lt;td&gt;Nc3&lt;br&gt;g6&lt;/td&gt;
		&lt;td&gt;Nf3&lt;br&gt;Bg7&lt;/td&gt;
		&lt;td&gt;Bb5&lt;br&gt;Nd4&lt;/td&gt;
		&lt;td&gt;=&lt;/td&gt;
	&lt;/tr&gt;
	&lt;tr&gt;
		&lt;th align=&quot;right&quot;&gt;&lt;/th&gt;
		&lt;td&gt;...&lt;br&gt;[[/2...d6|d6]]&lt;/td&gt;
		&lt;td&gt;Nc3&lt;br&gt;Nc6&lt;/td&gt;
		&lt;td&gt;Nf3&lt;br&gt;g6&lt;/td&gt;
		&lt;td&gt;Bc4&lt;br&gt;Bg7&lt;/td&gt;
		&lt;td&gt;=&lt;/td&gt;
	&lt;/tr&gt;
	&lt;tr&gt;
		&lt;th align=&quot;right&quot;&gt;&lt;/th&gt;
		&lt;td&gt;...&lt;br&gt;[[/2...e6|e6]]&lt;/td&gt;
		&lt;td&gt;Nf3&lt;br&gt;d5&lt;/td&gt;
		&lt;td&gt;Bb5+&lt;br&gt;Nc6&lt;/td&gt;
		&lt;td&gt;=&lt;/td&gt;
	&lt;/tr&gt;
	&lt;tr&gt;
		&lt;th align=&quot;right&quot;&gt;&lt;/th&gt;
		&lt;td&gt;...&lt;br&gt;[[/2...g6|g6]]&lt;/td&gt;
		&lt;td&gt;Nf3&lt;br&gt;Bg7&lt;/td&gt;
		&lt;td&gt;Nc3&lt;br&gt;Nc6&lt;/td&gt;
		&lt;td&gt;=&lt;/td&gt;
	&lt;/tr&gt;
	&lt;tr&gt;
		&lt;th align=&quot;right&quot;&gt;&lt;/th&gt;
		&lt;td&gt;...&lt;br&gt;[[/2...Nf6|Nf6]]&lt;/td&gt;
		&lt;td&gt;Nc3&lt;br&gt;d5&lt;/td&gt;
		&lt;td&gt;e5&lt;br&gt;d4&lt;/td&gt;
		&lt;td&gt;=&lt;/td&gt;
	&lt;/tr&gt;
&lt;/table&gt;
{{ChessMid}}
==References==
{{reflist}}
{{Wikipedia|Sicilian Defence}}
{{BCO2}}
==External links==
{{Chess Opening Theory/Footer}}


{{ChessStub}}</text>
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&lt;!-- EDIT TEMPLATE DOCUMENTATION BELOW THIS LINE --&gt;
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The  templates for using Harvard citations are:
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*{{tlx|Harvard citation no brackets}} or {{tlx|harvnb}} for a Harvard citation with no brackets
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*{{tlx|Harvard citations}} or {{tlx|harvs}} for multiple Harvard citations and other more complicated features. 
*{{tlx|citation}}  for formatting the reference.

This page describes the first 3; for the others see their documentation pages. 
==Usage==

: &lt;code&gt;&lt;nowiki&gt;{{&lt;/nowiki&gt;Harvard citation |''Last name of author(s)''|''Year''| loc = ''Location in the text''}}&lt;/code&gt;

Instead of using the optional loc parameter, you may also use one of the following parameters:

*&lt;code&gt;p = ''page''&lt;/code&gt;
*&lt;code&gt;pp = ''pages''&lt;/code&gt;

; Notes
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Editors editing this template are requested to make parallel changes to the other versions.

==Examples==

:{| class=&quot;wikitable&quot;
|-
! Markup !! Result
|-
| &lt;code&gt;&lt;nowiki&gt;{{Harv |Smith|2006| loc=&amp;amp;sect;8.5}}&lt;/nowiki&gt;&lt;/code&gt;
| {{Harvard citation |Smith|2006| loc=&amp;sect;8.5}}
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| {{Harv |Smith|2006| pp=25–26}}
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| &lt;code&gt;&lt;nowiki&gt;{{Harv |Smith|2006| pp=25&amp;amp;ndash;26 | Ref=none}}&lt;/nowiki&gt;&lt;/code&gt;
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| {{Harv |Smith|Jones|2006| p=25}}
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| &lt;code&gt;&lt;nowiki&gt;{{Harv |Smith|Jones|Brown|2006| p=25}}&lt;/nowiki&gt;&lt;/code&gt;
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|-
| &lt;code&gt;&lt;nowiki&gt;{{Harv |Smith|Jones|Brown|Black|2006| p=25}}&lt;/nowiki&gt;&lt;/code&gt;
| {{Harv |Smith|Jones|Brown|Black|2006| p=25}}
|-
| &lt;code&gt;&lt;nowiki&gt;{{Harvnb |Smith|2006| p=25}}&lt;/nowiki&gt;&lt;/code&gt;
| {{Harvnb |Smith|2006| p=25}}
|-
| &lt;code&gt;&lt;nowiki&gt;{{Harvtxt |Smith|2006| p=25}}&lt;/nowiki&gt;&lt;/code&gt;
| {{Harvtxt |Smith|2006| p=25}}
|}

==Recommended style==
The recommended Harvard referencing style potentially uses all four templates. Each automatically generates a hypertext link based on the name(s) and date. Here is an example
:;Markup
:: &lt;code&gt;&lt;nowiki&gt;Some works on gravitation are so massive they warp spacetime themselves {{Harv|Misner|Thorne|Wheeler|1973}}; yet {{Harvtxt|Einstein|1915}} presented essential equations with notable brevity. The essential ingredients are the curvature tensor and the stress-energy tensor ({{Harvnb|Einstein|1915|loc=p.&amp;amp;nbsp;844}}; {{Harvnb|Misner|Thorne|Wheeler|1973|loc=p.&amp;amp;nbsp;41}}).&lt;/nowiki&gt;&lt;/code&gt;
:;Result
:: Some works on gravitation are so massive they warp spacetime themselves {{Harv|Misner|Thorne|Wheeler|1973}}; yet {{Harvtxt|Einstein|1915}} presented essential equations with notable brevity. The two ingredients are the curvature tensor and the stress-energy tensor ({{Harvnb|Einstein|1915|loc=p.&amp;nbsp;844}}; {{Harvnb|Misner|Thorne|Wheeler|1973|loc=p.&amp;nbsp;41}}).
In short:
# For a single work with no author in the text (the most common case), use {{tlx|Harv}}.
# For a single work with the author named in the text, use {{tlx|Harvtxt}}.
# For multiple works at the same point, use explicit parentheses and {{tlx|Harvnb}} separated by semicolons.
# For anything more complicated use {{tlx|Harvs}}.

==&lt;nowiki&gt;#CITEREF&lt;/nowiki&gt;==

More exotic Harvard citations can be constructed using the {{tlx|harvs}} template. If even this is not enough, then as a last resort one can use &lt;nowiki&gt;#CITEREF&lt;/nowiki&gt; as in the following example:
:&lt;nowiki&gt;[[w:Property (T)|]] was introduced by [[w:David Kazhdan|]] ([[w:Property T#CITEREFKazhdan1967|1967]]).&lt;/nowiki&gt;
which produces
:[[w:Property (T)|Property]] was introduced by [[w:David Kazhdan|David Kazhdan]] ([[w:Property T #CITEREFKazhdan1967|1967]])
with a link to the author, and a link to a citation on a different page.
&lt;nowiki&gt;#CITEREF&lt;/nowiki&gt; should be followed by the last names of up to 4 authors and the year (with no spaces),
and if the link is to a different page it should be preceded by the name of the page (with spaces allowed). The [[Template:Citation|citation template]] marks the reference using &lt;nowiki&gt;#CITEREF&lt;/nowiki&gt;; see the source of
[[Template:Citation/core]] for details.

==Use with &lt;nowiki&gt;{{Citation}}&lt;/nowiki&gt;==
The {{tlx|Citation}} template can be used to format the citations in the ''References'' section. 
Links from the Harvard citation to the Citation are provided using a &lt;code&gt;#CITEREF&lt;/code&gt; link. The {{tlx|Harvard citation}} template creates a link &lt;code&gt;#CITEREF&lt;/code&gt; followed by the concatenation of the author names and the year. {{tlx|Citation}} creates an [[w:HTML element#Links and anchors|anchor]] &lt;code&gt;&lt;nowiki&gt;&lt;a name=&quot;CITEREF&quot;&gt;&lt;/a&gt;&lt;/nowiki&gt;&lt;/code&gt; followed by the concatenation of the following parameters:
*'''last''' or '''last1''' or '''surname''' or '''surname1''' or '''author''' or '''author1''' or '''authors''',
*'''last2''' or '''surname2''' or '''author2''',
*'''last3''' or '''surname3''' or '''author3''',
*'''last4''' or '''surname4''' or '''author4''',
*'''editor-last''' or '''editor-surname''' or '''editor1-last''' or '''editor1-surname''' or '''editor''' or '''editors''',
*'''editor2-last''' or '''editor2-surname''',
*'''editor3-last''' or '''editor3-surname''',
*'''editor4-last''' or '''editor4-surname''',
*'''year''' or '''date'''.

For example &lt;code&gt;&lt;nowiki&gt;{{Harv|Smith|2006| p=25}}&lt;/nowiki&gt;&lt;/code&gt; produces a link &lt;code&gt;#CITEREFSmith2006&lt;/code&gt; and &lt;code&gt;&lt;nowiki&gt;{{Citation|last=Smith|first=John|year=2006|title=My Life}}&lt;/nowiki&gt;&lt;/code&gt;
produces an anchor &lt;code&gt;&lt;nowiki&gt;CITEREFSmith2006&lt;/nowiki&gt;&lt;/code&gt;.

==References==
*{{Citation
 | last=Smith
 | first=John
 | year=2006
 | title=My Life
}}
*{{Citation
 | last=Smith
 | first=John
 | last2=Jones
 | first2=Jack
 | year=2006
 |title=Our life together
}}
*{{Citation
 | author1=Smith
 | author2=Jones
 | author3=Brown
 | year=2006
 | title=Three's a crowd
}}
*{{Citation
 | author1=Smith
 | author2=Jones
 | author3=Brown
 | author4=Black
 | year=2006
 | title=All together now
}}
*{{Citation
 | last=Misner
 | first=Charles W.
 | last2=Thorne
 | first2=Kip S.
 | first3=John Archibald
 | last3=Wheeler
 | title=Gravitation
 | publisher=W. H. Freeman
 | location = San Francisco
 | year = 1973 
 | month = September 
 | id = {{ISBN|0-7167-0344-0}}
}} 
*{{Citation
 | last =Einstein
 | first =Albert
 | title =Die Feldgleichungen der Gravitation (The Field Equations of Gravitation)
 | journal =Koniglich Preussische Akademie der Wissenschaften
 | pages =844–847
 | year =1915
}}

&lt;includeonly&gt;
&lt;!-- ADD CATEGORIES BELOW THIS LINE --&gt;
[[Category:Citation templates|{{PAGENAME}}]]

&lt;!-- ADD INTERWIKIS BELOW THIS LINE --&gt;
[[fr:Template:Référence Harvard]]
[[ja:Template:Harv]]
[[bn:টেমপ্লেট:Harv]]
&lt;/includeonly&gt;
&lt;noinclude&gt;[[Category:Template documentation|{{PAGENAME}}]]&lt;/noinclude&gt;</text>
      <sha1>sq2ks8vlfbph995ij7zd99646idzcj1</sha1>
    </revision>
  </page>
  <page>
    <title>Template:User gmail</title>
    <ns>10</ns>
    <id>202000</id>
    <revision>
      <id>4636930</id>
      <parentid>4028326</parentid>
      <timestamp>2026-05-21T21:32:05Z</timestamp>
      <contributor>
        <username>Alter73</username>
        <id>3447476</id>
      </contributor>
      <comment>/* */ New logo</comment>
      <origin>4636930</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="371" sha1="4zp76sf096zuczjsuddy0iq3brzy9ko" xml:space="preserve">{{userbox
| border-c = #90A3BD
| id       = [[File:Gmail icon (2026).svg|40px|Gmail logo]]
| id-c     = white
| info     = {{#if:{{{1|}}}|This user's '''[[Gmail]]''' account is [mailto:{{{1}}}@gmail.com {{{1}}}]|This user's primary email account is with [[Gmail]]}}
| info-c   = #F0F8FF
| info-a   = center
}}&lt;noinclude&gt;[[Category:Email user templates|Gmail]]&lt;/noinclude&gt;</text>
      <sha1>4zp76sf096zuczjsuddy0iq3brzy9ko</sha1>
    </revision>
  </page>
  <page>
    <title>Aros/Platforms/AROS USB support</title>
    <ns>0</ns>
    <id>202147</id>
    <revision>
      <id>4636985</id>
      <parentid>4636524</parentid>
      <timestamp>2026-05-22T08:46:10Z</timestamp>
      <contributor>
        <username>Jeff1138</username>
        <id>301139</id>
      </contributor>
      <minor />
      <origin>4636985</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="664956" sha1="mkrbvwwyjid4dhilo4stodkwr72e80j" xml:space="preserve">
{{ArosNav}}


==Host Adapter Protocol USB1 OHCI UHCI USB2 EHCI USB3.0 USB3.1 xHCI ==

Please let us know any mistakes or any information to be added, use Prefs/Trident to confirm Vendor and Product IDs 
Please chat at [https://www.arosworld.org/index.php AROS World]

*1996 USB1.0
*1998 USB1.1
*2000 USB2.0
*2008 USB3.0
*2013 USB3.1
*2017 USB3.2

[https://github.com/aros-development-team/AROS/tree/master/rom/usb AROS has these USB transfers] 

*Control     - 
*Bulk        - Midi 1.0 ( 'send my data when you can' )
*Interrupt   - Midi 2.0
*Isochronous - USBAudio, Webcams, etc (wip) 

Isochronous is the starting point of modern types of multimedia creativity. IsoChronous isoc code is already in place in poseidon.library and '''scheduled''' transfers are queued to be later rerouted in the host driver code (needs to be written for each host protocol e.g. OCHI, UCHI, EHCI and [https://cdrdv2-public.intel.com/625472/625472_xHCI_Rev1_2b.pdf#:~:text=Page%203.%20Document%20Number:%20625472%2C%20Revision:%201.2b.%203. XHCI rev1.2], [https://www.intel.com/content/www/us/en/content-details/868296/extensible-host-controller-interface-for-universal-serial-bus-xhci-requirements-specification-r2-0.html rev2], etc). There seems to be 2 types of isoc transfers, one is just the normal isoc transfer and the other is realtime implementation of isoc transfer. 

For isoc transfer there needs to be a scheduler that makes sure no isoc transfers are dropped (in or out) and that they happen at the right time. It all gets difficult as the device making use of the isoc transfer may be at any point on the device tree. One needs to calculate the USB bandwidth for the packet based periodic transfers that are initiated by the host which have fixed but guaranteed bandwidth. Host controllers guarantee this bandwidth by planning a schedule of transfers ahead of time to ensure there is enough time reserved on the bus.

[https://www.intel.co.uk/content/www/uk/en/products/docs/io/universal-serial-bus/ehci-specification.html EHCI] [https://www.thegoodpenguin.co.uk/blog/understanding-why-usb-isochronous-bandwidth-errors-occur/ bus-bandwidth] vs payload-bandwidth and the algorithm of the EHCI scheduler. 
The bandwidth of the endpoint in terms of payload data (stuff we put in a packet) and the protocol overhead, signalling imposed bit stuffing, host delays etc. 

Poseidon controls the driver and device tree and it provides an API to communicate with the USB devices. Poseidon really doesn't care much about what sort of transfer pipe is opened or used, it only provides the means to do so and forwards the iorequests to the correct driver. Poseidon code is the higher level code for USB communication and drivers are of course the lower level one.


[[File:Psd.svg|220px|right]]


; Best Hardware - NEC Chipset (OHCI + EHCI), Intel Chipset (UHCI + EHCI), 
; Early support - [https://github.com/aros-development-team/AROS/commit/03c5252d962941a56c816a9f2315134362089349 XHCI USB3.0, USB3.1 &amp; gen 2 Type-A Type-B Type-C] 
; Next Best Set - General OHCI, SIS (OHCI + EHCI), 
; Buggy Chipset - [ Early AMD OHCI], ALi OHCI, VIA UHCI, Nvidia OHCI &amp; EHCI, 


=== USB1.1 ===
OHCI USB 1.1 - USB-IF sanctioned standard but hardware physical form removed with USB2.0 and replaced with virtual emulation of USB1 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device 
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| ALi Agere M5273 A1 M5237 Lucent USS-312 
| 
| 
| 
| &lt;!--Boots--&gt;{{Maybe}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| StarTech PCI425USB, CompUSA Iogear GIC220U-b, Nvidia 220 mobo, USBA2041P, ALi SU2A-PS, 
|-
| AMD 756 Chipset (onboard motherboard) 
| 0x1022 
| 0x740c 
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| no [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=31308#forumpost31308 usb devices detected] Geode GX1, 
|-
| CMD DU-A2 Silicon Image 0670 (pci AMD chipset)
| 0x1095
| 0x0670
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Silicon Image 0673 (pci AMD chipset)
| 0x1095
| 0x0673
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Nvidia Nforce2 USB
| 0x10de 
| 
| 
| &lt;!--Boots--&gt;{{Maybe|Bios options vary but does with Plop Boot}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Tested with 20th Aug 2012 improvement 
|-
| NEC µPD720100AGM 
| 0x1033
| 0x0035
| 0x 
| &lt;!--Boots--&gt;{{Unk}}
| &lt;!--Detects--&gt;{{Unk}}
| &lt;!--Works--&gt;{{Maybe|}}
| untested - Amiga Spider card with possible bottleneck issues at higher speeds 
|-
| NEC µPD720101AGM 720101GJ
| 0x1033
| 0x0035
| 0x43
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Mac mini, Belkin F5U219vea (2+1 ports), Belkin F5U220vea1 (4+1 ports), Adaptec 3100LP, BAFO BF-460, GWC UC-160, IOGear GIC250U, Keyspan U2PCI-5, O'toLink U2-C2B U2-C2A U2-P20N U2-P50, Ratoc PCIU5, USBWholesale UII-PCIP 
|-
| NEC µPD720102
| 0x1033
| 0x00
| 0x 
| &lt;!--Boots--&gt;{{Unk|untested }}
| &lt;!--Detects--&gt;{{Unk|untested }}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Opti 82C861 2-port 
| 0x1045
| 0xc861
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| no USB devices detected - Belkin F5U005, 
|-
| SIS 7001 OCHI 
| 0x1039
| 0x7001
| 0x0f
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 20th Aug 2012 - not booting stalls on GRUB word with Plop Boot 
|-
|}


UHCI USB 1.1 - Intel standard but since 2009 no hardware support as USB2 introduced virtual emulation of USB1 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| Intel 
| 0x8086 
| 0x
| 0x01 
| &lt;!--Boots--&gt;{{No|not in bios use AROS floppy disc boot}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Intel 82371AB EB MB PIIX4 
| 0x8086 
| 0x7112
| 0x01 
| &lt;!--Boots--&gt;{{No|none in bios use other booting options}}
| &lt;!--Detects--&gt;{{Maybe|Detects most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not RTL8187b WG111v3 blue led not on and does not work}}
|  
|-
| Intel 82801DB/DBL/DBM (onboard i830 mbd)
| 0x8086 
| 0x24c4 
| 0x01 
| &lt;!--Boots--&gt;{{Yes|but not from bios but floppy options}}
| &lt;!--Detects--&gt;{{Yes|}}
| &lt;!--Works--&gt;{{Yes|}}
| RTL8187b WG111v3 blue led on and although device has software failure and recoverable error IT STILL WORKS. Fresh start sometimes needs Network Prefs Saved to work. 
|-
| VIA MVP4 (onboard mbd)
| 0x1106
| 0x30
| 0x40 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not wireless options}}
| RTL8187b WG111v3 detected but blue led not on and does not work 
|-
| VIA VT82xx (onboard mbd)
| 0x1106
| 0x3038
| 0x40 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not wireless usb}}
| RTL8187b WG111v3 blue led on but does not work 
|-
| VIA VT6202 (VIA VT83C572)
| 0x1106
| 0x3038
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}} 
| &lt;!--Works--&gt;{{Maybe|}}
| A-Best USB-200, Cables N Mor USBPCI, CompUSA, D-Link DSB500, Digital/Research DRUSBCARD, Kouwell IOFlex 580, StarMount USB VIA, 
|-
| VIA VT6112 
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6212 (pci card)
| 0x1106
| 0x3038
| 0x61
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 2011 seems to have issues with other identical via based USB controller(s) present 
|-
| VIA VT6214L 
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
|}


=== USB 2.0 EHCI ===
The USB-IF insisted on only one implementation of EHCI but it creates 4 virtual hcd to cover USB1.1 support. The virtual HCD on Intel and VIA EHCI controllers are UHCI. All other vendors use virtual OHCI controllers. Hardware EHCI USB2.0 ended in most chipsets in 2014/5 and is now virtual through most newer USB3.0 chipsets 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| ALi Agere M5273 A1 Lucent USS-344 
| 
| 
| 
| &lt;!--Boots--&gt;
| &lt;!--Detects--&gt;
| &lt;!--Works--&gt;{{Maybe|}}
| {{N/A|untested}} belkin F5U006, 
|-
| Nvidia Nforce2 USB
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Intel 82801DB/DBM (onboard mbd)
| 0x8086 
| 0x24cd 
| 0x01 
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| NEC µPD720100AGM 
| 0x1033
| 0x00E0
| 0x 
| &lt;!--Boots--&gt;
| &lt;!--Detects--&gt;
| &lt;!--Works--&gt;{{Maybe|}}
| {{N/A|untested - Amiga Spider card}}
|-
| NEC 72101 GJ
| 0x1033 
| 0x00e0 
| 0x04
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Belkin F5U219 VEA1 (pci), 
|-
| SIS ECHI 
| 0x1039
| 0x7002
| 0x00
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|issues about which port is used if it works at all}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6202 
| 0x1106
| 0x3104
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6212 (pci card)
| 0x1106
| 0x3104
| 0x62
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes|detects}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
|}


=== USB 3.x SuperSpeed SS (Speed 5Gbit/s 3.1 gen 1) aka xHCI eXtensible ===

USB Attached SCSI (UAS or UASP) is a protocol used for high-speed data transfer between computers and external storage devices like SSDs, HDDs, and some flash drives. It provides up to 70% faster read/write speeds than traditional Bulk-Only Transport (BOT) by allowing multiple commands to run in parallel, rather than waiting in a queue

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Fresco Logic FL1000 FL 1000 
| &lt;!--Vendor ID--&gt;0x1B73
| &lt;!--Product ID--&gt;0x1000 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;link power management (LPM, USB 3.0 power saving) cannot be disabled so random connection issues  
|-
| &lt;!--Description--&gt;Fresco Logic FL1009-200 FL 1009 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1009 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;Orico PFU3-2P
|-
| &lt;!--Description--&gt;Fresco Logic FL1100-100 FL 1100SX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1100 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;LPM cannot be disabled so issues with disconnecting WD drives etc - CalDigit, ORICO PFU3-2P, FASTA-6GU3 Pro, inatech KTU3FR-2P 2 port USB 3.0,  and Inateck KT4004 (KTU3FR-4PA rev B2) for storage and hubs, etc 
|-
| &lt;!--Description--&gt;Fresco Logic FL1400 FL 1400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1400 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Fresco Logic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720200 uPD720200a chip
| &lt;!--Vendor ID--&gt;0x1d6b
| &lt;!--Product ID--&gt;0x0194
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{Maybe|no USB3 but seems to works like USB2}}
| &lt;!--Opinion--&gt;recognized but not supported for USB3 but works like USB2 - ORICO PRU3-4P 4 Port USB, early Dell Wyse zx0 thin client,  
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720201 uPD720201 chip
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x114 0x0115 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported 
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720202 uPD720202 chip
| &lt;!--Vendor ID--&gt;0x1912 
| &lt;!--Product ID--&gt;0x0015
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported 
|-
| &lt;!--Description--&gt;[http://www.ti.com/product/tusb7340 TI] tusb7340 TUSB732 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x8241
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported Koutech IO-PEU436 but only one with open docs 
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported - integrated since Ivybridge 
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Via Labs VL800 xHCI 0.96 support in VL800, VIA VL811 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x3432 0x3438 0x3515 and 0x9201
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{Maybe|}} 2.0 backwards support 
| &lt;!--Opinion--&gt;Anker 68UPPCIE-2S20PU 2 port, Plugable 4-Port, GA-z77x-ud5h rev. 1.1 mobo, 
|-
| &lt;!--Description--&gt;Via Labs VL811+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Via Labs VL812 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;xHCI 1.0 support in VL805 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
|}


USB 3.1 (power up to 100W and data 10Gbit/s USB 3.2 gen 2 - USB-A Full size plug - USB-B micro USB size - USB-C reversible) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Asmedia ASM1142 
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;Connector: USB Type C and  USB Type A x 1 - Ugreen USB C PCI Card 2 Port USB 3.1 Type C 
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[ Intel] Revision 1.8 1.9 Updated  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;AUKEY 4 Ports USB C , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;Startech - PEXUSB312C - 2-port Usb 3.1 10Gbit/s
|-
|}

USB 3.2 (power up to 100W and data 20Gbit/s gen 2x2 - USB-A Full size plug - USB-B micro USB size - USB-C reversible) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[ Intel] Revision 2.6 Update  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;
|-
|}

=== USB 4 (40Gbps thunderbolt, pcie 3.0 tunnelling, ) ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;AMD Ryzen7 6800U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;Intel Goshen Ridge JHL8440 Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
|  
|-
|}


== hid.class (Human Interface Device) ==

=== Keyboard ===

 Some multi-finger touchpad support works but not on all touchpads  

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;8BitDo Retro N C64 edition Keyboard, the super button accessory and optional N30 mouse
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 87 keys Kailh white}}
|-
| &lt;!--Description--&gt;8bitdo 108 Retro Mechanical Keyboard (white kailh) and two superbuttons (green) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Apple Pro Keyboard
| 0x05ac
| 0x0205 
| 0x0122
| {{yes|works (its two hub ports) but mouse scroll wheel issues}}
|-
| Apple Pro Keyboard
| 0x05AC
| 0x020B 
| 
| {{yes|works (two onboard ports also)}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Aigo K68 60% red switches, A68 A87 wireless 2G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=49&amp;products_id=973 AmigaOne Keyboard]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Akko TAC87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 80% TKL }}
|-
| &lt;!--Description--&gt;Akko MonsGeek FUN60 PRO&amp;MAX HE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 60% hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Akko 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 hall effect, good but expensive and software poor}}
|-
| &lt;!--Description--&gt;Akko 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ATTACK SHARK X98 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 98% maybe silent linear feel with Two-color PBT keycap}}
|-
| &lt;!--Description--&gt;ATTACK SHARK X68HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Azio Cascade 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Chilkey ND75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  good 75% expensive}}
|-
| &lt;!--Description--&gt;Chilkey ND104 (Wuque Studios) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 premium clicky (WS Blue) or silent (WS White) key options with Ansi and ISO formats also numpad and calculator, aluminum machined, tri mode, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2026 untested magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Corsair K65 Mech MX no numeric keypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair CH-9000045 K70 Blue MX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K95 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cherry G80 G80-3000L[x]C[yy]-[z] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cooler Master CM Storm Quickfire Rapid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K100 Air 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2025 okay low profile but expensive 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;Dell SK-8135 Dell USB Keyboard for Internet and Multimedia rev H for Dimension 4500, Dimension 8250, OptiPlex GX260n, OptiPlex GX60n, Precision 350 (R42232) 
| &lt;!--Vendor ID--&gt;0x413C
| &lt;!--Product ID--&gt;0x2010 
| &lt;!--Revision--&gt;0200 
| &lt;!--Opinion--&gt;{{Yes| usb1.1 keyboard hub 0x413C 0x1003 works as well - multimedia keys not mapped }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Deepcool KG722
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 65% }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Ducky Channel Zero DK2108 Mech Mechanical Cherry MX Red 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Ducky Shine 3 Brown or Blue (DK9087) MX keys 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Das Keyboard Model S Ultimate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Epomaker Cidoo V75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;epomaker rt100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 plastic build and no screws, numpad with small 0, mostly quiet seasalt switches, gimmick usb-c 1in screen}}
|-
| &lt;!--Description--&gt;EPOMAKER TH99  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} USB-C full numpad keyboard 
|-
| &lt;!--Description--&gt;eopmaker P75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;eopmaker p87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;epomaker x Leobog Hi75
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;epomaker x Feker Galaxy80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;epomaker x Galaxy100 gmk/via 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 96% }}
|-
| &lt;!--Description--&gt;epomaker Aula F75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 budget version good 75% choice of 4 leobog switches}}
|-
| &lt;!--Description--&gt;eopmaker Tide75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 75% and not too expensive}}
|-
| &lt;!--Description--&gt;Epomaker Ajazz AK820 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Epomaker Ajazz AK35I V3 MAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 104 keys - two models: wired and tri-mode connection - }}
|-
| &lt;!--Description--&gt;epomaker Aula F108 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pricy but okay 100% but only leobog graywood switches but hotswap available afterwards}}
|-
| &lt;!--Description--&gt;eopmaker Ajazz AK980 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 97 keys }}
|-
| &lt;!--Description--&gt;Epomaker G87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Epomaker RT82 RT85
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Epomaker RT100 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 96% }}
|-
| &lt;!--Description--&gt;epomaker x Galaxy100 lite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 good 96% }}
|-
| &lt;!--Description--&gt;Epomaker 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Filco Ninja Majestouch-2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Focus FK-760 Wireless Keyboard &amp; Trackball
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{yes|works}} but quality build issues raised 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;GMMK Tenkeyless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested  default Gateron Brown switches for Kailh Box Jades default Gateron Brown switches for Kailh Box Jades}}
|-
| &lt;!--Description--&gt;GK61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }}
|-
| &lt;!--Description--&gt;GMK67 GMK87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested budget good option}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Hengchangtong HCT Limeme gk103s Entry Keyboard
| &lt;!--Vendor ID--&gt;0xC0F4
| &lt;!--Product ID--&gt;0x0009
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{yes|half Keyboard left side only}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Hexgears M2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested hotswap kaihl green switches}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hexgears 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Iqunix mq80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2025 good 75% low profile keys
|-
| &lt;!--Description--&gt;Iqunix Magi65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested good 65% low profile keys }}
|-
| &lt;!--Description--&gt;iqunix ez60 ez80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 untested specific hall effect switches - actuation point, rapid trigger, etc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Jomaa YiChip Wireless 50% key with touchpad 
| &lt;!--Vendor ID--&gt;0x3151 
| &lt;!--Product ID--&gt;0x3000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|dongle detected, keys and pad not working - 2 AAA NM}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Keychron q0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 untested numpad only}} 
|-
| &lt;!--Description--&gt;Keychron q1 v1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 untested okay}} 
|-
| &lt;!--Description--&gt;Keychron Q6 Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested 75% with numeric numpad, barebones so choose switches and keycaps to suit }}
|-
| &lt;!--Description--&gt;Keychron q1 MAX V1 MAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }} 
|-
| &lt;!--Description--&gt;Keychron Lemokey P1 QMK 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested best option to customise switches and keycaps}}
|-
| &lt;!--Description--&gt;Keychron LemoKey X1 X3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested keycap swap only not switches}}
|-
| &lt;!--Description--&gt;Keychron K2HE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested okay}} wireless hall effect analogue on all keys 
|-
| &lt;!--Description--&gt;Keychron K4HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 untested hall effect but software }}
|-
| &lt;!--Description--&gt;Keychron K5 K17 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 untested okay low profile but }}
|-
| &lt;!--Description--&gt;Keychron Q5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Keychron K10 HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Kiiboom Breeze 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 good 75% }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;Meletrix Boog 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 magnetic hall effect, good but expensive and software poor}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;Melgeek O2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 low profile 75% but not repairable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;MOSART 2.4G Wireless 60% Keyboard Trackball 
| &lt;!--Vendor ID--&gt;0x062a
| &lt;!--Product ID--&gt;0x4105
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|dongle recognised HID, keys worked, roller worked, scroll wheel works and shoulders works but buttons around left, top and right hand side (RHS) do not work and plastic and 2 AA MN1500}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Mucai SiGma Micro MKA610 
| &lt;!--Vendor ID--&gt;0x1c4f
| &lt;!--Product ID--&gt;0x0084
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| unknown red keys - rgb backlighting - }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;[http://hjldemo.clsc.cn/ Guangzhou Zhentian Electronics Ltd] Perixx Periboard 505 Plus with Trackball 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|okay dome keyboard - poor trackball}}
|-
| &lt;!--Description--&gt;Guangzhou Zhentian Electronics Co., Ltd Perixx Periboard 706 Plus with Trackball Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|generally okay dome with good sized keys but piano black surround fingerprint magnet, occasional brief trackball freezes after no use, takes some time to get used to the trackball size}} 
|-
| &lt;!--Description--&gt;Perixx Periboard-716 Wireless (Chicony)
| &lt;!--Vendor ID--&gt;04f2:1013
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|okay dome keyboard and trackpad}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Description--&gt;Perixx Periboard-
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Perixx Periboard-
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Lenovo SK-8825 41A5327 SIL12-W07 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;works manufactured for 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lite-On USB NetVista Full Width Keyboard 
| &lt;!--Vendor ID--&gt;0x04b3
| &lt;!--Product ID--&gt;0x3025
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;works 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech K320 Wireless Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|The Logitech USB Unifying, Bolt, Lightspeed, or Nano receiver pairing}}
|-
| &lt;!--Description--&gt;Logitech K340 Wireless Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|The Logitech Unifying Receiver pairing}}
|-
| &lt;!--Description--&gt;Logitech K400
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt; [http://www.logitech.com/en-us/product/wireless-touch-keyboard-k400r Logitech Wireless Touch Keyboard k400]
| &lt;!--Vendor ID--&gt; 0x046D
| &lt;!--Product ID--&gt; 0xC52B
| &lt;!--Revision--&gt; 1201
| &lt;!--Opinion--&gt; {{yes|All (including multimedia) keys work. Some keys requires remapping with Trident. Touchpad works and acts as normal mouse. Presents itself in Trident as USB Receiver from Logitech with 3 HID bindings}}
|-
| &lt;!--Description--&gt;Logitech K400 Plus K400+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech K600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech TK820 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech TK830 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech G915 TKL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard TKL means no number pad}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lofree Lite84 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Lofree Flow Lite100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 silent switches and low profile keys}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;MACHENIKE K500 Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 94 keys untested Hot Swappable 94 Keys 90% Layout }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MechLands Vibe99 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 100 keys untested Gasket-mounted Wired/Bluetooth/2.4GHz Wireless Mechanical Keyboard}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft Comfortable Curve 2000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| recognized but not supported}}
|-
| &lt;!--Description--&gt;Microsoft Natural Ergonomic Keyboard 4000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|recognized but not supported}}
|-
| &lt;!--Description--&gt;Microsoft Wireless Media Desktop 1000 (1356)
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x00f9 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|working but not mouse part}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Niz Micro84 Duo82 X87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 electro capacitive }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;nuphy gem80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;nuphy kick 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 low profile 75% }}
|-
| &lt;!--Description--&gt;nuphy Air75 V3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  75% }}
|-
| &lt;!--Description--&gt;nuphy node 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 96% layout, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Qpad MK-50 MK-80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Qpad MK-90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Razer Chroma 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0203
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://openrazer.github.io/ Razer] Lycosa 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Blackwidow 2013 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razr Blackwidow Ultimate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Cynosa Lite V2 
| &lt;!--Vendor ID--&gt;1532
| &lt;!--Product ID--&gt;0x023f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer DeathStalker 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer HuntsMan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Ornata 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Orbweaver Chroma Keypad 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0207
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Tartarus Keypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested not hall effect and very expensive}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Redragon K668 RGB Gaming Keyboard Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested 108 Keys Mechanical Keyboard w/Extra 4 Hotkeys Upgraded Hot-swappable Socket，Red Switch}}
|-
| &lt;!--Description--&gt;Redragon K689 PRO Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested Gasket RGB Gaming Keyboard, 108 Keys Mechanical Keyboard w/Extra 4 Hotkeys, Upgraded Hot-swappable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Risophy 60
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 75% mechanical, hotswap so okay for price untested }}
|-
| &lt;!--Description--&gt;Risophy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Royal Kludge RK65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested cream switches }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;SINO WEALTH Gaming KB SkyLion K68 
| &lt;!--Vendor ID--&gt;0x258a
| &lt;!--Product ID--&gt;0x003a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| blue stalks with rgb lighting}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;SKYLOONG GK104 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested gateron }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;SteelSeries 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;TeckNet x300 2.4G Keyboard Mouse MosART 
| &lt;!--Vendor ID--&gt;0x062A
| &lt;!--Product ID--&gt;0x4101
| &lt;!--Revision--&gt;0312 
| &lt;!--Opinion--&gt;{{Yes|1 AAA for each and works well - mouse slightly better built than keyboard rubberised membrane}}
|-
| &lt;!--Description--&gt;TeckNet X331 HDE 2.4G Keyboard wireless RCMCU 
| &lt;!--Vendor ID--&gt;0x0C45
| &lt;!--Product ID--&gt;0x7000
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{Yes|wireless can be glitchy but few extra keys are mapped }}
|-
| &lt;!--Description--&gt;TeckNet X500 2.4G Keyboard Mouse MOSArt 
| &lt;!--Vendor ID--&gt;0x062A
| &lt;!--Product ID--&gt;0x2901
| &lt;!--Revision--&gt;0112 
| &lt;!--Opinion--&gt;{{Yes|works well especially large touchpad - usual rubber domed membraned keyboard mechanism }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tecware Specter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested good 75%}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Unicomp Model M USB 104 key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} IBM's and later Lexmark buckling spring switches 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varmilo Minilo Bluebell (prestige silent) and Eculapytus (violet tactile)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 75% plastic build no screws not great to mod}}
|-
| &lt;!--Description--&gt;Varmilo Sword 68 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}} 
|-
| &lt;!--Description--&gt;Varmilo 98 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 expensive but good and Kailh silent}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Weikav Velocifire Choice65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Weikav Velocifire Lucky65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Wobkey Crush80 Reboot Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 very good but expensive Aluminum Hotswap Wireless RGB}}
|-
| &lt;!--Description--&gt;Wobkey Rainy 75
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 75% but not as expensive CNC Aluminum HMX/JWK/Cocoa Switches}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wooting HE60 HE80 HE90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 hall effect but expensive with good software}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Womier WK61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2021 untested }}
|-
| &lt;!--Description--&gt;Womier Sk71 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;Womier Sk75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;Womier Sk75 TMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xenta White Wireless HK6718B+HM3302--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|works with Raspberry Pi untested on AROS native}}
|-
| &lt;!--Description--&gt;Xinmeng X87 MAGIC_REFINER 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 untested keycap swap but not hotswapable switches}}
|-
| &lt;!--Description--&gt;Yunzii AL66 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| milk switches, cherry PBT, }}
|-
| &lt;!--Description--&gt;Yunzi B75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 budget good with cocoa cream switches }}
|-
| &lt;!--Description--&gt;Yunzii AL75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|good budget option with  swappable switches,  }}
|-
| &lt;!--Description--&gt;Yunzii AL80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 switches }}
|-
| &lt;!--Description--&gt;Yunzi C75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 budget good with  switches }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

&lt;pre&gt;
linear  - creamy
tactile - thocky
clicky  - clacky 
&lt;/pre&gt;

&lt;pre &gt;
Cherry MX Black are linear switches (no feedback); good for gaming. 
Cherry MX Red are linear (less noise no click) but more squishy; 
Cherry MX Brown are in between Blue and Red in style and tactile; 
Cherry MX Clear switches have soft tactile feedback (with no click). 
Cherry MX Blue have tactile feedback with a click (noisy); good for typing. 

Gateron Yellows KS-3, KS-3x47 or better Pros have a milky top and black bottom and linear 

TTC Silent Frozen v2. Linear and dead silent 
Mouse the huano brown with yellow dot for silent mouse clicks
Kailh red dust proof encoder for smooth and close to silent scrolling
Boba U4 Silent Tactile switches
Husky linears

HMX 
&lt;/pre &gt;


=== Mouse ===

if the USB mouse is non-functional put a USB pendrive in before or add the following to user-startup in '''s''' drawer/folder/directory

 sys:prefs/trident NOGUI &gt; NIL:

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Brand
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; | Model
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| 3Dconnexion 
| 3D Mouse 
| &lt;!--Model--&gt;[http://www.3dconnexion.com/products/spacenavigator.html SpaceNavigator]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| 3D Mouse
| &lt;!--Model--&gt;SpacePilot Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| Mouse 
| &lt;!--Model--&gt;SpaceExplorer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| Wireless Mouse 
| &lt;!--Model--&gt;SpaceMouse 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;3D Optical 
| &lt;!--Description--&gt;Wired 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;0000:3825
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Belkin
| Combo mouse
|
| 0x05FE
| 0x0011
| Low 0100
| {{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Cytec
| &lt;!--Description--&gt;Wired Mouse Gaming 
| &lt;!--Model--&gt;R.A.T 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Dell
| Mouse
| MO56UC
| 0x413C
| 0x3200
|
| {{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;equatech / clone logitech  
| &lt;!--Description--&gt;wireless mouse
| &lt;!--Model--&gt;49779 / M185 
| &lt;!--Vendor ID--&gt; 3151:2020 later 3151:3020 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{Yes|detected and works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Hama
| RF Optical Mouse
| AM-6000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;M3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;M5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keycron 
| &lt;!--Description--&gt;Optical Wireless 
| &lt;!--Model--&gt;M6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1k polling and 16k dpi }}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical Wireless 
| &lt;!--Model--&gt;M7
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested barebones 1k polling and 16k dpi, great for small hands, loud clicks}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;LogiCAD 3D
| &lt;!--Description--&gt;3D Mouse
| &lt;!--Model--&gt;Magellan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Logitech
| Cordless Desktop Navigator 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|The Logitech Unifying Receiver pairing}}
|-
| Logitech Inc.
| First/Pilot Wheel Mouse
| N48/M-BB48 M-BE58 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested }}
|-
| Logitech
| Wireless mouse
| [http://www.logitech.com/en-roeu/mice_pointers/mice/devices/5484 M305]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{yes|works}}
|-
| Logitech
| Wireless RF Mouse
| MK710
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|The Logitech Unifying Receiver pairing}}
|-
| &lt;!--Brand--&gt;Logitech
| &lt;!--Description--&gt;Wireless Mouse 
| &lt;!--Model--&gt;MX Master Anywhere 2S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|untested}} micro USB charge port on front 
|-
| &lt;!--Brand--&gt;Logitech 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;M220 silent 
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|}}
|-
| &lt;!--Brand--&gt;Logitech Logi 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;MX Master 3S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|2021 untested usb-c bluetooth, inbuilt battery but muted clicks}}
|-
| &lt;!--Brand--&gt;Logitach
| &lt;!--Description--&gt;Optical
| &lt;!--Model--&gt;G502 X Plus 
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 very clicky}}
|-
| &lt;!--Brand--&gt;Logitech
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;MX Master 4 MXM
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Bluetooth usb-c dongle, inbuilt lithium battery}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Brand
| Description
| Model
| Vendor ID
| Product ID
| Revision
| Opinion--&gt;
|-
| &lt;!--Brand--&gt;Maxxter 
| &lt;!--Description--&gt;Wireless
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8566
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Maxxter 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8518
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;OrzerHome Maxxter 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8514
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1 aa with no on/off switch }}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Microsoft
| Wheel Mouse optical
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| Sidewinder Mouse 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| IntelliMouse Explorer USB optical
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| Wireless Optical Mouse 2000
|
| 0x045E
| 0x00F9 
|
| {{no|not working see keyboard Media Desktop 2000 above}}
|-
| &lt;!--Brand--&gt;Microsoft 
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;1461 1447 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|usb dongle matched to one mouse only no others}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Orochi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Mamba 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Naga
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 17 buttons 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB Optical
| &lt;!--Model--&gt;Naga Hex V2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} MOBA Gaming Mouse, Professional Grade 16,000 DPI Sensor - RGB lighting 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical 
| &lt;!--Model--&gt;DeathAdder 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Viper 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Basilisk V3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1k polling, 35k dpi, }} 
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Trust
| Slimline Lasermouse 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| SteelSeries 
| Tobii EyeX EyeMobile PCEye 
| Eye Tracking Control 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}} gaze interaction track technology for augment augmentative and alternative communication (AAC). 
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;The Eye Tribe Tracker 
| &lt;!--Description--&gt;Eye 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;USB Optical Mouse 
| &lt;!--Model--&gt;MV3000
| &lt;!--Vendor ID--&gt;0x192f
| &lt;!--Product ID--&gt;0x0916
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|}

=== Trackball ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;3Dconnexion SpaceBall 5000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}} Labtec designed and rolled into new company 3dconnexion 2001 by owners Logitech 
|-
| &lt;!--Description--&gt;ACCO Kensington Orbit optical F1233A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kensington Turbo Mouse 64210
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Clearly Superior Technologies. Model:CST 1000-RC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Trackman Marble Mouse Wired USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Cordless Trackman Wheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Optical Trackman T-RB22 - Cordless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech M570 wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Microsoft Trackball Mouse Optical 1.0 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Microsoft X05-87473 Trackball USB Optical 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== KVM ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;NanoKVM 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== Gamepad ===

Controllers have mostly decided that the left analog joystick is keyboard equivalent of WASD and right joystick is your mouse. You also have 2 bumpers above the triggers. Shoot could be right trigger (so it doesn't involve taking your thumb off the right joystick). Face buttons for reloading or jump or other non-critical functions. Crank up the sensitivity and practice. 

Testing can be done with the TRIDENT Prefs, [https://devicetests.com/controller-tester html5], [https://greggman.github.io/html5-gamepad-test/ html5], or [https://gamepad-tester.com/ Tester]


==== Dinput Poseidon Default Plugin - Playstation(TM) style ====

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Betop Betong Bat D2E BTP-BD2E XD4D2E
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  
|- 
| &lt;!--Description--&gt;Gravis Eliminator Gamepad Pro USB  
| &lt;!--Vendor ID--&gt;047d
| &lt;!--Product ID--&gt;4005
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A}}
| &lt;!--Opinion--&gt;2002 2d only 
|-
| Hama Black Force USB Gamepad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2003 psx clone look 
|- 
| &lt;!--Description--&gt;Jess Tech Game Elements Philips GGE909 PC Recoil Pad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| [http://www.youtube.com/watch?v=TCbAmIhj6P4 Logitech Wingman Precision USB] G-UC3B 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A| }} 
| 2002 no 3D but good for 2D retro games like Turrican II
|-
| &lt;!--Description--&gt;Logitech Wingman Action Pad G-UB3A 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untested }} 
| &lt;!--Opinion--&gt;2002 1 blue lucid translucent - thin analog stick N64 type - 
|- 
| Logitech Wingman RumblePad UB05B
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc20a
| 1.12
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untesed }} 
| 2000 twin blue analogue sticks N64 type - poor 2d controls with single molded blue piece - vibration feedback - single shoulder buttons with throttle control below right one 
|-
| Logitech Wingman Cordless RumblePad G-RA4A 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc211
| 1.12
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untested }} 
| 2001 twin blue analogue sticks N64 type - poor 2d controls with single molded black piece - vibration feedback - dual shoulder buttons L1 L2 R1 R2 with blue throttle control below right one - 4 aa mn1500 batteries; life not great - C-UD10A usb dongle - overall big and bulky 
|-
| &lt;!--Description--&gt;Logitech Precision Wired G-UG15
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 psx styling blue outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| &lt;!--Description--&gt;Logitech Cordless Precision G-X2E14A
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 ps2 styling blue outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| &lt;!--Description--&gt;Logitech G-X5C11A Cordless Precision Wireless Controllers
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 psx styling black outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| [http://www.testfreaks.co.uk/game-console-accessories-controls/logitech-dual-actiontm-gamepad/ Logitech Dual Action] 
* G-UD8 has no mode (2D only?) button and no rumble 
* G-UF13A later 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc2
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|[http://www.morphzone.org/modules/newbb_plus/viewtopic.php?topic_id=7018&amp;forum=12 G-UF13A tested only]}} 
| 2003 New body shape psx style - dual analog 3D sticks - 4 small travel shoulder triggers no 5,6,7,8 
|-
| Logitech RumblePad 2 G-UF13
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc218
| 1.00
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes| }} 
| 2006 light blue top/black base - twin analogues 3D along with dual short travel shoulder buttons - rumble present - 
|-
| &lt;!--Description--&gt;[Logitech RumblePad 2 Cordless] 
* G-RC?? OLD version that take FOUR batteries and RED Logitech logo 
* G-RC14 uses TWO batteries has an ORANGE logo - dongle C-UE10 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;0xc219
| &lt;!--Revision--&gt;0x0200
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|mostly}}
| &lt;!--Opinion--&gt;2008 may have to remove 1 battery - G-RC?? 5 + 7 buttons - G-RC14 use buttons 6 + 8 to reset sticks - replace battery and push large button on receiver - 
|- 
| &lt;!--Description--&gt;Logitech F310 Wired Dual Action G-U0001 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0xc21
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|D mode switch}} 
| &lt;!--Opinion--&gt;2010 dual analog 3D with pc-xbox/psx switch on back (only D works) - both rear shoulder RT LT buttons have excess travel - no rumble vibration - 
|-
| &lt;!--Description--&gt;Logitech F510 Wired G-UG0002 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0xc21
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }} 
| &lt;!--Opinion--&gt;2010 dual analog with dual xbox pc/psx X/D switched compatibility modes - 
|-
| Logitech F710 Wireless / Cordless RumblePad 2 G-R0001 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc219
| 3.05
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }} 
| When switch on top set to D and nano receiver for each controller to pair - 2 aa mn1500 batteries required - rumble support sometimes - rear back shoulder buttons excessive travel needed 
|- 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Megaworld 'TIME' USB pad
| &lt;!--Vendor ID--&gt;0x0735
| &lt;!--Product ID--&gt;0x9902
| &lt;!--Revision--&gt;Low 0100
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No |}}
| &lt;!--Opinion--&gt;2000 Poor quality
|-
| &lt;!--Description--&gt;Microsoft 
* SideWinder Precision Pro USB (1997)
* SideWinder Precision 2 (1998)
* Game Pad Pro (1999)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Microsoft Sidewinder Game Pad USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{yes| }}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{yes| }}
| &lt;!--Opinion--&gt;[https://www.arosworld.org/infusions/forum/viewthread.php?thread_id=1149&amp;rowstart=140&amp;pid=5934#post_5931 must setup first]
|- 
| &lt;!--Description--&gt;Microsoft Sidewinder Gamepad X04 Freestyle 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A }} 
| &lt;!--Opinion--&gt;{{N/A|untested}} 1998 might need USB adapter 
|-
| &lt;!--Description--&gt;Microsoft Sidewinder X05 63895 92626 Flight stick
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;{{Yes|2000 [https://ae.amigalife.org/index.php?topic=929.msg11309#new tested]}}
|-
| &lt;!--Description--&gt;Microsoft Sidewinder Flight Stick X08-58736 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Microsoft 
    Plug &amp; Play Game Pad (2000)
    SideWinder Joystick (2000)
    Game Pad 2.0 (2001)
    SideWinder Force Feedback 2 (2002)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2002 long-standing static buildup problem and Force Feedback 2 was the removal of the power brick 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| Saitek [http://www.testfreaks.co.uk/game-console-accessories-controls/saitek-ps1000/ PS1000 Cyborg V.1], [http://www.testfreaks.co.uk/game-console-accessories-controls/saitek-ps2700-rumble-pad/ PS2700] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2000 no rumble function 
|- 
| Saitek [http://www.youtube.com/watch?v=xG0v-hf6ZPA P2600] [http://compactiongames.about.com/od/hardware/tp/gamepads.htm P3600], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2000 no rumble function
|- 
| Saitek P2900 wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{N/A|untested but runs on 1 AA battery}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Sony Batoh PS3 mini USB Wired hookup [http://ps3.jim.sh/sixaxis/usb/ SIXAXIS] 
*PCB  Ribbon      Notes
*Protos ALPS MSU Rev3 M3 and the later CBEH-1019
*?    SA1Q135A 	  for sixaxis
*PP4  
*V2   
*V25  
*VX   SA1Q146A    first dualshock 3 model
*VX   SA1Q147A    CECHZC2U (USA)
*VX35 SA1Q159A 	  
*VX3  SA1Q160A 	  
*VX?  SA1Q188A    
*VX4  SA1Q189A    shipped with a CECH-2504 datecode 0C 
*VX5  SA1Q194A    changed design ALPS, PS button changes
*VX6  SA1Q195A    red case, 
*VX7  SA1Q222A    superslims 2 ribbons
*VX8  SA1Q224A    superslims 2 ribbons 
| &lt;!--Vendor ID--&gt;0x054c
| &lt;!--Product ID--&gt;0x0268
| &lt;!--Revision--&gt;1.00 
| &lt;!--Merge with USB on Digital Pad--&gt;{{No|}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|}}
| &lt;!--Opinion--&gt;Sometimes detected but no support - no sixaxis features detected - mini usb lead will have varying results - 
|- 
| &lt;!--Description--&gt;Sony PS4 
*JDM JDS 001 010 011 
*JDM 030 040 055 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Sony PS5 Dual Sense 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Speed Link Strike 2 FX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Thrustmaster Firestorm Dual Power 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|[http://www.morphzone.org/modules/newbb_plus/viewtopic.php?topic_id=7018&amp;forum=12 only 1 axis joystick only]}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Trust Predator GM-1500 GM-1520
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 M series Aluminum Metal Joystick Hitbox Controller Arcade Fighting Stick
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 T series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 G series Gamefinger G12 G13 G16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; plastic - 
|- 
| &lt;!--Description--&gt;Haute42 S series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  thinner and lighter than G series 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mad Catz sf2 fightstick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Datel Paewang Arcade Pro Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mayflash F300 Fighting Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mayflash F500 Fighting Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Pico Flatbox GP2040-CE Hot Swappable Mini Hitbox Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  default it is configured for PS4 but before plugging usbc cable in, X for Dinput, B Xinput, RT HID - plastic build case - Rev4 based on RP2040 chip and firmware is based on GP2040-CE (Community Edition) - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Shenzhen Onebitdo Tech 8bitdo Fighting stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Venom 8 button 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
|}


==== Xinput Xbox Style Plugin ====

2018 extension added originally called AROSx but later redacted. Latest [https://github.com/medusalix/xone linux driver] might be useful. 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;8bitdo Ultimate C Wired 82CB (Shenzhen ONEBITDO TECH - GWOWO) 
| &lt;!--Vendor ID--&gt;0x2dc8 
| &lt;!--Product ID--&gt;0x3106 
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2022 - 4 t6 torx screws - non hall effect so drifting issues - triggers go faulty often - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 2C Wired Controller 82CD 
| &lt;!--Vendor ID--&gt;0x2dc8 
| &lt;!--Product ID--&gt;0x310A
| &lt;!--Revision--&gt;0114
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - HID keyboard assigned - 4 t6 torx screws - hall effect analogs and triggers  - 1000Hz polling - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 2C wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024  - 400mw battery - hall effect 3d nubs and triggers - micro switch shoulder buttons - d-pad poor for retro games - 
|- 
| &lt;!--Description--&gt;8bitdo ULtimate Mini Wired Controller for Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect 
|- 
| &lt;!--Description--&gt;8BitDo Pro 2 
*Wired Controller 
*Wireless
*Bluetooth
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect - playstation style layout for pc - slide button for S-A-D-X switch, android, dinput or xinput -  
|-
| &lt;!--Description--&gt;8BitDo Pro 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025  tmr hall effect analogs, hall effect triggers and some microswitches - button swap - ps2 style layout - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2026  - mw battery - hall effect 3d nubs and triggers - micro switch shoulder buttons - d-pad  for retro games - 
|- 
| &lt;!--Description--&gt;8BitDo Pro 3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2026  hall effect analogs, hall effect triggers and some microswitches - button swap - ps2 style layout - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Ace Aurora 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect joysticks with no deadzone mode, gyro, linear rumble, trigger stops, back paddles, button swap, macro, turbo, RGB LED effects -  tri-mode connection - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Betop Beitong Spartan BTP-2270U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;  no hall effect 
|- 
| &lt;!--Description--&gt;Betop Betong Asura 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;  no hall effect - noble linear trigger potentiometer and alps shoulder LB/RB micro switch 
|- 
| &lt;!--Description--&gt;BEITONG ASURA 2 Pro+ Game Controller Wireless Gamepad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Beitong Zeus 2  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BebonCool Dinofire Model Number: Q218 / TP28
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2021  - triggers aren't progressive but ON/OFF - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;EasySMX X05 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect analog and triggers - tri mode connection - 
|- 
| &lt;!--Description--&gt;EasySMX Wireless Controller PC PS3, 9013pro ESM-9013PRO
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 linear hall effect but device sometimes will not connect tried multiple attempts with the dongle
|- 
| &lt;!--Description--&gt;EasySMX X10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;EasySMX X20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 ABXY MICRO SWITCH - Bumpers Tactile switch Hall Effect analog 
|- 
| &lt;!--Description--&gt;EasySMX X15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect analog and triggers - membrane buttons - 
|- 
| &lt;!--Description--&gt;EasySMX S10 Wireless Gamepad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 TMR Hall effect and compatible with Switch 2/PC/Phone/TV/Steam, NFC, Gyro, HD Rumble - 
|- 
| &lt;!--Description--&gt;EasySMX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;202
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Fantech World EOS Pro WGP15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect trigger and sticks,2 back paddles, motion controlling 
|- 
| &lt;!--Description--&gt;Fantech EOS PRO II S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 controller with TMR hall effect analogues, mechanical face buttons and D-pad, 63 input macro, back paddles, turbo - analog triggers with trigger stops - tri mode bt wifi and wired - slide switch on back for switch, macos/android and xinput - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Flydigi Apex 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023  luxury model 
|- 
| &lt;!--Description--&gt;Flydigi Vader Pro 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023 the Pro(Hall Effects) and Non-Pro (No Hall) 
|- 
| &lt;!--Description--&gt;Flydigi Direwolf 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023 hall effect sticks and triggers - poor wifi connection - 
|- 
| &lt;!--Description--&gt;Flydigi Apex 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024  luxury model 
|-
| &lt;!--Description--&gt;Flydigi Vader 4 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - hall effect, DInput mode (o+A hold) - 
|- 
| &lt;!--Description--&gt;Flydigi Direwolf 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 hall effect analog and triggers but membrane buttons with gold contacts - 800mhA battery - 
|- 
| &lt;!--Description--&gt;Flydigi Dunefox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 basic model hall effect analog and triggers but membrane buttons - 500mha battery - no gyros - 
|- 
| &lt;!--Description--&gt;Flydigi Vader 5 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2025 - hall effect stick with tension control, linear triggers, DInput mode (o+A hold) - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Gamesir T4K Keleid, T4C Cyclone wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2023 poor to ok switch 
|- 
| &lt;!--Description--&gt;Gamesir Nova 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no|| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2024 - switch type layout 
|- 
| &lt;!--Description--&gt;Guangzhou Chicken Run Network Tech Nova Lite GameSir-T4n LITE - Zikway HID gamepad
*[https://www.reddit.com/r/Gamesir/comments/1c185ve/psa_keep_gamesir_nova_lite_t4n_lite_firmware_at/ fw 4200 seems to be xbox so B then Home for Xinput (green LED), A then Home for HID BT Android (green/yellow LED), Y then Home for Switch Pro (Red LED)] or X then Home for Wifi and start and select to alternatively swap modes 
* and if on [https://www.reddit.com/r/Gamesir/comments/1c185ve/psa_keep_gamesir_nova_lite_t4n_lite_firmware_at/ fw 5700 ds4 so Home + B (blue LED), ]
* firmware 6900 
| &lt;!--Vendor ID--&gt;0x3537
| &lt;!--Product ID--&gt;0x1040 0x1041
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2024 - hall effect 3d nubs - no usb-c cable - rubber membrane analog trigger travel and bumpers shoulder buttons - wifi 2.4G and bluetooth - xbox layout so ab and xy might need to be swapped via m and a buttons for switch type [https://www.youtube.com/watch?v=po-nNuC5fps fixes video] - 250Hz polling - 600mah battery - rigid carry case - poor d-pad esp diagonals - gamesir settings software only on android 6+ or ios based only - 
|- 
| &lt;!--Description--&gt;Gamesir Nova 2 Lite  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir G7 SE Wired Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect 
|- 
| &lt;!--Description--&gt;GameSir G8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Gamesir TEGENARIA T3 Lite Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 playstation aesthetic hall effect analog and membrane buttons - X+Home button connects as an Xbox controller
|- 
| &lt;!--Description--&gt;GameSir Cyclone 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 TMR Joysticks with anti-friction rings and metal anti-friction rings around the stems, gyro, rumble, macro, turbo, 2 back paddles, hall analog triggers with micro-switch trigger - tri mode bluetooth, 2.4GHz wifi and wired, 1000hz polling rate - gamesir connect software - 
|- 
| &lt;!--Description--&gt;GameSir G7 Pro for Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 TMR hall effect - hall effect triggers, tri mode connection - gamesir nexus software - 
|-
| &lt;!--Description--&gt;GameSir Super Nova Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2026 hall effect sticks and triggers, 1000Hz polling, tri mode connectivity, 
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GuliKit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GuliKit KingKong 2 NS08 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;Electromagnetic Stick hall effect - hall linear triggers - Mechanical face buttons - wired and wireless - Built-in rechargeable lithium battery 
|-
| &lt;!--Description--&gt;GuliKit KingKong 2 PRO NS09
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;hall efect - wired and wireless - Mechanical face buttons - Built-in rechargeable lithium battery 
|-
| &lt;!--Description--&gt;GuliKit KingKong MAX 3 KK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;hall effect - wired and wireless - lithium battery - 
|-
| &lt;!--Description--&gt;Gulikit KK3 Max USB-c Bluetooth Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 Hall Joysticks and Triggers, Maglev/Rotor/HD Vibration, 1000Hz Polling Rate, 4 Back Buttons,  
|- 
| &lt;!--Description--&gt;GuliKit KK3 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 smaller version of KK3 MAX - hall effect analog and triggers, face buttons , maglev rumble, gyro, 4 back paddles - rigid case - 950mAh up to 8 hrs - 
|-
| &lt;!--Description--&gt;GuliKit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Hyperkin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Hori EX2 Turbo UHX3-45 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Machenike G1 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 Wireless Gaming Controller with 1K Polling Rate Hall Effect Trigger Joystick For Nintendo Switch PC iOS Android 
|- 
| &lt;!--Description--&gt;Machenike G5 Pro Wireless Gaming Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 ABXY Switch Membrane, Bumpers Tactile switch and hall effect analog 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;microsoft sidewinder precision pro 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| [https://pineight.com/mw/index.php?title=USB_game_controllers Xbox 360 Wired Controller]
| 0x045e
| 0x028e
| 0x
| &lt;!--Merge with USB Digital Pad--&gt;{{No|needs specific driver and has poor 2D control pad}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|- 
| Microsoft (R) [https://blog.tkjelectronics.dk/2012/12/xbox-360-receiver-added-to-the-usb-host-library/ Xbox 360] (TM) Wireless Receiver for Windows(R) Model 1086 and Controller 
| 0x045e 
| 0x0719, 0x or 0x0291
| 0x0100
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;{{No|separate standalone usb dongle detected and shows as 8 vendor interfaces but no class associated and so not working - may need new class from code from xpad or xboxdrv to work the controllor}}
|-
| &lt;!--Description--&gt;Xbox 360 Kinect [http://hackaday.com/2010/11/10/kinect-open-source-driver-demo-and-hacking/ Video] 
[http://git.marcansoft.com/?p=libfreenect.git;a=commit;h=7655fcf7239ba4907654089dba535a196685dbe5 GIT]
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007  proprietary 2.4GHz RF protocol, 
|- 
| &lt;!--Description--&gt;Xbox One Wired Controller 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Xbox One wireless controller newer model with the 3.5mm headphone jack 1537 1697 and microsoft adapter 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02d1 or 0x02dd
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2014 
|- 
| &lt;!--Description--&gt;Microsoft Elite Series 1
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02e3
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2016 ok - 
|-
| &lt;!--Description--&gt;Xbox later models 1708+ Xbox One and Series use 5GHz and use Bluetooth, 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02e0
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2017 
|- 
| &lt;!--Description--&gt;Xbox One S
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02ea 0x02fd
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2019
|- 
| &lt;!--Description--&gt;Microsoft Elite Series 2 Core 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02ff
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2022 ok - no hall - 125Hz polling - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Minisform MGP01 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;MOBAPAD N1HD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 has liquid silicone face buttons, hall effect analog, D-Pad swap, two back paddles, USB-A dongle, HD Rumble - 
|- 
| &lt;!--Description--&gt;Mobapad Huben 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 
|- 
| &lt;!--Description--&gt;Mobapad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON Gale 墨将 mòjiāng 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON Blitz PRO 2 TMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON now MOJHON AETHER 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect joysticks, hall effect triggers, mechanical bumpers, 1000hz polling rate, mechanical D-pad, membrane face buttons, mechanical back paddles, rumble, deadzone issues - tri mode 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;MSI FORCE GC20 GC30 V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2021 not hall effect 
|- 
| &lt;!--Description--&gt;MSI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mytrix Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;NACON GC-100XF Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 average 
|- 
| &lt;!--Description--&gt;PXN P5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect joysticks &amp; triggers, limited trigger stops, 1000hz polling rate on wired, 4 back paddles, 32 macro record, anti-deadzone mode, RAW mode, gyro, turbo, tri-mode connection - 
|- 
| &lt;!--Description--&gt;PXN P50L 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;PowerA 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD Stellar T5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD Junior E5 Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Razer Wolverine V3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024  hall 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;RetroFlag 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Speedlink XEOX Pro Analog Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;enclosed lithium battery? - xbox layout - switchable on back of controller to directinput (dinput) or xinput - USB dongle switchable to pc and ps3 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;SCUF Instinct Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2022 good 
|- 
| &lt;!--Description--&gt;SCUF Envision Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2023 good 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Steel Series Stratus Duo XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;usb adapter needed 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;[https://inputlabs.io/Inputlabs InputLabs Alpakka Open Source and build yourself] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;DIY it with 3d printer, pcb and components  - pi pico needed - 2 gyros for better accuracy - 
|- 
| &lt;!--Description--&gt;[https://inputlabs.io/kapybara Inputlabs kapybara] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;DIY one handed version wip 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Vilcorn Z03 BT Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - other Bluetooth modes (green, red, blue, purple, etc.) Select + M1 (or M2) - 400mAh - not great latency wired - 800mhz polling -  
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;zd ultimate legend 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;zd 0+ elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;zd 0+excellent
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
|}

&lt;pre&gt;
#ifndef AROSX_LIBRARY_H
#define AROSX_LIBRARY_H

#include &lt;exec/types.h&gt;

#define AROSX_CONTROLLER_TYPE_UNKNOWN  0x00
#define AROSX_CONTROLLER_TYPE_GAMEPAD  0x01

#define AROSX_GAMEPAD_DPAD_UP          0x0001
#define AROSX_GAMEPAD_DPAD_DOWN        0x0002
#define AROSX_GAMEPAD_DPAD_LEFT        0x0004
#define AROSX_GAMEPAD_DPAD_RIGHT       0x0008
#define AROSX_GAMEPAD_START            0x0010
#define AROSX_GAMEPAD_BACK             0x0020
#define AROSX_GAMEPAD_LEFT_THUMB       0x0040
#define AROSX_GAMEPAD_RIGHT_THUMB      0x0080
#define AROSX_GAMEPAD_LEFT_SHOULDER    0x0100
#define AROSX_GAMEPAD_RIGHT_SHOULDER   0x0200
#define AROSX_GAMEPAD_A                0x1000
#define AROSX_GAMEPAD_B                0x2000
#define AROSX_GAMEPAD_X                0x4000
#define AROSX_GAMEPAD_Y                0x8000

struct AROSX_GAMEPAD {
    ULONG   Timestamp;
    UWORD   Buttons;
    UBYTE   LeftTrigger;
    UBYTE   RightTrigger;
    WORD    ThumbLX;
    WORD    ThumbLY;
    WORD    ThumbRX;
    WORD    ThumbRY;
};

#define AROSX_EHMB_CONNECT    0x00
#define AROSX_EHMB_DISCONNECT 0x01
#define AROSX_EHMF_CONNECT    (1L&lt;&lt;AROSX_EHMB_CONNECT)
#define AROSX_EHMF_DISCONNECT (1L&lt;&lt;AROSX_EHMB_DISCONNECT)

struct AROSX_EventHook {
    struct Node         eh_Node;
    struct MsgPort     *eh_MsgPort;
    ULONG               eh_MsgMask;
};

struct AROSX_EventNote {
    struct Message      en_Msg;
    ULONG               en_Event;
    APTR                en_Param1;
    APTR                en_Param2;
};

#endif /* AROSX_LIBRARY_H */
&lt;/pre&gt;


=== Joystick ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;CH Products CombatStick 568 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Cyborg X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Extreme 3D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| [Logitech Attack 3 Joystick] 
| 0x0464
| 0xC214
| 0205
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;saitek X-52 x52 pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;saitek aviator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Speedlink Competition Pro USB 
| 
|
| 
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{maybe|works but games not working &quot;out of the box&quot;}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Trust Predator QZ 501
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust Predator TH 400
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust Predator GM-2500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust XK 100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

===[https://github.com/JacKeTUs/linux-steering-wheels Gaming Racing Steering Wheels]=== 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;40%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  [https://www.usb.org/sites/default/files/documents/pid1_01.pdf USB PID standard not supported], 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cammus C5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fanatec CSL Elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS4 and Xbox - belt driven wheel - 30cm wheel swapping 
|-
| &lt;!--Description--&gt;Fanatec Club Sport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; top belt $600 £500 system 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;FFBeast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Genius TRIO RACER F1 Racing Wheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Cheap and cheerful but not great - may need calibrating 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hama PC Racing Wheel Thunder V18 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Average 
|-
| &lt;!--Description--&gt;Hori Racing Wheel 3 with pedals 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS3 PC 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Logic3 PXU450 TopDrive GT450 Steering Wheel for PS3, PS4, XBox One and PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Logitech MOMO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Very good 
|-
| &lt;!--Description--&gt;Logitech Driving Force GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Logitech Drive Force Pro DFP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; wheel 900 degree - weighs in at 15&amp;nbsp;lbs
|-
| &lt;!--Description--&gt;Logitech Formula Force EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;200 degrees turn for the EX model is arcade-like driving - adds PS3 compatibility via the PSx/2 adaptor - weighs in at 9&amp;nbsp;lbs
|-
| &lt;!--Description--&gt;Logitech G25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;   - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G27 PC/PS3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; comes with gear shifter - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G29 PC PS3/PS4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  may need additional shifter - gear 900deg wheel / rumble - 3 peddle - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G920 PC XboxOne 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  may need additional shifter - gear 900deg wheel / rumble - 3 peddle - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G923 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft(R) SideWinder Precision Racing Wheel (1999)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R3
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R5
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R9
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R12
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://github.com/Ultrawipf/OpenFFBoard OpenFFBoard], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V12 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V12 Lite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simagic M10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; base direct drive $900 £800 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simplicity Simwheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; direct 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simxperience Accuforce V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SPEEDLINK Drift O.Z. Racing Wheel with Pedals and Gear Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SteelSeries Simraceway SRW-S1 Steering Wheel (PC) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Thrustmaster Nascar Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Thrustmaster Ferrari Challenge Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; Poor  
|-
| &lt;!--Description--&gt;Thrustmaster Ferrari FGT Rumble GT Experience 3-in-1 (PC/PS3)
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;b658
| &lt;!--Revision--&gt;0102
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Wheel and all buttons detected}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|}}
| &lt;!--Opinion--&gt;Not great - gear driven 240deg wheel rotation - no psu needed - 2 peddle - flappy gear change - rumble untested - red switch for PC PS3 selection 
|-
| &lt;!--Description--&gt;Thrustmaster F430 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Thrustmaster T500 RS Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; belt driven wheel/rumble for GT5 
|-
| &lt;!--Description--&gt;Thrustmaster T60 Challenge 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Thrustmaster T150 Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  gear / belt combo wheel / rumble - 2 peddle 
|-
| &lt;!--Description--&gt;Thrustmaster TMX Pro PC/XboxOne
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt; direct drive rumble - no manual gear shift included 
|-
| &lt;!--Description--&gt;Thrustmaster T80 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Base level and OK - PS4 - 270deg rumble - 2 peddle 
|- 
| &lt;!--Description--&gt;Thrustmaster T300 RS GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS3 PS4 - belt driven - 900deg rotation and modular 28cm wheel out - 2 peddles but 3 available 
|-
| &lt;!--Description--&gt;Thrustmaster TX Leather 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;TX Xbox version - 900deg rotation 
|-
| &lt;!--Description--&gt;Thrustermaster TS PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PC only belt wheel 
|-
| &lt;!--Description--&gt; TS XW Racer PC Xbox1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; top belt system 
|-
| &lt;!--Description--&gt;Thrustmaster T-GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS4 $700 £600 with T-DFB 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Tracer Zonda Racing Steering Wheel PC PS3 Vibration Feedback Pedals Gearbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


===Gamepad Joypad Adapters===

* Most adapters will work in most OS's without installing a driver. Special functions needing drivers will be noted. 
* Some adapters do not work with some [http://www.stepmania.com/wiki/Dance_Pads dance pads] because of voltage issues. Other adapters map the dancemat arrows as axes and not as buttons, causing problems.
* If using an adapters should be compatible with '''original''' PlayStation PS/Xbox Xbox/GameCube GC /Dreamcast DC/Sega Saturn SS gamepads. 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|- 
| &lt;!--Description--&gt;[http://www.maplin.co.uk/psx-usb-bridge-34887?tabid=3&amp;worldid=&amp;doy=21m9&amp;faqitem=playstation%20controller%20to%20pc%20adaptor Maplin] [http://www.rockfire.com.tw/ Padix Co. Ltd. Rockfire] PX-205 PSX/USB Bridge 
| &lt;!--Vendor ID--&gt;0x0583 
| &lt;!--Product ID--&gt;0x2050
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes}} but buttons mapped different from others 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|poor}}
| &lt;!--Opinion--&gt;Ok with dpads, but very poor support with analogue hack 
|-
| Boom PS Joy Converter adaptor 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| discontinued (2004/5). Hold Up, Start, and Select for three seconds. Very good [http://www.stepmania.com stepmania] recommendation. 
|-
| [http://www.hkems.com/m_main.htm EMS] [http://www.hkems.com/product/ps2/ps2-usb2.htm USB2] grey plastic box with 2 PSX ports, one on either side - UP and Select pressed for 3 seconds at the same time or the dance code (start+select+up) 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Tests/joystick shows the PS port works in digital mode on d-pad}}
| &lt;!--Analogue Hack with Analog Stick--&gt;
| Set in PC switch mode. Does not work when using 2 pads at the same time, likely higher power requirements. FPSE emu DualShock untested, Mat and Guitar untested but known lag involved 
|-
| Joytech (play.com) (EMS USB2 bad clone) Black box twin PSX
| 0x0b43
| 0x0003
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|buggy hardware}} 
| but poor on dance ddr mat and guitar hero as the left and right keys do not like being pressed together, Dual shock untested 
|-
| [ EMS Trio Linker ] 1 PSone connection at bottom
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX discontinued 2005 
|-
| [http://psxemulator.proboards.com/index.cgi?board=support&amp;action=display&amp;thread=421 EMS Trio Linker Plus] (blue box) 1 PSx at bottom
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX discontinued 
|-
| Gamtec [http://www.gamestone.co.uk/gradius/guides_usb_smartjoy_guide.php SmartJoy Plus] Lik Sang PS-&gt;USB converter Red 2005 
| 0x0925
| 0x0005
| Low 0110
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe|detected and digital dpad works with [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4138&amp;forum=2&amp;post_id=35952#forumpost35952 joystick and testjoystick tests] but  the second analog control is not mapping correctly in digital mode}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|Analogue Hack - hardware buggy not useable}} 
| Dual shock untested, Mat and Guitar untested. Nothing picked up upon plugging it in. Quite common, these items have grounding issues or feed voltage back into the USB host and freeze the host controller, preventing any plugins or removals being detected. 
|-
| Gamtec SmartJoy Plus Dual PS-&gt;USB converter Red 
| 0x0925
| 0x00
| Low 
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|buggy hardware}}
| 
|-
| [http://uk.gear.ign.com/articles/700/700334p1.html Lik-Sang Super SmartJoy PSX] 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX 
|-
| Soyo Kiki Kiky 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| eXcel PSX adaptor shaped a little like a stealth bomber with USB pass through 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| Venom 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| Dragon Plus (Radio Shack) Pantherlord GreenAsia USB to PS2/PS3 converter single black cable
| 0x0e8f
| 0x03
| 1.07
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes| }}
| 
|-
| Deal Extreme 2 PSX black cables from 1 USB port
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{N/A|untested }}
|- 
| &lt;!--Description--&gt;HDE 2014 Personal Communication Systems Inc 
| &lt;!--Vendor ID--&gt;0x0810
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;0106
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Same as single cable above but with black block midway along cable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
|- 
| &lt;!--Description--&gt;TigerGame Ltd Mayflash PC001 Super Joy Box 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| TigerGame Ltd Mayflash PC016 Super Joy Box arrowhead triangle twin PSX] Original was lack with RED Leds. Clones Dilong pu203, Blue HDE Neewer ShineData SD-APS2USB, Red Octane and Black PC Power Box (NS3454) '''embossed circle''' on top 
| 0x0810
| 0x0001
| 1.06
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Tests/joystick shows one PS port does not work with analog control at all but the other port does and maps correctly in digital mode}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|Analogue hack works }}
| Still available 2013, poor construction though, falls to pieces easily. Dual Shock untested, Mat and Guitar untested 
|-
| &lt;!--Description--&gt;TigerGame Ltd [http://www.mayflash.com/pc/pc038/pc038-1.htm Mayflash PC038 Super Joy Box Pro triangle twin PSX] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| TigerGame Limited Mayflash SuperJoy Box 5 PC006 long V-shaped 4 port PS/PS2 Game Controller Adapter  
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|- 
| &lt;!--Description--&gt;TigerGame Limited Mayflash SuperJoy Box 5 PRO PC039 PS/PS2 Game Controller Adapter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion 
|- 
| Boom PSX+N64 USB converter (purple or blue see through box) (2003/4) - red led for psx and green led for n64
| 0x6666
| 0x0667
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{No|not detected by Tests/joystick}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|Analogue hack }}
| Rumble Pak untested
|-
| [http://www.hkems.com/product/ps2/TrioLinkerPlus2.htm EMS Trio Linker Plus II] 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4753&amp;forum=24&amp;post_id=43102#forumpost43102 ]
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1DC 1GC 1PSX but not for ddr mat games 
|-
| TigerGame Mayflash PC043 clone HuiJia Black twin N64 converter for PC USB 
| 0x0e8f
| 0x3013
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{No|detected by Tests/joystick though two digital pads have their settings wrong}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|Analogue hack works well with middle handle/grip little joystick}}
| Rumble Pack untested 
|-
| TigerGame Mayflash PC MagicBox SuperBox 3 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| untested 1SS 1DC 1PSX }
|-
| &lt;!--Description--&gt;Lik Sang SmartJoy X 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x0285
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SmartJoy X2 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x0289
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| TigerGame Mayflash PC018 Super Joy Box 9 Xbox (NOT 360) 
| 0x05e3
| 0x060
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| does not work. Hub(s) 0x0288 detected but 0x0289 xbox1 joypads are not detected as hid let alone as [http://www.amiga.org/forums/archive/index.php/t-62940.html xpad] or [http://pingus.seul.org/~grumbel/xboxdrv/ linux xboxdrv driver] 
|-
| TigerGame Mayflash PC019 Super Joy Box 10 Xbox Twin ports (NOT 360) 
| 0x05e3
| 0x060
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| does not work with the big Fatty Duke or smaller S Akebono controller(s) 
|-
| TigerGame Ltd Mayflash PC020 Super Joy Box 11 Xbox Quad ports (NOT 360) 
| 0x05e3
| 0x0604
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| 
|- 
| &lt;!--Description--&gt;TigerGame Ltd Mayflash PC035 3 in 1 Magic Joy box PS GC Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;USB to NES [http://wiki.nesdev.com/w/index.php/Standard_controller SPI like protocol] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Buffalo Classic USB Pad SNES like 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash PC044 USB to SNES 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;USB to MEGADRIVE GENESIS Joypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;[http://www.retrousb.com/product_info.php?cPath=21&amp;products_id=70 USB to 9 pin ATARI RETROPORT style JOYSTICK PORT] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Atari RetroLink 9pin to SB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;SLS Sega Saturn USB pad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash PC050 Dual Saturn ports 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Guitar Hero for PC/Mac 
| &lt;!--Vendor ID--&gt;0x1430
| &lt;!--Product ID--&gt;0x474C
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Cronus Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BrookX One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Gamecube to USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Magic NS 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; WiiU 
|- 
| &lt;!--Description--&gt;Brook Converter WiiU P3 P4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;CooV Xbox One Converter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
|}


* [http://www.bemanistyle.com/forum/f6/best-metal-pad-19066/ Metal dance pads with LEDs] - My My Box Blue Shark (Nexen), Cobalt Flux (CF) (Let's Groove), Red Octane Afterburner, TX-2000, Logic3 (Dance Dance Dance), Gamerose (Stay Cool), 
* Hard foam mat - [http://www.mayflash.eu/3in1-deluxe-dansmat-ignition-foam-ps2xboxpc-p-5.html Mayflash] FutureMax Deluxe 3 in 1 Ignition, [http://www.gamerose.com/ Gamerose] (Stay Cool), TrinPad orange, 
* Soft foam mat - Logic3 (PS420N), [http://www.positivegaming.com/index.php?id=36 Positive Gaming Impact],  Gamerose Miss Daisys Naki (Stay Cool), Pelican, MadCatz

*PS1 PS2 PS3 PS4 flex ribbon big source of button/trigger issues with all controllers 
*PS2 Phat KSA1Q40A (Board), SA1Q33A (Membrane) SCHP-10010 H 
*PS2 SA1Q42A SCHP-10010 A 
*PS2 SA1Q43-A SCHP-10010 H


The primary axes are either the Control Pad or the left stick. Buttons come in a rough order: face buttons, then shoulder buttons, then Select and Start, then buttons under sticks, and finally Control Pad directions if not assigned to a hat. But the order and number of buttons within a category are unpredictable, as is which button the user expects to use for each action.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Joypad 
! width=&quot;5%&quot; | HATS 
! width=&quot;5%&quot; | Button 01
! width=&quot;5%&quot; | Button 02
! width=&quot;5%&quot; | Button 03
! width=&quot;5%&quot; | Button 04
! width=&quot;5%&quot; | Button 05
! width=&quot;5%&quot; | Button 06
! width=&quot;5%&quot; | Button 07
! width=&quot;5%&quot; | Button 08
! width=&quot;5%&quot; | Button 09
! width=&quot;5%&quot; | Button 10
! width=&quot;5%&quot; | Button 11
! width=&quot;5%&quot; | Button 12
! width=&quot;5%&quot; | Button 13
! width=&quot;5%&quot; | Button 14
! width=&quot;5%&quot; | Axes 1 
! width=&quot;5%&quot; | Axes 2 
! width=&quot;5%&quot; | Axes 3 
! width=&quot;5%&quot; | Axes 4 
! width=&quot;5%&quot; | Axes 5 
! width=&quot;5%&quot; | Axes 6 
! width=&quot;10%&quot; | Comment 
|-
| [https://pineight.com/mw/index.php?title=USB_game_controllers Xbox 360 Wired Controller]
| 
| A (down-green) 
| B (right-red) 
| X (left-blue) 
| Y (up-yellow) 
| LB (white) 
| RB (black) 
| Back
| Start
| Guide 
| L3
| R3
| 
| 
| 
| Left X 
| Left Y
| LT
| Right X
| Right Y 
| RT 
| Poor 2D, Good 3D 
|- 
| &lt;!--Description--&gt;Gravis GamePad / Original PlayStation Controller 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Red (Sqleft)
| Yellow X (X down)
| Green O (O right)
| Blue (Tri up)
| L1
| R1
| L2
| R2
| Select
| &lt;!--Button 10--&gt;Start
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;Stick X
| Stick Y
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; PlayStation 2 Older Adapters 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Blue X (down) 
| Red O (right) 
| Pink Sq (left) 
| Green Tri (up) 
| L1
| R1
| L2
| R2
| Select
| &lt;!--Button 10--&gt;Start 
| Stick 1
| Stick 2
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; PlayStation 2 Newer Adapters 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Up
| Right
| Down
| Left
| L2
| R2
| L1
| R1
| Select
| &lt;!--Button 10--&gt;Start
| Stick 1 (analogue Hack) 
| Stick 2 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; Wish Technologies N64 Adaptoid 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt; A
| C Down
| C Right
| B
| C Left
| C Up
| L
| R
| Start
| &lt;!--Button 10--&gt;Z
| Pad Up
| Pad Down 
| Pad Left
| Pad Right 
| &lt;!--Axes 1--&gt;Stick X
| Stick Y 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;
| 
| 
| 
| 
| 
| 
| 
| 
| &lt;!--Button 10--&gt;
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;
| 
| 
| 
| 
| 
| 
| 
| 
| &lt;!--Button 10--&gt;
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
|}

Just plug in your digital/analogue joystick or gamepad into USB port. The device will be handled by Poseidon USB stack. Poseidon is the USB stack with Trident adding a GUI (graphical user interface) prefs. 


the context sensitive page would come up right on pressing the help key inside the relevant window. The manual is in this archive, just in case it isn't in SYS:Locale/Help  


*How to change joystick mode to analogue?

By default a connected USB joystick emulates Amiga digital joystick. To change this behaviour so that the joystick is presented as analogue you need to use Trident preferences application (System:Prefs/Trident).

Open Trident and go to Devices on the left hand side (mouse click once on it). Select your controller from the list to the right and then click on Settings button below. This will open a new window. On the &quot;General&quot; tab find the &quot;Lowlevel Library Joypad Emulation&quot; section near the bottom. Find ports which are set to &quot;Merge with USB&quot; or &quot;Override with USB&quot; and change them to &quot;Analogue Hack&quot;. 

Please note that analogue joystick support is an extension of original Amiga functionality, thus an Amiga application must be explicitly written to use it. AROS SDL library uses this functionality, thus all SDL applications that use joystick, can use the analogue joystick feature.

The HID class has several options how to handle the input data: 

* Don't touch: The movement and button data for is not modified by the hid class. This is the default for the ports 0, 2, and 3. 

* Overwrite with USB: This will kill the  original  data  that  might  had  come  from  the internal  ports  and  overwrites it with the joypad data for this USB interface. Note well: If you have multiple  joypads  connected,  take care  which setting you have selected for each port, because only the last interface with this option will actually send the joypad data to the game. 

* Merge with USB: This option merges the input data of the  lowlevel.library  with  the USB  stream. This only works, if the connected device on the original Amiga  ports  is  NOT  a  mouse  (because  then   the   streams   are incompatible).  Merging  should  be  the preferred method, because it leaves the original joysticks working. 

* Disable: Turns off the port for the application.

* Analogue Hack: Tells Poseidon to force reporting  of  analogue  data  at  the  port. Please  note  that  this only works with programs that understand the analogue  data,  because  it's   an   extension   to   the   original lowlevel.library   standard   made  by  Commodore.  If  you  want  to incorporate this feature in your software, just contact me and I will send you the necessary information. 

* Rumble Port: As addition to the analogue data, the HID class  supports  applications and  games  that want to utilize a rumble pack or force feedback motors in the gamepads. This field selects to  which  lowlevel  port  the  hid device responds, when attempting to use the rumble pack. Normally, this corresponds to the port that has  been  set  in  the  actions  for  the joypad.


*How to change joystick port assignment?

The low  level  library  supports up to four ports. Port 0 is usually used by the mouse, port 1 is the standard port for joysticks/joypads. By default a connected USB joystick is present in Port 1. To change its location to Port 0 you need to use Trident preferences. 

Open Trident and go to Devices window. Select your controller from the list and then click on Settings button. This will open a new window. On the &quot;General&quot; tab find the &quot;Lowlevel Library Joypad Emulation&quot; section. Port 1 should be set as either &quot;Merge with USB&quot; or &quot;Override with USB&quot;. Change this setting to &quot;Don't touch&quot;. Change Port 0 setting to &quot;Merge with USB&quot;.

Go to &quot;Actions&quot; tab. In the &quot;Reports and collection&quot; select first entry named &quot;Joystick&quot;. in the &quot;Usage items&quot; select &quot;X axis&quot;. Go to &quot;Performed actions&quot; area. On the left there will be a list of triggers. Each of them should have (port1) in their params. Click on the first trigger and using buttons to the right of the list change port1 into port 0. Repeat this for all triggers and for all items on &quot;Usage items&quot; list.


*How to make joystick simulate keyboard keys?

With Poseidon it is possible to make the joystick simulate the keyboard pressings. This might enable using joystick for playing games which only have keyboard support. This feature is configured in Trident preferences.

Open Trident and go to Devices window. Select your controller from the list and then click on Settings button. This will open a new window. Go to &quot;Actions&quot; tab. On the right top window select X axis. On the left bottom list select an entry &quot;Digital Joystick, Push left(port 1)&quot;. On the panel to the right change &quot;Digital joystick&quot; into &quot;Raw Key&quot;. A list of keys will be displayed. Select key you wish to send. Repeat the same procedure for &quot;Digital Joystick, Release left (port 1)&quot; option but this time check &quot;Send key up even instead of key down&quot;. Open shell and move your joystick to the left - your selected letter should appear in the shell. 


*Analogue in Trident Prefs
* Open the Trident USB Prefs -&gt; Devices -&gt; Select your joypad -&gt; Settings button -&gt; Action TAB 
* See some &quot;axis&quot; listed under &quot;Usage items&quot; in the top right of the window. They are your analog stick(s) 
* Check [x] Track Incoming Events which is half way down the window on the left 
And you should see some axis activity in &quot;Usage items&quot; when you move the analog stick 


*Actions

HID class item -&gt; Settings -&gt; HID Class Window -&gt; Action Tab -&gt; Action handling area 

Reports and collections -&gt; Usage Items -&gt; Performed actions 


Qualifier keys are *special*. You don't only need to create the actual keypress but also modify the qualifiers.
Go to the keyboard panel and find the windows menu key by enabling key tracking and pressing the windows menu key. Then assign the right amiga key to it.

Go to the actions panel and find the right amiga key (it's called &quot;Keyboard right GUI&quot;). Remember the actions stored there, best write them down in exact order. Then delete them.
Find the windows menu item and add the missing qualifier action. Be sure the parameters are exactly the same and the order is right.

Set them to Raw, then assign an up and down button for each character, etc.
when you change the settings to RAW so you can assign keyboard strokes. it will always say, KEYDOWN or what ever on the left, it never provides and option for key release.

The problem still remains though that if I try to assign the Directional Pad (Hat) to Arrow Keys, that things will get screwed up and you either can not move with the directional PAD (HAT), or movements are assigned to the Left Analog, and do not work as they should, it's as if the right and down arrow keys are ALWAYS On, regardless of the fact that I did indeed assign a Key release command to each input.

check that by pressing analog directions and see the current values, and the thresholds configured in poseidon to bind them to left/right/up/down.

misconfigured too much stuff in the HID settings, you can always go in poseidon-&gt;config list entry and delete the config item related to your device (or the HID class setting itself), back to basics.


*Rumble in Trident Prefs
Open Trident Prefs and click on the Devices option in the left hand window. Click with the mouse once on your gamepad choice on the right hand side and again on the Settings button below. In the new window, select the '''General''' TAB and half way down on the right there is an &quot;Open Now&quot; button in the section &quot;HID output control window&quot;. Clicking on that button opens another window (HID Control) with sliders for the two rumble engines inside the controllers and you can test if they work. '''Sometimes clicking that button does nothing, other times it will open the window and say nothing is detected.''' The leftmost two sliders do nothing, the third one has a large rumble effect, and the fourth one has a small rumble effect.

===Graphic Drawing Tablet===

There is a standard in HID for tablets possibly mouse type. If the tablet is HID conforming in that sense, it should work. Aiptek does a fairly good job at this. The other competitor, Wacom, didn't pay too much attention to this and simply adapted their legacy serial protocol into HID in a very awkward way. Older Wacom tablets have worked with the special support in the HID class, but not the more recent ones. 

 to use graphic tablets fully, applications need to be written that make use of the AmigaOS NewTablet events (which AROS has) 


* Entry level - A6 (6x4) work area 
* Medium A5 (6x8) A4 (10x7) size   (recommended but only a few ie years 2000 to 2003 models supported) 
* Semi Pro A3 (12x9) 
* Pro  Cintiq


* 2005/6 Some support added for Wacom tablets  
* 2008 Wacom's patent on battery free pens expires


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Micrograf Tabby (late 1980s and early 1990s) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;podscat pt 3030 graphics tablet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Summagraphics 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Wacom IV compatible (Graphire, ArtPad, A3, A4, A5 and PenPartner CT-0405-P - Wacom intuos GD-0405-R) Waycom Digitiser II UD-0608-R
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Wacom Artpad II (KT-0405-R) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AceCad boards 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AipTek HyperPen 6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Calcomp 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AipTek HyperPen 8000 - Aldi/Medion MD 9310 and Aldi/Tevion LT 9310 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Tablet PC penabled 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based like x61t X60t NC4200 NC4400 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
* Wacom PenPartner
* PenPartner 2
* PenStation 2
| &lt;!--Vendor ID--&gt;0x056a
| &lt;!--Product ID--&gt;0x0000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Graphire - Wacom Tablet ET-0405-U UV1.1-1 (Slate Blue)  ET-0405UL (lime)  (orange)  (red)  (purple) 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0X0010
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{Yes|late 90s with A6 size - [Wacom Support] of X-axis 00000-10205  Y-AXIS 0000-7421 Tip Pressure 000-511 under Trident prefs. Air pen mouse type movements }}
|-
| &lt;!--Description--&gt;
* Grapphire 2 4x5  ET-0405A-U UV2.0-3 (Steel Blue) 
* Graphire 2 5x7 ET-0507A 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0011 and 0x0012
| &lt;!--Revision--&gt;0110
| &lt;!--Opinion--&gt;{{Yes|A6 and A5 versions - [Wacom Support] of X-axis 00000-10205  Y-AXIS 0000-7421 Tip Pressure 000-511. Air pen mouse type movements - mouse EC-120-0K tested}}
|-
| &lt;!--Description--&gt;Wacom Graphire 3
* cte-430/w 4x5 pearl   sapphire 
* cte 630 6x8 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0013 and 0x0014 
| &lt;!--Revision--&gt;0314
| &lt;!--Opinion--&gt;{{Yes|A6 and A5 size - [Wacom Support] Xaxis 0-10207 yaxis 0-7423 tip pressure 0-511 and the erase end appears to respond but avoid bluetooth BT versions }}
|-
| Wacom Graphire 4 
* cte-440/B Blue cte 440/s Silver 4x5
* cte-640 6x8 cte 640 u 0403 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0015 and 0x0016 
| &lt;!--Revision--&gt;403
| {{Yes|A6 and A5 work area detected [Wacom Support] x-axis 0000-10207 Y axis 0000-7423 Tip Pressure 000-511 and delete rub out end of the pencil seems detected but avoid bluetooth BT versions }}
|-
| &lt;!--Description--&gt;
* Wacom Intuos 4x5 GD-0405 
* Intuos 6x8    GD-0608
* Intuos 9x12    GD-0912
* Intuos 12x12  GD-1212-U 
* Intuos 12x18 GD-1218
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0020 0x0021 0x0022 0x0023 0x0024 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|detected and responses delivered back - x axis up to 30479 and y axis 31679, tip pressure up to 1023 and x and y tilt up to 127 - Wacom intuos GD-0912-A for Apple Macs NOT SUPPORTED}}
|-
| &lt;!--Description--&gt;
* Intuos 2 4x5 A6 - XD-0405-U 
* Intuos 2 6x8 A5 - xd 0608u uoc
* Intuos 2 9x12 XD-0912-U
* Intuos 2 12x12 XD-1212-U
* Intuos 2 12x18 XD-1218-U
| &lt;!--Vendor ID--&gt;0x056a
| &lt;!--Product ID--&gt;0x0041 0x0042 0x0043 0x0044 0x0045 
| &lt;!--Revision--&gt;0126
| &lt;!--Opinion--&gt;{{No|various sizes and recognised as [Wacom Support] but not working. x-axis 00000-20319 y-axis 00000-16239 tip presure 0000-1023 x-tilt y-tilt 000-127.  HID mouse xc-100-03 works but never could use it as a real tablet with pressure with TVPaint 3.6 }}
|-
| &lt;!--Description--&gt;
* Intuos 3 4x5 (PTZ-430) 
* Intuos 3 4x6   (PTZ-431W ) 
* Intuos 3 6x8   (PTZ-630 PTZ630) 
* Intuos 3 6x11 (PTZ-631W A3 wide)  
* Intuos 3 9x12 (A4 PTZ-930 PTZ930)  
* Intuos 3 
| &lt;!--Vendor ID--&gt;056a
| &lt;!--Product ID--&gt;0x00b0 0x00b1 0x00b2 0x00b3 0x00b4 0x00b5
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No}} Actions in HID setup window definitively locks the Pointer (mouse) reports settings and even after a clear and save, nothing changes, the configuration returns to default values.  &quot;[Wacom]&quot; reports don't see any events from the tablet, even with &quot;Pointer&quot; reports cleared and save, so is locked a in &quot;mouse&quot; state - but can send a special command to the tablet in order to put it into a special vendor mode. This mode enables Wacom specificities like pressure, tilt, absolute position, buttons, etc... you should send an HID report feature with ReportID=2 and data=2, the current HID class driver doesn't give a way to change that, even using the &quot;initial startup actions&quot; item in the extra collection. No listed features work 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Wacom Volito - Promethean FT-0405-U06 UV1.4-1 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0060
| &lt;!--Revision--&gt;0141
| &lt;!--Opinion--&gt;{{Yes|A6 work area with [Wacom Support] of x-axis 0000-5103 Y axis 0000-3711 Tip Pressure 000-511. Air and touch mouse movement - appears to be the budget option with some but limited features}}
|-
| &lt;!--Description--&gt;Wacom Volito 2 
* CTF-??? 2x3 
* CTF-420G CTF-420 V2.0-0 4x5
* Serif Penabled 6742 rebadge of CTF 420/020-B CTF-420/02
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0062
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{Yes|A6 work area with [Wacom Support] of x-axis 0000-5103 Y axis 0000-3711 Tip Pressure 000-511. Air and touch mouse movement - no erase function on the end of the pen - nylon nibs value option}}
|-
| &lt;!--Description--&gt;
* Wacom PL-400 LCD 
* PL-500
* PL-510
* PL-550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0030 0x0031 0x0032 0x0034 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
* PL-600
* PL-600 SX
* PL-700
* PL-710
* PL-800
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0033 0x0035 0x0036 0x0037 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Cintiq 21 UX and Cintiq Partner DTF-720
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Wacom PenTablet Bamboo (MTE), Bamboo Craft (CTH), Bamboo Fun (CTE), Bamboo Pen (CTL) and Bamboo Pen &amp; Touch (CTH) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Wacom Bamboo Fun Medium CTE-650 
| 
| 0x0018 
| 
| {{Maybe|[http://www.a1k.org/forum/showthread.php?t=11432 works on a1k forum]}}
|-
| &lt;!--Description--&gt;Bamboo Fun Small CTE-450 white 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0017 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Bamboo One CTF-430 V2.0-0 CTF 430/S
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0069
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{Maybe|A5 wired air pen and acts like a mouse only}}
|-
| &lt;!--Description--&gt;Wacom Intuos 4 
* Small PTK-440 PTK-540
* Medium - PTK-640 - PTK 540WL Wireless - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested  Intuos4 surface sheet was revised in October 2010 to reduce nib wear}}
|-
| &lt;!--Description--&gt;Wacom Intuos 5 Touch 
*
* Medium - PTH-650 - USB Wired and Wireless Kit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0027 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested work, however wireless may glitch or drag }}
|-
| &lt;!--Description--&gt;Wacom Intuos Pro Medium - PTH-651 - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Bamboo Small Pen Tablet - MTE 450 MTE-450A (MTE-450/k) - 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0065
| &lt;!--Revision--&gt;0116
| &lt;!--Opinion--&gt;{{Maybe|A6 work area - mouse movement but no pen detection except x-axis 2 to -2 and y-axis 2 to -2 - mini usb lead - 4 blue led lit buttons not detected as well as circular touch button??  }}
|-
| &lt;!--Description--&gt;Bamboo Pen CTL 460
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested all Bamboo versions were criticized for the drawing surface's roughness (which got smoother over time), which caused the small pressure-sensitive 'nib' to wear down, and become slanted or scratchy in the same way as pencil lead, albeit more slowly}}
|-
| &lt;!--Description--&gt;Wacom Bamboo Fun CTH-461/S wired 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x00D2
| &lt;!--Revision--&gt;0106
| &lt;!--Opinion--&gt;{{Maybe|A6 size - Pen tracking not working but finger touch works }}
|-
| &lt;!--Description--&gt;Wacom Bamboo Connect Pen Tablet CTL-470 CTL-470K 470-DE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;CTH 470K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom CTH 480/S wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} lithium battery for pad - 
|-
| &lt;!--Description--&gt;Wacom Intuos Pen Small CTL-480/S CTL 480 K wired 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x030E
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{No|A5 detected as Intuos PS  but not working although the RHS blue led responds to pen on tablet }}
|-
| &lt;!--Description--&gt;CTH 490 PK S Photo - CTH-490CK-S Comic - CTH-490AK-S Art 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested lower hovering height pen nibs wear fast and input lag/responsiveness}}
|-
| &lt;!--Description--&gt;Intuos Pen &amp; Touch Medium - CTH-680 - USB Wired and Wireless Kit work 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Intuos Pro (PTH-660 and PTH-860) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Waltop Media Tablet 10.6&quot;
    Genius G-Pen M609
    Genius G-Pen M609X
    iVista Media Tablet 10.6
    Aiptek MediaTablet 10000u

| &lt;!--Vendor ID--&gt;172f:0501
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Slim Tablet 12.1&quot;
| &lt;!--Vendor ID--&gt;0x172F
| &lt;!--Product ID--&gt;0x0034
| &lt;!--Revision--&gt;0x1105
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Waltop Media Tablet 12 by 9&quot; 
    Aiptek HyperPen 12000u T-12000U Tablet Series 
    Nisis T-12000u USB Tablet Series Version 1.05 (aiptek rebadged)

    Trust item #1535
    ADESSO Cyber Tablet 12000 Graphic design tablet
    iVista Media Tablet 12
    PENTAGRAM O'pen Wide P 2003
    Genius G-Pen M712
| &lt;!--Vendor ID--&gt;172f:0500, 0x08ca
| &lt;!--Product ID--&gt;0x0010
| &lt;!--Revision--&gt;0105
| &lt;!--Opinion--&gt;{{Yes|detected with Nisis/Aiptek functioning as a tablet, untested with others  - Puck (mouse) x axis 0000 to 6000 y axis 0000 to 6000 - stylus (pen) x axis 00000 to 12000 y axis 00000 to 12000 tip pressure 0000 to 1023 - 16 function keys - AAA battery needed for pen and another for the mouse}}
|-
| &lt;!--Description--&gt;Waltop Media Tablet 14.1&quot; v5.1e
    Genius G-Pen M714X
    Aiptek MediaTablet 14000u WMK-H141 
    Trust item #15358
    Adesso CyberTablet 14000 M14
    iVista Media Tablet 14.1
    PENTAGRAM O'pen Wide P 2004

| &lt;!--Vendor ID--&gt;0X172f
| &lt;!--Product ID--&gt;0X0500
| &lt;!--Revision--&gt;0114
| &lt;!--Opinion--&gt;{{Yes|detected with Nisis/Aiptek functioning as a tablet - Stylus (Pen) X 16838 Y 16838 Tip Pressure 1023 }}
|-
| &lt;!--Description--&gt;Waltop PID 0038
    Genius G-Pen F509
    Manhattan 177405

| &lt;!--Vendor ID--&gt;172f:0038
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop PID 0052
    Yiynova MSP19

| &lt;!--Vendor ID--&gt;172f:0052
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Q Pad
    Aiptek HyperPen Mini
    NGS Flexi Style
    VisTablet PenPad
    iVistaTablet Q Flex Pad
    Bravod Q-PD65-S
    Trust Flex Design Tablet (#16937)

| &lt;!--Vendor ID--&gt;172f:0037
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Sirius Battery Free Tablet
    VisTablet Muse
    PENTAGRAM Designer P 2700
    Princeton PTB-S1BK

| &lt;!--Vendor ID--&gt;172f:0502
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Slim Tablet 12.1&quot;
    Genius G-Pen F610
    Trust Slimline Widescreen Tablet (#16529)
    VisTablet Original 12&quot;
    Adesso CyberTablet Z12
    Adesso CT-Z12A
    PenPower Tooya Pro
    Aiptek Slim 12.1 Inch
    Aiptek SlimTablet 600u Premium II
    NGS Slim Proguess
    iVistaTablet Slim 12.1
    PENTAGRAM ThinType P 2006

| &lt;!--Vendor ID--&gt;172f:0034
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Slim Tablet 5.8&quot;
    Genius G-Pen F350
    Trust item #16485
    VisTablet Mini
    iVistaTablet Slim 5.8
| &lt;!--Vendor ID--&gt;172f:0032
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Venus S Tablet
    Trust eBrush Widescreen Tablet (#17939)

| &lt;!--Vendor ID--&gt;172f:0503
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Aiptek GmBH MediaTablet Ultimate II - 16:10 Professional Graphic Tablet Model 1400U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Hanvon Beijing HanWang HW Micro Drawing Tablet ET0504U 
| &lt;!--Vendor ID--&gt;0x0b57
| &lt;!--Product ID--&gt;0x8030
| &lt;!--Revision--&gt;01111
| &lt;!--Opinion--&gt;{{No|does not work - recognised as an HID mouse - no tablet extensions detected}}
|-
| &lt;!--Description--&gt;KYE EasyPen 340, Genius EasyPen 340 
| &lt;!--Vendor ID--&gt;0458:5014
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| Aiptek Hyper Pen 6000u PC Tablet APT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|detected but does not work - win98 era cordless 6in by 4.5in - }}
|-
| &lt;!--Description--&gt;nisis T-8000U APT-2 Aiptek rebadge 
| &lt;!--Vendor ID--&gt;0x08CA
| &lt;!--Product ID--&gt;0x0021
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|A5 detected but no responses }}
|-
| &lt;!--Description--&gt;Acecad Flair II GT-504 Init Fkt  Fkt 0x5ab450c0
AIPTEK HyperPen 10000 U
Aiptek HyperPen 10000U, 
AIPTEK Slim Tablet U600 Premium II
| &lt;!--Vendor ID--&gt;0x0460
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Ace Cad Enterprise Co., Ltd Tablet - 5x3.75 drawing area 
| &lt;!--Vendor ID--&gt;0x0460
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Bosto's 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} UCLogic Digitizer 
|-
| &lt;!--Description--&gt;Adesso CyberTablet Z7, Adesso CyberTablet 12000, Adesso CT-12000A  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;UC-Logic / Lapazz WP8060, UC-Logic / Lapazz PF1209, UC-Logic / Lapazz Artistic Tablet 5540,   Manhattan 8&quot;x6&quot;, Manhattan 3&quot;x4&quot;, Manhattan
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested but suspect not working}}
|-
| &lt;!--Description--&gt;DigiPro 5.5×4” Graphics Tablet
Digital Ink Pad (A4 format) 
DigiPro WP8060, DigiPro WP5540,  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius G-pen
G-Pen 4500
Genius Wizardpen
Genius Mousepen
Genius Easypen i405 M610 
Genius PenSketch 9x12, Genius MousePen i608, Genius MousePen 8x6, Genius MousePen / WizardPen 5x4, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius G-Pen F610
Genius G-Pen M610 
Genius G-Pen 340 (UC-LOGIC Tablet WP4030U)
Genius G-Pen 450 (UC-LOGIC Tablet WP5540U)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius
UC-LOGIC
iBall Tablet PF8060
iBall
Iball Pen Tablet 8060U, Iball Pen Tablet 5540U, Iball Pen Tablet 4030U, Iball Design Tablet PF1209,
NGS CADBOY (UC-LOGIC Tablet WP5540U)
Pentagram
QWare
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Trust TB-3100
Trust TB-5300 Trust 15356 
Trust TB-6300 Trust 15357  WP8060U  Slimline but bulky with metal backing A5 size 
Trust 16486, Trust 16447,  Sketch Design Tablet,
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|clashes with usb and crashes AROS }}
|-
| &lt;!--Description--&gt;UC-Logic Tablet WP1062
    Aiptek HyperPen 10000U
    Monoprice 10X6.25 Inches Graphic Drawing Tablet
    Pickle 10x6.25 Inch Graphic Drawing tabletguess

| &lt;!--Vendor ID--&gt;5543:0064
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| [ VTech KidiPhoto Art Studio] 
| 
| 
|  
| {{yes|works}}
|-
|}

Tablet has a squared lines of wires which induce a current into the pen which is then detected by the metal grid in the tablet pad. Tablets report pressure (and tilt on expensive models) and are absolute pointing devices (put the pen at the top left and the mouse pointer will go to the top left of the screen). Graphic drawing area, what keys, report rate, resolution lpi lpmm, accuracy, pressure levels (may come from the app), origin position,

Wacom tablets use electromagnetic resonance technology.  Since the tablet provides power to the pen through resonant inductive coupling, no power is required for the pointing device. As a result, no batteries are inside the pen (or the accompanying puck), making them lighter and slimmer.

Under the tablet's surface (or LCD in the case of the Cintiq) is a printed circuit board with a grid of multiple send/receive coils and a magnetic reflector attached behind the grid. In send mode, the tablet generates a close-coupled electromagnetic field (also known as a B-field) at a frequency of 531&amp;nbsp;kHz. This close-coupled field stimulates oscillation in the pen's coil/capacitor (LC) circuit when brought into range of the B-field. Any excess resonant electromagnetic energy is reflected back to the tablet. In receive mode, the energy of the resonant circuit’s oscillations in the pen is detected by the tablet's grid. This information is analyzed by the computer to determine the pen's position, by interpolation and Fourier analysis of the signal intensity.

In addition, the pen communicates information such as pen tip pressure, side-switch status, tip vs. eraser orientation and ID number (to differentiate between different pens, mice, etc.). For example, applying more or less pressure to the tip of the pen changes the value of the pen's timing circuit capacitor. This signal change can be communicated in an analog or digital method. An analog implementation modulates the phase angle of the resonant frequency, while a digital method is communicated to a modulator that distributes the information digitally. The tablet forwards this and other relevant tool information in packets, up to 200 times per second, to the computer.


If you disable (delete all of them except for one that needs to be set to &quot;no action&quot;, so that it will not be regenerated as default) the Extra Startup actions, the tablet should remain in relative mouse mode—you will not get pressure information in that mode though. [http://tech.groups.yahoo.com/group/highway_usb/message/2394]}}


=== Handheld Barcode Scanner Readers ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Farsun 9100 barcode scanner 0-12&quot; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola Symbol LS2203 CMOS 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Tysso 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Simple}} Code 11, Code 39, Code 93, Code 128, Coda Bar, UPC-A, UPC-E, EAN-8, EAN-13, MSI/Plessey, Telepen, Interleaved 2 of 5, Industrial 2 of 5, Matrix 2 of 5 
|-
| &lt;!--Description--&gt;Unitech MS320 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wasp WCS3905 CCD 1&quot; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Code 93, Matrix 2 of 5, Industrial 2 of 5, Code 39, UCC/EAN-128, ISBN, Code 32, EAN/JAN-8 , EAN/JAN-13 , UPC-A, UPC-E, Codabar, Code 128, Code 11, Interleaved 2 of 5, MSI-Plessey, China Post, IATA 2 of 5, ISSN, UK-Plessey 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Datalogic Touch 90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Intermec  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell Metrologic MK9540-32A38 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola LS2208 Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wasp WWS800 Laser 1D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Datalogic GD4130-BK-C066 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell 1202G-1USB-5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola / Symbol DS6707-DC20007ZZR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;DataMan 8000 2D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell Voyager 9520/40 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Metrologic MS1690 USB 2D Barcode Scanner  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} QR Code GS1 Databar PDF417
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Syscan GM800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

[http://www.scandit.com/2011/11/04/types-of-barcodes-choosing-the-right-barcode-type-ean-upc-code128-itf-14-or-code39/ Types of Barcode]

&lt;pre&gt;
UPC-A       Grocery most common 
Code 128    
EAN-13      Library Books ISBN &amp; ISSN, 
Code 39     
Codabar     blood bank,

2D barcodes such as 
Data Matrix 
PDF417e     
Maxicode    
Aztec       
QR Code     old Nokia handsets, 
MicroPDF417 
&lt;/pre&gt;


===TouchScreens===

Projected capacitive (PCAP) touch screen product, amongst many options the widely used are I2C and USB 

*USB host–device structure which dominates consumer and industrial electronics devices where higher bandwidth needed and user-friendly (multiswipes)
*I2C Inter-Integrated Circuit simple serial standard for LCD display in embedded systems because of cost and low power 
*SPI arduino and rpi single boards 

We cover the USB here 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| eGalax Touch 4a
| 0eef 
| 0001 
| 0001
| {{yes|2009 works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lilliput HDMI Monitors
669GL-70NP/C/T (7 inch)
869GL-80NP/C/T (8 inch)
FA1011-NP/C/T (10 inch)
FA1046-NP/C/T (10 inch)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Iilyama Prolite Monitors
PROLITE T1513SR-1 (15 inch)
PROLITE T1730 (17 inch)
PROLITE T1713SR-1 (17 inch)
PROLITE T1913SR-1 (19 inch)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Smart Display Company (SDC) Touchscreens TFT Monitors
TOUCH-TFT-TS07 (7 inch)
TOUCH-TFT-TS08 (8 inch)
TOUCH-TFT-TS10 (10 inch)
TOUCH-TFT-TS12 (12 inch)
TOUCH-TFT-TS15 (15 inch)
TOUCH-TFT-TS17 (17 inch)
TOUCH-TFT-TS19W (19 inch wide)
TOUCH-TFT-TS22W (22 inch wide)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;XENARC Monitors 7 inch models
700TSH
700TSU
700TSV
702TSV
705TSV
706TSA
700IDT
MDT-X7000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;XENARC 
8 inch models:
800TSV
805TSV

10 inch models:
1020TSV
1026TSA
1040TS

12 inch models:
1200TS
1200TR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Asus VT229H 21.5&quot;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;CUQI 7&quot; Monitor Touchscreen 1024x600 IPS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Espresso 15&quot; Portable Touchscreen Display Monitor
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hannspree HT225HPB 21.5 inch
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;WaveShare 13.3inch HDMI LCD (H) (with case)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


===GPS tracking, running, cycling, biking, walking, hiking, ORIENTEERING, boaters and mapping===

Support for OpenStreetMap but not for Ordnance Survey, Map Pilot or National Geographic's Topo maps data gdb,

Data output supported nmea 0183 V1.5 APA, V1.5 XTE and V2.1 GSA formats, gpx, kml/kmz, tracks from tcx files, geo: URIs,  
NMEA0183(which is RS232, voltages range from -15 volts to 15 volts, 4800 baud), or need NMEA sentences connected to your computer

other method that some units support is a special serial cable that actually emits raw RS232 NMEA. These usually take 10-&gt;30 volts input, can run the unit, and have full voltage I/O for RS232 (not like spanner mode, which effectively turns the unit into a USB-&gt;Serial adapter inside the case).

Equivalent apps - merkator, mapsource,

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Garmin gpsmap 180 GPS/chart plotter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;1992 GARMIN GPS 55 AVD Portable System 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin GPS V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - waas pinpoint within 3 metres - nmea - 4AA battery}}
|- 
| &lt;!--Description--&gt;Garmin GPS 12 12XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Legend C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin eMap 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|possibly through usbmodem rs232 connection nmea 0183 protocol}}
|-
| &lt;!--Description--&gt;Garmin eTrex 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} rs232 these older units supported it and would provide the stream in either the standard NMEA 0183 format or a proprietary Garmin format.
|-
| &lt;!--Description--&gt;Garmin GPS 75 AVD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS Map 7000 model 45006 (1994) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS Tracker
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan Pioneer Satellite Navigator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS 300 315 320 Mentor Receiver (2003) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Not for dedicated sat nav units like the Nuvi, TomTom, etc 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;NaviLock NL-402U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested u-blox 5 SuperSense® chipset with receivers for GPS, GLONASS, Galileo, BeiDou and QZSS}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;GM1-86UB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| U-BLOX UB-6010 GGA,GSA,GSV, RMC and support VTG, GLL, TXT ublox binary and NMEA Command Dynamic Condition }}
|-
| &lt;!--Description--&gt;NAVILOCK GPS NL-602U USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|works via usbmodem.device - ublox ag 6 chipset - 50 channel}}
|-
| &lt;!--Description--&gt;TOPGNSS ton Receiver &amp; Antenna GM702  u-blox 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|UBLOX7020 chip design bloc u-blox}}
|-
| &lt;!--Description--&gt;VK-162 G-MOUSE u blox 7 
| &lt;!--Vendor ID--&gt;0x1546
| &lt;!--Product ID--&gt;0x01a7
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{N/A|UBX G70xx with RMC VTG GSV TXT GLL GGA GSA}}
|-
| &lt;!--Description--&gt;VK-172 u-blox 7 G7020-KT gps gnss white pen stick receiver - over 1 inch long 
| &lt;!--Vendor ID--&gt;0x1546 
| &lt;!--Product ID--&gt;0x01a7
| &lt;!--Revision--&gt;0100 
| &lt;!--Opinion--&gt;{{N/A| detected as cdc controlled plug in device - 18x18x2mm patch antenna but can be slow to update - nmea 0183 and ublox binary protocol}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;GlobalSat BU-353 WaterProof USB GPS Receiver 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested SiRF Star III}}
|-
| &lt;!--Description--&gt;Haicom HI-206 USB GPS receiver with RS-232 interfaces, RJ11 and PS/II connector EB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|usb-serial prolific pl2303 detected but GSP3F SiRF Star IV technology not detected or bound}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;BT760Y, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 5 GPS chipset}}
|-
| &lt;!--Description--&gt;GM-65 USB GPS Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 6 GPS chipset - 65 channel}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 7 GPS chipset}}
|-
| &lt;!--Description--&gt;GM-65 USB GPS Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 8 GPS chipset - 167 channels}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Garmin Colorado 300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} USB 
|-
| &lt;!--Description--&gt;Garmin Geko 101 201 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} limited waas enabled only - waypoints - aaa battery 
|-
| &lt;!--Description--&gt;Garmin Edge 200 bike mount 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin ForeRunner 10 15 watch 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Montana 600
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Dakota 10 20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Map76s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Oregon 450T  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} USB nmea 0183 
|-
| &lt;!--Description--&gt;Garmin eTrex 10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - no nmea0183 sentences data stream output - configuration an option to set it to &quot;Garmin&quot; mode, or &quot;Mass Storage&quot; mode. Since the mass storage mode seems to be required for waypoint/track/etc data exchange, the 'Garmin' mode would be for this data stream. Yet putting it in that mode doesnt seem to produce anything.}}
|-
| &lt;!--Description--&gt;Garmin Oregon 650T 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin GPSMAP 64S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|untested}}
|-
| &lt;!--Description--&gt;GPSMap 78S or GPSMap 76CSX which has a NMEA port for talking to Nav equipment
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|untested}}
|-
| &lt;!--Description--&gt;Garmin eTrex Vista Cx GPS Receiver 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - 2AA battery}}
|-
| &lt;!--Description--&gt;Garmin GPSmap 276c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 2000 XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan Triton 300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} SiRFstarIII™, Antenna Type Multidirectional Patch with WAAS, EGNOS, MSAS support 
|-
| &lt;!--Description--&gt;Magellan Triton 400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


==massstorage.class (MSC/UMS - most cameras and mp3 players)==

=== USB Card Readers ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;15%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Installing
! width=&quot;15%&quot; |Booting
! width=&quot;30%&quot; |Opinion
|-
| A-Tec Model CR-362 
| 
| 
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{N/A|untested}}
|-
| [http://www.belkin.com/IWCatProductPage.process?Merchant_Id=&amp;Section_Id=200406&amp;pcount=&amp;Product_Id=179164 Belkin 15 in 1 Card Reader]
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Conrad CP440 60 in 1 
| 
| 
| 
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works on a1k forum}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Genesys Gtech Logic 19 in 1
| 0x05E3
| 0x0710
| High 0200
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Hama 19 in 1 Card Reader 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| Hama 35 in 1 Card Reader 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Integral Single Slot SD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kingston USB 3.0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lexar microsd adapter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} but wider than Sandisk version - could block other slot if below 
|-
| Pretec CardDriver 
|
|
| 
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{no|no driver}}
|-
| Sandisk MicroMate 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;Sandisk MobileMate SD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Sandisk MobileMate Micro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} has satisfying 'click' when microsd inserted 
|-
| &lt;!--Description--&gt;Sandisk MobileMate Duo MicroSD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} no 'click' insertion uses pressure so future wear and tear issues 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Serena metal cased microsd only 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|Maybe}} hit or miss on quality 
|-
| &lt;!--Description--&gt;Serena &quot;Sandisk MobileMate&quot; look-alike 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|Maybe}} hit or miss on quality 
|-
| SilverCrest 16in1 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;Transcend 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Transcend P5 8 in 1 TSRDP5K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Transcend P8 15 in 1 TSRDP8K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Zyxel integralmemory 8 in 1 
| 0x0aec
| 0x3260
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{no|not detected}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

=== USB Hard Drives ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Datel MaxDrive 
| 
| 
|  
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Inateck 2.5 Inch USB 3.0 Hard Drive Disk Enclosure/ Case (FE2001) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Full USB 3.0 port but plastic teeth keeping drive in place can snap 
|-
| &lt;!--Description--&gt;Inateck case (FE2002) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} full USB 3.0 port - updated design 
|-
| &lt;!--Description--&gt;Inateck case (FE3001) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} wider USB 3.0 port and no on/off switch  Jmicron JMS578 chipset
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Iomega Desktop Hard Drive 500GB, 3,5“, USB2.0 
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Samsung T3 SSD 
|
|
|
| {{N/A|untested}} USB 3.1 Gen 1 space grey / black metal/ plastic 
|-
| Samsung T5 SSD 
|
|
|
| {{N/A|untested}} USB 3.1 Gen 2 256GB 512GB alluring blue 1Tb 2Tb black unibody metal 
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Seagate
|
|
|
| {{N/A|untested}}
|-
| Seagate 
|
|
|
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Toshiba Canvio 1TB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|partition fat32 or sfs to 100GB max - ntfs partitions not detected out of the box - select usb drive in trident prefs and press disable to shutdown}}
|-
| Verbatim 160GB Smartdisk 
| 
| 
|  
| {{yes|works }}
|-
| Western Digital USB 
|
|
|
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;WD Essential 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;WD Passport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== USB DVD CD ROM Drives ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;12.5mm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;12.5mm enclosure mini-sata dvd-rw 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested needs sole usb3 port to power it}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;9.5mm enclosure ECD829 mini-sata dvd-rw with Initio Corporation INIC-1618L SATA 
| &lt;!--Vendor ID--&gt;0x13fd
| &lt;!--Product ID--&gt;0x0840
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested but probably needs sole usb3 port to power it}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|}


=== USB to NGFF NVMe SDD HDD DVD CD ROM Drives ===

The older Jmicron JMS539B seems to result in massive filesystem corruption given the amount of corrupted content. Prehaps always avoided Jmicron and opted for Asmedia even if it costed a bit more. Realtek seems to be working okay for me generally speaking and newer Jmicron chipsets are less buggy – but evidently not perfect. 

From [https://goughlui.com/2025/08/17/psa-validate-your-storage-jmicron-jms583-kioxia-bg4-series-ssd-issue/ thread] 

Here is a [https://forums.anandtech.com/threads/stable-nvme-usb-adapter.2572973/ very long thread] that discusses data corruption and stability issues with these bridges. The majority of the posts are complaining of dropouts, hangs and the like, which usually down to either a poor USB 3.x implementation (SuperSpeed connections are very picky as to cables, ports and trace routing) or problematic compatibility. Regardless, the [https://www.legitreviews.com/jmicron-jms583-controller-version-matters-for-portable-usb-drives_219422 JMS583 is known to have several versions] noting that the last revision (C) in that article is a 2021 release which should fix earlier stability and cable quality compatibility issues. 
JMS583-STD-Release-v00.02.01.04-Bus Power.bin is the latest JMS583 firmware as of August 2025. 

Early firmware RTL9210 seems to have issues as well 


* RTL9210B
* JMS583 rev1 with firmware A2 or A3  

* RTL9210A
* JMS583 firmware 2.0.9 
* Asmedia ASM2362

* RTL9201A


The reference Hardware ID for the JMS583 chipset from JMicron is:
VID_152D&amp;PID_0583&amp;REV_0209
where &quot;VID_152D&quot; identifies a JMicron product;
&quot;PID_0583&quot; is the generation chipset;
&quot;REV_0209&quot; is the firmware version installed.

In the same way, the reference Hardware ID for the RTL9210 from Realtek is:
VID_0BDA&amp;PID_9210&amp;REV_3100
&quot;VID_0BDA&quot; is for a Realtek product, &quot;PID_9210&quot; is referred to the chipset and &quot;REV_3100&quot; to the firmware.


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;ASM1153E / ASM1153 with firmware 140509_A1_82_40 or 141126_A1_EE_82. Both supports UASP and TRIM on USB 3.1 Gen.1 adapter
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|works with sabrent ec-uasp}}
|-
| &lt;!--Description--&gt;ASM235CM Ugreen aluminum bridging the USB3.2 Gen2x1 to Serial ATA host interface 
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;TI 9261 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;ASM225
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;JMicron JMS578 issues USB 3.1 Gen.1 adapter 
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0578
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;JMicron JMS576 issues USB 3 to usb-c adapter 
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0576
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|orico}}
|-
| &lt;!--Description--&gt;JMS562 JMicron Technology Corp
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0562
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;JMS561U
| &lt;!--Vendor ID--&gt;0x152d
| &lt;!--Product ID--&gt;0x1561
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|works with sabrent ec-uasp}}
|-
| &lt;!--Description--&gt;VL716Q4 Orico black meshed aluminum usb c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Asmedia ASM1053E 
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;ASmedia ASM1051E
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Asmedia ASM1053
| &lt;!--Vendor ID--&gt;0x174C
| &lt;!--Product ID--&gt;0x1536
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Asmedia ASM104x
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;0x1042 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Unknown Chinese version 
| &lt;!--Vendor ID--&gt;0x0bc2
| &lt;!--Product ID--&gt;0x2312 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|sometimes works}}
|-
| &lt;!--Description--&gt;JMicron N5321 gr
| &lt;!--Vendor ID--&gt;0x152d
| &lt;!--Product ID--&gt;0xa583
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Initio Corp INIC-1618L mini slimline sata 6 + 7 pins to usb2 adapter 
| &lt;!--Vendor ID--&gt;0x13FD
| &lt;!--Product ID--&gt;0x0840
| &lt;!--Revision--&gt;0114
| &lt;!--Opinion--&gt;{{maybe|sometimes works mini sata to usb2 detects 201x laptop DVD as MassStorage(CD/DVD) but may need powered USB hub}}
|-
| &lt;!--Description--&gt;Unknown mini sata to usb3 adaptor 
| &lt;!--Vendor ID--&gt;0x01F75
| &lt;!--Product ID--&gt;0x0621
| &lt;!--Revision--&gt;0036 
| &lt;!--Opinion--&gt;{{maybe|sometimes works mini sata to usb3 detects 201x notebook DVD drive as MassStorage(SCSI) but 5V 1.5Amp needs powered hub to burn }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|}


=== External Floppy ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;[http://techtravels.org/amiga/amigablog/ Amiga Floppy Project]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;[http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=842 Catweasel Mk4]
| 0xE159
| 0x0001
| 0x00
| {{yes|[http://archives.aros-exec.org/index.php?function=browse&amp;cat=driver/storage works]}}
|-
| &lt;!--Description--&gt;[http://hxc2001.free.fr/floppy_drive_emulator/ HxC Floppy Emulator]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;[http://www.softpres.org/glossary:kryoflux KyroFlux]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;Samsung SFD-321U/EP USB Floppy
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}} 
|-
| &lt;!--Description--&gt;[http://www.cbmstuff.com/proddetail.php?prod=SCP SuperCard Pro] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://www.facebook.com/groups/greaseweazle Greaseweazle STM hardware], [https://cowlark.com/fluxengine/index.html Greaseweasel support], [https://github.com/keirf/Greaseweazle/wiki software], [https://amigakit.amiga.store/greaseweazle-p-91279.html buy], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FL-2501 USB Portable Diskette Drive  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2009 usb - [https://amiga.robsmithdev.co.uk/ Drawbridge] [https://github.com/RobSmithDev/ArduinoFloppyDiskReader software] ribbon cable compat with p/n 19308801-19 and s/n U356244 - model ASM P/N 27l4226 and FRU P/N 05k9283 - 
|-
| &lt;!--Description--&gt;Dell Floppy Drive Module USB External 3.5&quot; - Teac FD-05PUB 1.44mb 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2004 usb 1.1 
|-
| &lt;!--Description--&gt;USB FLOPPY DISK DRIVE (USB External Floppy Disk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://github.com/SukkoPera/OpenFlops OpenFlops] with [https://github.com/keirf/flashfloppy FlashFloppy] Gotech clone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://github.com/hmerrett/HenryFlops HenryFlops reworked OpenFlops] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


==ptp.class (PTP and MTP - other cameras and mp3 players)==

=== Cameras ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Canon EOS 20D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004  }}
|-
| &lt;!--Description--&gt;Canon 350D (also known as the Digital Rebel XT/Kiss Digital N) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 DIGIC II processor 8-megapixel }}
|-
| &lt;!--Description--&gt;Canon PowerShot A430 A560 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 }}
|-
| &lt;!--Description--&gt;Canon EOS 400D (XTi) digital SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;Canon EOS 1000D also known as Rebel XS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10.2mp 720p  }}
|-
| &lt;!--Description--&gt;Canon 450D aka Rebel Xsi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 12.2mp }}
|-
| &lt;!--Description--&gt;Canon PowerShot S90 S95 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 2010 720p video - 10Mpixel }}
|-
| &lt;!--Description--&gt;Canon Powershot SD960 IS Digtal ELPH 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 Still Image: Exif 2.2 (JPEG), Movie: MOV (Image: H.264; Audio: Linear PCM) Lithium-ion Battery Pack NB-4L }}
|-
| &lt;!--Description--&gt;Canon EOS 500D aka Rebel  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 1080p 15.1MP Lithium  }}
|-
| &lt;!--Description--&gt;Canon EOS 550D 600D aka Rebel T2i T3i DSLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010-2011 1080p 18MP Lithium LP-E8 }}
|-
| &lt;!--Description--&gt;Canon Powershot S100 S110 S120  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011-2013 720p-1080p video 12.1MP and above versions - }}
|-
| &lt;!--Description--&gt;Canon EOS 1100D DSLR Camera aka Rebel T3 SLR, EOS Kiss X50 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p 10Mpixels Lithium  }}
|-
| &lt;!--Description--&gt;Canon EOS 650D 700D aka Rebel T4i T5i T6i SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2013 1080p 18Mpixels Lithium LP-E8 articulating flip out twistable screen }}
|-
| &lt;!--Description--&gt;Canon ELPH 300 HS (IXUS 220 HS) 230 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 blogging camera }}
|-
| &lt;!--Description--&gt;Canon PowerShot N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013  12.1 MP CMOS, DIGIC 5 Wifi Lithium Battery Pack NB-9L }}
|-
| &lt;!--Description--&gt;Canon Powershot G7 X, G7X-II 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014-2016 1080p video 12.1MP and above versions - }}
|-
| &lt;!--Description--&gt;Canon EOS 1300D DSLR Camera aka Rebel T6 SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 1080p 16Mpixels Lithium  }}
|-
| &lt;!--Description--&gt;Canon Powershot G7x G5X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| G7X flip up and G5X flip out - same batteries - no external microphone input - }}
|-
| &lt;!--Description--&gt;Canon EOS M3 M5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| flip out - same batteries - }}
|-
| &lt;!--Description--&gt;Canon EOS 60D 70D 80D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 6D 7D 8D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;Canon 5D Mark II III IV DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji FinePix A850
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;FujiFilm Finepix F100fd
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji FinePix F810
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xf1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| pocketable exr cmos 12mp }}
|-
| &lt;!--Description--&gt;Fuji xt1  x-t1  x10 x-t10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 1080p }}
|-
| &lt;!--Description--&gt;Fujifilm x100 x100s x100t 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xPro1 xPro2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xt2 / x-t2 x-t20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4K video }}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;GoPro HERO 3 HERO4 HERO 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon D100, D60
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 Compact flash storage - non interchangeable lenses up to 12.3MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D50, D50x 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005  storage - 6.1MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D70, D80, D90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 Compact flash storage - 10MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D40, D40x 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007  storage -  10MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D300, D700
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008  storage -  12.3MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D2Xs, D2Hs, D3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006-2008  storage - sensor }}
|-
| &lt;!--Description--&gt;Nikon D3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 720p video }}
|-
| &lt;!--Description--&gt;Nikon D5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 720p video unlike D3000 }}
|-
| &lt;!--Description--&gt;Nikon D6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 16mpixel}}
|-
| &lt;!--Description--&gt;Nikon D7000  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 16.2mp 720p video }}
|-
| &lt;!--Description--&gt;Nikon L26 L27 L28 L29 L31 Coolpix compact cameras 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p video - 2 AA - pocket sized }}
|-
| &lt;!--Description--&gt;Nikon D3100   
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p video 14.2mp}}
|-
| &lt;!--Description--&gt;Nikon D5100 DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 16.2mp  720p}}
|-
| &lt;!--Description--&gt;Nikon L810 L820 L830 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2014 720p video }}
|-
| &lt;!--Description--&gt;Nikon D4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012  storage - sensor }}
|-
| &lt;!--Description--&gt;Nikon D7100 D7200  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2014 up to 24.2mp 1080p video }}
|-
| &lt;!--Description--&gt;Nikon D3200  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 1080p 24MPixel}}
|-
| &lt;!--Description--&gt;Nikon D5200 D5300  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 24.1MP 1080p }}
|-
| &lt;!--Description--&gt;Nikon D800 D600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 1080p video sd card storage - dust/oil issue at start}}
|-
| &lt;!--Description--&gt;Nikon D3300 DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24.2MP 1080p  }}
|-
| &lt;!--Description--&gt;Nikon D500, a high-performance DX-format (APS-C) DSLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 }}
|-
| &lt;!--Description--&gt;Nikon D5500 D5600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016-2018 24.1MP 1080p }}
|-
| &lt;!--Description--&gt;Nikon D810 D610 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 1080p video sd card storage }}
|-
| &lt;!--Description--&gt;Nikon D7300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4K UHD video }}
|-
| &lt;!--Description--&gt;Nikon D900 D850 D820 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4k 46MP }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Olympus C-370 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 3.2mp }}
|- 
| &lt;!--Description--&gt;Olympus Camedia C-725 Ultrazoom
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 3mp aa batteries, }}
|-
| &lt;!--Description--&gt;Olympus Evolt E-500
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 8mp  }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Olympus Evolt E-410 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007  }}
|- 
| &lt;!--Description--&gt;Olympus Evolt E-510
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 10MP Live MOS sensor with TruePic III processor,  }}
|-
| &lt;!--Description--&gt;Olympus E-420
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10mp, compactflash and xD cards,  }}
|-
| &lt;!--Description--&gt;Olympus E-520
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10mp, compactflash and xD cards,  }}
|- 
| &lt;!--Description--&gt;Olympus E-620
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 12.3mp, compactflash, xD and microdrive cards,  }}
|- 
| &lt;!--Description--&gt;Olympus E-30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  }}
|- 
| &lt;!--Description--&gt;Olympus E-450 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 10mp,  }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Pentax * ist DS DSLR camera
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 6.1mp  }}
|- 
| &lt;!--Description--&gt;Pentax K10D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 10.2mp APS-C CCD no video and older manual Pentax K-mount lenses}}
|-
| &lt;!--Description--&gt;Pentax K20D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2008 14.6MP APS-C but no video recording mode }}
|-
| &lt;!--Description--&gt;Pentax K30 K-5 II 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2012 16MP full HD (1080p) recording at 24/25/30 fps}}
|-
| &lt;!--Description--&gt;Pentax K-3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24MP 1080p  }}
|-
| &lt;!--Description--&gt;Pentax K-3 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 24MP  }}
|-
| &lt;!--Description--&gt;Pentax K-3 III
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 25.7MP BSI CMOS sensor  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix LZ10 LZ20 DMC-LZ30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 720p video }}
|-
| &lt;!--Description--&gt;Panasonic TZ1 TZ5  TZ9 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix GH1 GH2 like the DMC-GH2HEB-K - GH3 DMC-GH3HEB-K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| Four Thirds (GH2)  MFT Micro Four Thirds (GH3) limited to 29mins recording }}
|-
| &lt;!--Description--&gt;Panasonic AF series AF100 AF101 AF102 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix DMC-G2 DMC-G3 G5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic TZ60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic DMC LX7 10 LX15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic GF7 GX8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic G80 G85 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| micro 4/3 }}
|-
| &lt;!--Description--&gt;Panasonic GH4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| micro 4/3 - shooting in MOV or MP4 formats recording limited to sd card size but split files because the FAT32 file system only supports files up 4GB in size, which amounts to around 5 minutes of 4K (100mbps) footage - GH4 appears to create 4GB files as a rule, regardless of whether the memory card’s file system supports larger files or not - }}
|-
| &lt;!--Description--&gt;Panasonic GH5 gx80 gx85 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| Effective: 20.3 Megapixel 5184 x 3888 - 2 sd card slots compatible with high-speed, high capacity UHS-II - sd card v rating like the v90 should record at 60MB/s to be compatible with the GH5 in the All-I format - possible file corruption with .mdt files - new firmware 2.0 update, the Panasonic GH5 becomes the first 5K - }}
|-
| &lt;!--Description--&gt;Panasonic FZ2000 FZ2500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung WB100 WB1100 WB150 WB2200 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 16MP }}
|-
| &lt;!--Description--&gt;Samsung NX11 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung  NX200, NX20, NX1000 and NX210
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 20.3Mp APS-C sized CMOS image sensor }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sanyo Xacti CG65
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sanyo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 6.1MP }}
|-
| &lt;!--Description--&gt;Sony Cyber-shot DSC camera models W110 W220 H300 H400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10.2MP }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A230
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 10.2MP }}
|-
| &lt;!--Description--&gt;Sony Cybershot HX20V HX30V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 18mp 720p  - steady shot unit / optical block can cause buzzing noise and/or jumping image in lcd / viewfinder - dots are dirt and this voids the warranty }} 
|-
| &lt;!--Description--&gt;Sony Cybershot HX50V HX60V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 20.2MP 1080p  - steady shot unit / optical block can cause buzzing noise and/or jumping image in lcd / viewfinder - dots are dirt and this voids the warranty }} 
|-
| &lt;!--Description--&gt;Sony A77 A99 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 }}
|-
| &lt;!--Description--&gt;Sony WX100 WX150 wx220 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 2014 }}
|-
| &lt;!--Description--&gt;Sony NEX-6 Sony NEX-7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 16 to 24MP }}
|-
| &lt;!--Description--&gt;Sony NEX-3N Sony NEX-5N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 16MP }}
|-
| &lt;!--Description--&gt;Sony α58 Sony α68 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 20.1 MP  2014 24mp }}
|-
| &lt;!--Description--&gt;Sony rx100 mk III 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 20.1MP 1.0-type back-illuminated Exmor R CMOS sensor, often after boot-up, the motor starts running for no reason for first versions' -  }}
|-
| &lt;!--Description--&gt;Sony α5000 a5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 20.1 Megapixel APS-C Exmor APS HD CMOS 1080p Sony E-mount [https://github.com/ma1co/Sony-PMCA-RE hack] using [https://www.youtube.com/watch?v=8M4hR9HiOzM this] }}
|-
| &lt;!--Description--&gt;Sony α6000 a6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24MP APS-C sensor }}
|-
| &lt;!--Description--&gt;Sony α7 A7S a7r a7c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 mirror less - more compact }}
|-
| &lt;!--Description--&gt;Sony α77 II, α99 II, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 24.3 MP,  2016 42.4mp   }}
|-
| &lt;!--Description--&gt;Sony rx100 mk IV V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 2016 }}
|-
| &lt;!--Description--&gt;Sony RX0 RX zero, RX0 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 2017 }}
|-
| &lt;!--Description--&gt;Sony α6500 a6500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 24.2MP APS-C sensor 4K }}
|-
| &lt;!--Description--&gt;Sony α7 Alpha 7 II E-mount interchangeable lens mirrorless camera 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 24.2mp,  }}
|-
| &lt;!--Description--&gt;Sony α7 A7Sii a7r a7c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 mirror less - more compact }}
|-
| &lt;!--Description--&gt;Sony a7 III α77 ILCE7M3/B Full-Frame Mirrorless Interchangeable-Lens Camera
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 24.2mp,  }}
|-
| &lt;!--Description--&gt;Sony ZV-1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 24mm optical zoom, }}
|-
| &lt;!--Description--&gt;Sony ZV-1F
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 entry-level vlogging, 1-inch 20.1MP, ultra-wide 20mm f/2 prime lens}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}

&lt;pre &gt;
Lens Mounts

Canon EF EF-S
Nikon F 
Panasonic 
Olympus OM 
Pentax DA, FA, F, A, M, and K series
Fujifilm X mount 
&lt;/pre &gt;

&lt;pre &gt;
Sensors

APS-C 
S35 
Full Frame 
43 Four Thirds 
M43 MFT Micro four thirds 
&lt;/pre &gt;


=== Digital Voice Recorder Dictaphone Dictation Machine Handheld ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-7000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2011 }}
|-
| &lt;!--Description--&gt;Olympus VN-7200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested 2012 no usb }}
|-
| &lt;!--Description--&gt;Olympus VN-7500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2012 }}
|-
| &lt;!--Description--&gt;Olympus VN-7600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2013 }}
|-
| &lt;!--Description--&gt;Olympus WS-100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested usb}}
|-
| &lt;!--Description--&gt;Olympus VN-7700 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-8600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-711PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-712PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-731PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus WS-811
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested slide out usb-a - aaa battery - ok recordings }}
|-
| &lt;!--Description--&gt;Olympus VN-540PC Olympus VN-541PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Philips DVT1250
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX470
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX560
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX570 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


=== USB eBooks Readers drm free EPUB version 2.0.1 (2007), 3.0 (2011), 3.1 (2015) or [https://www.w3.org/TR/epub-33/ 3.3 (2024)] [https://github.com/thansen0/sample-epub-minimal epub examples] formats access ===

EPUB file format is an open standard based on XHTML for content and XML for metadata, contained in a zip file archive 

PDF v2.0 in 2017, 2009 takeover by ISO Org, 1.7 in 2006 , 1.6 in 2005, 1.4 in 2001, 1.3 in 1999, 1.0 in 1993 


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Access
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Barnes and Noble Nook Simple Touch NST BNRV300 
| &lt;!--Vendor ID--&gt;0x2080
| &lt;!--Product ID--&gt;0x0003
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;when finding the right micro usb cable that works, internal nook memory not accessible but sd card fat32 readable and writable outside 
| &lt;!--Opinion--&gt;{{N/A|2011 6in 600x800 e-ink 16 grayscale .jpg}} battery remove sd card and Torx T5 back top for Cameron Sino CS-BNR003SL - USA 1.2.2 md5sum 351e26527e80156183e74be2da2ce89f *nook_1_2_update.zip - 1.2.1 UK fdba3981f7f221cc5143db6329645bc2 *nook_1_2_update.zip - skip registration, Turn on the device, but do NOT start setting it up. Hold down the top right button on the front of the device and slide your finger from left to right across the top of the E Ink screen. A ‘Factory’ button should appear in the top left corner of the screen. Press it. Once in the Factory menu, hold down the top right button on the front of the device and tap the bottom right corner of the screen should now see a ‘Skip Oobe’ button. Tap that and the Nook should finally load the home screen. Poor battery management - 
|-
| &lt;!--Description--&gt;Barnes and Noble Nook Simple Touch with Glowlight 
*2012 Nook Simple Touch with GlowLight BNRV350 
*2013 Nook GlowLight BNRV500
| &lt;!--Vendor ID--&gt;0x2080
| &lt;!--Product ID--&gt;0x0004 0x0007 
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2012 untested }} perform a hard reset: Turn off the nook completely, turn it on, as soon as you see the screen flash begin holding the bottom page turn buttons until the screen flashes with a message asking reset, press the 'n' key twice to start the reset - Poor battery management - 
|-
| &lt;!--Description--&gt;Nook Glowlight 4 Plus 7.8-inch screen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Poor battery management - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
*NOOK 1st Edition (2009-2018) BNRZ100
*NOOK Color (2010-2024) BNRV200
*NOOK Tablet (8GB/16GB) (2011-2024) BNTV250A / BNTV250
*NOOK HD (2012-2024) BNTV400 
*NOOK HD+ (2012-2024) BNTV600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Elonex 511EB 
| &lt;!--Vendor ID--&gt;045e:ffff
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2009 untested Preferences-&gt;advanced-&gt;debug device detection}}
|-
| &lt;!--Description--&gt;[https://jaforeck.wordpress.com/2012/08/05/ready-to-meet-viktor-navorski-gained-access-to-elonex-621ebs-terminal-52/ Elonex 621EB] eBook 
| &lt;!--Vendor ID--&gt;0x1f85
| &lt;!--Product ID--&gt;0x1688
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;unlocked ootb 
| &lt;!--Opinion--&gt;{{N/A|2010 untested usb mini charging 6&quot; diagonal eInk Screen - 800 x 600 pixels, 8 Level 166dpi Paperlike screen, Embedded 1GB Flash NAND, full SD Card Slot up to 16GB - WAV, MP3, JPG, PNG, BMP, GIF support and ePub and PDF(with reflow) (TXT, HTML) support}}
|-
| &lt;!--Description--&gt;Elonex 700eb 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2011 untested adjust screen blanking by menu then settings then device standby, you can then turn it off}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;iRiver Story HD eBook 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} freescale imx.508 arm mcimx508cvkbb cpu with 2gb samsung nand, m13892aj charging chip, eb07_main_mp1_110321 mobo, mini usb, atheros ar61026 wifi - 
|-
| &lt;!--Description--&gt;iRiver Story 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Rakuten Touch A/B	kobo3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Touch C, Kobo Mini, Kobo Glo N613, Kobo Aura HD N514 N204	kobo4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Aura, Kobo Aura H2O, kobo5
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2013 6in untested }}
|-
| &lt;!--Description--&gt;Kobo Aura H2O Edition 2 v1, Kobo Glo HD, Kobo Touch 2.0, Kobo Aura ONE N709, Kobo Aura ONE Limited Edition, Kobo Aura Edition 2 v1 N236,	kobo6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Aura H2O Edition 2 v2, Kobo Aura Edition 2 v2, Kobo Nia, Kobo Clara HD, Kobo Forma, Kobo Libra H2O	kobo7
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Elipsa, Kobo Sage	kobo8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
*Kobo Libra 2  kobo9, Kobo Clara 2E	kobo10, Kobo Elipsa 2E	kobo11
*Kobo Libra Colour	kobo13, Kobo Clara BW, Kobo Clara Colour	kobo12
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pandigital Personal eReader aka? Papyre 6.2 very similar to BQ Avant Firmware
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2011  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PRS 300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PRS 350 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2009 epub bbeb cbz untested }}
|-
| &lt;!--Description--&gt;Sony PRS-650
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle K1 D00111 - Main Menu=: Settings: Menu=: Device Info shows S/N 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0002
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;256mb 
| &lt;!--Opinion--&gt;{{N/A|2007 untested Marvell Xscale PXA255}}
|-
| &lt;!--Description--&gt;Kindle K2, D00511 170-1012-00, D00701 D00801 S11S01B  
* k2 means K2 US
* k2i means K2 GW
* dx means KDX US
* dxi means KDX GW
* dxg means KDX Graphite 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0003
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb unless jb 
| &lt;!--Opinion--&gt;{{N/A|2010 untested Freescale i.MX31 }} the Kindle is a small computer running Linux 2.6 on an ARM processor
|-
| &lt;!--Description--&gt;AMAZON Kindle D00901 3rd Gen with keyboard - Menu, Settings for S/N and then Menu again to choose Update 
* S/N starts B006 means k3g aka K3 3G US 
* S/N starts B008 means k3w aka K3 WiFi 
* S/N starts B00A means k3gb aka K3 3G UK EU 
 - debug mode with ;debugON and ~help
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;{{yes|4Gb internal no access until jailbroken JB}} 
| &lt;!--Opinion--&gt;2010 with mobi and azw3 formats only - micro usb 5v 0.85a - freescale i.mx35 ARM soc with 12bit parallel interface with epson e-ink cpu, 256MB synchronous dynamic RAM, 4GB eMMC internal memory only but no sd slot, MC13892 PMIC - atheros wifi 54mbit pci-e a e keyed wifi - ?? later models wm96103 audio codec - display has 2Mbit serial memory ic on ribbon cable with 4bpp inverse grayscale display not touchscreen - 3g module - screen replacement really annoying - 4 test points near T07 = TX RX GND ? - as of 2025, JB v0.13.N, MKK2014, MKK2025, KUAL, KoReader Legacy2025, and maybe later SS v0.47.N, Python 0.14.N, Fonts v5.16.N, USBNet v0.57.N - USB-downloader mode when Vol+ is pressed during startup - Shift + Alt + M for Minesweeper - 
|-
| &lt;!--Description--&gt;Amazon Kindle 4th Generation k4 D01100 two buttons, square movement and two buttons at bottom 
*B00E 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0005
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb unless jb with USB MS, USBMS aka also known as USB MSC or UMS
| &lt;!--Opinion--&gt;{{N/A|2012 untested }} plastic back clipped in but taped down to battery cover, use Torx T5 to remove battery cover screws - battery glued down S2011-001-A 515-1058-01 DR-A015 MC-265360 - Freescale i.MX508 SOC, 2Gb eMMC storage, 256MiB of LPDDR1, MC13892 PMIC - vendor modified u-boot imximage based on u-boot v2009.08 - USB-downloader mode press the fiveway down button during startup resetmykindle - as of 2025 upgrade firmware from 4.1.x and to 4.1.4, sign into account and copy jb.1.8 bits, mkk-2014, mkk-2025, kual and then uninstall kual, koreader2025 - 
|-
| &lt;!--Description--&gt;Kindle Touch WiFi (Kindle 5th Gen) D01200 K5, KT
*Once signed into an Amazon Account get S/N under Settings -&gt; Device Options
*B00F 	Kindle Touch 3G + WiFi (Kindle 5) (U.S. and Canada) [Mostly]
*B011 	Kindle Touch WiFi (Kindle 5)
*B010 	Kindle Touch 3G + WiFi (Kindle 5) (Europe) 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0006
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;4gb unless jb 
| &lt;!--Opinion--&gt;{{N/A|untested }}  touchscreen i.MX508 SOC, 256MiB of LPDDR1 and USB-downloader mode by the SOC microcode when a specific key is pressed during startup: the home button on model D01200 - update firmware 5.3.2 to 5.3.7.3, access account, 
|-
| &lt;!--Description--&gt;Kindle PaperWhite 3G + WiFi (U.S.) [Mostly] PW 
&lt;pre&gt;
B024 	Kindle PaperWhite WiFi 
B01B 	Kindle PaperWhite 3G + WiFi (U.S.) [Mostly]
B020 	Kindle PaperWhite 3G + WiFi (Brazil) 
B01C 	Kindle PaperWhite 3G + WiFi (Canada)
B01D 	Kindle PaperWhite 3G + WiFi (Europe)
B01F 	Kindle PaperWhite 3G + WiFi (Japan)
&lt;/pre&gt;
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0007
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb 
| &lt;!--Opinion--&gt;{{N/A|untested Freescale i.MX508 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0008
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle PaperWhite 2 (2013) PW2 
*B0D4, 90D4 WiFi (U.S., Intl.) 
*B05A, 905A WiFi (Japan)
*B0D5, 90D5 3G + WiFi (U.S.) [Mostly]
*B0D6, 90D6 3G + WiFi (Canada] 
*B0D7, 90D7 3G + WiFi (Europe)
*B0D8, 90D8 3G + WiFi (Russia)
*B0F2, 90F2 3G + WiFi (Japan)
*B017, 9017 WiFi (4GB) (U.S., Intl.)
*B060, 9060 3G + WiFi (4GB) (Europe)
*B062, 9062 3G + WiFi (4GB) (U.S.) [Mostly]
*B05F, 905F 3G + WiFi (4GB) (Canada)
*B061, 9061 3G + WiFi (4GB) (Brazil) 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0009
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb or 4gb 
| &lt;!--Opinion--&gt;{{N/A|untested }} PW2 uses Freescale/NXP i.MX6 SoloLite 
|-
| &lt;!--Description--&gt;Kindle Paperwhite 3 PW3 i.e. Kindle 7th gen 
*G090G1 (2015) WiFi 
*G090G2 (2015) 3G + WiFi (U.S.) [Mostly] 
*G090G4 (2015) 3G + WiFi (Mexico)
*G090G5 (2015) 3G + WiFi (Europe, Australia) 
*G090G6 (2015) 3G + WiFi (Canada)
*G090G7 (2015) 3G + WiFi (Japan) 
*G090KB (2015) WiFi 
*G090KC (2015) 3G + WiFi (Japan) 
*G090KE (2016) 3G + WiFi (International) White 
*G090KF (2016) 3G + WiFi (International) White 
*G090LK (2016) WiFi, 32GB (Japan) 
*G090LL (2016) WiFi, 32GB (Japan) White 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x000A
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;4gb 
| &lt;!--Opinion--&gt;{{N/A|untested }} ease up glued down front bezel rim panel gently, remove 11 screws underneath and lift screen up from bottom end - battery underneath - 
|-
| &lt;!--Description--&gt;Kindle PaperWhite 4 (2018) PW4
*G000PP, G8S0PP WiFi, 8GB
*G000T6, G8S0T6 WiFi, 32GB
*G000T1  WiFi+4G, 32GB
*G000T2  WiFi+4G, 32GB (Europe)
*G00102  WiFi, 8GB (India)
*G000T3  WiFi+4G, 32GB (Japan)
*G0016T, G8S16T WiFi, 8GB Twilight Blue
*G0016Q, G8S16Q WiFi, 32GB Twilight Blue
*G0016U  WiFi, 8GB Plum
*G0016V, G8S16V WiFi, 8GB Sage 
*G00103  WiFi, 32GB (India) 
*G0016R  WiFi, 32GB Plum
*G0016S  WiFi, 32GB Sage 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x000B
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;8gb or 32gb
| &lt;!--Opinion--&gt;{{N/A|untested Freescale/NXP i.MX6 SoloLite }}
|-
| &lt;!--Description--&gt;Kindle Oasis 2 and 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 32gb
| &lt;!--Opinion--&gt;{{N/A|untested NXP i.MX7D  }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 16gb
| &lt;!--Opinion--&gt;{{N/A|untested MediaTek MT8110  }}
|-
| &lt;!--Description--&gt;Kindle 11 Scribe 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 16gb
| &lt;!--Opinion--&gt;{{N/A|untested MediaTek MT8113 }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;16gb or 32gb
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite Gen 11 and 12 - Signature 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;16Gb or 32Gb 
| &lt;!--Opinion--&gt;{{unk|2024 account not blocked,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://github.com/Modos-Labs Modos Labs] open source e-ink 60Hz 75Hz caster controller and glider monitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xteink X3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.xteink.com Xteink X4] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;2025 4.3in 220ppi no touchscreen so [https://www.youtube.com/watch?v=R7RuokaVauo buttons navigation] - 650mAh battery - micro-sd slot up to 512Gb covering epub, txt, and jpg in directories with [https://github.com/crosspoint-reader crosspoint reader] esp32 cpu custom rom firmware using [https://xteink.dve.al/ Flash website] on usb-c but no ecosystem store 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;15%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Access
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Amazon D01400 Kindle Fire (1st Generation) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{No|2010 too old }} android 2.3 and touchscreen digitizer fails often, battery SWE P/N 1002000004742 Model KC1 (EU) QP01 (US) 16.28whr, ti 257epl9l omap 4430 with elpida 88164b3pf-10-f88164b3pf or hynix,  mobo ??,, DAOKC1MB8F0 Rev F, ti aic3110 audio codec, 
|-
| &lt;!--Description--&gt;Amazon Fire 7in X43260 X43Z60 2nd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 untested FireOS Android 4 omap 4460 and PowerVR SGX540}}
|-
| &lt;!--Description--&gt;Amazon Kindle Fire HD (3rd Gen) P48WVB4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 untested }}
|-
| &lt;!--Description--&gt;Amazon 
*Amazon Fire HD10 (2015) 
*Amazon Fire HD8 (2015)	
*Amazon Fire HD7 (2015)	(5th Generation) 7 inch 8GB SV98LN 
*Amazon Fire HD7 (2014)	
*Amazon Fire HD6 (2014) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|untested android 5.1 max}}
|-
| &lt;!--Description--&gt;
*Amazon Fire 10 (2017) 
*Amazon Fire 8 (2017) 7th Gen 8 inch SX034OT 
*Amazon Fire 7 (2017) (7th Generation) 7 inch 16GB (SR043KL) 
*Amazon Kindle Fire 7 (7th Generation) 7 inch 8GB WIFI Tablet (SR043KL) 
*Amazon Fire HD8 (2016)	
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| Android 5.1 max 7in screen resolution of 1024 x 600, }}
|-
| &lt;!--Description--&gt;
*Amazon Fire 10/10+ (2021) 
*Amazon Fire 8/8+ (2020) 
*Amazon Fire 10 (2019) 
*Amazon Fire 7 (2019) 
*Amazon Kindle Fire 7 9th Gen 16GB M8S26G 
*Amazon Fire 8 (2018) 8th Gen 8 inch 32GB L5S83A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| android 9 max}}
|-
| &lt;!--Description--&gt;Amazon 
*Amazon Fire HD 10 (2023)	
*Amazon Fire Max 11 (2023)	
*Amazon Fire 8 (2022)	
*Amazon Fire 7 (2022)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| android 11 max}}
|-
| &lt;!--Description--&gt;Amazon Kindle Scribe 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;Amazon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Minimal Phone, Mudita Kompakt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| eink }}
|-
| &lt;!--Description--&gt;Bigme B751C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 android untested }}
|-
| &lt;!--Description--&gt;Bigme B7 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;Bigme B6
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android based color eink small - 300dpi b/w 150ppi color -}}
|-
| &lt;!--Description--&gt;Bigme 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| e-ink }}
|-
| &lt;!--Description--&gt;Bigme Hibreak Pro, Hisense A9
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| e-ink}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;iFlyTech AINote 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;iFlyTech AINote 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Meebook 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Page Palma 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 android untested }}
|-
| &lt;!--Description--&gt;Onyx Boox Leaf3C
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Go Color 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 untested 7in e-ink e-reader android tablet }}
|-
| &lt;!--Description--&gt;Onyx BooxTab Ultra X C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Note Max Air4 C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Leaf5C
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Poke6S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Go 10.3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox MC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| color e-ink 13.3in }}
|-
| &lt;!--Description--&gt;Onyx Boox Go 10.3 (Gen 2) Lumi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 b/w eink with front light, no EMR annd capacitance pen,  }}
|-
| &lt;!--Description--&gt;Onyx Moaan Pantone 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;reMarkable 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2021 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable Paper Pro Move 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 untested but subscriptions needed for some features}}
|-
| &lt;!--Description--&gt;reMarkable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Supernote A5 X2 Manta
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;Supernote A6 X2 Nomad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2023  }}
|-
| &lt;!--Description--&gt;Supernote 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tolino Vision 2 3 4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tolino Epos2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viwoods AI Paper and AI Paper Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


==printer.class - PostScript 3 and internal ghostscript drivers==


As the only printer driver that AROS supports natively is Postscript, our focus is on applications that generally output postscript formatted data for printing purposes and since the general Joe Public finds postscript capable printer very expensive, postscript interpreters (eg ghostscript) have been developed aas a cheaper option which sit in between postscript data streams and non postscript (HP PCL?) printers.

Set up Printer Prefs for Postscript and set the print to file option.


Ghostscript has internal printer drivers

 gs -h

and with something like

 gs -sDEVICE=stcolor -r300 -sOutputFile=RAM:tempfile gs813:examples/tiger.ps
 copytopar ram:tempfile

It checks if in RAM: exists a outputfile (Cinnamon can export to PS postscript) then it sends this via copytopar to the printer. There was only support for parport (parallel) but Terminillis added support for USB and ethernet. A big issue with using ghostscript for drivers is that data has to originate as postscript (.PS) file.

 gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=ljet4 -sOutputFile=RAM:tempfile RAM:file.pdf

the ljet4 output device generates PCL

also the pxlmono driver, which generates more generic PXL (PCL 6)

 gs -q -sstdout=%stderr -sDEVICE=pswrite -sOutputFile=- -dBATCH -dNOPAUSE -dPARANOIDSAFER testpage-a4.ps &gt; test.pdf

 gs -q -sstdout=%stderr -sDEVICE=pxlmono -sOutputFile=- -dBATCH -dNOPAUSE -dPARANOIDSAFER test.pdf &gt; test.pxl


Printers supported by ghostscript...Explanation [http://freebooks.by.ru/view/RedHatLinux6Unleashed/rhl6u151.htm here] or [http://www.gnu.org/software/ghostscript/devices.html here] and [http://pages.cs.wisc.edu/~ghost/doc/printer.htm here]

&lt;pre&gt;
bit            cljet5          ljet4d          pjxl300         pxlcolor
bitcmyk        cljet5c         ljetplus        pkm             pxlmono
bitrgb         deskjet         nullpage        pkmraw          stp
bj10e          djet500         pbm             pksm            tiff12nc
bj200          epswrite        pbmraw          pksmraw         tiff24nc
bjc600         faxg3           pcx16           png16           tiffcrle
bjc800         faxg32d         pcx24b          png16m          tiffg3
bmp16          faxg4           pcx256          png256          tiffg32d
bmp16m         ijs             pcxcmyk         pnggray         tiffg4
bmp256         jpeg            pcxgray         pngmono         tifflzw
bmp32b         jpeggray        pcxmono         pnm             tiffpack
bmpgray        laserjet        pdfwrite        pnmraw          uniprint
bmpmono        lj5gray         pgm             ppm             x11
bmpsep1        lj5mono         pgmraw          ppmraw          x11alpha
bmpsep8        ljet2p          pgnm            psgray          x11cmyk
cdeskjet       ljet3           pgnmraw         psmono          x11gray2
cdj550         ljet3d          pj              psrgb           x11gray4
cdjcolor       ljet4           pjxl            pswrite         x11mono
cdjmono
&lt;/pre&gt;

=== Internal Ghostscript support ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| Canon BJ10e
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested with Ghostscript drivers }}
|-
| Canon BJ200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested with Ghostscript drivers }}
|-
| Epson Stylus Color 600 parport inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - internal ghostscript support}}
|-
| &lt;!--Description--&gt;HP Deskjet 500 Parallel Port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| HP1220C/PS USB Inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - PS3 emulation only}}
|-
| HP 1700PS USB Inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - PS3 emulation only}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| &lt;!--Description--&gt;LJ-III
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested HP PostScript Cartridge Plus (C2089A) a.. Press &lt;ON LINE&gt; (and take machine off line)
b.. Press &lt;Plus &amp; Minus&gt;, and while holding, press &lt;ALT&gt; and &lt;RESET&gt; together and watch the LCD and let go when the desired mode is displayed.}} 
|-
| &lt;!--Description--&gt;HP Laserjet 4 4M 4MP (1992)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested PS2 emulation HP 4 with optional ps cartridge - HP 4M and 4M+ built in}} 
|-
| &lt;!--Description--&gt;HP Laserjet 4L Parport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{no|PCL5 HP 4L only - no postscript}} 
|-
| &lt;!--Description--&gt;HP Laserjet 5M (1995) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS2 emulation
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested you can try the ljet4 for the various lj5 drivers which produce various flavours of PCL. The 4, 4+ and 5 only really had one issue that plagued them, and it's hardly an issue at all. You would get accordian jams at the exit. A lot of people worked through this by pulling the sheet out before it got caught. Easily fixed by opening back door and scrubbing grime off of rubber rollers. }}
|-
| HP Laserjet 5L Parport (1997) (C3906A bk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;{{N/A}}
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{no|PCL5 support only.}}
|-
| HP Laserjet 5P 6P (1995) (C3906A bk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested HP 5p, 6p - Less tiny, slightly less slow. They are pretty bullet proof for low volume best to get postscript module though }}
|-
| HP Laserjet 2100 2100N 2100TN (1999) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested PS2 emulation }}
|-
| HP Laserjet 4000 Series Parport (1998) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|PS3 emulation only (4200 and 4600 have issues)}}
|-
| HP Laserjet 4050 Parport (1999) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|works }}
|-
| HP Laserjet 5000 Parallel Port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|}}
|-
| HP LaserJet 6M, 1200, 1300, 2100, 2200, P2050 (and P2055) P3005, M3025, M3027, 3050, 3300, 4000, 4050, 4100, 4200, 4300, M4345, P3005, P3015, P4010, P4410, M5025, M5035, 5100, 5200, 8000, 8100, or 9000 series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation optional only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{untested }}
|-
| &lt;!--Description--&gt;HP Color LaserJet 2550, 3700, 4650, 8500 and 8550 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lexmark Optra C, T, and W series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Xerox Phaser 850, 860 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

=== USB Monochrome ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| &lt;!--Description--&gt;Brother HL-1270N
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRScript
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL-3070CW Printer USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|BR-Script3 (PS3) untested}}
|-				
| &lt;!--Description--&gt;Brother HL5240 HL5240L 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRScript (PostScript Level 2) 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL-7050N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR3
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother MFC-7860DW Monochrome B/W BW 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR-Script BRScript (PostScript Level 3) 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL4570CDWT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Epson EPL-6200 Laser Printer USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|cheap to buy but untested - running cost unknown}}
|-		
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kyocera FS-1370DN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| HP LaserJet CP1515n USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|cheap to buy but untested - running cost unknown}}
|-
| &lt;!--Description--&gt;Lexmark Optra E312 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;built in? 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== USB Color ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother hl-3075cw
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR-Script 3 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother MFC-9120CN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRS3 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;HP Color LaserJet 2500L (2003) USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| HP Color LaserJet 2550L 2550Ln (2004) USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| HP Color LaserJet CP1218, 2605, 3700, 4500, 4600, or 4650 series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Konica Minolta Magicolour 4650EN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| Kyocera FS-1010 FS-1010N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| Kyocera FS-C5200DN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Kyocera Mita FS-1030D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kyocera FS-C5150DN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Lexmark C540n 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| Lexmark [http://www1.lexmark.com/products/view/Printers/Lexmark%20C780n/catId=cat10006-category&amp;prodId=3907-product C780n]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;{{yes|works PS3 emulation only}}
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| OKI C3600 Color Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Samsung CLP-315
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;untested 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Xerox 618x Color Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

See [http://www.irseesoft.de/tp_drive7.htm here] for compatibility with TP7 (TurboPrint 7) Last update 2004. Not tested under emulation. Janus-UAE, Emumiga, 

OS3.x support via [http://aminet.net/package/comm/tcp/NetPrinter NetPrinter] and [http://www.os4depot.net/index.php?function=browse&amp;cat=driver/printer OS4 drivers] and [http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=33955&amp;forum=27#622365 experiences].

usbparallel.device

untested with USB-&gt;Centronics - The printer.class is rather 'clever'. It remembers to which unit the printers were connected (until you reboot). So if you first plug in Printer1, it gets unit 0, and Printer2 gets unit 1. If you now remove both printers and replug Printer2, it still will get unit 1 and not 0. This is used not to confuse the programs using the different units (moreover, if some program uses the usbparallel.device unit of an USB printer, and the printer is unplugged, the device unit cannot be freed immediately as the application still keeps it open). Sticking to the same units is generally a good idea I think (and therefore this mechanism is also used with all other classes creating exec.devices).

You may not send a short packet (packet less than maxpktsize == 64) nor zero byte packets until the very last byte of your printout. Otherwise the printer will silently ignore the data you sent. Some printer drivers print very short sequences that never fill the endpoint buffer, so printer ignore them. Bufferize all printer driver writes in the ieee1284.device and send them by epsize packets. So my hppsc2210 works fine with a classic HP560C driver, on a classic A2000 subwayized :)


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Beige cream D shape centronics end (Prolific chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Belkin F5U002v1 centronics end (chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Belkin F5U002VEA v2 centronics end (Prolific PL2305L chipset) 
| 
| 
| 
| {{N/A|untested}}
|-
| DYNAMODE USB-C-PP-1284 USB to 36pin (Prolific 2305 chipset) 
| 0x067b
| 0x2305
| 0x02
| {{N/A|untested but similar to BAFO below}}
|-
| IOGear GUC1284B 
| 
| 
| 
| {{N/A|untested}}
|-
| My-Link (raised ellipse on centronics plastic end) (unknown chipset) 
| 
| 
| 
| {{N/A|untested but more expensive }}
|-
| NEWLink (Prolific chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Targus PA096E centronics end (chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| TRENDnet ware TU-P1284
| 
| 
| 
| {{N/A|untested}}
|-
| True PnP (Prolific chipset 2305) cheap 36pin Centronics (series of ridges along both short sides) 
| 0x067b
| 0x2305
| 2.00
| {{N/A|untested on BAFO BF-1284 but reports of poor quality and lack of support on other OSs }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| Transparent See Through Blue 
| 
| 
| 
| {{N/A|untested but possible poor quality build }}
|-
| Dynamode USB-PARALLEL 25pin female (prolific) 
| 0x067b
| 0x2305 
| 0x02 
| {{N/A|untested}}
|-
| FDL USB to 25pin 
| 
| 
| 
| {{N/A|untested}}
|-
| PlusKom USB to 25pin female connector for printer (IEEE 1284) 
| 
| 
| 
| {{N/A|untested}}
|-
| QinHeng Electronics (CH340S chipset) 
| 0x1a86
| 0x7584
| 
| {{N/A|untested curvy sides - flat top }}
|-
| StarTech 
| 
| 
| 
| {{N/A|untested}}
|-
| Syba SD-USB-DB25 
| 
| 
| 
| {{N/A|untested}}
|-
|}


==rawwrap.class - some old flatbed scanners supported==

Scandal is the MUI frontend to [http://www.ppa.pl/bugtracker/ Betascan Bugtracker] and [http://aminet.net/search?query=betascan Search for Betascan scanner drivers] derived from [http://www.sane-project.org/sane-backends.html sane backends] 


[http://www.sane-project.org/sane-backends.html#S-EPSON2 Epson2] 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Expression 1600 1640XL 1680 10000XL
| 0x04b8
| 0x0107 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Prefection 1200U, 1200 Photo, 
| 0x04b8
| 0x0104
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 1240U
| 0x04b8
| 0x010b
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{[https://amigaworld.net/modules/newbb/viewtopic.php?topic_id=45760&amp;forum=25 works]|Needs 24V 0.8A psu but in Trident, click on &quot;Classes&quot;, then on &quot;rawwrap.class&quot;, then on &quot;Configure&quot;. There, under &quot;Global&quot;, activate the Option &quot;Bind to Vendor/Unknown Interfaces&quot;. Now go to the second tab &quot;Default Interface&quot; and select/enter these values: 
Default usbraw.device Unit: 0
Exclusive access: Yes
Out NAK Timeout: 20000ms
In NAK Timeout: 20000ms
In Buffer Mode: No buffering
Buffer Size: 36 KB
Short Reads Terminate: Yes
Now click on &quot;Use as Default&quot; and select &quot;Devices&quot; on the left. There, click on your scanner and click on &quot;Class Scan&quot;. Now close Trident by clicking on &quot;Save&quot;. }}
|-
| Perfection 1640SU Photo
| 0x04b8
| 0x010a
| 0x0104
| {{yes|works, even the transparency unit}}
|-
| Perfection 1650 Photo, 1660 Photo, 3200 Photo
| 0x04b8
| 0x011c
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 2400 Photo, 2450 Photo 
| 0x04b8
| 0x011b 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 4870 Photo, 4990 Photo, 
| 0x04b8
| 0x0128
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection V700 V750 Photo
| 0x04b8
| 0x012c
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Stylus CX2800 2900 3200 3500 3600 3650 3700 3800 3900

Stylus CX4100 4200 3500 4600 4700 4800 4900 500 5100 5200 5300 5400 5900
| 0x04b8 
| 0x0802 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Stylus Office BX300F USB 
| 0x04b8
| 0x0848
| 
| {{yes| works with good scan quality}}
|-
|}


[http://www.meier-geinitz.de/sane/gt68xx-backend/ gt68xx] scanners based on the Grandtech GT-6801 and GT-6816 &quot;System-On-Chip&quot; scanner chipsets 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Artec Ultima 2000 and e+, Trust Flat Scan USB 19200 (ePlus2k.usb / Gt680xfw.usb) 
| 0x05d8
| 0x4002
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Genius Colorpage Vivid3x 4x 1200x
| 0x0458
| 0x2011 to 0x201f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (ccd548.fw)}}
|-
| &lt;!--Description--&gt;Lexmark	X70	also X73 [http://subfusion.net/drivers/oslo3071b2.usb OSLO3071b2.usb]
| &lt;!--Vendor ID--&gt;0x043d
| &lt;!--Product ID--&gt;0x002d
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Medion/Lifetec/Tevion/Cytron MD/LT 9375 and Artec Ultima 2000, MD LT 9385 Gt680xfw.usb 
| &lt;!--Vendor ID--&gt;0x05d8
| &lt;!--Product ID--&gt;0x4002
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| BearPaw 2448 CS and TA Plus [http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/A2Nfw.usb A2Nfw.usb]
| 0x055f
| 0x021a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  }}
|-
| Mustek BearPaw 1200 CS 
| 0x055f
| 0x021e
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/A1fw.usb A1fw.usb])}}
|-
| &lt;!--Description--&gt;Mustek 1200 CU Plus Scanner [http://www.meier-geinitz.de/sane/gt68xx-backend PS1Dfw.usb / SBSfw.usb]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2000 }}
|-
| Mustek ScanExpress 1200 UB plus, Trust Compact Scan USB 19200, ScanMagic 1200 UB Plus
| 0x05d8
| 0x4002 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/sbfw.usb sbfw.usb])}}
|-
| Mustek ScanExpress 1248 UB aka PC-World PC Line PCL-3000 
| 0x055f
| 0x021f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/SBSfw.usb SBSfw.usb])}}
|-
| Mustek BearPaw 2400CS TA aka Goodmans GSC 12/24
| 0x055f
| 0x0218
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| (Transparency adapter untested) }}
|-
| BearPaw 2400 CS aka TA Plus
| 0x055f
| 0x0219
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (Transparency adapter) }}
|-
| Packard Bell Diamond 1200 Plus
| 0x055f
| 0x021c or 0x021b 
| 0x0
| {{yes|works - [http://www.meier-geinitz.de/sane/gt68xx-backend/ firmware required] but slow usb 1.1 speed with poor quality output (scanner fault not scandal)}}
|-
| Packard Bell Diamond 2400 Plus aka BearPaw 2400 CU Plus [http://www.meier-geinitz.de/sane/gt68xx-backend/ PS2Dfw2.usb firmware rename to PS2Dfw.usb]
| 0x055f
| 0x021d 
| 1.00
| {{yes|works slow usb 1.1 speed with ok quality output (scanner fault not scandal)}}
|-
| Plustek OpticPro 1248U
| 0x07B3
| 0x0400 0x0401
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| (ccd548.fw)}}
|-
| Plustek OpticSlim 2400
| 0x07b3
| 0x0422
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (cis3R5B1.fw)}}
|-
| Visioneer OneTouch 7300
| 0x04a7
| 0x0444
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (Cis3r5b1.fw)}}
|-
| &lt;!--Description--&gt;Mustek ScanEpress 1200 UB (Plus) clone [http://www.meier-geinitz.de/sane/ use mustek_usb backend]
| &lt;!--Vendor ID--&gt;0x055f
| &lt;!--Product ID--&gt;0x0006
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Lexmark - needs testing
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Lexmark X1110 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1140
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1150 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1170 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1180 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1185
| 0x043d
| 0x007c
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Lexmark X12xx 
| 
| 
| 
| {{N/A|untested in USB1.1, not fully tested in USB2.0}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Dell A920 
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


HP - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| HP ScanJet 4100C
| 0x03f0 
| 0x0101
| 
| {{no|no driver}}
|-
| HP ScanJet 5200C
| 0x03f0 
| 0x0401
| 
| {{no|no driver}}
|-
| HP ScanJet 62X0C
| 0x03f0 
| 0x0201
| 
| {{no|no driver}}
|-
| HP ScanJet 63X0C
| 0x03f0 
| 0x0601
| 
| {{no|no driver}}
|-
| HP  
| 0x03f0
| 0x0102, 0x0105, 0x0205, 0x0305, 0x0405
| 
| {{no|no driver}}
|-
| HP
| 0x03f0
| 0x0705, 0x0805, 0x0901, 0x0a01
| 
| {{no|no driver}}
|-
| HP
| 0x03f0
| 0x1205, 0x1305, 0x2005, 0x2205
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Plustek [http://www.sane-project.org/sane-backends.html#S-PLUSTEK LM983x] - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Plustek OticPro U12 UT12 UT16 U24 UT24
| 0x07B3
| 0x0010 to 0x0017
| 
| {{no|no driver}}
|-
| KYE/Genius Colorpage HR6-V2 HR6A HR7 HR7LE HR6X
| 0x0458
| 0x2008 to 0x2016 
| 
| {{no|no driver}}
|-
| Hewlett-Packard ScanJet 2100C and 2200C
| 0x03F0
| 0x0505 and 0x0605
| 
| {{no|no driver}}
|-
| Mustek BearPaw 1200 and 2400 
| 0x0400 	
| 0x1000 and 0x1001
| 
| {{no|no driver}}
|-
| UMAX 3400/3450 and 5400 	
| 0x1606
| 0x0050, 0x0060 and 0x0160 
| 
| {{no|no driver}}
|-
| Epson Perfection 1250 and 1260
| 0x04B8
| 0x010f and 0x011d
| 
| {{no|no driver}}
|-
| CANON CanoScan N650/656U N1220U D660U N670/676U N1240U LIDE20 LIDE25 LIDE30
| 0x04A9
| 0x2206 to 0x2220
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


[http://snapscan.sourceforge.net/ SnapScan] - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Acer Benq 310U, 320U, 340U
| 0x4a5
| 0x0
| 
| {{no|no driver}}
|-
| Acer Benq 620U, 620UT, 640U, 640UT
| 0x4a5
| 0x20
| 
| {{no|no driver}}
|-
| Acer Benq 1240 3300 4300
| 0x4a5
| 0x020
| 
| {{no|no driver}}
|-
| Agfa SnapScan e10 e20 e25 e26 e40 e42 e50 e52
| 0x06bd
| 0x20
| 
| {{no|no driver}}
|-
| Epson Perfection 660
| 0x04b8
| 0x0114
| 
| {{no|no driver}}
|-
| Epson Perfection 1270 1670
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Epson Perfection 2480 2580
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Epson Perfection 3490 3590
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Mitsubishi
| 0x0
| 0x0
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}

==hub.class (self-powered and external ac powered hubs)==

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Dynamode USB-H41 4 ports 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Belkin 4 Port 
| 
| 
| 
| {{yes|works}}
|-
| Conrad
| 
| 
| 
| {{yes|[http://www.a1k.org/forum/showthread.php?t=11432 works on a1k forum] }}
|-
| DLink DUB-H4 AC Adapter 
| 0x05e3
| 0x0608
| High 0200
| {{maybe|WARNING Genesys Logic Hub Broken - Will cause failures with USB}}
|-
| [http://service.targa.co.uk/faq.php?lang_id=2&amp;baseid=178&amp;artdesc=SilverCrest+USB+Hub+2040&amp;artid=760&amp;artpic=silvercrestHUB2040.jpg SilverCrest 4-port slim USB 2.0 HUB - HUB2040 (40775) - Targa GmbH]
| 0x05e3
| 0x0608
| 0901
| {{yes|works  Genesys Logic, Inc., [http://service.targa.co.uk/dokumente/USB_HUB_2040_0109_manual_EN.pdf Manual]}}
|-
| Skymaster
| 0x05e3
| 0x0605
| 060B
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| No Name active 4-port
| 0x1a40
| 0x0101
| 0111
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Thinkpad USB 3.0 Dock DU9019D1 
| &lt;!--Vendor ID--&gt;0x17e9
| &lt;!--Product ID--&gt;0x4302
| &lt;!--Revision--&gt;0014
| &lt;!--Opinion--&gt;{{Maybe|works a bit}} classed as dfu.class with two further USB 2.0 hubs - USB 3.0 ports detected and work (2.0 backwards compatibility) - DisplayLink DL-3900 with VIA VL811 chipset - usb ethernet not working - two dvi not working - 20V psu 2a (40w) with a 5.5 - 2.5mm tip (no bus power) - data through a-b printer/scanner usb lead - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


==Internet==

===rndis.class USB Tethering ===

The rndis class provides support for Ethernet access over Remote NDIS. Most USB based devices should be supported including smartfones.

Before opening Network Prefs, activate USB Tethering on the Smartfon, on Network prefs, type in usbrndis.device and tick &quot;Start Network during system boot&quot; and saved the configuration, the Connection is immediate no reboot is needed.

When restart AROS my Smartphone deactivates the connection and to access the network again, have to reactivate it before starting the browser.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Alcatel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| Huawei U8800
| 0x12d1
| 0x1039
| 
| {{yes|works}}
|- 
| &lt;!--Description--&gt;Huawei
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| HTC (Android phone)
| 0x0bb4
| 0x0ffe
| 
| {{Yes|any android phone with usb tethering option}}
|- 
| &lt;!--Description--&gt;Nokia 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;Oppo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;Samsung Galaxy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
|- 
| &lt;!--Description--&gt;iPhone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Microsoft winPhone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


===USB &amp;rarr; ethernet lan adaptor===

*2002 playstation 2 usb1.1 era - a little support but very old and slow 
*2006 wii asix era - a little support but very much miss than hit 
*2026 usb0: or eth0: of CDC Ethernet protocol (cdcether) with Ethernet Control Model (ECM) and [https://www.usb.org/document-library/class-definitions-communication-devices-12 others like Wireless Mobile Communication Devices WMC] and later CDC EEM (Ethernet Emulation Model) and NCM (Network Control Model) are USB Communication Device Class (CDC) protocols packing more Ethernet traffic over every USB bundle. For CDC Ethernet - NCM is better than EEM is better than ECM 


* USB1.1 Up to 010 meg broadband (1.25MBytes/s) - ADM8511, DM9601 poor speeds 
* USB2.0 Up to 400 meg broadband (60MBytes/s) - MCS7830, AX88772 a little especially the 2010 apple version but buy many as very very poor odds of working one 
* USB3.0 Over 400 meg broadband (60+MBytes/s) - not supported at the moment 


SANA (Standard Amiga Network Architecture) to usb 

ADMtek Infineon ADM8511 Pegasus II (USB 1.1 and 10Mbit/s - Sony PlayStation 2 network adapter) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| 3Com 3c460b 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| Abocom UFE1000 / Abocom DSB650TX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Accton USB320-EC / Accton SpeedStream Ethernet
| 0x083a
| 0x0320
| &lt;!--Revision--&gt;
| {{unk|2002 }}
|-
| AEI USB Fast Ethernet / Allied Telesyn AT-USB100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2002 }}
|-
| ATEN UC-110T
| 0x0557
| 0x4000
|
| {{unk|2001 }}
|-
| BAFO USB To Ethernet Adapter BF-310
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| Belkin F5D5050 v1 1101 
| 0x050D
| 
| &lt;!--Revision--&gt;
| {{maybe|2002 sometimes works from old amiga.org post which is now removed}}
|-
| Belkin F5D5050 v2 2101
| 0x050D
| 0x0121
| &lt;!--Revision--&gt;
| {{no|2006 does not works}} 
|-
| Belkin F5U122-PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Billionton USB-100 / Billionton USBLP-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Billionton USBEL-100 / Billionton USBE-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Compex LinkPort/UE202A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DSB-H3ETX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DSB-650 / D-Link DSB-650TX / D-Link DSB-650TX-PNA
| 0x2001
| 0x4000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DU-E10 / D-Link DU-E100
| 0x2001
| 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Edimax USB Ethernet Adapter EU-4201 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Elsa AG MicroLink USB2 Lan Ethernet adapter
| 0x05cc
| 0x3000
| &lt;!--Revision--&gt;1.01
| &lt;!--Opinion--&gt;{{unk| }}
|-
| GetNet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| GIGABYTE GN-BR402W Wireless Router
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Goodway Fellowes USB UE-120 REV:V1 UE120 ADMTek 1011594 HO2419741 
| &lt;!--Vendor ID--&gt;0x07a6
| &lt;!--Product ID--&gt;0x0986
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{maybe|2001 USB Specification 1.1 compliant}} 
|-
| GWC Tech USB Ethernet Adapter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Hawking UF100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| HP HN210E / I/O DATA USB ETTX / Kingston KNU101TX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Jinco USB Ethernet Adapter 10/100 Base-T UE-110
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Kouwell USB to Ethernet 588A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Linksys USB10T / TA / TX
| 0x066b
| 0x2202
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested - possible peg1/peg2}}
|-
| Linksys (Cisco) USB100TX / H1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitec LAN-TX/U1 H2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| [http://www.mayflash.com/psps2/ps2024/ps2024.htm Mayflash PS2024] Playstation2 compatible clone of Proxim/Farallon NetLine?
| 0x07a6
| 0x8511
| &lt;!--Revision--&gt;1.01
| &lt;!--Opinion--&gt;{{maybe|works with DHCP router option on old 32bit distros but not on newer 64bit, best to go asixeth apple 2010 but buy many of them as poor success rate i.e. a lottery}}
|-
| Netgear FA101
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Philips CPWUE01/00 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Planet UE-9500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| PlayStation 2 SCPH-10000 50000 models 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Proxim (formerly Farallon) NetLine USB PN796-650
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Siemens SpeedStream USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| SOHOware NUB100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| SMC EZNET-USB 2202USB/ETH / SMC 2206USB/ETH
| 0x0707
| 0x0100 0x0200 0x0201
| &lt;!--Revision--&gt;
| {{unk|untested but should work very well }}
|-
| Surecom EP-1427X 100/10M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Target USB to 10/100M Fast Ethernet Converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Trendnet TU-ET100C
| 0x07a6
| 0x8511 
| &lt;!--Revision--&gt;0x0
| {{yes| sometimes works well, very stable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Digitus USB NIC DN-3016-A 
| 0x07a6
| 0x8513
| 1.01
| {{unk|untested new chipset }}
|-
| Digitus lanusb ADM8515
| 0x07a6
| 0x8515
| 1.01
| {{unk|untested because new chipset }}
|-
| VE285 usblan ADMtek 8515 
| 0x07a6
| 0x8515
| 1.01
| {{no|not working as new chipset }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Davicom DM9601 eth (USB 1.1 and up to 10Mbit/s) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Davicom USB-100 see clone below 
| 0x0a46
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| [http://wiki.maemo.org/USB_to_ethernet_networking chinese translucent transparent crystal blue] but variants are also found in clear, white and black. Just over 6&amp;nbsp;cm long. 
| 0x0a46
| 0x9601
| 0x0
| {{yes|2002 success can be sporadic so technically okay, but lacking in reliability. Out of 4 tested by me, only 2 worked. One case cracked open. }}
|-
| Corega FEther USB-TXC
| 0x07aa
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Dynamode USB-NIC-1427-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Hirose USB-100
| 0x0a47
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| KY-RS9600
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585358&amp;postcount=12 works] }}
|-
| ShanTou ST268 USB NIC
| 0x0a46
| 0x0268
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| ZT6688 USB NIC 
| 0x0a46
| 0x6688
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ICS Advent DM9601 USB 2.0 10/100M Ethenet Adaptor JP1081B 
| &lt;!--Vendor ID--&gt;0x0FE6
| &lt;!--Product ID--&gt;0x9700
| &lt;!--Revision--&gt;0101
| &lt;!--Opinion--&gt;{{No|only USB 1.1 10M ethernet support but will plug into an usb 2.0 port}} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


MosChip MCS7830 (USB 2)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Digitus DN-10050
| 0x9710
| 0x7830
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 }}
|-
| Edimax [http://www.edimax.co.uk/images/Image/datasheet/USB/EU-4206/EU-4206.pdf EU-4206]
|
| 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 }}
|-
| Speed Dragon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| STLabs 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| StarTech Compact USB2105S [http://www.kustompcs.co.uk/acatalog/info_6790.html USB2106S]
| 0x9710
| 0x7830
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| Sunrich Technologies [http://www.st-lab.com/admin/upfile/UploadFile/manual/manual(u-250).zip U-250]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 }}
|-
| Syba 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;MCS 7832 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2008 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


* USB2 [https://www.asix.com.tw/en/product/USBEthernet Asix Ethernet] AX88178A, AX88772C, AX88772B, AX88772A (wii), AX88172A 
* USB3 AX88179A, AX88179  

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| AirLink101 AGIGAUSB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  AX88172}}
|-
| ATEN UC210T 
| 0x0557
| 0x2009
| 0x
| &lt;!--Opinion--&gt;{{unk| AX88172}}
|-
| &lt;!--Description--&gt;Billionton Systems USB2AR
| &lt;!--Vendor ID--&gt;0x08dd
| &lt;!--Product ID--&gt;0x90ff
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;Buffalo LUA-U2-KTX
| &lt;!--Vendor ID--&gt;0x0411
| &lt;!--Product ID--&gt;0x003d
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;corega FEther USB2-TX
| &lt;!--Vendor ID--&gt;0x07aa
| &lt;!--Product ID--&gt;0x0017
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| }}
|-
| D-Link DUB-E100 up to rev A4
| 0x2001
| 0x1a00
| 
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;D-Link DUB-E100 rev B1 onwards 
| 0x07d1 or 0x2001 
| 0x3c05
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|AX88172 works on Deneb with [http://amigax.com/2010/02/21/usb-ethernet-speed-test-amigaos-4-0-classic/ Amiga OS4 Classic] and [http://www.a1k.org/forum/showthread.php?t=11432 on a1k] }}
|-
| &lt;!--Description--&gt;goodway corp USB gwusb2e
| &lt;!--Vendor ID--&gt;0x1631
| &lt;!--Product ID--&gt;0x6200
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hawking UF200 
| 0x07b8
| 0x420a 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[Linksys USB200M] 
| 0x077b
| 0x2226
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585601&amp;postcount=20 works] }}
|-
| &lt;!--Description--&gt;Netgear FA120 
| 0x0846 
| 0x1040
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2002 10/100 Rev.B1&quot; is silkscreened on the board of the device populating this entry (S/N: FA12254CB100409, date code 0508). This device may be manuf. by [http://www.cameo.com.tw/ Cameo] &quot;AX88172 L&quot;, &quot;F05040157&quot;, and &quot;ED3&quot; Chip1 ASIX AX88172  Chip2 Realtek RTL8201BL}}
|-
| &lt;!--Description--&gt;Intellinet
| 0x0b95 
| 0x1720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;JVC MP-PRX1 Port Replicator
| &lt;!--Vendor ID--&gt;0x04f1
| &lt;!--Product ID--&gt;0x3008
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ST Lab USB Ethernet
| &lt;!--Vendor ID--&gt;0x0b95 
| &lt;!--Product ID--&gt;0x1720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Sitecom LN-029 &quot;USB 2.0 10/100 Ethernet adapter&quot;
| &lt;!--Vendor ID--&gt;0x6189
| &lt;!--Product ID--&gt;0x182d
| &lt;!--Revision--&gt;0
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;Surecom EP-1427X-2
| &lt;!--Vendor ID--&gt;0x1189
| &lt;!--Product ID--&gt;0x0893
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v2
| 0x07b8
| 0x420a 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|version 2}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;A-LINK NA1GU 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 88772}}
|-
| &lt;!--Description--&gt;AirLink101 ASOHOUSB Wii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AirLive EtherWe-1000U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;APPLE AX88772 Model No. A1277 MC704LL/A P/N 825-7098-A 
| &lt;!--Vendor ID--&gt;0x05ac 
| &lt;!--Product ID--&gt;0x1402
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2008  usb2, }}
|-
| &lt;!--Description--&gt;APPLE Model No. A1277 (MB442Z/A 0885909217434) MC704ZM/A PN 825-7579-A 
| &lt;!--Vendor ID--&gt;0x05ac 
| &lt;!--Product ID--&gt;0x1402
| &lt;!--Revision--&gt; 
| &lt;!--Opinion--&gt;{{Maybe|2010 model, usb2 and controller AX88772 where prehaps 1in3 units working with owb - really poor odds i.e. a lottery, could be situation where various ethernet phy chipsets are used - press Use in network prefs after Save initial setup typing in usbasixeth.device, }}
|-
| &lt;!--Description--&gt;ASIX AX88772 bulbous casing 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{maybe|2008 works on 32bit and 64bit though setup can take a few attempts but may have issues with phy ethernet chip changing,  }}
|-
| &lt;!--Description--&gt;Datel Wii Lan Adapter DUS0204 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;EdiMax EU-4207 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;Goodway HE2230 Maplin ASIX 88772 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;Intec LAN G5626 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;LevelOne USB-0202
| 0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;LevelOne USB-0301
| 0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{unk|2009 }}
|-
| &lt;!--Description--&gt;Linksys USB200M Rev 2
| &lt;!--Vendor ID--&gt;0x13b1
| &lt;!--Product ID--&gt;0x0018
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|2008 sparsely randomly working AX88772 or with &quot;Sana-II Meter Tool 37.11&quot; network monitoring program, showing continuous &quot;Bad Packet&quot; errors which could means &quot;CRC&quot; errors}}
|-
| &lt;!--Description--&gt;Linksys USB300M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|2009 AX88772  }}
|-
| &lt;!--Description--&gt;Mayflash W001 or clones Lupo/PEGA S-Wii-0680 light gray rectangular with third of one top 45 degree angled slope
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{unk| may have randomly changed phy ethernet chips, }}
|-
| &lt;!--Description--&gt;Max Value MVF00446 ASIN B006EG568A 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{Maybe|Trident prefs recognises as AX88772 sometimes works on 32bit and 64bit}} 
|-
| &lt;!--Description--&gt;NEWLink N14050 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;NEWLink Wii-ETH USB2.0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nintendo Wii LAN Adaptor 2110566 and clones 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{Maybe|Poseidon recognises as AX88772 with usbasixeth.device sometimes works seems different ethernet phy chips can be matched affecting compatibility}} 
|-
| &lt;!--Description--&gt;Nyko Wii Net Connect 87024
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585624&amp;postcount=22 works] }}
|-
| &lt;!--Description--&gt;0Q0 cable ethernet
| &lt;!--Vendor ID--&gt;0x1557
| &lt;!--Product ID--&gt;0x7720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB2-E100 (2009/2010) Bulbous housing 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{Maybe|Trident prefs recognises it as ax88772A and typing in usbasixeth.device sometimes works}}
|-
| &lt;!--Description--&gt;Sabrent KINAMAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SpeedLink SL-3401-SGY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;UGreen 20254 USB2 to 10/100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| AX88772}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Afunta Apple-style White USB2.0 I/O Crest SY-ADA24005 ASIX Electronics Corp. AX88772A Fast Ethernet Adapter 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{no|usbasixeth.device accepted by network prefs but does not work}}
|-
| &lt;!--Description--&gt;Amazon Basics USB 2.0 AX88772A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Digitus DN-10050-1
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;0x0 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Edimax EU-4230  
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sabrent KINAMAX NT-USB20 AX88772A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt; AX88772B USB 2.0 to 10/100M 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EdiMax EU-4208 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt;0x772b
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{No|Detected but not working}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB2100 ASIX AX88772C 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.asix.com.tw/en/product/USBEthernet/High-Speed_USB_Ethernet/AX88772D AX88772D]
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.asix.com.tw/en/product/USBEthernet/High-Speed_USB_Ethernet/AX88772E AX88772E]
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;AX88178 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2004 }} 
|-
| &lt;!--Description--&gt;Plugable USB2-E1000 i.e. USB 2.0 to Gigabit Ethernet 10/100/1000 LAN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 ASIX AX88178 Controller and Realtek RTL8211CL PHY}}
|-
| &lt;!--Description--&gt;AX88178A USB 2.0 to 10/100/1000M Gigabit Ethernet controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2005 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AmazonBasics USB3.0 adapter [https://github.com/nothingstopsme/AX88179_178A_Linux_Driver AX88179] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cable Matters SuperSpeed USB 3.0 RJ45 adapter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hori Nintendo Switch 1 USB3 ethernet AX88179 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 AX88179 not binding to asixeth.class }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB3-E1000  
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2020 ASIX AX88179 not binding to class, USB 3.2 Gen1 to Gigabit Ethernet controller with integrated 10/100/1000Mbps Gigabit Ethernet PHY}}  
|-
| &lt;!--Description--&gt;Plugable AX88179 = [https://plugable.com/products/usb3-e1000-deal USB3-E1000] before mid-2023 or USB3-E1000; AX88179A = USBC-E1000 after mid-2023
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022  controller is AX88179 phy is ??, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000SPTW ax88179 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| AX88179 not binding to asixeth.class, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000NDS AX88179 USB-A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech US1GC301AU AX88179 USB-c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech US1GC30B2 AX88179A USB-c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB32000SPT AX88179A USB-c Rev 1 (AX88179) Rev 2 (AX88179A) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;USB32000SPT the Lot code sticker will have a bar code accompanied by a 10 digit number. The 5th and 6th digits of this lot code number would signify the revision. (Ex. xxxx02xxxx which would indicate rev. 2)
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SYBA SY-ADA24029 Gigabit AX88179 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} may depend on the PHY chip connected to the controller chipset
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TP-Link UE306 AX88179 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TeckNet® Orico UL677G 10/100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TeckNet® UL688G USB 3.0 10/100/1000 Base-T Ethernet port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;AX88179 178A 
|-
| &lt;!--Description--&gt;Tecknet UL699G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v6 
| &lt;!--Vendor ID--&gt;0x07b8
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|no support }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;uGreen 50922 USB3-A to 100/1000 dark grey rounded barrels 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| ax88179 not binding to asixeth.class, }}
|-
| &lt;!--Description--&gt;UGreen USB3-C to 100/1000 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;uGreen CR111 20256 usb3 a black plastic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| AX88179}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;  AX88179A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB3-E1000 USBC-E1000 after mid-2023 i.e. AX88179A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000SPTB 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  AX88179A USB-A, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;  AX88179B
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


==USB  &amp;rarr; SerialPort Converter==

*2002 some support for early revisions of PL2303 
*2005 Prolific PL2303H PL-2303X and Pl-2303HX (same usb ids as pl2303) no support 
*2025 FTDI 232R [https://www.arosworld.org/infusions/forum/viewthread.php?thread_id=1135&amp;highlight=232r&amp;rowstart=20 work in progress] 
*2026 CDC-ACM i.e. Serial port over USB standard 

serialpl2303.class make sure you specify serialpl2303.device or Echo &quot;Test&quot; &gt;SER1: 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| ATEN UC-232A 
| 0x0557 
| 0x2008 
| Full 0x0300
| {{N/A|untested}}
|- 
| IOGear GUC232A 
| 0x0557  
| 0x2008 
| Full 0x0110
| {{N/A|untested}}
|- 
| Alcatel 
| 0x11f7 
| 0x02df 
|
| {{N/A|untested}}
|- 
| BAFO BF-810 
| 0x067B  
| 0x2303 
| 0x0
| {{N/A|untested}}
|- 
| Belkin F5U103 
| 0x
| 0x
| 0x0
| {{N/A|untested}}
|- 
| Davibe SP611 
| 0x067B 
| 0x2303 
| 0x0 
| {{N/A|untested}}
|- 
| Dcu10 
| 0x0731
| 0x0528
| 
| {{N/A|untested}}
|- 
| Elcom 
| 0x056e
| 0x5003
| 
| {{N/A|untested}}
|- 
| IOData 
| 0x04bb 
| 0x0a03 
| 0x0
| {{N/A|untested}}
|- 
| Itegno 
| 0x0eba
| 0x1080
| 
| {{N/A|untested}}
|- 
| Nokia CA42 
| 
| 
| 
| {{N/A|untested}}
|- 
| Radioshack 
| 0x1453
| 0x4026
| 
| {{N/A|untested}}
|- 
| Ratoc 
| 0x0584
| 0xb000
| 
| {{N/A|untested}}
|- 
| Samsung 
| 0x04e8
| 0x8001
|
| {{N/A|untested}}
|- 
| Siemens DCA-510 
| 0x067B 
| 0x2303 
| 0x0 
| {{N/A|untested}}
|- 
| Sitecom CN104
| 0x6189
| 0x2068
|
| {{N/A|untested}}
|- 
| Sitecom CN116 
| 0x6189
| 0x2068
|
| {{N/A|untested}}
|- 
| Some Cut Ma620 
| 0x0df7
| 0x0620
| 
| {{N/A|untested}}
|- 
| Speed Dragon Multimedia MS3303H 
| 
| 
| 
| {{N/A|untested}}
|- 
| Syntech 
| 
| 
| 
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Tripp 
| 0x2478
| 0x2008
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Airlink101 AC-USBS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Belkin F5U103v
| 0x067B  
| 0x2303 
| 0x0
| {{no|no driver }}
|- 
| Dynamode U232-P9
| 0x067B
| 0x2303
| 300
| {{no| no driver [http://koti.mbnet.fi/lonnberg/pl2303x.html linux patch] and using lsusb -v -d 067b:2303 gave bMaxPacketSize as 64 - pl2303x }}
|- 
| Konig CABLE-146/2 USB to RS232 
| 0x067b
| 0x2303
| 400
| {{no|no driver }}
|-
| MANHATTAN 205146 USB to Serial Converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|- 
| Sabrent SBT-USC1M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Trendnet TU-59
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Unbranded black case and lead USB 232 Converter
| &lt;!--Vendor ID--&gt;0x067B
| &lt;!--Product ID--&gt;0x2303
| &lt;!--Revision--&gt;0300
| &lt;!--Opinion--&gt;{{No| }}
|-
|}


[http://www.ftdichip.com/index.html Future Technology Devices International Ltd FTDI]-FT232R.class [https://ftdichip.com/software-examples/code-examples/c-builder/ FTProg src], [http://rtr.ca/ft232r/ ft232r src], [https://ftdichip.com/wp-content/uploads/2020/08/DS_FT232R.pdf FT232R datasheet], [], 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt;0x6001 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} [https://www.youtube.com/watch?v=1GE-gKgHxZI beware of cheap clones fake with s/n A50285BI SN]
|-
| &lt;!--Description--&gt;Lynx Astro FTDI 
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232R 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Sabrent CB-FTDI
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver TTL-232R cables use FTDI's [http://n1mm.hamdocs.com/tiki-index.php?page=USB+Interface+Devices FT232RQ ic device] }}
|-
| &lt;!--Description--&gt;Startech.com 1 Port FTDI USB to Serial RS232 DB9M Adapter Cable with COM Retention ICUSB2321F 
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232RL Chipset
|-
| &lt;!--Description--&gt;StarTech.com 2 Port FTDI USB to Serial RS232 Adapter Cable ICUSB2322F
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FTDI FT2232D Chipset
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232RL is the SSOP-28 and the FT232RQ is the QFN-32 package option 
|}


[https://www.onetransistor.eu/2017/08/ch341a-mini-programmer-schematic.html ch341a.class] 

*I2C EEPROMS (3.3V and 5V) compatible and also SPI FLASH memories (3.3V devices) making sure 1.8V is covered  
*each having their own [https://winraid.level1techs.com/t/guide-how-to-use-a-ch341a-spi-programmer-flasher-with-pictures/33041 4x2 connection blocks] using [https://github.com/flashrom/flashrom flashrom] 

 sudo flashrom --programmer ch341a_spi -r backup.bin
 sudo flashrom --programmer ch341a_spi -w &lt;new bios name&gt;

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Jiangsu QinHeng Ltd CH341A emulate UART communication, standard parallel port, memory parallel port and synchronous serial (I2C, SPI) 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x5512
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;QinHeng USB2.0-Serial HL-340 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x7523
| &lt;!--Revision--&gt;0252
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|}


==simplemidi.class and CAMD==

Currently support includes 

* simplemidi.class SimpleMidi maps some keyboard keys to corresponding computer keys as used by music trackers to emulate a musical keyboard 
* camdusbmidi.class follows the rules of the m68k implementation of Commodore's CAMD midi specification and usb class compliant 

for 

* usb host like a computer 
* usb device controllers - keyboards, drum machines, djay turntables, grooveboxes, etc 
* interfaces - cables or boxes which convert usb to 5pin DIN plug midi 


What is needed is a fully class-compliant '''brand name''' USB MIDI keyboard, especially manufactured in the last 10 years are best 

*Arturia
*Novation
*M-Audio
*Akai

Plugging this in one of your USB ports, the camd.library will make the keyboard's MIDI IN/OUT ports available in the system. 

Then select the keyboard's MIDI IN port (known as a &quot;cluster&quot; in CAMD) for input, and the software instrument's cluster as output 


ShowCluster (shows midi ports available in and out)

MidiWatch (usually port usbmidi.in.0 less often usbmidi.out.0) (Ctrl-C to end output stream) 
 usbmidi.in.0 Message on channel 01, NoteOn  90  39  08  00
 usbmidi.in.0 Message on channel 01, NoteOff 80  39  00  00

MidiThru (forwards messages from one port to another)
 run &gt;nil: c:midithru usbmidi.out.0 usbmidi.out.2 

MidiSendC (sends a middle C to a specific port)


Midi Controller + Sound Module (together aka as a synth) -&gt; Audio Output 


The difference between midi and midi over USB is that in old school Midi the transmitter transmits whenever it wants and the receiver always has to be prepared to receive data. Easy to do at the rate of a 1990's modem speed these days.

USB over midi.. turns midi into a polled protocol.. So the USB host (typically the computer) has to ask &quot;do you have anything for me&quot; before the remote will send. If the USB host gets busy doing other things or there is a lot of things on the USB bus to get polled, you can get delays.

For its age midi is still a great protocol for music

* [https://www.usb.org/sites/default/files/midi10.pdf USBIF's &quot;USB Device Class Definition for MIDI Devices&quot; document, version 1.0 from Nov 1, 1999]
* [https://www.usb.org/sites/default/files/USB%20MIDI%20v2_0.pdf MIDI v2.0 from 2020 which AROS still needs, adds support for MIDI 2.0, MIDI-CI, and Universal MIDI Packet] 

Nearly all synthesizers now use the 16 MIDI channels available on a MIDI bus in one instrument alone, requiring multiple MIDI busses in a typical setup with more than
one MIDI instrument. In addition, by handling multiple &quot;virtual&quot; cables, USB offers a solution to go beyond MIDI's 16-channel limit. 

MIDI data is transferred over USB using 32-bit USB-MIDI Event Packets. These packets provide an efficient method to transfer multiple MIDI streams with fixed length messages. The 32-bit USB-MIDI Event Packet allows multiple &quot;virtual MIDI cables&quot; routed over the same USB endpoint. This approach minimizes the number of required endpoints. It also makes parsing MIDI events easier by packetizing the separate bytes of a MIDI event into one parsed USB-MIDI event. 


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Computer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{Yes|which acts as USB midi host to get all usb devices talking together}} 
|-
| &lt;!--Description--&gt;Hobbytronics usb host standalone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;bomebox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;raspberry pi with several midi interface(s) and linux scripting 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Kenton MIDI USB Host mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acorn Instruments Masterkey 49 device 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 untested usb powered 5V regulated - similar keybed to keystation 49es but unplug then re-plug the USB cable while it is powered the device might reconnect 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Akai SynthStation 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 - sticky rubber keys - usb 
|-
| &lt;!--Description--&gt;Akai MPK Mini Laptop Production Keyboard 
| &lt;!--Vendor ID--&gt;0x09e8
| &lt;!--Product ID--&gt;0x007c
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected and camd usb to use, not tested with apps}}
| &lt;!--Opinion--&gt;2010 25 mini key self powered by mini USB lead - sustain port - no top left corner joystick - tested icaros 2.3 -  
|-
| &lt;!--Description--&gt;Akai LPK25 LPK37 LPK49 Laptop Production Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }}
| &lt;!--Opinion--&gt;2012 untested velocity sensitive mini keys with synth action - weak mini USB port - latency issues -  
|-
| &lt;!--Description--&gt;Akai Professional APC Key 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;Akai MPK49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2012 untested 49 key 49-key full-sized, semi-weighted keyboard with aftertouch - 
|-
| &lt;!--Description--&gt;AKAI Max25 MAX49 control keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }} 
| &lt;!--Opinion--&gt;2014 usb compliant 
|-
| &lt;!--Description--&gt;Akai Professional MPK249 MPK261 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}} 
| &lt;!--Opinion--&gt;2015 USB2 USB-b - full keys semi-weighted aftertouch - midi in out - sustain and peddle port 
|-
| &lt;!--Description--&gt;Akai Professional Advance 49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 
|-
| &lt;!--Description--&gt;Akai MPK Mini MKII MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2017 untested USB2 USB-b midi connection only - 4 way thumb joystick top left - 25 tiny keys - velocity drum pads - plastic build quality - 
|-
| &lt;!--Description--&gt;AKAI Professional APC Key 25 MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| driver}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;Akai MPK Mini Play
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 untested USB2 USB-b midi connection only - synth basic samples - class compliant? - small led display top centre - 25 mini keys - press and hold the &quot;Prog Select&quot; button then use the &quot;Program&quot; knob to assign a MIDI channel - 
|-
| &lt;!--Description--&gt;Akai MPK Mini 3 MKIII MK3 
| &lt;!--Vendor ID--&gt;0x09E8
| &lt;!--Product ID--&gt;0x1049 
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class -  - midi in out untested - }}
| &lt;!--Opinion--&gt;2021 USB2 USB-b midi controller connection no 5pin legacy - small led display top centre - 25 mini keys goofy uneven feel of the akai keyboards - press and hold the &quot;Prog Select&quot; button and press pad 1 to 8 to assign a MIDI channel - tested on AROS One 2.4 usb
|-
| &lt;!--Description--&gt;Akai Force / MPC One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Akai Pro MPK Mini Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2023 untested 37 mini keys - class compliant device - usb-b bus powered only with 5pin midi in and out - Shift and Global for Midi Ch - 
|-
| &lt;!--Description--&gt;Akai Pro Ableton Push Mk 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Akai Professional MPC Key 37 49 61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2023 untested USB2 usb-b
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Alesis Photon PH-25 X25 Midi &amp; USB keyboard/synth
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2005 midi keyboard controller  
|-
| &lt;!--Description--&gt;Alesis Q25 Q49 Q61 Q88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2014 untested 
|-
| &lt;!--Description--&gt;Alesis Coda Pro Portable 88-Key Digital Piano USB MIDI Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 
|-
| &lt;!--Description--&gt;Alesis V25 V49 V61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;Alesis V Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Alesis VI49 VI61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Alesis VX49 VX61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 1 5-pin MIDI input, 1 5-pin MIDI output, 1 USB port,
|-
| &lt;!--Description--&gt;Alesis Q25 Q49 Q61 Mk2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Alesis Recital 88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;Alesis V25 V49 V61 MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022
|-
| &lt;!--Description--&gt;Alesis Qmini portable 32-key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;audiothingies MicroMonsta 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested synth - 
|-
| &lt;!--Description--&gt;audiothingies MicroMonsta 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019  synth - 
|-
| &lt;!--Description--&gt;Arturia Analog Experience “The Player” USB MIDI Master Keyboard Model APE25
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 usb-b bus powered - 
|-
| &lt;!--Description--&gt;Arturia MiniLab Mk1
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2013 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia MiniLab MkII Mk2
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia Keystep 32 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2016 untested 32 mini keys  usb compliant 
|-
| &lt;!--Description--&gt;Arturia KeyLab 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2017 untested hammer-action Fatar keybed - reset Press and hold Oct + and Oct – buttons then insert the USB cable - 
|-
| &lt;!--Description--&gt;Arturia MiniLab mkII
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt;0x2209 
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class -  - midi in out untested - }}
| &lt;!--Opinion--&gt;2017 USB2 usb-b bus power - metal base heavier than most - Shift and press a key to select the MIDI Channel - To reset to original factory, unplug the USB cable, hold down the Oct- and Oct + buttons, plug the USB cable back in and continue to hold the buttons until the pads turn white - need software to change parameters like velocity sensitive assistance - 
|-
| &lt;!--Description--&gt;Arturia KeyLab MK2 MKII 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }}
| &lt;!--Opinion--&gt;2017 untested hammer-action Fatar keybed 
|-
| &lt;!--Description--&gt;Arturia MicroFreak
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019 hybrid digital/analog synthesis, 
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=PeYIAfn3UMs Arturia Minilab 3] 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2020 untested usb-c bus powered - 25 mini keys semi - 
|-
| &lt;!--Description--&gt;Arturia Keystep Pro 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;Arturia MiniLab 3 Mk3
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2022 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia MiniFreak
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2022 
|-
| &lt;!--Description--&gt;Arturia KeyLab Essential 49 61 88 mk3 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested usb-c and 1 midi out - lack of aftertouch - 
|-
| &lt;!--Description--&gt;Arturia AstroLab 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;Arturia KeyLab MK3 MKIII 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2025 untested hammer-action Fatar keybed 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer UMX61
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe|untested}}
| &lt;!--Opinion--&gt;2007 
|-
| &lt;!--Description--&gt;Behringer U-Control UMX490 UMX610 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Behringer U-Control 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer Swing 32-Key
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer MOTOR 49 - 49-Key USB/MIDI Master Controller Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Creative EMU Xboard 25 E-MU X-Board 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|untested}}
| &lt;!--Opinion--&gt;2008 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;CME M-Key Mkey 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2008 stops sending MIDI on a regular basis. The simplest &quot;fix&quot; is to flip it off and on via the power switch at the back
|-
| &lt;!--Description--&gt;CME Ukey U-Key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2009 
|-
| &lt;!--Description--&gt;CME Xkey 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 low-profile aluminium  full size pressure sensitive with polyphonic aftertouch but keys make too much noise and that they can be too sensitive to velocity - low power draw 25ma 
|-
| &lt;!--Description--&gt;CME M-Key 49 V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 simplified version of the U-key Mobiltone 
|-
| &lt;!--Description--&gt;CME XKEY AIR 37
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019
|-
| &lt;!--Description--&gt;cme xkey 37 le
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Donner Spaceline DMK-25 Donnerdeal Rantion 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Donner DMK25 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;  25 mini velocity keys with limited aftertouch - usb-c powered - 8 drum pads - 3.5mm &quot;midi out&quot; socket - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Digitakt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 expensive later midi usb class compliant with since 1.5 Update
|-
| &lt;!--Description--&gt;Elecktron Digitone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Digitone Keys 37-key Digital FM Synthesizer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2018 expensive 
|-
| &lt;!--Description--&gt;Elektron Analog Four MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Octatrak MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 49+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 25xt
| &lt;!--Vendor ID--&gt;0x2702 
| &lt;!--Product ID--&gt;0x2702
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected and usb driver working}}
| &lt;!--Opinion--&gt;2011 bus powered or 12v 0.5a dc in - metal base so heavy - midi out 5pin - sustain pedal port - modulation slider - rubber coated knobs becomes sticky - 
|-
| &lt;!--Description--&gt;ESI keycontrol 49xt 61xt 88xt 
| &lt;!--Vendor ID--&gt;0x2702
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected}}
| &lt;!--Opinion--&gt;2011 12v 0.5a center pin +ve external psu required - USB i/o and 1 legacy 5pin out - full sized keys - heavy aluminium case keyboard metal base - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Evolution MK-125 MK-149
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2000 9v 
|-
| &lt;!--Description--&gt;Evolution MK-225C MK-249C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 9v 
|-
| &lt;!--Description--&gt;Evolution USB/Midi Controller MK-425C MK-449C MK-461C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|25, 49, 61 keys -  }}
| &lt;!--Opinion--&gt;2006  9V or 12V - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 37 full keys 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys Pro Mobile
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 25 or 37 mini keys 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 mini velocity keys no aftertouch - 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 2 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 full velocity keys no aftertouch - 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Kawai VPC 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; weighted keys - heavy build - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Keith McMillen Instruments K-Board
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; omni class compliant to all channels? each keypad makes them velocity, pressure, and location sensitive but  not really suited for piano playing 
|-
| &lt;!--Description--&gt;Keith McMillen  BopPad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; omni class compliant to all channels? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg NanoKontrol 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;mini usb
|-
| &lt;!--Description--&gt;Korg Prophecy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;KORG microKONTROL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010
|-
| &lt;!--Description--&gt;Korg microKEY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2011 velocity-sensitive Natural Touch keys but  joystick is an alternative to the common pitch/modulation wheel design - power draw - 
|-
| &lt;!--Description--&gt;Korg nanoKey nanoPad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 
|-
| &lt;!--Description--&gt;Korg Taktile 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg microKEY2 25 37 49 61 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|2015 untested}}
| &lt;!--Opinion--&gt;2015 USB powered - semi weighted - 
|-
| &lt;!--Description--&gt;Korg MiniList 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg MinKey nanoPad nanoPad 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Nautilus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Kurzweil PC3 7 series - Artis 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}} 
| &lt;!--Opinion--&gt;fatar TP-8 semi-weighted action  
|-
| &lt;!--Description--&gt;Kurzweil PC1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Kurzweil PC3 A8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Line 6 Mobile keys 25
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Line 6 POD Studio KB37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Line 6 Tone Port KB37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Midiman (later M-Audio) Oxygen8 Ozone Ozonic 25 32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|not class compliant - untested 5pin legacy }}
| &lt;!--Opinion--&gt;2002 2004 untested - 25 full keys - slider/fader to left of lcd display - 
|-
| &lt;!--Description--&gt;m-audio oxygen keystation (61 key) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;M-Audio eKeys 37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;M-Audio Axiom 25, 49, 61
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 bus powered and 12v psu - if sliders/faders are on right - legacy midi 5pin - chunky unit -
|-
| &lt;!--Description--&gt;M-Audio Oxygen 8v2, 49, 61 (silver) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 full size velocity sensitive 12v psu - sending random pitchbend info - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 37e 49e, 61e MK1 MKI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 - ok key action - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 37es 49se 61es, 88es MK1 MKI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 - 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25/49/61/88 (blue) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 [https://m-audio.com/products/view/oxygen-25-legacy advised Class-compliant and GM/GM2/XG SysEx messages] with full size velocity sensitive 12v psu - sending random pitchbend info - 
|-
| &lt;!--Description--&gt;M-Audio Axiom 25, 49, 61 (2nd Gen) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 semi-weighted mini keys - bus powered and 9v psu for 25/49 and 12v for 61 - if sliders/faders are on left - legacy midi 5pin - chunky unit - 
|-
| &lt;!--Description--&gt;M-Audio Axiom Pro 25, 49, 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 poor construction 
|-
| &lt;!--Description--&gt;MAudio Axiom AIR 25 M-Audio Axiom Air Mini 32
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25 III (3rd Gen) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 untested - usb only - rubber keys sticky - 
|-
| &lt;!--Description--&gt;MAudio Keyrig 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Keystation Mini 32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 - mini usb - plays a few notes and then stops responding randomly - try plugging it into port 1 or 2 on your pc - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 49 MK2 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 USB port and class compliant
|-
| &lt;!--Description--&gt;M-Audio Keystation 61 MK3 MKIII MIDI keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 usb compliant untested 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25 IV
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2016  choice 
|-
| &lt;!--Description--&gt;M-Audio CTRL-49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;M-Audio ProKeys 88, 88sx 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Keystation Mini 32 MK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019 mini usb - some power or incompatibility issue with the native USB ports of the laptop, plugged in a passive USB 2.0 HUB (not USB 3.0, not powered)
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=3328SvuJsLw M-Audio Oxygen25 MKV]
| &lt;!--Vendor ID--&gt;0x0763
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;0023
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class  - midi in out untested}}
| &lt;!--Opinion--&gt;2020 25 full size semi keys - USB2 usb-b but no 5pin classic plugs - channel select SHIFT button and CHANNEL on keybed - plastic build - holding down both the Octave + and - for factory reset -  more limited in what you can do with it than IV 4th one - tested on AROS One 2.4 usb
|-
| &lt;!--Description--&gt;M-Audio Oxygen Pro 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 untested semi full keys 
|-
| &lt;!--Description--&gt;M-Audio Oxygen Pro Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested - 32 smaller keys - not endless encoders - usb only - 
|-
| &lt;!--Description--&gt;M-Audio Hammer 88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Moog 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Moog Minitaur 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-VAVE SMK-25mini 25key MIDI Control Keyboard Y6I0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Native Instruments NI Primus A25 JamMate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2008 not compliant, 
|-
| &lt;!--Description--&gt;Native Instruments Maschine MK1 MKI
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2009 not compliant uses snd-usb-caiaq module, 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol S88 S61 S49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 - weighted keys - 
|-
| &lt;!--Description--&gt;Native Instruments Maschine MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe compliant, 
|-
| &lt;!--Description--&gt;Native Instruments Maschine Micro Mikro MK2 MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe? 
|-
| &lt;!--Description--&gt;NI Komplete Kontrol S49 S61 S88 MkII MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 all MK2 MK3 power up the keyboard using USB, it will set the keyboards MIDI port to computer MIDI only without any option to set it to use the MIDI DIN, meaning you cannot connect the keyboard to hardware and power from USB, you MUST power with the power adapter and physically unplug from any USB connection - 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol A25 A49 A61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe compliant,  
|-
| &lt;!--Description--&gt;[https://github.com/sikorak666/maschine-mikro-mk3-driver Native Instruments Maschine Micro Mikro Plus MK3 MKIII]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol M32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 untested 32 smaller keys - no drum pads - USB only - 
|-
| &lt;!--Description--&gt;NI Komplete Kontrol S49 S61 S88 MkIII MK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;NI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2025 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Neusonik iBoard 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nektar Impact LX25+ LX49+ LX61+ LX88+ SE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 budget full-size velocity-sensitive synth-action keyboard - 
|-
| &lt;!--Description--&gt;Nektar Impact GX49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; USB port - 
|-
| &lt;!--Description--&gt;Nektar Panorama P4 P6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  USB &amp; USB Micro B, 5-pin MIDI out, 2 x TRS inputs with 49 semi-weighted, velocity sensitive with aftertouch
|-
| &lt;!--Description--&gt;Nektar SE25 SE49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; mini keys - micro usb bus powered - velocity and sustain button 
|-
| &lt;!--Description--&gt;Nektar Panorama P6 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nektar Panorama T6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nord Stage 3 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; sysex 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Novation ReMote 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 lhs XY touchpad and the joystick -
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 49 61 88 Mk1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 not USB class compliant 
|-
| &lt;!--Description--&gt;Novation 49 61 SL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 semi-weighted Fatar TP-8 or TP-9 keybed
|-
| &lt;!--Description--&gt;Novation ReMote 25SL 49SL 61SL soft label 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 - two long top liquid-crystal display LCD strips - XY touchpad and the joystick - 
|-
| &lt;!--Description--&gt;Novation ReMOTE 25LE 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;0001
| &lt;!--CAMD--&gt;{{Yes|detected, usb driver in devs/midi for camd to use}}
| &lt;!--Opinion--&gt;2007 USB-b powered, 9v center pin positive or 6 MN1500 AA batteries - X/Y touchpad and the combined pitch and modulation joystick - no aftertouch but can use both the legacy MIDI OUT and USB port simultaneously 
|-
| &lt;!--Description--&gt;Novation Nocturn 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Unk| }} 
| &lt;!--Opinion--&gt;2008 untested sending random pitchbend info
|-
| &lt;!--Description--&gt;Novation 49 61 SL MkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 semi-weighted Fatar TP-8 or TP-9 keybed 
|-
| &lt;!--Description--&gt;Novation MiniNova 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2013 
|-
| &lt;!--Description--&gt;Novation Impulse 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 velocity aftertouch‑sensitive semi-weighted keyboards and eight backlit pads -  USB, 5-pin MIDI out - 
|-
| &lt;!--Description--&gt;Novation Circuit Tracks / Rhythm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 untested 
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 49 61 88 MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 USB class compliant - full keys - 
|-
| &lt;!--Description--&gt;Novation Launchpad Mini MK2 MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested 8x8 buttons with 16 backlit
|-
| &lt;!--Description--&gt;Novation LaunchKey Mini MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 untested - 25 soft mini keys - 2 rotary wheels lhs - 
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 37 49 61 88 MK3 MKIII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 USB class compliant choice - full keys - 
|-
| &lt;!--Description--&gt;Novation LaunchKey Mini MK3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested - 25 soft mini keys - 2 sliders lhs -  
|-
| &lt;!--Description--&gt;Novation 61SL Mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Nymphes Dreadbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; 6 voice analog synth
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Oberheim MC 2000 EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 88 keys fully weighted - very heavy - 
|-
| &lt;!--Description--&gt;PreSonus ATOM SQ Hybrid MIDI Keyboard/Pad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://polyend.com/tracker/ Polyend Tracker]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland ED PC-300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2002 USB MIDI keyboard controller 49-key
|-
| &lt;!--Description--&gt;Roland EDIROL PCR-M30 PCR-M50 PCR-M80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;Roland Edirol PCR-30 PCR-50 PCR-80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 untested 32 key - 
|-
| &lt;!--Description--&gt;Roland PC-50 PC-80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 
|-
| &lt;!--Description--&gt;Roland PCR-500 PCR-800
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 61 velocity-sensitive keys with aftertouch 
|-
| &lt;!--Description--&gt;Roland A-88 a-49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 USB port - weighted keys velocity no aftertouch - class compliant with press FUNCTION so it is lit. Press the key labelled &quot;ADV.&quot;, Press the &quot;+&quot; button so it is lit - 
|-
| &lt;!--Description--&gt;Roland PC-200 mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 some had fatar keys 
|-
| &lt;!--Description--&gt;Roland MC-707 Groovebox
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 
|-
| &lt;!--Description--&gt;Roland MC-101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 untested 
|-
| &lt;!--Description--&gt;Roland A-500 A500Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Roland A-300 A300Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Roland JUNO DS, FA, Fantom, JUPITER X / Xm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 (be sure that USB driver is set to &quot;Generic&quot; - requires device rebooting) 
|-
| &lt;!--Description--&gt;Roland A-88 a-49 MKii MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 expensive with USB-c port - hammer-action keyboard weighted keys - Class-compliant if  USB-C enables bus power - MIDI 2.0 later - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ROLI Seaboard RISE 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Samson Graphite 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Samson Carbon 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Sequential TAKE 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic VMK-161 and VMK-161 Plus Organ version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;TP-8O action is the unweighted, organ-style waterfall keybed - usb midi in out - 9v psu - 
|-
| &lt;!--Description--&gt;Studiologic SL990XP midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic VMK176 Plus
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;USB and midi connectivity
|-
| &lt;!--Description--&gt;Studiologic SL880 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic SL73 SL88 Studio midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; hammer-action Fatar TP semi-weighted keys 
|-
| &lt;!--Description--&gt;Studiologic Numa Organ 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 73 key TP-8O action is the unweighted, organ-style waterfall keybed used in nearly all clonewheels 
|-
| &lt;!--Description--&gt;Studiologic Numacompact 2/2x, Numa X Piano
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero CommandKey49 CommandKey25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero SZ-MiniCommand Mini-Command USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero SPC61 MIDI Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; bus powered - 5 octave 
|-
| &lt;!--Description--&gt;SubZero ControlKey49S 49 Key Slim MIDI Controller Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Synido TempoKey K25
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 25 mini keys - usb-c powered 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Worlde Panda 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha KX8 KX49 KX61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2008 not compliant 
|-
| &lt;!--Description--&gt;Yamaha CMC-PD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Yamaha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 not class compliant 
|-
| &lt;!--Description--&gt;Yamaha P45B P-45 Digital Piano 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2011 not compliant 
|-
| &lt;!--Description--&gt;Yamaha P-115 midi controller  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested weighted keys - USB midi port 
|-
| &lt;!--Description--&gt;Yamaha MX49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 should compliant untested 
|-
| &lt;!--Description--&gt;Yamaha Montage, CP73/88, YC, MODX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi keyboard controller 
|-
| &lt;!--Description--&gt;Yamaha PSR-E353, PSR-E443
PSR-S670, PSR-S770, PSR-S970, PSR-A3000, TYROS-5
NP-12, NP-32
DGX-650, DGX-660
P-105, P-115, P-255
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha MX49 II V2 Black Blue 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;DJM V10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; dj 
|-
| &lt;!--Description--&gt;Native Instruments Kontrol DJ Pro midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; detected but untested 
|-
| &lt;!--Description--&gt;Numark Mixtrack Pro II USB DJ Controller Djay 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;older generation pioneer DDJ-SX2 dj 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Alyseum AL-22 AL22c  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alyseum AL-88 Schneidersladen AL88c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alyseum U3-88c Midi Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; no CopperLan support Midi network using a UTP Ethernet patch cable) 
|-
| &lt;!--Description--&gt;Behringer BCF2000 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[http://www.behringer.com/EN/home.aspx Behringer] BCR2000 1in 2out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer B-CONTROL DEEJAY BCD3000 DJ Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer UMD404 UMD202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Creative EMU 0404/USB midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;DigiDesign / Focusrite Command 8 Control Surface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005 supports MIDI continuous controller (CC) and note data. SysEx dumping and loading is also supported  
|-
| &lt;!--Description--&gt;Digidesign Digi 002
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006   firewire only 
|-
| &lt;!--Description--&gt;Digidesign Digi 003
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2009   firewire only 
|-
| &lt;!--Description--&gt;emagic m4 2x4 AMT8 Unitor 8 Mk2  8x8 
| &lt;!--Vendor ID--&gt;0x00d0
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;0x010 0x0103
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2000 offers MTS (Midi Time Stamping) - 12v 2a psu centre pos - usb mini with rs232 and rs422 serial ports - 16 channels (8-in / 8-out), this rack-mountable unit - 
|-
| &lt;!--Description--&gt;Evolution U-Control UC-16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| detected}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Focusrite Saffire 6 USB 1.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Guillemot Maxi Studio ISIS Vintage Sound Card MIDI Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;1998 
|-
| &lt;!--Description--&gt;[http://www.ucapps.de/mbhp_usb.html MidiBox] Hardware Platform USB Module
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Mackie Control Universal Pro XT with One Two Extenders 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2008 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Audiophile USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Midisport UNO old version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio MidiMan 1x1 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004  [http://sourceforge.net/projects/linux-hotplug/ firmware update]
|-
| &lt;!--Description--&gt;M-Audio Midisport 2x2 yellowy green blue, green or silver chassis plastic box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|MIDISPORT 2x2 or 4x4 interfaces from previous production series (blue, green or silver chassis) are not class-compliant}}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;MAudio Audiosport Quattro USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant as [http://usb-midi-fw.sourceforge.net/ firmware required and that is buggy], 
|-
| &lt;!--Description--&gt;M-Audio UC-33
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Midisport 1x1 2x2 4x4 Anniversary Edition, black box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe class compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;[http://www.amiga.org/forums/showthread.php?t=52920 Mark of the Unicorn Motu Fastlane] 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|[http://www.amiga.org/forums/showpost.php?p=560852&amp;postcount=8 not working on OS4]}} 
| &lt;!--Opinion--&gt; not class compliant, 
|-
| &lt;!--Description--&gt;Motu Micro Lite 1x1 and MOTU microlite 5x5 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt; good unit but poor just plug in support and not class compliant - USB2 usb-b - 
|-
| &lt;!--Description--&gt;Motu MIDI Express 128 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;poor support serial port only - offers MTS (Midi Time Stamping) A serial port based MIDI interface or a USB interface without MTS will have a MIDI slop of up to 2ms on record and playback. MTS provides accuracy for record and playback to around .3ms - five times more accurate than serial or non-MTS.&quot; 
|-
| &lt;!--Description--&gt;MOTU.com MIDI Express XT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;2008 for many USB should have octocoupled connection to reduce groundloop humm, usually the timing is off 
|-
| &lt;!--Description--&gt;MOTU MIDI Timepiece AV 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt; not class compliant is one of the best multi-port MIDI interfaces ever made as USB model connects to the computer as an 8x16 interface
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Native Instruments GmbH Audio 8 DJ, 4 DJ, 2 DJ
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|needs dedicated driver}}
| &lt;!--Opinion--&gt;2006 not class compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Qcon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Roland Edirol UA-100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|did not match to camdusbmidi.class USB audio midi with onboard DSP}}
| &lt;!--Opinion--&gt;1998 
|-
| &lt;!--Description--&gt;Roland Corp Edirol UM-2 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0005
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{no|is not bound via camdusbmidi.class }}
| &lt;!--Opinion--&gt;1999 not bound to any midi class - 2x2 - tested Aros One USb 2.4 
|-
| &lt;!--Description--&gt;Roland Edirol UA-100G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;1999 USB audio midi with onboard DSP 
|-
| &lt;!--Description--&gt;Roland Edirol UM-880 8x8 midi interface 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2000 under poseidon but could work with run &gt;nil: c:midithru out.0 &quot;EDIROL UM-880.out.2&quot;
|-
| &lt;!--Description--&gt;Roland Edirol UM-1 blue plastic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Unk| bound??? via camdusbmidi.class - untested midi in out}}
| &lt;!--Opinion--&gt;2000 UM-1 -  1-in/1-out (16 channels) 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1S
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2000 1-in/1-out (16 channels)
|-
| &lt;!--Description--&gt;Roland Edirol UM-2E
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2000 
|-
| &lt;!--Description--&gt;Roland Edirol UM550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1X midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|do not have the Advanced Driver Switch on them}}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1SX
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0052
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{No|do not have the Advanced Driver Switch on them}}
| &lt;!--Opinion--&gt;2003 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-2C - 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-1G 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-2G 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;[https://github.com/spotify/linux/blob/master/sound/usb/usbquirks.h Roland Edirol UA20 UA-20] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;Roland UM-1EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005
|-
| &lt;!--Description--&gt;Roland Edirol UM-2EX 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005  adds a second MIDI OUT
|-
| &lt;!--Description--&gt;Roland Cakewalk UM-3G - 3x3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Roland Cakewalk ua-25excw 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2009 not class compliant mode 
|-
| &lt;!--Description--&gt;[https://alsa.opensrc.org/Edirol_UA-25EX Roland Edirol UA55 UA-55 Cakewalk UA25 EX] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2011 not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Sonuus B2M Bass MIDI Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Sonuus G2M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Steinberg CMC Series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Subzero SZ-MB44 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Swisssonic MIDI1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2012 AmigaOS there is no output at midichannel one and two but if play a midi file there is only output on some channels and if pressed stop the prog freezes or the whole system crashes
|-
| &lt;!--Description--&gt;Teac Tascam US-428 US-422 midi interface 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 2000 not compatible 
|-
| &lt;!--Description--&gt;Teac Tascam [http://web.archive.org/web/*/http://www.tascam.com/Products/US-224.html US-224]
| &lt;!--Vendor ID--&gt;0x1604
| &lt;!--Product ID--&gt;0x8004
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 2002 does not bind to any class
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-1x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }} 
| &lt;!--Opinion--&gt;2002 
|-
| &lt;!--Description--&gt;Teac Tascam US-122 MKII midi interface 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt;0x8021
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{No|not detected / binding to camdusbmidi.class on AROS 2.4 usb }} 
| &lt;!--Opinion--&gt;2004 detected but not working 2-in/2-out USB two XLR microphone preamps with phantom power for condenser microphones 
|-
| &lt;!--Description--&gt;Teac Tascam US-200 US-400 US-600 US-800 US-1200 US-1800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|no driver}}
| &lt;!--Opinion--&gt;2010 may not be totally usb compliant 
|-
| &lt;!--Description--&gt;Yamaha UX-16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|no driver}}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Akai EIE and Pro version midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 dc 6v power - 3 USB hubs, midi in out , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alesis I/O2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 powered USB hub required, not compliant 
|-
| &lt;!--Description--&gt;Alesis IO2 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 usb compliant?
|-
| &lt;!--Description--&gt;Alesis IO4 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Behringer XTouch 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; psu needed 
|-
| &lt;!--Description--&gt;Behringer X-Touch Compact
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant?
|-
| &lt;!--Description--&gt;Behringer X-Touch Mini
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant?,  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Behringer U-Phoria UMD404HD UMD202HD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe class compliant - volume low, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;CME U2 MIDI Pro 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; current model 
|-
| Creative EMU XMIDI 1X1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 early versions with sysex checksum errors 
|-
| &lt;!--Description--&gt;Creative E-MU Xmidi 1x1 Tab (V3) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 tab version class compliant but report that when transferring 'System Exclusive' messages (SysEx) the unit could not handle the highest data rate leading to data corruption 
|-
| Creative EMU XMIDI 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 sysex errors 
|-
| &lt;!--Description--&gt;Digidesign Mbox 2 Mini now Avid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 USB powered but not compliant 
|-
| &lt;!--Description--&gt;Digidesign Mbox II Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 USB powered but not compliant 
|-
| &lt;!--Description--&gt;Engl Z7 MIDI Interface (E660/E610/E360/E930)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; guitar?
|-
| &lt;!--Description--&gt;Elektron TurboMidi TM-1 1in 1out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI MidiTerminal M4U 4x4 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;supposedly class compliant - USB bus powered - 
|-
| &lt;!--Description--&gt;ESI MidiTerminal M8U 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI MidiTerminal M4U XL 4x4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; ploytec chipset 
|-
| &lt;!--Description--&gt;ESI MidiTerminal M8U XL 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; no hardware routing e.g. x on input 5 to synth y on output 7 - ploytec chipset 
|-
| &lt;!--Description--&gt;ESI MidiMate 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; supposedly class compliant - USB bus powered 
|-
| &lt;!--Description--&gt;ESI MidiMate II 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI ROM I/O
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2005 romio version 
|-
| &lt;!--Description--&gt;ESI M4U XT
| &lt;!--Vendor ID--&gt;0x2573
| &lt;!--Product ID--&gt;0x0002
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Maybe|is bound via camdusbmidi.class AROS One 2.4  - untested midi in out}}
| &lt;!--Opinion--&gt;2010  - 
|-
| &lt;!--Description--&gt;ESI M8U XT 8in 8out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 discontinued 2018 
|-
| &lt;!--Description--&gt;ESI M8UEX USB3.0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 current model 
|-
| &lt;!--Description--&gt;ESI M4U eX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 current model 
|-
| &lt;!--Description--&gt;ESI MidiMate eX midi interface 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 curent model, well liked and might class compliant?? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;icon midiport 2x2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;iCON CubeMi 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant? 
|-
| &lt;!--Description--&gt;iConnectivity 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;iConnectivity mio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 class compliant but reported issues with sending System Exclusive (SysEx) MIDI messages and MIDI signals getting cut off 
|-
| &lt;!--Description--&gt; iConnectMidi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;iCM2 iCM4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;iConnectivity iConnectMIDI4+ L
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 class compliant?? 
|-
| &lt;!--Description--&gt;iConnectivity MioXL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;IK Multimedia iRig MIDI 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant 
|-
| &lt;!--Description--&gt;iRig Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton Electronics pro solo mk2 midi to cv converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton Midi Thru-25 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Keytech MT18E 8 Way Midi Thru box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 9 to 12v psu required 
|-
| &lt;!--Description--&gt;MidiPlus Midi 2x2 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;MidiPlus Midi 4x4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; supposedly class compliant - USB bus powered 
|-
| &lt;!--Description--&gt;MidiTech MIT-00151 Midiface 4x4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;MidiTech Midiface 4x4 8x8 16x16 thru merge 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Miditech Midilink mini 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;M-Audio Midisport UNO only if box is labeled Class Compliant and latest MIDISPORT 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Fast Track Ultra (6 in 6 out) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 not usb compliant, - 
|-
| &lt;!--Description--&gt;M-Audio Midiman Midisport 2x2 Anniversary Edition [https://gearspace.com/board/electronic-music-instruments-and-electronic-music-production/1133862-why-there-hardly-any-midi-interfaces.html not stable enough] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 USB2 usb-b - does not need firmware and supposedly plug and play - 
|-
| &lt;!--Description--&gt;M-Audio Midisport 4x4 Anniversary Edition
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; rumored does not need firmware - supposedly plug and play -  issues with its firmware for some and lacks configurable routing
|-
| &lt;!--Description--&gt;Maudio Fast Track Ultra 8R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Audio 6 Mk1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 maybe usb compliant but bus powered, 
|-
| &lt;!--Description--&gt;Nektar Midiflex 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 class compliant and usb-b powered - used as a 1 in / 3 out, 2 in / 2 out or 4 out 5pin sockets - 
|-
| &lt;!--Description--&gt;Neusonik IM-One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Peavey Xport
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; guitars only 
|-
| &lt;!--Description--&gt;Roland UM-ONE UM-1 mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 USB class compliant if switch to TAB for class compliant mode rather than the COMPUTER mode 
|-
| &lt;!--Description--&gt;Squarp Hermid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Steinberg Midex 8x8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant?  supporting MIDI Time Stamping protocol
|-
| &lt;!--Description--&gt;Swissonic MidiConnect 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Tapco LiNK.midi USB 4x4 (Loud technologies) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|dedicated driver}}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-2x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt; 2014 5v dc power, midi out in, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-4x4
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;Teac Tascam US-16x08 US-20x20
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;Zoom U-24
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi to 5pin interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi to 5pin interface 
|-
| &lt;!--Description--&gt;Unbranded cable 
| 0x552d
| 0x4348
| F110 
| &lt;!--CAMD--&gt;{{Maybe|detected but no usb driver in devs/midi for camd to use}}
| &lt;!--Opinion--&gt;detected but not working the USB-MIDI conversion functionality of the cheapo USB MIDI &quot;cable&quot; interface is simply lacking, possibly being incapable of handling MIDI strings longer than 3 bytes long SysEx strings (e.g. SysEx dumps) - tested in Icaros 2.3 - 
|-
| &lt;!--Description--&gt;USB2.0-MIDI Unbranded cable with clear braided underneath leads 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x752D 
| &lt;!--Revision--&gt;0254 
| &lt;!--CAMD--&gt;{{Maybe|detected binding to camdusbmidi.class but untested midi in / out}}
| &lt;!--Opinion--&gt;untested but better to get a branded version - tested AROS One 2.4 usb
|-
| &lt;!--Description--&gt;LogiLink USB to Midi In-Out 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|}}
| &lt;!--Opinion--&gt;untested cheap cable version but issues with latency on other systems 
|-
| &lt;!--Description--&gt; gm5 USB midi chip  DIY option only
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Doremidi LEKATO MIDI USB C Interface 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Thomann Midi USB 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;   Prodipe made 
|-
| &lt;!--Description--&gt;Prodipe MIDI 1i/1o 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|}


Classic 5pin DIN controllers for above interfaces 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Akai s5000 s6000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi digital samplers 
|-
| &lt;!--Description--&gt;Akai AX80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Casio CZ-5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Casio CZ-3000 CZ-1000 CZ-101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Cheetah MS6 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|untested}}
| &lt;!--Opinion--&gt;2000 multi-timbral, six-voice (twelve-oscillator), analogue synthesiser module is loaded with CEM 3396s 
|-
| &lt;!--Description--&gt;Ensoniq ESQ1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Integra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Wavestation Ex A/D SR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1986 ex has piano and drum sounds 
|-
| &lt;!--Description--&gt;Korg DW-8000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg DW-6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Poly 800 MK1 Poly-800ii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  all plastic and can run on batteries - 49 keys non-velocity dco synt analogue filter 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland D-50
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|1987 untested greater concern would be moisture and wear}}
|-
| &lt;!--Description--&gt;Roland A50 (76) A80 (88) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|1989 untested}}
|-
| &lt;!--Description--&gt;ROLAND JUNO-D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Roland Juno 106 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;80s kx73 or kx88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Roland ED PC-160A PC-180A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} legacy DIN5 MIDI port only - 6 AA batteries or 9v psu - One regular source of failure for me were emty batteries (even with red control light still active). Another source was a bad MIDI cable - unplug then re-plug the USB cable while it is powered the device might reconnect 
|-
| &lt;!--Description--&gt;Roland M1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland S-550 S-760 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; digital samplers kontakt replaced these? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha DX7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1983 12bit 
|-
| &lt;!--Description--&gt;Yamaha DX7S DX72IID DX7IIFD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1987 16bit versions 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
|}


The MIDI standard was published in August 1983. The inventors, Kakehashi and Smith finally received a Technical Grammy Award in 2013 for their work. 

The MIDI files that contained just the note data, velocity and timing meant you could transfer an entire studio session from one place to another on one floppy disk and it could control all the synths and drum samplers. Pass-thru meant that one computer could run an entire bands worth of instruments. 

It's bulletproof too. MIDI never goes wrong, it's always a bug in software that causes any issue - you can absolutely rely on it to go gigging with, take your synths, controllers and computers and not crash an entire gig at your 100,000 person venue. 

The MIDI hardware specification is very simple (voltage, polarity, screening, protection and a fast enough opto-isolator), it assumes that the data it sends and receives between MIDI devices is to the MIDI data standard and just passes it on. The microprocessor in the hardware does all the work.

The minimum for a computer/MIDI interface is that it meets the MIDI hardware specification. It is attached to the computer bus and handles the electrical conversions required. To meet the MIDI hardware specification, to be class compliant as a USB device all it has to do is report itself properly when plugged in.

The other half of the equation is the MIDI data standard, and for a computer MIDI interface the main issue is the speed of data transmission. The bus speed of the computer is faster than the speed of the MIDI standard so it can generate and send MIDI data faster than a MIDI device can receive it. The MIDI standards have nothing to say on that bottleneck at all. MIDI was designed to be very simple and very open, it just defines a standard for the messages and leaves it up to manufacturers to implement them in the way they want. That's what makes it so powerful a tool, and also what makes it so confusing and frustrating at times.

For midi, the hardware/software combination at various connection points handles the translation to/from midi (or other protocols). Drivers would be needed for midi, including clock and SysEx signal (actually claiming to handle ALL midi quirks transparently

All the important MIDI data types can be sent (CC, NRPN, RPN, MMC, Note On/Off, program change)

There is no official way to solve the data bottleneck. Early software sequencers and librarians tried to solve it by having an option to buffer SYSEX data in software and transmit it at the MIDI data rate. The downside is that hogs the bus and can hit computer performance. Interface manufacturers would add a hardware buffer which would take all the MIDI data from the PC bus and feed it into the MIDI at the slower data rate, but that added cost and created timing issues.

Things have moved on since then, but the principles remain the same. You can buffer in the hardware or in software, whether that is in the application or the interface driver. SYSEX will work perfectly well with that budget cable if your software handles the buffering. And while the cables with hardware buffers make SYSEX easier, they still have potential problems because of the limitations of the MIDI data rate. Your MIDI clock doesn't like being interrupted with a big program dump 

The serial / parallel ports were a direct connection, so faster. Now, everything in the computer is virtual and the only thing connected to the hardware is the kernel, hence everything is by default bottlenecked and jittery, regardless of which connection. So by the time the interface gets the information it's already too late. 

Ethernet network cable to transport MIDI over large distances, connect 2 MIDI In and 2 MIDI Out ports to patch, remap, filter and merge MIDI flows on a fine channel basis for tight MIDI throughput, latency and jitter 

Possibilities for DAWs of the future including a kind of sync reference for timing reference which an interface could sync to, hence all the timings then would be locked between the grid on the DAW screen and the MIDI info. 

Preemptible, low latency and accuracy are essential for good communication.  

One of the first things you need to do, is make sure your MIDI software sets the interface to the same MIDI channel as your keyboard (usually 1) 


Do you want to send just your master keyboard to other synths or to be able to use any keyboard with any synth?

1st option is relatively simple. Just need to send midi from your master keyboard into a midi splitter that redistributes the signal onto your synths. Each synth will be set up to receive midi on a specific channel so the only challenge is to find a way to select to which channel you are sending midi. Some master keyboards can do that although not many that have a dedicated knob or switch on the panel and most require a bit of menu diving. Could use a midi box that offers channel selection but usually this is not very workflow friendly. The software route would require using the mouse. 

2nd option is a bit more complex but superior workflow by sending midi messages into a merge box, from there into a hardware sequencer that allows to select midi channel, then on to a midi interface that distributes the signal to the synths. 

Master keyboard MIDI-in to computer. External hardware sampler MIDI-out from computer. Audio-out from sampler to audio-in on computer/device. 


Blue Ribbon Soundworks Bars &amp; Pipes Professional (1993/4) 

GM (1984), GS (1987), XG level 1-3 (1994-1997), GM level 2 (1999) 	

GM GM1 imposes several requirements beyond the MIDI 1.0 specification. While MIDI 1.0 by itself provides a communication protocol which ensures that different instruments can interoperate at a fundamental level e.g sound modules. GM goes further in two ways. First, GM requires that all compliant MIDI instruments meet a certain minimal set of features, such as being able to play at least 24 notes simultaneously (polyphony). Second, GM attaches specific interpretations to many parameters and control messages which were left unspecified in the MIDI 1.0 specification. A minimum of 128 MIDI Program Numbers (conforming to the GM 1 Instrument Patch Map) and 47 percussion sounds (conforming to the GM 1 Percussion Key Map). Support for controller number 1, 7, 10, 11, 64, 100, 101, 121 and 123; support for channel pressure and pitch bend controllers. 

General MIDI Level 2 or GM2 is a specification for synthesizers which defines several requirements beyond the MIDI standard and is based on General MIDI (GM) and Roland GS extensions. It was adopted in 1999 by the MIDI Manufacturers Association (MMA).

* Number of Notes: 32 simultaneous notes
* MIDI Channels: 16
* Simultaneous Melodic Instruments – up to 16 (all Channels)
* Simultaneous Percussion Kits – up to 2 (Channel 10/11)

Program and bank change events
General MIDI 2 compatible synthesizers access all of the 256 instruments by setting cc#0 (Bank Select MSB) to 121 and using cc#32 (Bank Select LSB) to select the variation bank before a Program Change. Variation bank 0 contains the full GM (General MIDI 1) sound set. Variations using other bank numbers are new to General MIDI 2, and correspond to variation sounds introduced in Roland GS. 


[https://www.youtube.com/watch?v=CluuHrr7HG4 Major WWHWWWH, Minor WHWWHWW scale], [https://www.youtube.com/watch?v=Jjm7Ti-iwz0 Chords], 


==usb audio==

 AROS currently does not support natively any USB audio interface for recording audio 

USB audio is only available for limited Amiga like OSs, independent of the USB protocol version USB1.x USB2, USB3.x, which are not backwards compatible. 

*Introduced 2000 and from 2014 USB Audio 1 UAC1 16bit 44.1kHz
*Introduced 2006 and from 2014 USB Audio 2 [https://www.usb.org/document-library/usb-device-class-definition-audio-devices-release-20-errata-and-ecn-through-april UAC2] 24bit 192kHz
*Introduced 2016 and from 2024 USB Audio 3 [https://www.usb.org/documents UAC3] 32bit 384kHz 

USB group decided to rewrite the audio standard, so [https://os4depot.net/?function=showfile&amp;file=audio/record/usbaudio2.lha UAC2] and [https://archive.fosdem.org/2019/schedule/event/linux_and_usb_audio_class_3/attachments/slides/3345/export/events/attachments/linux_and_usb_audio_class_3/slides/3345/Linux_and_USB_Audio_Class_3___FOSDEM_2019.pdf UAC3]. They added clock selection and control, timing domains and others. Part of the changes included changing many of the descriptors that an audio device uses to describe itself to the machine. 

PsdErrorlog/PsdDevlister? The AHI driver generated only supports mono/stereo at any bit rates between 8 and 32 bit per sample, but not multichannel modes and only rates up to 65KHz (because AHI uses a 16-bit word for frequencies). If the soundcard does not offer such a PCM 8-32 bit mode at frequencies lower than 65 KHz, there's nothing much that can be done about it on the computer side other than revising and expanding the AHI standard. Most cheap USB soundcards do though. 

AHI does not support six channel playback. It only supports mono, stereo and multichannel (8 channels). Due to the multichannel mode not being used by any application so far, the usbaudio.class does not support multichannel playback, especially not &quot;upchannelling&quot; stereo to six or more channels. If this USB device does not support a two channel mode, you can't use it under AHI.

Untested but most likely to work, at least 2 mic inputs (low impedance) &amp; instruments (high impedance) and made in the last 10 years 
*[https://www.youtube.com/watch?v=gMuA-2FbJxE Entry level &lt;100Euro]   BOMGE U202, Behringer UMC, Presonus Studio, 
*[ Next tier &lt;200Euro]   Audient iD, Solid SSL2 and SSL2+, Lewitt, Focusrite Scarlett, Arturia MiniFuse, 
*[ Prosumer &lt;300Euro]   Focusrite Clarett+, 
*[ Professional &lt;500Euro]   RME Babyface, 
*[ Studio &gt;500Euros]    

Bands may need 4 or more mic inputs 

[http://forum.xda-developers.com/showthread.php?p=38364030 XDA Forum thread],

&lt;pre&gt;
                                            &lt;- Computer 
                                            &lt;- Mobile Phone / Tablet (OTG)
                                            &lt;- Digital Cameras 
                            &lt;- Video        &lt;- Webcams 

Base Computer &lt;-&gt; OBS like  &lt;- Audio Mixer  &lt;- Microphone(s) 

                            -&gt; Internet     -&gt; Youtube &amp; Chat 

&lt;/pre&gt;

USB AUDIO CARDS - UAC Compliant 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; |Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |Playback
! width=&quot;10%&quot; |Records 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Arturia Mini Fuse 1
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant, okay pre amp 1 combi input, cirrus logic cs4272 ad converter, 
|-
| &lt;!--Description--&gt;Arturia MiniFuse 2
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant usb-c with usb2.0, okay pre amps with good dynamic range 110dB, cirrus logic cs4272 ad converter, two combi inputs for mic, line or guitar, 
|-
| &lt;!--Description--&gt;Arturia MiniFuse 4 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, okay 110dB dynamic range, -129dB EIN, 
|-
| &lt;!--Description--&gt;Arturia AudioFuse 16Rig 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audient iD44 mk1 mki 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2018 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Audient evo4 EVO8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Audient iD4 mk2 mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Audient id14 mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Audient iD24 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 maybe usb compliant and usb-c bus powered, good, , 0-in/14-out audio interface with ADAT expandability, balanced inserts
|-
| &lt;!--Description--&gt;Audient iD44 Mk2 Mkii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC22 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC202HD 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps ein -129 dBu, 24bit ADC, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC404HD 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps, 24bit adc, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC204HD 192 Empower Tribe 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt;0x0508
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 maybe usb compliant, okay, midas pre-amps
|-
| &lt;!--Description--&gt;Behringer UMC1820 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2016, bus complaint?, okay midas pre amps, adc, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UM2 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, poor zenyx pre-amps with high noise floor, plastic build no rf shielding, latency issues, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Focusrite Saffire 6 USB 1.1
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, , , midi, strictly NEC USB 2.0, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 8i6 Gen 1 MOSC0001 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, but 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 1 MOSC0003 
*TP1 - 3.3V, tested ok
*TP2 - U4 control signal, 3.3V present at all time.
*TP4 - Ground
*TP6 - 48V, tested ok
*TP7 - Ground
*TP8 - Ground
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 usually avoid early Gen 1, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2021/08/75-focusrite-scarlett-2i4-1st-gen.html Focusrite Scarlet 2i4 Gen 1 (slide toggles) MOSC0004] 
*TP1 - 3.3V, tested 3.22v
*TP2 - U4 control signal, 3.3V present 
*TP4 - Ground
*TP6 - measure 47.72v 
* AKM 4384ET (VDD 5v)
* Cirrus Logic CS4272-CZZ (VA 4.94v/ VD 3.2v/ VL 3.2v)
* all four HC4066 (VCC 4.96v)
* XMOS XS1-L01A-TQ128-C5 (all VDD 1.08v/ all VVDIO 3.23v/ PPLAVDD 0.99v/ PCU-VDDIO 3.23v)
2i4S
*TP1 seems to be 0V
*TP2 should be 5V
*TP3 should be 
*TP6 should be 48V
*TP8 should be 3.3V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, pre amps JRC NJM2122 and NJM4565, [https://statics.cirrus.com/pubs/proDatasheet/CS4272_F1.pdf CS4272 adc], [https://pdf.datasheet.live/e5e5fd1c/akm.com/AK4384.pdf AK4384 output pair], Xmos XS1-L8A-64-TQ128 processor and firmware in Winbond 25X40CL 4Mbit, an SMSC Microchip USB3343 interface and a Microchip PL611 clock generator - two Intersil / Renesas ISL97519A for the phantom power rail, two OnSemi NCP1521B for the 3.3V (digital) and 1V (Xmos core) rails - 
|-
| &lt;!--Description--&gt;Focusrite iTrack Solo USB Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2012 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 1st Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, , Cirrus CS4272, 
|-
| &lt;!--Description--&gt;[http://wiki.linuxaudio.org/wiki/current_audio_gear Focusrite ] Scarlett 4i4 Gen  MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, , Cirrus CS4272, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 6i6 Gen1 MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;2013 maybe usb compliant, , , 12v psu, the headphone outs mirror the outs on the back panel, so that's six independent outs. 4 independent analog output paths, plus two over spdif, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2019/03/38-focusrite-scarlett-18i8-gen1-teardown.html Focusrite Scarlett 18i8 1st Gen MOSC0008]
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, JRC NJM4565 provide most of the opamps, pair of JRC NJM2122's for inputs 1 and 2, [http://www.mouser.com/ds/2/76/cs4272_f1-43250.pdf Cirrus CS4272], 12v 1a +central psu to a pair of National Semiconductor LM2672 for 3.3V rail and the +6.9V rail, Xmos XS1–L16A–128 dual-row QFN package, firmware a Winbond 25X40C 4Mbit SPI Flash and an SMSC USB3343 interface chip, the two headphone outs are completely independent so 6 independent analog output paths, plus two over spdif, 
|-
| &lt;!--Description--&gt;Focusrite Clarett+ 8Pre 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 great, expensive, maybe usb compliant?  
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 2 (slide toggles) MOSC0006 
*TP6 should be 48V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8202
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, USB-b bus powered, good preamps ein equivalent input noise -128 dBu, 24-bit 192kHz CS4272 as well as an additional AKM AK4384ET for the second stereo output pair, 4 screws under bottom rubber,  
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2021/07/focusrite-scarlett-2i4-2nd-gen-teardown.html Focusrite Scarlett 2i4 Gen 2 (slide toggles) MOSC0014]
*TP6 should be 48V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, USB-b bus powered, good preamps NJM2122's, NJM4565's and CMOS switches (HEF4053 and HEF4066), CS4272 and a AKM AK4384ET, Xmos XU208-256-TQ64-C10 with firmware stored in a Macronix MX25L8006E 8Mbit flash memory, clocking by a Cirrus Logic CS2100, an MP1542 boost converter creates +6V and -6V rails, powering the opamps and the rest of the analog circuitry, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 6i6 Gen2 MOSC0016
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 2nd Gen MOSC0019
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2024/03/focusrite-scarlett-18i8-gen2-teardown.html Focusrite Scarlett 18i8 2nd Gen MOSC00]
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 3rd Gen MOSC0024
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant usb-c but usb2, preamps, ad/dc 24bit 192kHz, most Focusrite gen3 interfaces have encrypted processors, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i6 Gen3 MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, USB2 class compliant device, but with custom mixer interface
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 3 (push in switches) MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8210
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, USB-c bus powered, good preamps ein equivalent input noise -128 dBu, 24-bit 192kHz Cirrus Logic xfr002c and cs4272 chips, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 3rd gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i8 3rd Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8214
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, , , no screws under the rubber pads on the bottom, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo Studio Mk3 USB Audio Interface MOSC0030 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2020
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 4i4 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Studio 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 4th Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 4th Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Lewitt Connect 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Lewitt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Motu UltraLite AVB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt; usb not compliant? 
|-
| &lt;!--Description--&gt;MOTU M2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant?, usb-c, good pre amps, ad/dc, 
|-
| &lt;!--Description--&gt;MOTU M4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;MOTU U2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  maybe not usb compliant, good but latest had hardware revision 
|-
| &lt;!--Description--&gt;MOTU UltraLite-mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 not usb compliant, great 
|-
| &lt;!--Description--&gt;MOTU UltraLite-mk5
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 not usb compliant, great 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nuemann MT48 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, okay 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Presonus AudioBox USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe not usb compliant, usb1.1 usb-b bus powered, okay pre-amps, 24bit ADC 48Khz max, 
|-
| &lt;!--Description--&gt;Presonus Audiobox 1818VSL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Presonus AudioBox 44VSL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 may not be usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;PreSonus AudioBox 22VSL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 2|4 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, usb-b, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 2|6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 6|8 USB Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe compliant, needs ext psu, 
|-
| &lt;!--Description--&gt;PreSonus Studio 24c 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, good, adc, 
|-
| &lt;!--Description--&gt;PreSonus Studio 26c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, 
|-
| &lt;!--Description--&gt;PreSonus® Studio 68c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, 
|-
| &lt;!--Description--&gt;PreSonus AudioBox USB 96 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, high preamp noise, 
|-
| &lt;!--Description--&gt;Presonus Quantum ES2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, okay, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Prism 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Prism Lyra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe not usb compliant, great 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Platane UP1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant usb- UAC2 asynchronous protocol, 64dB Low-noise Mic amplifier, 32Bit High End ADC and DAC, 16dBu High-power ti headphone amplifier
|-
| &lt;!--Description--&gt;Platane UP2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Platane 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;RME Babyface/UC/UFX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant, good 
|-
| &lt;!--Description--&gt;RME Fireface UCX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 might be able to put into class compliant cc although a firewire device, pre amps, adc,  
|-
| &lt;!--Description--&gt;RME Babyface Pro FS  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe not usb compliant, good 
|-
| &lt;!--Description--&gt;RME Fireface UCX II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 might be class compliant usb-b, pre amps, adc,  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Solid State Logic SSL2 SSL2+ Mk1 1st Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, good, adc, 
|-
| &lt;!--Description--&gt;Solid State Logic SSL12 SSL18 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, bus powered, good pre-amps, up to 32-bit 192kHz AD/DA converters, 12-in 8-out, 
|-
| &lt;!--Description--&gt;Solid State Logic SSL2 SSL2+ MkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, good pre amps ein -130 dBu, ad/dc, okay latency, 
|-
| &lt;!--Description--&gt;Solid State Logic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Topping E1x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;Topping Pro E2x2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;UAD UA Apollo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;UA apollo 2nd Gen twin X (Duo/Quad), X4, X6, X8, X8P, and X16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 bus compliant?, usb-
|-
| &lt;!--Description--&gt;UA apollo twin x quad 3rd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 bus compliant?, usb-
|-
| &lt;!--Description--&gt;Universal Audio Volt 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;|Universal Audio Volt 276 2|76 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Universal Audio Volt 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;Akai EIE Pro AI01 Electromusic Interface Expander - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 4-in/4-out USB 2.0 audio interface with a built-in USB hub and MIDI I/O, up to 24-bit/96kHz 
|-
| &lt;!--Description--&gt;Akai EIE Pro AI02 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;|Alesis io2 io|2, io14 io|14, io26 io|26 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 bus powered but not usb compliant, okay pre-amps, 2, 4 or 8 mics respectively, 
|-
| &lt;!--Description--&gt;Alesis iO2 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010  not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Alesis Core 1 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe cc, mini usb, poor latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Apogee Duet 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 firewire only, not usb compliant micro-usb with most features, , ,  two‑channel two‑in, two‑out, 
|-
| &lt;!--Description--&gt;Apogee Ensemble 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 firewire, not usb compliant micro-usb with most features, , ,  two‑channel 
|-
| &lt;!--Description--&gt;Apogee One USB 1st Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant micro-usb for basic features, , , single‑channel up to 48kHz
|-
| &lt;!--Description--&gt;Apogee One USB 2nd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant usb- and maybe aa batteries, 
|-
| &lt;!--Description--&gt;Apogee Duet 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c with most features, , , 
|-
| &lt;!--Description--&gt;Apogee One USB 3rd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Apogee Ensemble Thunderbolt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe not usb compliant micro-usb with most features, , ,  two‑channel 
|-
| &lt;!--Description--&gt;Apogee Boom 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c, , , 
|-
| &lt;!--Description--&gt;Apogee Duet 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c with most features, , , 
|-
| &lt;!--Description--&gt;Apogee 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ART PRO Audio Usb Mix 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant bus powered, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 1 USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt;01000
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2002 mbox original was usb1 and not a usb class compliant device, and had the much hated &quot;focusrite designed&quot; mic preamps, light blue front plate and the sticky out feet 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 midi not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Pro USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Mini USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Micro USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not usb compliant 
|-
| &lt;!--Description--&gt;AVID MBox 3rd gen Mini or Standard but Pro is Firewire 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2010 maybe usb compliant, 
|-
| &lt;!--Description--&gt;behringer u-control uca202 
| &lt;!--Vendor ID--&gt;0x8bb
| &lt;!--Product ID--&gt;0x2902
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, draws a lot of power - dac ti burr-brown - no microphone pre-amp - 
|-
| &lt;!--Description--&gt;Behringer U-CONTROL UCA 222 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 maybe usb compliant,  - no microphone pre-amp - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Black Lion Audio 2x2 evolution 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant but , okay with 109dB range - poor noise floor, 24-bit 192kHz Cirrus Logic CS4272, average latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Bomge 11s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 
|-
| &lt;!--Description--&gt;Bomge 22s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 
|-
| &lt;!--Description--&gt;Bomge BMG22 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 usb-c, 24bit 192kHz but only use much lower, may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge U202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-c, 32bit 192kHz but only use much lower, may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge U204 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-c, 32bit 192kHz but only use much lower , may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;TI Burr-Brown PCM2702E PCM2704 PCM2704C Muse Audio Mini USB DAC board 
| &lt;!--Vendor ID--&gt;0x08bb 
| &lt;!--Product ID--&gt;0x2704
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, no mic input - goodish quality
|-
| &lt;!--Description--&gt;TI Burr-Brown PCM2900 PCM2902 PCM2906 USB DAC board 
| &lt;!--Vendor ID--&gt;0x08bb
| &lt;!--Product ID--&gt;0x2900
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, no mic input - goodish quality 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Depusheng MD22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-b powered, 24bit 192kHz though is 96kHz, 
|-
| &lt;!--Description--&gt;Depusheng USB Audio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 usb-b powered, 24bit 192kHz though is 96kHz, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;|Emagic emi 2|6 em2|6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2002 not uac 
|-
| &lt;!--Description--&gt;|Emagic emi 6|2m 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 not uac 
|-
| &lt;!--Description--&gt;|Emagic emi 6|2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 not uac 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Ego Systems, Inc. in Korea (ESI) joining with RIDI GmbH 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2006 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;esi Mixvibes U46 Mk II USB audio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 not usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;ESI ESU22
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2008 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;esi U24XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, 24 bits, 2 analogue inputs and outputs with 6.3 mm jack connection, Output L can be used as a headphone output, S / PDIF digital input - 
|-
| &lt;!--Description--&gt;esi U46XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;ESI Originals, Inc ESIO MAYA22USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;ESI MAYA44USB+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, usb-b powered,  xlr, 
|-
| &lt;!--Description--&gt;ESI Originals, Inc ESIO MARA22XTU 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;ESI U22XT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb class compliant
|-
| &lt;!--Description--&gt;ESI Gigaport Ex
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 usb compliant?, usb-c usb3.1, , , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;iConnectivity iConnectAUDIO2+ icaudio-02 USB audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;LexiconPro - Omega 8x4x2 (USB-1.1)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2003 not usb complaint 
|-
| &lt;!--Description--&gt;Lexicon Alpha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;Lexicon Lambda
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 may not be compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Line 6 Toneport UX1 and Tone Port UX2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2004  not usb compliant, 
|-
| &lt;!--Description--&gt;Line 6 TonePort UX8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 maybe not class compliant, 
|-
| &lt;!--Description--&gt;Line 6 POD Studio UX1 UX2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2006  not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Lokchonk UX22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=ljSiNmudMm0 Lokchonk UX44HD] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 usb-b , , , 2in 2out only, average latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mackie Onyx Artist 1·2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 maybe not usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;Mackie Onyx Producer 2X2 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b midi 
|-
| &lt;!--Description--&gt;Mackie Onyx Blackjack
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 USB powered but maybe not usb compliant, Two Onyx Preamps, 2-in, 2-out which are combo Neutrik-type connectors to handle XLR, instrument or line level 
|-
| &lt;!--Description--&gt;Mackie 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, , , 
|-
| &lt;!--Description--&gt;Media Assistance USB-One
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not uac cc comliant, 
|-
| &lt;!--Description--&gt;M-Audio Fast Track USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2004 maybe not usb compliant, - guitar 
|-
| &lt;!--Description--&gt;M-Audio Fast Track Ultra (6 in 6 out) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2008 maybe usb cc providing 24-bit/96kHz audio capabilities but requires manual configuration of the mixer settings 
|-
| &lt;!--Description--&gt;M-Audio M-Track 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 usb compliant?, okay - guitar and vocal mainly 
|-
| &lt;!--Description--&gt;[https://htyp.org/M-Audio/Fast_Track_Ultra/Linux M-Audio FastTrack Ultra] and Ultra 8R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe usb compliant, low round-trip latency, okay octane pre amps, adc, 
|-
| &lt;!--Description--&gt;M-Audio M-Track 2x2M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb compliant? usb-c - okay pre-amps, , 
|-
| &lt;!--Description--&gt;M-Audio M-Track (MkII) 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb compliant? usb-c - okay pre amps, , 
|-
| &lt;!--Description--&gt;M-Audio M-Track Solo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 usb compliant? - okay but issues, MJN4580C opamps (lower gain 55 dB at volume 9-10), ti PCM2900C ADC 16bit means there is a hard noise floor at -96 dB, plastic build no rf shielding, 
|-
| &lt;!--Description--&gt;M-Audio M-Track DUO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 usb compliant? - okay but issues, MJN4580C opamps (lower gain 55 dB at volume 9-10), ti PCM2900C ADC 16bit means there is a hard noise floor at -96 dB, plastic build no rf sheild, 
|-
| &lt;!--Description--&gt;M-Audio Air
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, okay 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;NI AK1 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, 
|-
| &lt;!--Description--&gt;[https://www.pogo.org.uk/~mark/linuxdj/ Native Instruments Traktor Audio 8 DJ], [ Traktor Audio 4 DJ], [ Traktor Audio 2 DJ], 
| &lt;!--Vendor ID--&gt;0x17cc
| &lt;!--Product ID--&gt;0x1978, 0x0839, 0x041C 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not usb compliant uses snd-usb-caiaq module, [https://mixxx.discourse.group/t/problems-with-native-instruments-audio-8-dj-on-linux/14719/2 Audio 8 device has 4 subunits which are not recognized correctly], Cirrus Logic DACs spec'd at 24-bit/96KHz over a USB2, 
|-
| &lt;!--Description--&gt;NI Komplete Audio 6 Mk1 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, pre amps, 24bit 96kHz adc, ocassional dropouts, plastic build top with metal around 3/4, 
|-
| &lt;!--Description--&gt;Native Instruments NI Komplete Audio 1 and 2 USB 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, good pre amp ein -129.5 dBu, ad/dc, 
|-
| &lt;!--Description--&gt;[https://support.native-instruments.com/hc/en-us/articles/360014683497-Apple-Silicon-Compatibility-News Native Instruments Komplete Audio 6 Mk2] 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, pre amps, 24bit 192kHz adc, black aluminum glass build, 
|-
| &lt;!--Description--&gt;[ Native Instruments Traktor Pro] 
| &lt;!--Vendor ID--&gt;0x17cc
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Novation AudioHub 2x4 NOVHUB01 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, no xlr, focusrite sounds inside, 
|-
| &lt;!--Description--&gt;Novation AudioHub 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Prodipe Studio 22 Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland Edirol UA-3 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1998 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-30 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;1999 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA1A UA-1D Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-5 Audio Capture (Roland)
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-1000 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-1EX, Cakewalk UA-1G  
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2005 not usb compliant driver also supports ASIO (Steinberg Audio Stream I/O Interface), noisy 
|-
| &lt;!--Description--&gt;Roland Duo Capture UA-11 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland QUAD-CAPTURE Analog 2x2 Digital 2x2 USB 2.0 4in/4out
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2005 not usb compliant, usb-b powered 
|-
| &lt;!--Description--&gt;[https://wiki.debian.org/DebianEdu/Documentation/Manuals/Rosegarden/Setup Roland Edirol UA-101 and UA-1000 (Clemens Ladisch driver)]
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;[https://github.com/mmueller-kaffeeschluerfercom/UA-25-Firmware-Modification Roland Edirol ua-25]
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2007 maybe usb compliant 16bit 44.1kHz sampling without MIDI but not USB class complient when in Advanced mode for 24bit or midi 
|-
| &lt;!--Description--&gt;Edirol by Roland USB AudioCapture UA-25EX 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x00e6, 0x00e7
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant if ADVANCED DRIVER switched to OFF might play and record at 44.1kHz and 16-bit samples 
|-
| &lt;!--Description--&gt;Roland Audio Interface V-Studio 20 VS-20 Cakewalk
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;Roland Edirol UA55 UA-55 Quad Cakewalk 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x012f
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2011 not USB class compliant, 
|-
| &lt;!--Description--&gt;Roland DUO-CAPTURE EX UA-22 USB Audio
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0159
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant but not be used with a USB 3.0 port that is not compatible with USB 2.0 specification, vs pre amps, adc, three AA batteries in base, or an AC adapter psb-1u 9V 2A - 
|-
| &lt;!--Description--&gt;Roland Rubix series Roland Rubix22 USB 2.0 Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Roland Rubix series Roland Rubix24 USB 2.0 Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Roland 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant 
|-
| &lt;!--Description--&gt;Steinberg MI2, Steinberg MI4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 not usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg (2004 Yamaha buys) MIDI interface hardware including the CC like CC121 CC-121 and CI1 CI2 series.
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2008 not usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg UR12 UR22
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR44 usb audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR242 audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 maybe usb compliant, usb powered or 5v psu, okay pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR22mkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, okay pre-amps ein -123 dBu, ad/dc, 
|-
| &lt;!--Description--&gt;Steinberg UR-RT 2 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, usb2.0 usb-b, pre-amps, ad/dc, 
|-
| &lt;!--Description--&gt;Steinberg UR44C (USB3) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg URX22C UR22C  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, preamps okay but little noisy, ad/dc. 
|-
| &lt;!--Description--&gt;Steinberg UR22 MkIII UR series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant usb-c, okay pre-amps, adc, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Tapco LiNK.USB 2x2 (Loud technologies WA, USA) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 maybe not compliant, usb-b, poor pre-amps hum, latency issues, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://git.alsa-project.org/?p=alsa-tools.git;a=blob;f=usx2yloader/README;hb=3843634ef0310a952b256bcb6a4ddd0ad4ebe396 Teac Tascam US-422 US-428 US2XYloader] 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Tascam US-122 US-224 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2003 not usb compliant, needing firmware usx2yloader/us122fw.ihx for audio sound card - Tascam US-122 and US-122L are not the same - 
|-
| &lt;!--Description--&gt;Tascam US-122L 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt;0x800e
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2006 not usb compliant, obsolete needs tascam_loader.ihx and us122fw.ihx firmware loaded each time unless automated 
|-
| &lt;!--Description--&gt;Tascam US122 US-122 Mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant although USB2 downgrade so using USB1.1 UHCI, tascam units suffer from high round-trip latency as do most typical USB units
|-
| &lt;!--Description--&gt;Tascam US144 US-144 Mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 maybe usb compliant although USB2 downgrade so using USB1.1 UHCI, tascam units suffer from high round-trip latency as do most typical USB units
|-
| &lt;!--Description--&gt;Teac TASCAM US-200 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac US-366 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac TASCAM US-600 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac TASCAM US-800 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 may not be totally usb compliant 
|-
| &lt;!--Description--&gt;Teac Tascam iU2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2012 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-2x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 usb compliant?, 5v dc power, midi out in, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-4x4
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; usb compliant?, 
|-
| &lt;!--Description--&gt;Teac Tascam US-16x08 US-20x20
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;teyun q12 Q-12, q22 Q-22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant - unknown pre amp, unknown ad/dc, 
|-
| &lt;!--Description--&gt;Teyun q26 Q-26, q24 Q-24 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant - unknown pre amp, unknown ad/dc, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha UW500
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2000 not class compliant, 
|-
| &lt;!--Description--&gt;Yamaha Audiogram 3 USB Digital Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 maybe usb compliant, okay pre amp, 16bit 44kHz adc no advanced features without dedicated asio driver, 1 xlr, 1 instrument, 
|-
| &lt;!--Description--&gt;Yamaha Audiogram 6 USB Digital Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, okay, 2 xlr, 2 instrument, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Zoom UAC-232 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;Zoom UAC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;[http://www.arcam.co.uk/products,rseries,usb-dacs,rPAC.htm Arcam rPac] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audioquest Dragonfly 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audioengine D1 Premium 24-bit DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Beresford TC-7520 (Burr Brown PCM 1716) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Beresford TC-7520 + Burson Buffer + MK3 JKSPDIF
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[http://epiphany-acoustics.co.uk/products-page/dacs/e-dac-24bit-miniature-usb-dac/ Epiphany E-DAC 24bit] ES9023 DAC chip 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Firestone Audio FUBAR II Mk2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Firestone Audio iLoveTW 24Bit USB DAC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO D5 ta2020 chip amp 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO E07K Andes 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO E17 Alpen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Magnum 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Martini-U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Vulcan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Halide Design DAC HD (Wolfson WM8716) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;HRT Steamer II USB DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;John Kenny JKDAC uses a 24-bit/192&amp;nbsp;kHz Sabre ES9022 DAC or better JKDAC32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt; iBasso D12  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Leckerton UHA-6S MKII  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;MyST 1866 PortaDAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Objective DAC ODAC+O2  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Rega DAC (Wolfson WM8742) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;[http://www.henryaudio.com/open-source.php Henry Audio USB DAC 128 also known as QNKTC AB-1.2 open source DAC] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Henry Audio mkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;AKM4430 DAC chip comes from Asahi Kasai 
|-
| &lt;!--Description--&gt;DevilSound USB DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Zoom U series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;KingRex UD-01 SE (Burr-Brown PCM 2702E) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SuperPro 24/192 USB DAC (24bit 192&amp;nbsp;kHz, CS-4398 D/A chip) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| CMedia CM108 7.1ch emulation I2S in and out
| 0x1926
| 0x0003
| 0x0100
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| [http://www.lindy.co.uk/usb-2-audio-adapter/42961.html Lindy USB 2.0] (Chipset CM108)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Speed-Link SL-8850-SBK Vigo ([http://mightyohm.com/forum/viewtopic.php?p=1036#p1030 CMedia CM108])
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Dynamode USB SOUNDCARD 2.0 
| &lt;!--Vendor ID--&gt;0x0003
| &lt;!--Product ID--&gt;0x1130
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Dynamode Virtual 7.1 USB-SOUND7 (C-Media )
| 0x0d8c
| 0x000c 0x000e
| 1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Generic White box with very little red led and white USB lead (CMedia )
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt; 0c000e
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
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|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
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| Product ID
| Revision 
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| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Opinion--&gt;
|-
| CM109 CiT SC-U119 5.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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|-
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|-
| &lt;!--Description--&gt;
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| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| CMedia CM1197.1ch I2C MCU port Penguin 
| 0x0D8C
| 0x0000
| 0x010
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
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| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;Sweex 7.1 Startech External USB, WMA Blue metal box SYBA SD-AUD20040, Sabrent USB-SND8, Sewell Vantec NBA-200U (C-Media CM6206 CM106 like) 
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x0102
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;50/50 if the item is detected but does not work 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
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|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative Labs SoundBlaster X-fi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative X-Fi Go 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative X-Fi 5.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative Sound Blaster Play! USB sound adapter (SB1140) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; working with [http://www.amiga.org/forums/showpost.php?p=646431&amp;postcount=15 Deneb on OS3] 
|-
| &lt;!--Description--&gt;Asus Xonar U1 (ASUS UA100 USB Audio Chip) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Asus Xonar U3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Griffin iMic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Transit
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Icemat Siberia (steel series) (Cmedia chipset) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;JMTek HY554, ZyXEL NSA-220, Logilink (Tenx Technology TP6911 and SSS-1623 headphone set) 
| 0x0C76 0x1130
| 0x1605 0x1607  0xf211
| 0x
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; reports on other OS not good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Plantronics &quot;DSP Adapter-01&quot; (or &quot;USB Adapter-02&quot;) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Rocksmith Real Tone Cable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;RSA Intruder Predator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;StarTech ICUSBAUDIO7
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x000c
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Stoner Acoustics UD100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Teac UDH01-B  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Terratec Aureon 5.1 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Terratec Aureon 5.1 USB MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;TerraTec Electronic GmbH Aureon Dual USB
| 0x0ccd
| 0x0077 
| &lt;!--Product ID--&gt; 
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Terratec Phase26
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Trust 510 EX 5.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Logitech A-5572A USB 2.0  to 3.5mm jacks Virtual 7.1 Surround Sound Adapter or accessory of Logitech Clearchat pro USB or Logitech USB Headset H530 
| &lt;!--Vendor ID--&gt;0x0003 
| &lt;!--Product ID--&gt;0x046D
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Trumix TM-10 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2024  maybe cc 
|-
| &lt;!--Description--&gt;Trumix TM-12 USB-C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe cc usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Turtle Beach Audio Advantage Amigo Micro II USB Sound Card &amp; Headset Adapter 
| &lt;!--Vendor ID--&gt;0x10F5
| &lt;!--Product ID--&gt;0x0211
| &lt;!--Revision--&gt;0100
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Vantec NBA-100U 7.1 Channel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|}

 Companies including Access, Alesis, Allen&amp;Heath, American Audio, CME, ESI, Infrasonic, Lexicon, Numark, Presonus, Reloop, SIMS, Sound Devices, Steinberg, Swissonic, Tascam, Terrasoniq, Terratec, Yamaha and Yellowtec decided to license and bundle this driver. So fully functional custom drivers are available for Access Virus TI, Access Virus TI snow, Alesis Multimix 8 USB2.0, Alesis Multimix 16 USB2.0, Allen&amp;Heath XONE:2D, Allen&amp;Heath XONE:3D, Allen&amp;Heath XONE:4D, Allen&amp;Heath XONE:DX, Allen&amp;Heath XONE:DB4, American Audio Versa Port, CME XCORPIO, ESI ESU1808, ESI Gigaport AG / DG, ESI Maya 44 USB, Infrasonic Amon, Lexicon I-ONIX U22, Lexicon I-ONIX U42S, Lexicon I-ONIX U82S, Mindprint DI-MOD USB, Numark DJ IO, Numark NS6, Numark NS7, Numark Omni Control, Numark V7, Presonus Audiobox USB, Reloop Digital Jockey, SIMS Primus, Sound Devices USB pre, Steinberg MI2, Steinberg MI4, Swissonic Easy USB, Tascam M-164UF, Tascam US-122L, Tascam US-144, Tascam US-Tascam US-144mkII 122mkII, Tascam US-200, Tascam US-600, Tascam US-1641, Tascam US-1800, Tascam US-2000, Terratec Area 61, Terrasoniq Phase X64, Terratec Phase 26 USB, Yamaha UW10, Yamaha UW500, Yellowtec PUC2 and many others.

Well, those companies are using the same driver framework because all of those interfaces use the same microprocessor/firmware architecture to communicate with the USB bus. Just like almost all FireWire audio interfaces use the same TC Dice or BridgeCo chipsets. Usually it does not make sense for companies to develop their own USB1.1/USB2/FW framework for a product they are going to sell for &lt;$500.

However, that isn't the end of the story. The companies who develop audio interfaces implement different features into their devices and must update the driver and firmware to accommodate those features. That is where things can go wrong. Sometimes there is miss-communication about how things are coded, sometimes the developer who started a project leaves without transferring his knowledge to his successor, etc. You have to keep in mind that there are no &quot;big&quot; computer audio companies. Even the companies that seem big in the scale of the market, probably have fewer employees than you'd think.

A very well made interface that is designed from scratch from the ground up would be a very expensive device, regardless of whether it's USB, FW, PCIe or whatever.

Round-trip latency is the sum of the following:
&lt;pre&gt;
    ASIO input buffer
    ASIO output buffer
    A/D D/A converter latency
    The driver's hidden safety buffer
&lt;/pre&gt;
At a 64-sample ASIO buffer size/44.1k, Tascam units yield ~18ms total round-trip latency.

Typical USB audio interfaces use a large hidden safety buffer.
This helps ensure glitch-free playback... even under less than ideal circumstances. But... this comes at the expense of much higher round-trip latency. Short of doubling the sample-rate, there's no means of mitigating the higher round-trip latency.
If you have no plans of ever monitoring in realtime thru software based EFX/processing (ie: playing/monitoring DI bass thru an AmpSim plugin as you're playing), then this may not matter to you.
If you want the ability this play/monitor in realtime thru software based EFX/processing, make sure to get an audio interface that yields low round-trip latency.

As a point of reference the best PCI/e audio interfaces yield about 5ms total round-trip latency at a 64-sample ASIO buffer size/44.1k
The best Firewire and USB units yield 5.5-5.6ms total round-trip latency at those same settings.
Typical USB and Firewire units (that use a large hidden safety buffer) yield 12-18ms total round-trip latency at those same settings.

Anything above ~6ms starts to feel sluggish.
Anything above ~10ms feels like playing thru molasses.


USB Microphones 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;C-Media Electronics, Inc. CM108 Audio Controller Mic
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x013c 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato WaveMic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato Wave:1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 no driver }}
|-
| &lt;!--Description--&gt;Elgato Wave:3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 no driver lightweight }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;hyperx solocast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver}}
|-
| &lt;!--Description--&gt;hyperx quadcast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sennheiser CC510 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Alesis USB-Mic microphone podcasting kit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio-Technica AT2020 (AT202) AT4040
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio-Technica AT2035 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Behringer B1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Blue Microphones Snowball 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Blue Microphones Snowball iCE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| cardioid only }}
|-
| &lt;!--Description--&gt;Blue Microphones Yeti 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|can pick up a lot of background noise but not sure if right mode used }}
|-
| &lt;!--Description--&gt;Blue Microphones Yeti Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| can pick up a lot of background noise but not sure if right mode used }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MXL 2001A/600 Studio Microphone Pack / MXL 2003A Studio Condenser
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft LifeChat LX-3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Namtai SingStar(TM) PS2 SCEH-0001 USBMIC 
| &lt;!--Vendor ID--&gt;0x1415
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;0.01
| &lt;!--Opinion--&gt;{{unk| mono microphones }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Neumann 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Razer Seiren X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Razer Seiren Mini USB Condenser Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rockband USB Mic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rode NT1A VideoMic Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rode Podcaster 2 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| RODECaster Pro usb audio compatible}}
|-
| &lt;!--Description--&gt;Rode NT1A NT2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  NT2 better }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Roland R-07
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samson Go Mic - Portable USB Microphone for Recording 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| mini usb r.h.s. and clip on the bottom left hand side}}
|-
| &lt;!--Description--&gt;Samson Go Mic Clip On USB Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| switch to choose between Cardiod, Omni and -10&amp;nbsp;dB modes, a 3.5mm headphone socket and a USB socket}}
|-
| &lt;!--Description--&gt;Samson C01U  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| cardoid only}}
|-
| &lt;!--Description--&gt;Samson C03U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Shure MV7 USB Podcast Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;SONY PCM-D50 handy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb 5V, }}
|-
| &lt;!--Description--&gt;Sony PCM-M10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out 5V, }}
|-
| &lt;!--Description--&gt;SONY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out, }}
|-
| &lt;!--Description--&gt;SONY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out, }}
|-
| &lt;!--Description--&gt;TASCAM DR-1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008, one mini usb out, lithium battery}}
|-
| &lt;!--Description--&gt;Tascam DR-07 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009, one mini usb out, aa battery}}
|-
| &lt;!--Description--&gt;Tascam DR05 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011, one mini usb port for file transfer and charging the AA batteries }}
|-
| &lt;!--Description--&gt;Tascam DR-40
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011  mini usb aa battery }}
|-
| &lt;!--Description--&gt;Tascam DR-07mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 , one mini usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-05X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-07X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-40X
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb 3 aa battery }}
|-
| &lt;!--Description--&gt;Tascam DR-05XP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c , }}
|-
| &lt;!--Description--&gt;Tascam DR-07XP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c , }}
|-
| &lt;!--Description--&gt;Tascam DR-40XP
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c, }}
|-
| &lt;!--Description--&gt;Tascam DR-100mkIII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| , usb , }}
|-
| &lt;!--Description--&gt;Tascam 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| , usb , }}
|-
| &lt;!--Description--&gt;Zoom H4 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H2 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;0x0095
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 no driver, mini usb 5V audio i/f USB Card and USB Audio; press the Record button when USB Audio is displayed. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H4n 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H1 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;0x0120
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 no driver, mini usb 5V and display will alternate between USB Card and USB Audio; press the Record button when USB Audio is displayed. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H2n 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 no driver, mini usb 5V audio i/f press the Record. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H4n PRO 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H6 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 untested, 2xlr, 5v mini usb, }}
|-
| &lt;!--Description--&gt;Zoom H5 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 no driver, 5v mini usb, 2 xlr, }}
|-
| &lt;!--Description--&gt;Zoom H1n-vp handy 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H6studio 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 untested}}
|-
| &lt;!--Description--&gt;Zoom 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|no driver}}
|-
| &lt;!--Description--&gt;Zoom Q3
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 untested usb a cord, no hdmi, 480p}}
|-
| &lt;!--Description--&gt;Zoom Q3HD Handy Video Recorder 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 untested, built in usb-a cord, mini hdmi, 1 hour on 2 AA batteries, H.264 movies 480p }}
|-
| &lt;!--Description--&gt;Zoom Q2HD Handy 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 untested, up 720p but no stablisation, mini usb cord, 1 hour on 2 AA batteries}}
|-
| &lt;!--Description--&gt;Zoom Q4
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 untested, li-ion battery}}
|-
| &lt;!--Description--&gt;Zoom Q4N 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 untested, li-ion battery}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio Technica ATR4697-USB Boundary Microphone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;CAD Audio CAD USB Condenser Boundary Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MXL AC-44 Boundary Conferencing Mic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samson Audio SAUB1 Boundary Microphone (USB)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


USB Speakers 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Focal XS 2.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


USB Headset Wired/Wireless 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Logitech Vantage Wired (came free with PS2 Socom3)
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech G330 
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech Premium USB Stereo Headset 350
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Plantronics DSP-300 
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Plantronics GameCom 777
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech G-930 Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| [http://www.makeuseof.com/tag/set-usb-wireless-earphones/ Plantronics Audio 995 Wireless RF] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Sennheiser  Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


[https://www.youtube.com/watch?v=Be1e0QPIPK0 Mixers]

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;ALESIS MULTIMIX 4 CHANNEL USB MIXER
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Alesis - MultiMix 8 USB FX (USB 1.0)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2010 usb compliant?, up to 16-bit/48kHz, 18v 500mA - 
|-
| &lt;!--Description--&gt;Alesis - MultiMix 8 USB 2.0 FX (USB 2.0)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2012 usb compliant?, up to 16-bit/48kHz, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Allen&amp;Heath MixWiz16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Allen and Heath ZED Power 1000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 8 xlr, usb-b out, }}
|-
| &lt;!--Description--&gt;Allen &amp; Heath ZEDi-10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Behringer XENYX 302USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 5-Input Mixer/Audio Interface - 1 xlr - }}
|-
| &lt;!--Description--&gt;Behringer Xenyx Q502USB Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|no driver}} Behringer 2*18.5V 250ma psu - 1 xlr - phanton power - 
|-
| &lt;!--Description--&gt;Behringer Xenyx Q802USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} Behringer 2*18.5V 250ma psu - 2 xlr - phanton power - 
|-
| &lt;!--Description--&gt;BEHRINGER XENYX 1204USB 8-Channel 2-Bus Mixer USB/Audio Interface Studio/Live
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} iec kettle psu lead - can develop constant background hiss over time 
|-
| &lt;!--Description--&gt;Behringer XENYX X1222USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver - 12-Channel Analog Mixer with USB Interface and Effects}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Depusheng HT-7 HT7USB 7 Channel Audio Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2023 cheap no driver, USB MP3 player to work, format your USB stick Fat32 as a Logical drive - not primary}}
|-
| &lt;!--Description--&gt;Depusheng XT7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2025 cheap no driver}}
|-
| &lt;!--Description--&gt;Depusheng DT8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2025 cheap no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Spirit soundcraft Folio FX8 with Lexicon Effects Processor
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} unusual power connector - [https://github.com/lack/soundcraft-utils usb routing] -  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Weymic Professional F7 7-Channel 2-Bus Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2022 no driver, cheap mixer with 3pin ac input (introduces noise) and 1 usb-a port}}
|-
| &lt;!--Description--&gt;Weymic Professional F7-Pro 7-Channel 2-Bus Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2022 no driver}}
|-
| &lt;!--Description--&gt;Weymic A80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2024 no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Yamaha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


Mixer no hardware usb 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;ALTO Lynx MIX82FX Audio Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Alto L16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer MXUL5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer MX602A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB502
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 17.5V 3pin psu needed}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB802 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 2 xlr,}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1002 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 2 xlr,}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 4 xlr, }}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1602 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer RX1602 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer 802 XENYX 8-Input 2-Bus Mixer Small Format Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} Behringer 18.5V ???ma psu - 2 xlr - phanton power - 
|-
| &lt;!--Description--&gt;Behringer Xenyx 502 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer Xenyx 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;IMG stage Line MMX-122 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, 4 xlr, iec cable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Mackie 802VLZ4 Mackie 802-VLZ4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb , psu}}
|-
| &lt;!--Description--&gt;Mackie 1202-VLZ Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, mains iec}}
|-
| &lt;!--Description--&gt;Mackie Mix5 Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}} 18v 300mA psu - 5 Channel - 
|-
| &lt;!--Description--&gt;Mackie Mix8 Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}} 9v x2 600mA psu - 
|-
| &lt;!--Description--&gt;Mackie MIX12FX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, 4 xlr, 9v 500mA x2 psu, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;[https://www.soundcraft.com/en/product_documents/en/owners_manual Soundcraft] Spirit Folio F1 Fader 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} 16 Channel Mixer - 
|-
| &lt;!--Description--&gt;Soundcraft EPM6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Soundcraft EPM8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Harman Soundcraft EPM 12 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} iec kettle power lead - 
|-
| &lt;!--Description--&gt;Soundcraft EPM 16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Soundcraft Notepad 8FX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Soundcraft Notepad UI12
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; connect via wifi 
|-
| &lt;!--Description--&gt;Soundcraft Notepad UI16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; connect via wifi 
|-
| &lt;!--Description--&gt;Soundcraft Notepad 124FX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection, 14.8V x2 3 pin psu}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;t.mix xmix 1402fx mp usb
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection, mains iec, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
|}


==Webcameras==

A USB camera has two dedicated chips: a controller or bridge and an image sensor.

There was no Commodore support for video interfaces. The only commercial, now discontinued application that defined some sort of standard was VHI Studio by iospirit.

===OLD standards===

See [http://www.e3b.de/usb/main_supported_e.html support pages] and [http://www.e3b.de/usb/main_faq_e.html here] and some [http://webcam-osx.sourceforge.net/cameras/index.php?orderBy=status further compatibility]


Pencam STV680
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| AIPTEK stv680 
| 0x0553 
| 0x0202 
| 
| {{N/A|untested}}
|-
| Konica e-mini 
| 0x04c8 
| 0x0722 
|
| {{N/A|untested }}
|-
| DigitalDream l'espion XS 
| 0x1183 
| 0x0001 
|
| {{N/A|untested}}
|-
| [http://reviews.cnet.com/webcams/creative-webcam-go/1707-6502_7-1446174.html Creative WebCam Go mini] 
| 0x041e 
| 0x4007 
|
| {{N/A|untested}}
|-
|}


SonixcamTool (Sonix webcams and derivates)

'''Note [http://amigadev.free.fr/sonix/ some] Sonix Webcams with a Sonix SN9C1xx controller ''and'' a pas106b or tas5110c1b sensor support bulk mode which works even with pciusb.device!'''
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Macally IceCam II
| 0x0c45
| 0x05d8
| 
| {{N/A|untested}}
|-
| Sweex MiniCam 100K 
| 0x0c45 
| 0x6005 
| 
| {{N/A|untested - sensor tas5110c1b}}
|-
| Macally IceCam Portable 
| 0x0c45
| 0x6007
| 
| {{N/A|untested - sensor tas5110d}}
|-
| Sweex 100K 
| 0x0c45 
| 0x6009 
| 0x0101
| {{yes|bulk works - sensor pas106b}}
|-
| [http://www.epinions.com/pr-Chicony_TwinkleCam_Webcam/display_~full_specs Chicony Twinkle DC-2110A] 
| 0x0c45
| 0x600d
| 
| {{no|no}}
|-
| Unknown
| 0x0c45
| 0x601e
| 
| {{no|no}}
|-
| USB PC Camera (SN9C102)
| 0x0c45 
| 0x6028
| 
| {{no|no - sn9c10x + pas202b}}
|-
| Trust SpaceC@m 120 and 150
| 0x0c45 
| 0x6029
| 
| {{N/A|untested - sensor pas106a}}
|-
| HiRes Webcam Live
| 0x0c45 
| 0x602c
| 
| {{no|no - sensor ov7630}}
|-
| [http://www.sweex.com/en/assortiment/sound-vision/webcams/JA000020 Sweex USB Webcam 300K]
| 0x0c45
| 0x608f
| 
| {{no|no - sensor ov7630}}
|-
| Speedlink Sphere Webcam SL-6820, 350K
| 0x0c45
| 0x613c
| 0x0101
| {{N/A|untested - sensor HV7131R}}
|-
| WB-3250P
| 0x0c45
| 0x613e
| 
| {{no|no - sensor ov7630}}
|-
| Unknown
| 0x0c45 
| 0x6207
| 
| {{no|no}}
|}

&lt;pre&gt;
micromaxx USB Camera 	STM 	1363 	514 	works 	---
USB Tower 	Lego 	1684 	1 	works 	need NCQ
Trust Spycam 100plus 	STM 	1363 	514 	works
&lt;/pre&gt;


ov51x.class - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| D-Link VGA Webcam (640x480) 
| 0x05a9
| 0x8519
| 
| {{no|no driver}}
|-
| Sony PS2 EyeToy Logitech/Logicool Black (ov519) SCEH-0004 
| 0x054c
| 0x0154
| 
| {{no|no driver}}
|-
| Sony PS2 EyeToy Namtai Silver (ov519) SLEH-00031 SLEH-00030
| 0x054c
| 0x0155
| 
| {{no|no driver}}
|-
|}


===UVC.class - [https://www.usb.org/document-library/video-class-v15-document-set USB Device Class Definition for Video Devices or USB Video Class]===

 AROS needs realtime isochronous transfers in EHCI and XHCI, then a usb uvc.class which might create a virtual UVC.VHI type device driver for use by AROS apps 

since 2019 the market is filled with UVC Compliant USB HDMI Capture

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acasis 4K30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Acasis 4K60 HD VS009
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|4k 60hz ok for chat streams}}
|-
| &lt;!--Description--&gt;Acasis 4K60 HDMI HDR Game Live Video Capture
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| for chat streams }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AJA U-tap HDMI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;ASUS TUF CU4K30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ATEN CAMLIVE HDMI to USB-C UVC Video Capture adapter UC3020 HDMI (F) TO USB-C M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 possibly UVC and UAC standard support allows up to 1080P @ 60}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Avermedia Live Streamer Cap 4K - BU113 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 uvc usb3}}  
|-
| &lt;!--Description--&gt;AVerMedia GC515 video capturing device 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.2 Gen 1 (3.1 Gen 1)}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra GC553
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 usb3 powered by Type C USB cable and 4K HDMI cable}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra S GC553PROW 302AGC553DL2 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1553
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 powered by good quality type C USB3 cable and 4K HDMI 2.0 cable}}
|-
| &lt;!--Description--&gt;AVermedia Live Gamer Mini GC311 302AGC311DG9 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1311
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 uvc compliant up to 1080p 60fps capture and supports internal hardware H.264 encoding }}
|-
| &lt;!--Description--&gt;AVerMedia Ez Recorder 330 (ER330) 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 designed to work independently and is generally not compatible as a plug-and-play UVC capture card }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer extreme3 GC551G2 (LGX3) 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x3551
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc compliant for intensive gaming streams, some vrr but no hdr with maximum recording resolution of 4K30/1080p60 from fully wired usb3 compatible cable - passing through 4K60/1080p120 Game Capture video capturing device HDMI}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra Pro GC553Pro 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 usb3 }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra 2.1 GC553G2 61GC553G20BV video capturing device 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 USB 3.2 Gen 1 (3.1 Gen 1)}}
|-
| &lt;!--Description--&gt;AVerMedia GC575
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 usb3 powered by Type C USB cable and 4K HDMI cable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AVMatrix 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ClonerAlliance Flint 4KP Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;DIGITNOW U600 video capture card 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc uac  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Epiphan AV.io HD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Epiphan AV.io 4K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato Cam Link 4K 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 uvc }}
|-
| &lt;!--Description--&gt;[https://github.com/elgatosf/capture-device-support Elgato HD60 S+]
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt;0x006C, 0x006E
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 4K 30FPS capture, 1080p 60FPS uvc}} 
|-
| &lt;!--Description--&gt;Elgato HD60 X 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc }}
|-
| &lt;!--Description--&gt;Elgato Cam Link 4K HDMI video capture card 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 uvc compliant but can have usb disconnects}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EVGA XR1 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.0 device with 1080/60 capture and 4K/60 passthrough}}
|-
| &lt;!--Description--&gt;EVGA XR1 lite USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 USB 3.0 device }}
|-
| &lt;!--Description--&gt;EVGA XR1 Pro USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.0 device with 1080/60 capture and 4K/60 passthrough}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EZcap Game Link Raw - ezcap321 usb3.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 2160p30, 1080p120 and 1440p60 HDMI input and pass-through. - 1080p120, 2160p30 and 1440p60 recording. - Latency less than 50ms uvc}} 
|-
| &lt;!--Description--&gt;EZCap GameDock Ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 record at 4K30, 1440p60, and 1080p120}}
|-
| &lt;!--Description--&gt;EZcap 360 Game Capture Extreme 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 USB 3.0, 4K 60FPS passthru and 1080p 240FPS}}
|-
| &lt;!--Description--&gt;EZCAP 364 GameDock Extreme 2.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Genki ShadowCast 1 &amp; 2, the Pro version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HAUPPAUGE HD PVR Pro 60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021  4K in/Out 1080P 60fps Capture and Streaming PC Connected and Stand Alone }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kondor Blue 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nanjing Magewell Electronics Co ltd USB 3.0 XI100DUSB-HDMI Pro Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 }}
|-
| &lt;!--Description--&gt;Magewell USB3.0 Silver HDMI Full HD Video Capture Device 1080p 32011 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 usb audio extract HDMI embedded audio output via headphones}}
|-
| &lt;!--Description--&gt;Magewell USB capture HDMI PLUS 2K 32040 320400000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 captures video up to 1920×1200, 1920×1080 or 2048×1080 at 60 fps over an HDMI capture from devices such as game consoles in up to DCI 4Kp60 4:2:0 input resolution, and it automatically upscales/downscales the signal to 2K for recording or streaming}} 
|-
| &lt;!--Description--&gt;Magewell USB capture HDMI Gen2 32060 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 1080p gets hot, 165M HDMI receiver, max input 2048x1080 60fps 4:4:4, RGB/YUV 4:4:4 8/10/12-bit, YUY 4:2:2 12-bit, up to 8-channel 24-bit HDMI-embedded audio at 192kHz, HDMI 1.4a, output from 480p to 1080p, YUY2/UYVY/RGB24/RGB32 support video cropping, up/down scaling, de-interlacing, aspect ratio conversion, color format conversion, frame rate conversion, flip and mirror, up to 2-channel IEC60958 audio streams, 5V 0.5A 2.5W, }}
|-
| &lt;!--Description--&gt;Magewell USB Capture 4K Plus 32090 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 limited by the bandwidth of USB 3.0, the maximum frame rate can only reach 30 fps when capturing}}
|-
| &lt;!--Description--&gt;Magewell USB Capture 4K PRO
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Magewell Pro Convert IP to USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Captures one network eth NDI® High Bandwidth, NDI® HX2, NDI® HX3 sources or H.264/H.265 video source into software at resolutions up to 1080p60}}
|-
| &lt;!--Description--&gt;Magewell USB Fusion 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|versatile USB video capture device that allows users to switch between two HDMI inputs and one USB webcam input for live presentations}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ROLAND UVC-01 USB Video Capture
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sunplus Innovation Technology Inc. MiraBox HSV321 ARX321 Video Capture device 
| &lt;!--Vendor ID--&gt;ox1bcf
| &lt;!--Product ID--&gt;0x2c99
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc uac  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;UGREEN CM716 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| uvc uac but disable HDCP on your source device (PS4/PS5, Xbox) }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;VisionTek UVC HD60 Capture Card
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acer Aspire Crystal Eye AOA110 AOA150 0.3M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2008 webcam }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;AVerMedia Live Streamer CAM 313 (PW313) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2019 uvc 1080p/30 webcam}}
|-
| &lt;!--Description--&gt;AVerMedia Live Streamer DUO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2021 uvc 1080p/60 webcam}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;[http://reviews.cnet.co.uk/webcams/creative-live-cam-optia-af-review-49294183/ Creative Live Cam Optia AF] 2.0M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| {{no|2008 }}
|-
| &lt;!--Description--&gt;DSLR macro extensions + a cheap 50mm E-Series lens + some PVC tubing and a negative holder 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes| if uvc camera chosen}}
|-
| &lt;!--Description--&gt;DSLR scanning using a macro lens, for the adapter, for a 3d printed negative holder) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes| if uvc camera used }}
|-
| &lt;!--Description--&gt;Logitech C270 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;0x0825
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|720p }}
|-
| &lt;!--Description--&gt;Logitech C910 C920 HD Pro 5Megapixels 720p 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Output mjpg 1080p}} 
|-
| &lt;!--Description--&gt;Logitech C920s c922 HD Pro 5Megapixels 1080p 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Output mjpg 1080p}} 
|-
| &lt;!--Description--&gt;Logitech 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Logitech Brio 100 300 500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}} 1080p 
|-
| &lt;!--Description--&gt;Logitech MX Brio 4k 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|4k}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Microsoft's LifeCam HD-3000 HD-5000 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt; 0x0779
| &lt;!--Revision--&gt;1.06
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Microsoft LifeCam Cinema 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Microsoft LifeCam Studio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} sony imx179 1080p 
|-
| &lt;!--Description--&gt;Pi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} 1/2.8” Sony IMX291 image sensor, it's a 2MP, UVC-compliant, ultra-wide-angle, low light, high-speed USB 2.0 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} OV5648 
|-
| &lt;!--Description--&gt;razer kiyo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} 4 megapixel sensor 1080p 30fps 720p 60fps - 12 led ring light adjustable 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;TeckNet C068 1.3mpixel HTD USB2.0 Camera Vimicro Z-Star Corp 
| &lt;!--Vendor ID--&gt;0x0AC8
| &lt;!--Product ID--&gt; 0x3420 
| &lt;!--Revision--&gt;0x01FA
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;YEALINK(XIAMEN) NETWORK UVC50 is compatible with the UVC 1.1 protocol CP960-UVC50 and CP960-UVC80 kits PTZ, CP960-UVC30 Kit is UVC 1.5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Amcrest ProHD 1080P WiFi Wireless IP Security Camera - 1080P (1920TVL), [https://www.ispyconnect.com/man.aspx%3Fn%3DAmcrest IP2M-841] nvr 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} h264/rtsp, motion detection, features Sony image sensor and Ambarella processor - rtsp://[username]:[password]@[IPaddress]:[port]/cam/realmonitor?channel=[channel]&amp;subtype=[stream] - [username] - username to login to the DVR or NVR, [password] - password, [IPaddress] - IP address of the device. If you are not on the same local network, this should be the external IP address of the device's network, [port] - port number, [channel] - channel number of the stream, [stream] - view the Main or Sub stream. (main stream is 0, sub stream is 1) , eg. rtsp://admin:admin@192.108.1.108:80/cam/realmonitor?channel=1&amp;subtype=1 - utilizing RTSP ( rtsp://user:pass@ipcam1 )  
|-
| &lt;!--Description--&gt;Axis all modern ones 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} RTSP/RTP + H264/mjpeg or MJPEG over HTTP
|-
| &lt;!--Description--&gt;PTZ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;DLink DCS-5222 5222L network camera 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} camera streams H.264 over RTP controlled by RTSP 
|-
| &lt;!--Description--&gt;Dlink DCS900 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Wansview 1080p [http://marc.merlins.org/perso/linuxha/post_2013-11-10_Reviewing-IP-Webcams-for-Linux-and-Zoneminder_Dlink-DCS900_-Ubnt-Aircam_-Foscam-FI8904W-FI8910W_-FFI9820W_-FI9821W_-Wansview-NCB541W_-and-Zavio-F3210.html#NCM625GA NCM625GA] IP Camera WiFi Wireless IP Security Camera , Full HD Plug n Play Home Surveillance / Baby Monitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} RTSP/RTP + H264/mjpeg - play its HD stream without problem with vlc rtsp://ip/live/ch0 and getting  jpegs http://ipaddr/mjpeg/snap.cgi?chn=0 - methods involve transcoding h.264 video from the camera into jpeg's, which is cpu intensive - able to pull images manually, using http://username:password@ip/mjpeg/snap.cgi - 
|-
| &lt;!--Description--&gt;Wansview NCB541W
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;Avermedia Game Capture HD C281 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2011 standalone h.264 recording of up to component cable not hdmi but not uvc}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Avermedia GL310 Live Gamer Portable (LGP Lite)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 not working usb2 and USB Lite no uvc}} 
|-
| &lt;!--Description--&gt;Avermedia AVerMedia Live Gamer Portable ([https://github.com/Trouffman/octv_gears_lgp Model C875])  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 usb2 no uvc}}   
|-
| &lt;!--Description--&gt;AVerMedia LGX Live Gamer extreme GC550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2015 but [https://github.com/ChrisAJS/lgx2userspace driver]}}
|-
| &lt;!--Description--&gt;AVerMedia LGX2 Live Gamer extreme2 gc550 plus gc551 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 but [https://github.com/ChrisAJS/lgx2userspace driver]}}
|-
| &lt;!--Description--&gt;Avermedia ExtremeCap UVC - BU110 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 maybe not uvc and uac}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Portable 2 Plus GC513 Micro-USB Capture Box LGP2 Plus
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1513
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 powered by a standard Micro-USB cable, video capture output up to 1080p60 capture to hdmi in, standalone sd card recording on exFAT or FAT32 of .MOV, 2160p pass-through hdmi out to tv - no vrr - [https://www.avermedia.com/uk/support/download#ans_part firmware latest 2.1.7.13, 2.1.7.14], SN74AVC8T245 8bit, DRV604 stereo, iTE IT6663FN hdmi 2.0 splitter, TLV320DAC3101 DAC, CS42L73 audio codec, CDCE913 PLL clock, W29N01HVSINA nand bios, I-Catch V35MA SOC CPU 32bit MIPS24K, ADV7480 hdmi mhl, }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer 4K LG4K GC573 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2018 not uvc but [https://github.com/derrod/lg4k-linux drivers here], }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Blackmagic intensity Extreme Capture Card
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2011 not uvc }}
|-
| &lt;!--Description--&gt;BlackMagic Intensity Pro 4k 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2015 }}
|-
| &lt;!--Description--&gt;Elgato Video Capture (1VC108601000)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Elgato Game Capture HD60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc, }}
|-
| &lt;!--Description--&gt;Elgato Game Capture HD GCHD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc https://github.com/tolga9009/elgato-gchd needs firmware mb86h57_h58_idle.bin and mb86h57_h58_enc_h.bin}}
|-
| &lt;!--Description--&gt;Elgato HD60S Elgato Game Capture 4K60 S+ Video Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|non uvc, }}
|-
| &lt;!--Description--&gt;August EZCap.tv model 116 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} poor audio recording 
|-
| &lt;!--Description--&gt;E-SDS Diamond Maplin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Hauppauge 1212 HD PVR 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} analog and component only - PlayStation (.m2ts), AVCHD (ts), or XBox(.mp4) recording formats - switched the component output from the default YPbPr to RGB. 
|-
| &lt;!--Description--&gt;Hauppauge 1431 1445 HD PVR Gaming Edition HDMI Capture 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 not working, can get warm}}  
|-
| &lt;!--Description--&gt;Hauppauge HD Rocket 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;Hauppauge HD-PVR2 (model 145210 Rev E4) 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xE502
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Hauppauge 1480 1482 HD PVR 2 GE Gaming Edition HDMI Capture green LED - 1498 1503 1504 Plus version with Mac support 
| &lt;!--Vendor ID--&gt;0x2040 
| &lt;!--Product ID--&gt;0xe514 0xe524
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| can get warm - [https://ez.analog.com/video/w/documents/581/adv7482-design-support-files ADV7482] [https://patchwork.kernel.org/patch/9201075/ video chip] with Magnum DXT H.264 encoder blob, IDR keyframe generation poor - best for model 157210 and not 157221 and Game Edition Plus (model 157320) 2040:E505 E505-00-00AF1234 [http://www.hauppauge.com/site/support/linux.html#tabs-3 ]}} 
* HDMI: 1920x1080p50/60, 1920x1080i50/60, 1280x720p50/60, 720x480i, 720x576i, 640x480p60.
* Component: 1920x1080p50/60, 1920x1080i50/60*, 1280x720p50/60, 720x480p60, 720x480i, 720x576i.
* Composite: 720x480i and 720x576i 
* Audio Inputs : HDMI PCM and RCA support with Adjustable Bitrate Quality 2 Channel AAC/AC3 audio codec 
|-
| &lt;!--Description--&gt;Hauppauge 1512 HD PVR 2 PC blue LED with optical in input on the back 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xe525
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} can get quite warm - IR Blaster added - 
|-
| &lt;!--Description--&gt;Hauppauge Colossus2 E585-00-00AF4321 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xe585
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Ion SLIDES2PC 35mm Portable Slide &amp; Film Scanner 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Ion Pics 2 PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;ION PowerScan USB film and slide scanner
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2011 not uvc }}
|-
| &lt;!--Description--&gt;Koolertron Sunny 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;FilmScan35 35mm Film Negative Scanner 1304 marks spencer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;U3 HD Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Razer Ripsaw HD - Game Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}} put in usb2 slot and use video BGR3 (Emulated) and OpenRazer drivers 
|-
| &lt;!--Description--&gt;Razer Ripsaw HD USB HDMI Capture Card 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0x0d01
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| not uvc compliant}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Silvercrest 35mm Photo Slide Scanner 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc but not great quality}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Z-Star Microelectronics Corp. Traveler TV 6500 SF Dia-scanner
| &lt;!--Vendor ID--&gt;0x0ac8
| &lt;!--Product ID--&gt;0x3370
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2010 not uvc and poor scans}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
|}


=== AR VR XR Headset ===

 AROS needs realtime isochronous transfers in EHCI and XHCI, then an usb based uvc.class to vhi type driver for virtual display and maybe more 

The primary engineering challenge of VR is motion sickness caused by a mismatch of visual and inner ear information, which is extremely well established as causing people to throw up in a wide range of contexts outside of VR. The experiences that make some people sick are low framerate. Foveated rendering doesn't solve vergence accommodation. Your eye will still be focused at infinity regardless of where you are looking, you'll just have the illusion that the foreground or background are out of focus. Eye tracking plus dynamic lenses (perhaps liquid lenses) or real light fields are necessary. 

First start with apps that have simple static features at first, then advance to dioramasa and teleportation options for 10, 20 minutes and then gradually upgrade over a timespan of four weeks to train your brain. Avoid smooth motion stuff like rollercoaster or mountain heights until much later. Even with this preparation, VR makes 40% of people seasick nausea. If so, you may be able to use VR glasses just to watch videos and some slow moving apps [https://www.emuvr.net/ emuVR] instead.

*2014-2019 1st Gen, low resolution, 
*2020-2025 2nd Gen, higher resolution, 
*2026-

Most hardware typically has a 1-3 year retail lifespan with 1-3 years of updates after. Really need &quot;right&quot; tethered PCVR rather than wireless. 
The advantage to being tethered to a PC is processing power. Any standalone headset is going to be running purely off of batteries.

VR and AR are known as XR

Technology will get immersed enough so not making people sick. Higher resolution, faster frame rates, and [https://github.com/opentrack/opentrack better tracking]. 
Eventually, hyper reality brings VR, AR and MR digital layers together as a less chaotic, optic tracking with no delay, agents understanding, experiences with objects 

3Dgs 4Dgs gassian splats bullet time slice photo snaps .ply for WebXR 

[https://lvra.gitlab.io/docs/hardware/ ], 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Big Screen Beyond 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 pcvr 2560 x 2560, fixed IPD,  }}
|-
| &lt;!--Description--&gt;bigscreen Beyond 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pcvr oled 5120 x 2560 @75Hz 2688x2688 @90Hz over pancake lenses, 116 FOV, virtual screens, custom facial plate from iphone app, streamvr 2.0 basestations and controllers not included, no passthrough, 107g-196g, }}
|-
| &lt;!--Description--&gt;bigscreen Beyond 2e 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 pcvr oled 5120 x 2560 total up to 90Hz pancake lens 116 FOV adjustable IPD app needed for adjustment, eye tracking, custom face mask cushion, streamvr 2.0 basestations and controllers not included, seperate head strap and speaker modules extra costs, 110g-300g }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Dpvr P1 Pro 4k Ultra Vr Headset 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 wireless snapdragon, }}
|-
| &lt;!--Description--&gt;DPVR P2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Play for Dream MR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android modular 3840x3552 uoled per eye 90Hz or qled mura issues, Arm snapdragon XR2+ Gen 2, eye tracking and 11 cameras 7 sensors 22 ir leds 14ms latency and foveated rendering, 1.5hrs battery, }}
|-
| &lt;!--Description--&gt;Play for Dream GravityXR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 ultralight head gear gx100 3w }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} 
|-
| &lt;!--Description--&gt;[https://lvra.gitlab.io/docs/community/ Valve Index HMD] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 tethered PC VR headset 1440 x 1600 120Hz, 108° and 104° FOV, fresnel lenses, SteamVR2 compatible tracking ir basestations, controllers aka Knuckles, dp 1.2 and usb3 cable proprietary cable end, no battery, }}
|-
| &lt;!--Description--&gt;Valve Steam Frame (Valve Deckard / Valve’s Index 2) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 - 2160 x 2160 up to 144Hz pancake lens, 108° and 96° FOV, wifi 6 fovelated streaming, Qualcomm Snapdragon 8 Gen 3 with [https://github.com/FEX-Emu/FEX fex] arm-to-x86 x64 translation layer, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PSVR2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 PCVR with adapter, two, one for each eye, 2000 x 2040 resolution OLED panels from 90Hz 120Hz refresh rates,  fresnel lenses, 116° and 102° FOV, sony proprietary headset cable end, needs additional comfort options, }}
|-
| &lt;!--Description--&gt;VisionPro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Goertek glasses 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive ?
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| 2016 2x 1080x1200 needs external power supply, }} 
|-
| &lt;!--Description--&gt;HTC Vive Original 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 108° and 96° FOV}}
|-
| &lt;!--Description--&gt;HTC Vive Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 , uvc, at least 2 powered steamvr basestations so 3 to 5 wall warts in total, proprietary cable end, }}
|-
| &lt;!--Description--&gt;HTC Vive Pro 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 dual 1440x1600 oled displays, 116° and 100° FOV - steamvr 2.0 basestation 2 for 5m2 area 4 for 10m2 - steamvr 2.0 joypads - low latency wireless later - type USB-c headphone adapter required, [https://github.com/CertainLach/VivePro2-Linux-Driver Rust on Linux] with [https://github.com/santeri3700/vive-pro-2-on-linux Shell], proprietary cable end, }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lynx R1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 android Qualcomm Snapdragon XR2 Gen 1, }}
|-
| &lt;!--Description--&gt;Lynx R2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2026 company liquidated, 2 x 2312x2160 110 FOV pancake lenses, LynxOS android Qualcomm Snapdragon XR2 Gen, openxr 1.1, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Oculus Rift prototype development kit [https://www.virtual-boy.com/forums/t/the-oculus-rift-dk1-thread/ DK1] with [https://www.youtube.com/watch?v=X_T4DJyy2Bo wired razer hydra controllers]
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2013 pcvr LCD 1280 × 800 resolution 640 × 800 per eye up to 110° FOV, and 3DoF rotational tracking via a 1000Hz 9-axis IMU (Accelerometer, gyroscope, and magnetometer), no positional optical tracking either inside-out or outside-in, 380g, nausea issues, , }}
|-
| &lt;!--Description--&gt;Oculus Rift prototype development kit [https://github.com/facebookarchive/RiftDK2/tree/master DK2], [https://www.ifixit.com/Teardown/Oculus+Rift+Development+Kit+2+Teardown/27613 ifixit teardown] 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 pcvr, 5.7&quot; Super AMOLED display with a resolution of 960 x 1080 per eye 100° field of view, 1 usb Positional Tracker DK2 camera, lots of wires}}
|-
| &lt;!--Description--&gt;Facebook [https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter Oculus Rift CV1] [https://noraisin.net/diary/?m=202201 some Linux support] [] [https://github.com/OpenHMD/OpenHMD/issues/330 AMD usb issues] [https://github.com/OpenHMD/OpenHMD/wiki/Xorg ] [https://github.com/Doc-Ok/OculusRiftCV1Camera Live Video] [https://www.youtube.com/@thaytan Youtube] [https://github.com/Fredrum/riftOnLinux Pi] [https://github.com/OhioIon/riftDriverPi ], but not quite there with the [https://www.youtube.com/watch?v=DSsCN6HFkWc consumer CV1], [https://forum.dcs.world/topic/142259-cv1-not-working-in-dcs/#comment-2878168 orange led could be HDMI Signal is not within HDMI Spec and might be Overclocked or usb3 not getting enough power frustrating],  
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x3031, 0x2031, 0x0031 and 0x0211 for 3p-a basestations lighthouses, 0x045e 0x02e6 for xbox wireless adapter 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2016 powered run from your PC maybe uvc via wired dual PenTile OLED 2160x1200 (1080x1200 per eye) @ exactly 90Hz but screen door effect (space between pixels), 87 FOV, IPD from 58mm to 72mm, good 3D audio and okay mic, constellation headset 6DOF (3-axis rotational tracking + 3-axis positional tracking) with up to 3 usb infrared basestation (1 in front and 2 behind pointing upwards) on usb3 and usb2 to your PC but the tracking can be fragile so set it up on a weekly basis, wired only HDMI 1.3, USB 3.0 bus powered with proprietary plug in headset, 470g 1lb front heavy, 2 robust 1st Gen touch controllers with external sensors i.e. outside-in - 1 aa alkaline over rechargable battery each , press occulus and B buttons for 2 secs to connect, headset traps air so gets very warm inside and random disconnects due to twisting action on the top of the headset and/or cables, t4 torx screws }} 
|-
| &lt;!--Description--&gt;Facebook Occulus Go 32Gb 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2018 discontinued 2020 android based, 1280x1440 per eye 60Hz LCD, not gaming, no inside-out and limited self tracking, }} 
|-
| &lt;!--Description--&gt;Facebook Oculus Rift S [https://noraisin.net/diary/?m=202201 some Linux support] 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x0051 headset (cdc, audio, tracking data), 0x2052 usb hub, 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 PCVR wired dual LCD 1080 by 1200, 88 horizontal FOV, display port (fibre optic strands) and annoying USB3 copper cables (power, audio and other data) but proprietary port in the headset, cameras on the headset (&quot;inside-out&quot;) tracking so no base stations, non removeable head band and cushions and ipd hard to set, requires specific fragile Rift S/Quest1 2nd Gen Touch controllers which has a ring of translucent plastic with leds inside - t5 torx to disassemble for sticks drifting}} 
|-
| &lt;!--Description--&gt;Facebook Occulus Quest 1 
*032Gb
*064Gb
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x0183 (single adb boot), 0x0
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 android standalone wireless, 1440 x 1600 72Hz oled, front heavy though, play area 2m x 2m or bigger, low clocked Qualcomm Snapdragon 835 (MSM8998) (4x Kryo 280 Gold cores ARM Cortex-A73) + (4x Kryo 280 Silver A53), 2 to 3 hrs play time, 575g, 2nd Gen touch controllers, }}
|-
| &lt;!--Description--&gt;Meta Oculus Quest 2 KW49CM aka Codename Del Mar [https://www.meta.com/en-gb/help/quest/967070027432609/ fragile 3rd Gen Touch controllers] [https://www.youtube.com/watch?v=Cgejky8ZeoM internal battery] and selling over 20 million, more than all other quest headsets combined 
*064Gb 
*128Gb (110Gb free) 
*256Gb 
Setup continuous wifi, create Meta Oculus account, [https://developers.meta.com/horizon/ verify dev account, click on My apps], [ create Organization -&gt; My Organization Groupings], [https://www.youtube.com/watch?v=QPInS5xxF-0 finally, meta quest mobile app to switch on adb], 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x5010 (), 0x0083 (massstorage), 0x0086 (), 0x0186 (adb and xrsp [https://github.com/shinyquagsire23/xrsp_tests tests]), 0x0090 (composite adb), 0x0081 (), 
| &lt;!--Revision--&gt;0419
| &lt;!--Opinion--&gt;{{unk|2021 android stand alone, lcd 1832x1920 per-eye 90Hz refresh rate, 97 FOV, fresnel lenses, 6DOF (degrees of freedom), 58-63-68 IPD settings, low clocked Arm snapdragon xr2 gen 1 apps with Meta Link cable USB-C usb3.2 pcvr maybe, b/w but no color passthrough, 6 t2 torx and 5 ph00 screws in headset (long bit), discontinued December 31, 2024, feature updates until December 2026, critical bug fixes and security updates until December 2027, 470g, Oculus + B button on right controller (move) and Menu + Y button on left controller (click) for about 3 seconds, 10W 5v 2a, RTL8153 chipset usb support, 
*V60 unable to 
*V77 pcvr issues 
*V79 unable to }}
|-
| &lt;!--Description--&gt;Facebook Occulus Quest Pro aka Codename Seacliffe 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 android standalone wireless 1440 x 1600 72Hz oled, 106° and 96° FOV mini lcd local dimming, pancake lenses, limited eye tracking, play area 2m x 2m or bigger, higher clocked snapdragon xr2 gen 1 arm cpu Arm apps, 1 to 2 hrs play time, new pro controllers with 3 cameras each, battery at rear, wireless charging, color passthrough, 9V 3A or 5V 3A, 
*v77 capped wifi }}
|-
| &lt;!--Description--&gt;Meta Oculus Quest 3 aka Codename Eureka [ Air Light ALVR] or [ WiVRn] with fragile touch plus q3 controllers 
*128Gb
*512Gb
streaming from PC with [https://github.com/alvr-org/Monado-ALVR ALVR], runtime of [https://monado.freedesktop.org/ Monado steamvr alternative openxr openVR], with Envision GUI, 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 standalone, pancake lenses on lcd 2064 x 2208 res panel per eye 1200ppi - 104° and 96° FOV - up to 120Hz, Arm snapdragon xr2 gen 2 apps,  foveated rendering, Meta Link cable USB-C 3.2, headstrap clamshell or halo style, speaker arms fragile, color passthrough, 510g, 18W 9v 2A or 15W 5V 3A, 
*v74 ok }}
*v76 pcvr issues }}
|-
| &lt;!--Description--&gt;Meta Quest 3S aka Codename Ventura 
*128Gb
*256Gb
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 Arm snapdragon xr2 gen 2 cpu, lcd 1832 x 1920 fresnel lenses, 97 FOV, headphone arms fragile, better air flow, no promixity sensor inside, Meta Link cable USB-C 3.2, passthrough, }}
|-
| &lt;!--Description--&gt;Meta Boba 3 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 ultra-wide 180° x 120° FOV, snapdragon XR2 G2,  }}
|-
| &lt;!--Description--&gt;Meta Tiramisu 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027  µOLED displays with 90 pixels per degree,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pimax 5K Super Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 }}
|-
| &lt;!--Description--&gt;Pimax 8K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020  }}
|-
| &lt;!--Description--&gt;Pimax 8K-X 8KX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021  }}
|-
| &lt;!--Description--&gt;Pimax Crystal Light 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tethered to PC with 2160 x 2160 4k 120Hz, 115° and 96° FOV, inside-out tracking, no battery, display port cable, variable qc and customer service, }}
|-
| &lt;!--Description--&gt;Pimax Crystal Super 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tethered to PC with 3640 x 3640 4k 90hz, 116°+ and 100° FOV,  eye tracking, inside-out tracking, no battery, display port cable, }}
|-
| &lt;!--Description--&gt;Pimax Dream Air with Lighthouse(s)  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 tethered 3840 by 3552 @90Hz micro oled with pancake lens, 100 HFOV 96 VFOV but FOV IPD changes in app, link box for headset 2 split y cables, removable face gasket, 290g, steamVR2 bases and controllers, eye tracking, }}
|-
| &lt;!--Description--&gt;Pimax Dream Air SLAM 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026  Simultaneous Localization and Mapping (SLAM) tracking inside-out so no base stations,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://somniumspace.com/ Somnium VR One VR1] [https://portal.vrgineers.com/user-guide/software/ open source] VR headset
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pcvr 2880 x 2880 per eye @90 @120Hz, 125° horizontal 100° vertical FOV, 2 x SteamVR 2.0 bases, passthrough, 900g }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero VR-1 Headset 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 psu needed, 2 x Mini LED binocular of 150 nits, 2880x2720 per, 90Hz, FOV 102° horizontal, 73° vertical, 720g with headstrap, 2 x SteamVR 2.0 basestations, no speakers/mic, hdmi and usb3.0}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero XR-3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero XR-4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Camelo La Melaza Music Shield 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2026 no usb only bluetooth ,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;InAir 2 elite suite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar  nits 46FOV , , 4h battery life, 80g, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Oakley Vanguard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;RayNeo Air 3s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 100in 46FOV 650nits, usb-c 79g  }}
|-
| &lt;!--Description--&gt;RayNeo Air 3S Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 135in virtual display 46FOV 1200nits, usb-c 80g }}
|-
| &lt;!--Description--&gt;RayNeo Air 4 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 AR oled vision 4000 processing, HDR10, 47 FOV }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rokid Max 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 147in 50 FOV 650nits, usb-c back left, 76g, }}
|-
| &lt;!--Description--&gt;Rokid AI Spatial with Station 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 600nits 147in 50FOV  75g, }}
|-
| &lt;!--Description--&gt;Rokid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| ar ai smart glass}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viture Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 135in 46 FOV 1000nits, magnetic connector, 77g, }}
|-
| &lt;!--Description--&gt;VITURE XR Luma 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 147in 1200p 50 FOV, }}
|-
| &lt;!--Description--&gt;Viture Luma Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 152in 52 FOV 1000nits 1200p, 3dof, , 79g, }}
|-
| &lt;!--Description--&gt;Viture Luma Ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 in  FOV, 2 cameras, 3dof 6dof,  }}
|-
| &lt;!--Description--&gt;[https://github.com/wheaney/XRLinuxDriver Viture Luma Pro] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viture Beast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 1250nits 58FOV 174in, magnetic,  88g,  }}
|-
| &lt;!--Description--&gt;VITURE Beast X Glasses models (Immersive 3D Moonlight) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 based 2D to 3D conversion with support DP Alt Mode (DisplayPort over USB-C), 1200p, 3df tracking, practic lenses 58deg POV, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xreal One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 600nits, 50FOV, 3dof, usb-c 84g,  }}
|-
| &lt;!--Description--&gt;XReal One Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 700nits 57FOV 171in, usb-c, x1 3dof, }}
|-
| &lt;!--Description--&gt;Nreal now Xreal Air 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , micro-oled 1080p, audio, virtual uvc ar displays, }}
|-
| &lt;!--Description--&gt;Nreal now Xreal Real3D 1S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 AI based 2D to 3D conversion 57 FOV, , virtual uvc ar displays not vr, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xiami XR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xtal 8k
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Apple Vision Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 tethered AR mixed reality glasses,   3300ppi, 800g, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Google XR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive Focus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 standalone }}
|-
| &lt;!--Description--&gt;HTC Vive Focus Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 android with 2 1440 x 1600 75Hz amoled, inside-out, durable motion controllers, Vive port,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive Pro EYE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 dual-OLED displays 2880 x 1600 combined resolution), SteamVR 2.0 tracking, foveated rendering, Tobii, it enables gaze-based menu navigation with avatar eye contact, proprietary cables, }}
|-
| &lt;!--Description--&gt;HTC Vibe Cosmos 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2018  poor tracking and lifespan on controllers,  }}
|-
| &lt;!--Description--&gt;HTC Vibe Cosmos Elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2020 1440x1700 per eye resolution, 90 Hz refresh rate, 6 DoF tracking, 2880 x 1700 combined pixel resolution, 97° FoV, two controllers and two base stations. Lighthouse tracking, }}
|-
| &lt;!--Description--&gt;HTC Vive Focus Vision Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;HTC Vive Focus 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 per-eye resolution of 2448×2448 at 90 Hz, a 120-degree field of view, Qualcomm Snapdragon XR2 Gen 1,  }}
|-
| &lt;!--Description--&gt;HTC Vive XR Elite VR Headset Deluxe Pack 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 snapdragon xr2 gen 1, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pico Goblin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 android based, 2.5K 1280x1440 per eye @70Hz, 92° FoV, and 3DoF (three degrees of freedom) tracking (Orientation tracking only—yaw, pitch, roll), single controller, snapdragon 820, ipd adjustment 54-71 mm, 600g,  }}
|-
| &lt;!--Description--&gt;ByteDance Pico G2 4K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 android standalone VR headset, 3840 x 2160 (4K) LCD screen, Snapdragon 835 processor, 3DoF so rotational movement (looking around, pointing) rather than positional movement (walking, leaning), does not support hand or eye tracking, 800g }}
|-
| &lt;!--Description--&gt;ByteDance Pico NEO 2 EYE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 6DoF 360g snapdragon 845 display 4k 75Hz tracking inside-out - magnetic field for controllers - pico software on android 8 - eye tracking }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 Snapdragon XR2 Gen, 4K 3664 x 1920 90Hz lcd, battery at rear, displayport, Pico apparently emulates Oculus controllers, }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 Link 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;ByteDance Pico 4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 2160x2160 panel per eye 75Hz 90Hz 105 FOV, Arm snapdragon xr gen 1, }}
|-
| &lt;!--Description--&gt;ByteDance Pico 4 ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 2160 x 2160 @90 105 FOV, snapdragon XR2 G2, streaming from PC with alvr, wireless streaming from PC with WiVRn, Pico apparently emulates Oculus controllers, not plug and play, }}
|-
| &lt;!--Description--&gt;ByteDance Pico 5 aka Project Swan aka Vision Pro Competitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 micro-oled BOE 3840 x 3840 4000ppi per eye, MLA pancake lenses, custom pico arm cpu, pico os 6 android, eye and hand tracking, 300g,  }}
|-
| &lt;!--Description--&gt;ByteDance Pico  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung Galaxy XR VR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 3552 x 3840 @60-90 109 FOV , Arm snapdragon XR2+ Gen 2, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Shiftall MeganeX 8K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 android  }}
|-
| &lt;!--Description--&gt;[https://en.shiftall.net/products/meganex8k MeganeX Superlight 8K] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android (3552 x 3840 pixels) into pixel count yields 27.27MP 10-bit HDR-compatible 4K resolution micro OLED panels @90Hz, pancake lenses 94 FOV, SteamVR™ tracking, 180g, 5V 2A, }}
|-
| &lt;!--Description--&gt;[https://en.shiftall.net/products/meganex8kmk2 MeganeX 8K Mk2 MkII] [https://github.com/sboys3/CustomHeadsetOpenVR community] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 pcvr linux, 4K per eye (1.35inch micro OLED 3552x3840 10 bit HDR) 27MP @90Hz 75Hz 72Hz pancake, upto 108 hor 100 vert FOV, usb-c and dp cables to breakout box, 5V 2.1A, 200g}}
|-
| &lt;!--Description--&gt;Shiftall 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 }}
|-
| &lt;!--Description--&gt;Shiftall 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Acer Windows(TM) MR AH101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 Dual 2.89” LCD panels 2880 x 1440 combined (1440 x 1440 per eye) Up to 90Hz (HDMI 2.0), or 60Hz (HDMI 1.4), Field of View FOV 95, Tracking Inside-out, lots of light leak, }} 
|-
| &lt;!--Description--&gt;Acer H7001 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 wmr 1440 x 1440 per-eye resolution @90Hz refresh rate, and 100-degree field of view FOV, inside-out tracking with front-mounted cameras so no external sensors, flip-up visor design but has a &quot;screen door effect,&quot; subpar foam padding, win10 to win11 24H2,  }}
|-
| &lt;!--Description--&gt;Dell Visor Mixed Reality VRP100 VR118
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 2x 1440x1440 a bit of nose light leak }}
|-
| &lt;!--Description--&gt;Fujitsu 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 cheap and lots of light leak }}
|-
| &lt;!--Description--&gt;[https://github.com/HadesVR HadesVR] with [https://github.com/ManoloMancelli/Persephone-Classic-Controller Persephone Controller]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=HFaVjB1uNOM Persephone 3 Pro DiY 6Dof SteamVR Headset], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HP Reverb G1 VR1000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 WMR 2160 x 2160 @90Hz, 115 FOV, , hp proprietary headset cable end, 2 camera tracking but poor and controllers can be unresponsive, 500g front heavy, flight sims rather than gaming,  }}
|-
| &lt;!--Description--&gt;HP 1440p Spatial Computing 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 dim display }}
|-
| &lt;!--Description--&gt;[https://forums.x-plane.org/forums/topic/294764-vr-in-linux-without-steam/ HP Reverb G2] WMR VR3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 2 2160 x 2160 90Hz, needs Windows10 or Win 11 24H2, 4 camera tracking, controllers can be unresponsive, hp proprietary headset cable end, , }} 
|-
| &lt;!--Description--&gt;HP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Mirage Solo is a Standalone VR headset
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 Qualcomm Snapdragon 835, 1280x1440 per eye resolution, 75 Hz refresh rate, }}
|-
| &lt;!--Description--&gt;Lenovo Explorer VR2511N (G0A2) VR windows mixed reality (WMR) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 LCD 2.89&quot; 1440 x 1440 per eye @90Hz, 6 DOF position tracking, 400g, }}
|-
| &lt;!--Description--&gt;[https://github.com/relativty/relativty open source relativty] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung MHD Odyssey XE800ZAA WMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 9V 500mA oled screens 2x 1440x1600 with usb3 and hdmi cables but bluetooth dongle required }}
|-
| &lt;!--Description--&gt;Samsung MHD Odyssey+ Plus WMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 dual 3.5-inch AMOLED displays 2880 x 1600 total @90Hz, 6DOF inside-out tracking with usb3 and hdmi cables but bluetooth dongle required, use only win10 or win11 24H2,  }}
|-
| &lt;!--Description--&gt;Sony PSVR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2016 2x 1080x960 up to 120Hz, lots of cables and computation brick, sony camera needed for tracking, ps4 or move controllers, }} 
|-
| &lt;!--Description--&gt;Virtuality 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|1992 , , Amiga 3000 with TI chips, }}
|-
| &lt;!--Description--&gt;Virtuix Omni 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 VR treadmill changed course to commercial VR and pivotted back again 2020, }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


=== HDMI CEC transmitter and receiver ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


=== TV Remote Control MCE IR transmitter and receiver ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Compro K100 K300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|need extra software support}}
|-
| &lt;!--Description--&gt;Elitegroup Computer Systems
| &lt;!--Vendor ID--&gt;0x1019
| &lt;!--Product ID--&gt;0x0f38
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;GMYLE MCE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|acts as usb-hid with limited keyboard like controls }}
|-
| &lt;!--Description--&gt;Hauppauge WinTV-PVR kit
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested}}
|-
| &lt;!--Description--&gt;Logitech Harmony 300 i300 600 650 800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|need extra software support}}
|-
| &lt;!--Description--&gt;Microsoft MCE Commander 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2005 need extra software support}}
|-
| &lt;!--Description--&gt;Microsoft 1039 rev 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2005 home top of square shape direction keys}}
|-
| &lt;!--Description--&gt;Microsoft 1039 rev 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2006 home under circle spaced direction keys}}
|-
| &lt;!--Description--&gt;Microsoft 1069 SMK Manufacturing, Inc
| &lt;!--Vendor ID--&gt;0x0609
| &lt;!--Product ID--&gt;0x0334 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2007 untested}}
|-
| &lt;!--Description--&gt;Philips RC1974506/00 
| &lt;!--Vendor ID--&gt;0x0471
| &lt;!--Product ID--&gt;0x0815
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE10E PC REMOTE CONTROL VGN-AR21M VGX-XL100 VGN-AR21B/AR21S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE20E PC REMOTE CONTROL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE30E PC REMOTE CONTROL VGN-AW21XY VGX-TP3E VGX-TP3G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE50E PC REMOTE CONTROL VGC-LA2R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;TSDX-IR14 USB MCE Media Center External Infrared IR Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;chipsets support CIR (consumer IR) Winbond W83977F/AF, SMC IrCC 2.0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|technical reasons it's not possible to use USB IrDA dongles}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Zotac RC2604323/01G Zbox Media Remote Control with IR USB Receiver OVU710
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Anycubic Cobra 2 Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Bambu Labs A1 Mini 3D printer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 EMS proprietary slicer app and cloud use, eSUN}}
|-
| &lt;!--Description--&gt;Bambu Labs X2D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality K1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality K2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lulzbot 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Prusa 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Qidi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Snapmaker U1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tool changer  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sovol SV08 Max
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| open source voron model, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


==ethwrap.class - Host Data Link &quot;Cable Bridge&quot; for data transfer==

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Advance USBNET (eTEK design)
| 0x0525
| 0x9901
| 
| {{N/A|untested}}
|-
| ALi Uli M5632 (chip)
| 
| 
| 
| {{N/A|untested}}
|-
| Aten (Ali Corporation) UN201
| 0x0402
| 0x5632
| 
| {{maybe|force binding from rawwarp to ethwrap}}
|-
| Belkin (eTek design see below)
| 0x050d
| 0x0004
| 
| {{N/A|untested}}
|-
| Digitus DN-3004 - USB Host Link
| 
| 
| 
| {{yes|works}}
|-
| EPSON USB client
| 0x0525
| 0x2888
| 
| {{N/A|untested}}
|-
| eTEK
| 0x056c
| 0x8100
| 
| {{N/A|untested}}
|-
| KC-190
| 0x050f
| 0x0190
| 
| {{N/A|untested}}
|-
| GeneSys GL620USB
| 
| 
| 
| {{no|no driver the half-duplex GL620USB is NOT supported, products using it include the Inland Pro USB Quick Link}}
|-
| GeneSys GL620USB-A
| 
| 
| 
| {{N/A|untested}}
|-
| Laplink Gold (uses NetChip 1080)
| 
| 
| 
| {{N/A|untested}}
|-
| Prolific 2301/2302 (Jaton USB ConNET) (BAFO DirectLinq) 
| 0x067b
| 0x0000 and 0x0001
| 0x0004
| {{maybe|detected but untested}}
|-
| Xircom PGUNET (uses AnchorChips 2720)
| 0x0547
| 0x2727
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}

==cdcacm.class - USB modem==

The CDC ACM driver exposes the USB modem as a virtual serial modem or a virtual COM port to the operating system. The driver enables sending both data and AT commands, either through ACM (separating data and AT commands over different channels) or through Serial Emulation (passing the AT commands as is and as part of the data stream).

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Alcatel OT-I650 
| 0x1bbb
| 0x0003
| 
| {{N/A|untested}}
|-
| Acatel Dymamode/Dynamite
| 0x06b9
| 0xa5a5
| 
| {{N/A|untested Zyxel Prestige 630-13 - untested PROLiNK Hurricane 8000 external link }}
|-
| AnyData ADU-100A ADU-E100A ADU-E100D ADU-E100H D10
| 0x16d5
| 0x6501
| 
| {{N/A|untested}}
|-
| AnyData ADU-310
| 0x16d5
| 0x650
| 
| {{N/A|untested}}
|-
| AnyData ADU-500A ADU-510A ADU-510L ADU-520A
| 0x16d5
| 0x6502
| 
| {{N/A|untested}}
|-
| AnyData ADU-610 ADU-620
| 0x16d5
| 0x650
| 
| {{N/A|untested}}
|-
| BT On-Air USB MODEM 
| 0x079b
| 0x000f
| 
| {{N/A|untested}}
|-
| Conexant USB MODEM CX93010 
| 0x0572
| 0x1321
| 
| {{N/A|untested}}
|-
| Conexant USB MODEM RD02-D400 
| 0x0572
| 0x1324
| 
| {{N/A|untested}}
|-
| Conexant Chipset 
| 0x06ea
| 0x0002
| 
| {{N/A|untested AUS N367 Roadster II 56 USB (Model AM5050R3) - untested }}
|-
| [http://accessrunner.sourceforge.net/ Conexant AccessRunner]
| 0x0586
| 0x330a
| 
| {{N/A|untested }}
|-
| Creative Modem Blaster USB DE5670
| 0x1690
| 0x0101
| 
| {{N/A|untested}}
|-
| FIREFLY, MediaTek Inc
| 0x0e8d
| 0x0003
| 
| {{N/A|untested}}
|-
| Huawei E122
| 0x12d1
| 0x1446
| 
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=49126#forumpost49126]
|-
| Huawei E160, E160E, E160G
| 0x12d1
| 0x1003
| 
|{{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=51888#forumpost51888] (Chipset: Qualcomm MSM6246)
|-
| Huawei E169 also known as Vodafone K3715 and Huawei K3715 
| 0x12d1
| 0x1001
| 
|{{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4941&amp;forum=4&amp;post_id=44683#forumpost44683] (Chipset: Qualcomm MSM7200)
|-
| Huawei E220 &quot;Vodafone EasyBox II&quot; &quot;T-Mobile wnw Box Micro&quot; also known as Huawei K3565 
| 0x12d1
| 0x1003
|
| {{yes|works, see E169 above (Chipset: Qualcomm MSM6280)}}
|-
| Huawei E1750
| 0x12d1
| 0x1001
| 
| {{N/A|untested (Chipset: Qualcomm MSM6290)}}
|-
| Huawei E170, E172, E176 
| 0x12d1
| 0x1003
| 
| {{N/A|untested (Chipset: Qualcomm MSM7200)}}
|-
| Huawei E180
| 0x12d1  
| 0x1406
| 
| {{yes|Works (Chipset: Qualcomm MSM7200)}}
|-
| KYOCERA AH-K3001V 
| 0x0482
| 0x0203
| 
| {{N/A|untested}}
|-
| LG CU515
| 
| 
| 
| {{N/A|untested}}
|-
| MediaTek Inc GPS 
| 0x0e8d
| 0x3329
| 
| {{N/A|untested}}
|-
| Metricom GS Modem 
| 0x0870
| 0x0001
| 
| {{N/A|untested}}
|-
| Motorola MOTOMAGX phones 
| 0x22b8
| 0x6425
| 
| {{N/A|untested}}
|-
| Motorola Q Phone 
| 0x22b8
| 0x7000
| 
| {{N/A|untested}}
|-
| Hummingbird huc56s (Conexant) 
| 0x0572
| 0x1329
| 
| {{N/A|untested}}
|-
| Netcomm Roadster II 128 ISDN
| 
| 
| 
| {{N/A|untested}}
|-
| Nokia n70 N95 HSDPA
| 
| 
| 
| {{yes|works - see [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=4415&amp;viewmode=flat&amp;order=ASC here]}}
|-
| OGO
| 0x045E
| 0x0079
| 0090
| {{no|no driver}}
|-
| Olitec ADSL Modem V2 
| 0x08e3
| 0x0100 / 0x0102
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;Onda PT502HS 
| &lt;!--Vendor ID--&gt;0x19D2
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| Radicom V92HU-E2
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;Samsung i8510 Innov8 Symbian smartphone
| 0x04e8
| 0x6651
| &lt;!--Revision--&gt;
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=5552&amp;viewmode=flat&amp;order=ASC&amp;type=&amp;mode=0] 
|-
| Samsung Tocco Lite (aka GT-S5230)
| 0x04e8
| 0x6795
| &lt;!--Revision--&gt;
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=5552&amp;viewmode=flat&amp;order=ASC&amp;type=&amp;mode=0] 
|-
| Shiro / Aztech USB MODEM UM-3100 
| 0x0572
| 0x1328
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM 
| 0x0ace
| 0x1602
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM 
| 0x0ace
| 0x1608
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM - new version 
| 0x0ace
| 0x1611
| 
| {{N/A|untested}}
|-
| Zoom Telephonics Model 3095F USB MODEM 
| 0x0803
| 0x3095
| 
| {{N/A|untested}}
|-
| Ugobe Pleo
| 0x6962
| 0x0100
| 0x0100
| {{Yes|Works}}
|}


==Misc==

palmpda.class - no [http://aminet.net/package/util/libs/PdaLinkPoseidon pdalink.library and tools] in AROS 

 Palm PDA (discontinued) synchronisation requires a port of pdalink.library and its tools through virtual usbpalm.device.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Palm IIIx (OS3.1) serial rs-232 only
| 
| 
| 
| {{no|no }}
|-
| Palm IIIc (OS3.5)
| 
| 
| 
| {{no|no }}
|-
| Palm V
| 
| 
| 
| {{no|no }}
|-
| Palm m100
| 
| 
| 
| {{no|no }}
|-
| Palm m125 first USB - last with aaa batteries
| 
| 
| 
| {{no|no }}
|-
| Palm m500 (OS4)
| 
| 
| 
| {{no|no }}
|-
| Tungsten T (OS5) first arm cpu 
| 0x
| 0x
| 0x
| {{no|no }}
|-
| Zire 31 (OS 5.28) color arm-based
| 
| 
| 
| {{no|no }}
|-
| [[:w:Handspring (company)|Handspring Visor]] – USB support out of box
|
|
|
| {{no|no }}
|-
| Handspring Treo 600 – last one for [[:w:Handspring (company)|Handspring]] 
| 
| 
| 
| {{no|no }}
|-
| Treo 700w
| 
| 
| 
| {{no|no }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


bluetooth.class - needs Bluetooth (Viking King Harald &quot;Bluetooth&quot; Gormsson (Old Norse: Haraldr Blátǫnn Gormsson; Danish: Harald Blåtand Gormsen) stack to work (not written due to licensing fees to use the symbol merging the Younger Futhark runes for H (ᚼ) and B (ᛒ), representing Harald's initials)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


ccid.class - Chip/Smart Card Interface Devices (not implemented)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;cyberJack RFID basis
| &lt;!--Vendor ID--&gt;0x0C4B
| &lt;!--Product ID--&gt;0x9102
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


dfu.class - DFU firmware upgrade
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;iPhone 3, 4, 5, 5c 
| &lt;!--Vendor ID--&gt;0x05ac
| &lt;!--Product ID--&gt;0x1290 0x1292 0x1294
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 32bit use with caution could cause damage}}
|-
| &lt;!--Description--&gt;iPhone 5s, 6, 7, 8, X 
| &lt;!--Vendor ID--&gt;0x05ac
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 64bit use with caution could cause damage}}
|-
| &lt;!--Description--&gt;M-Audio/Midiman USB audio
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;iPad 1, iPad 2 A1395 A1430, iPad 3, ipad mini A1432, iPad A1458 4th Gen (MD512LL/A),  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2008-2013 32bit A4, A5 up to Apple A6X, iOS 1 to 10, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;iPad Air (1st generation) A1474, A1475, A1476, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2014-2015 [https://github.com/AsahiLinux 64bit], A7, iOS 11 up to 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2015 64bit A8, A8X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2016 64bit A9, A9X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2017 64bit A10, A10X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2018 64bit A11 
|-
| &lt;!--Description--&gt;iPad Air 3rd Gen A2153, A2123, A2154, iPad Mini 5th Gen, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2019 64bit A12 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


RocketTool (USB Rocket Launchers - Toy missile launchers)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;3px&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Original Launcher and StrikerII (includes laser)
| 0x1130
| 0x0202
| 
| {{yes|works }}
|-
| Dream Cheeky USB Missile Launcher or USB Cirus Cannon
| 0x1941
| 0x8021
| 
| {{no|no driver }}
|-
| Dream Cheeky USB Webcam Missile Launcher
| 0x1941
|
| 
| {{no|no driver }}
|-
| Rocket Baby
| 0x0a81
| 0x0701
| 
| {{no|no driver }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|}


DRadioTool (FM Radios - USB radio devices D-Link/Gemtek)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| D-Link DSB-R100 USB 
| 0x04b4
| 0x1002
| 0x0410
| {{yes|works }}
|-
| [http://www.neoseeker.com/forums/383/t257009-link-usb-dru-r100-radio/ GemTek USB FM Radio 21]
| 0x04b4
| 0x1002
| 
| {{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|}


UproarTool (Valencia MPX mp3 player and others)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;3px&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Korean D Square Valencia MPX-Player
| 0x04e8
| various
| 
| {{N/A|untested }}
|-
|}


[https://www.youtube.com/watch?v=vIuT7rJgc8w with unlocked android bootloader], 

&lt;pre&gt;

Kill and restart the server a few times

 sudo adb kill-server
 sudo adb start-server 

And finally type in

sudo adb devices

adb devices                 Lists connected devices              

adb shell                   Opens a terminal shell on the device hollywood:/ $
su 
id
df -h
top
ls -la
ls sdcard
ls sdcard/Android
ls sdcard/Oculus
wm size 

cd ..
cd data/system              look inside bad Corejava folder 
cd data/system/etc/init     look 
cd data/system/app
cd /data
cd /dev/block


 adb shell 
 pm disable-user --user 0 com.oculus.nux.ota


adb shell am start -a android.intent.action.VIEW -d com.oculus.tv -e uri com.android.settings/.DevelopmentSettings com.oculus.vrshell/.MainActivity

Don't change your Oculus account password after doing the FB account bypass. You'll break the log-in session, and have to factory-reset and start over 

adb shell 'setprop debug.oculus.cpuLevel 5 &amp;&amp; setprop debug.oculus.gpuLevel 5 &amp;&amp; setprop debug.oculus.adaclocks.force 0 &amp;&amp; setprop debug.oculus.phaseSync 1 &amp;&amp; settings put global always_finish_activities 1 &amp;&amp; settings put global wifi_scan_throttle_enabled 1 &amp;&amp; settings put global window_animation_scale 0.25 &amp;&amp; settings put global transition_animation_scale 0.25 &amp;&amp; settings put global animator_duration_scale 0.25 &amp;&amp; sync'


 settings list --user 0 secure or global or system 
   user_setup_complete=0

 adb shell 
 screenrecord

 adb shell reboot


 adb install &lt;path_to_apk&gt;   Installs an app like adb install -g -r alvr_client_android.apk or adb install -r app.apk 

 memtester 

 lsmod 

 
adb command to enable hand tracking, possible, but root access is required 
 adb root
 oculussetting --set hand_tracking_opt_in 1 hand_tracking_enabled 1 

adb push &lt;local&gt; &lt;remote&gt;   Copies files to the device
adb pull &lt;remote&gt; &lt;local&gt;   Copies files from the device 

pull them using CFB, extract original apk using LL 

adb forward tcp:9943 tcp:9943 (Used for advanced, such as ALVR streaming)

 adb shell pm disable-user --user 0 com.oculus.partnercustomization  Enterprise versions 

adb reboot                       Performs a standard system restart
adb reboot bootloader            Restarts the device into fastboot/bootloader mode
adb reboot recovery              Restarts the device into recovery mode
adb reboot download              Reboots Samsung devices into Download Mode
adb reboot fastboot              Directly enters fastboot mode

[https://gist.github.com/pantasio/3d0eb4bb03a1e696aae8696f60730859#file-enable-usb-debug-adb usb dev debug adb]

&lt;/pre&gt;


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{{ArosNav}}


==Host Adapter Protocol USB1 OHCI UHCI USB2 EHCI USB3.0 USB3.1 xHCI ==

Please let us know any mistakes or any information to be added, use Prefs/Trident to confirm Vendor and Product IDs 
Please chat at [https://www.arosworld.org/index.php AROS World]

*1996 USB1.0
*1998 USB1.1
*2000 USB2.0
*2008 USB3.0
*2013 USB3.1
*2017 USB3.2

[https://github.com/aros-development-team/AROS/tree/master/rom/usb AROS has these USB transfers] 

*Control     - 
*Bulk        - Midi 1.0 ( 'send my data when you can' )
*Interrupt   - Midi 2.0
*Isochronous - USBAudio, Webcams, etc (wip) 

Isochronous is the starting point of modern types of multimedia creativity. IsoChronous isoc code is already in place in poseidon.library and '''scheduled''' transfers are queued to be later rerouted in the host driver code (needs to be written for each host protocol e.g. OCHI, UCHI, EHCI and [https://cdrdv2-public.intel.com/625472/625472_xHCI_Rev1_2b.pdf#:~:text=Page%203.%20Document%20Number:%20625472%2C%20Revision:%201.2b.%203. XHCI rev1.2], [https://www.intel.com/content/www/us/en/content-details/868296/extensible-host-controller-interface-for-universal-serial-bus-xhci-requirements-specification-r2-0.html rev2], etc). There seems to be 2 types of isoc transfers, one is just the normal isoc transfer and the other is realtime implementation of isoc transfer. 

For isoc transfer there needs to be a scheduler that makes sure no isoc transfers are dropped (in or out) and that they happen at the right time. It all gets difficult as the device making use of the isoc transfer may be at any point on the device tree. One needs to calculate the USB bandwidth for the packet based periodic transfers that are initiated by the host which have fixed but guaranteed bandwidth. Host controllers guarantee this bandwidth by planning a schedule of transfers ahead of time to ensure there is enough time reserved on the bus.

[https://www.intel.co.uk/content/www/uk/en/products/docs/io/universal-serial-bus/ehci-specification.html EHCI] [https://www.thegoodpenguin.co.uk/blog/understanding-why-usb-isochronous-bandwidth-errors-occur/ bus-bandwidth] vs payload-bandwidth and the algorithm of the EHCI scheduler. 
The bandwidth of the endpoint in terms of payload data (stuff we put in a packet) and the protocol overhead, signalling imposed bit stuffing, host delays etc. 

Poseidon controls the driver and device tree and it provides an API to communicate with the USB devices. Poseidon really doesn't care much about what sort of transfer pipe is opened or used, it only provides the means to do so and forwards the iorequests to the correct driver. Poseidon code is the higher level code for USB communication and drivers are of course the lower level one.


[[File:Psd.svg|220px|right]]


; Best Hardware - NEC Chipset (OHCI + EHCI), Intel Chipset (UHCI + EHCI), 
; Early support - [https://github.com/aros-development-team/AROS/commit/03c5252d962941a56c816a9f2315134362089349 XHCI USB3.0, USB3.1 &amp; gen 2 Type-A Type-B Type-C] 
; Next Best Set - General OHCI, SIS (OHCI + EHCI), 
; Buggy Chipset - [ Early AMD OHCI], ALi OHCI, VIA UHCI, Nvidia OHCI &amp; EHCI, 


=== USB1.1 ===
OHCI USB 1.1 - USB-IF sanctioned standard but hardware physical form removed with USB2.0 and replaced with virtual emulation of USB1 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device 
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| ALi Agere M5273 A1 M5237 Lucent USS-312 
| 
| 
| 
| &lt;!--Boots--&gt;{{Maybe}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| StarTech PCI425USB, CompUSA Iogear GIC220U-b, Nvidia 220 mobo, USBA2041P, ALi SU2A-PS, 
|-
| AMD 756 Chipset (onboard motherboard) 
| 0x1022 
| 0x740c 
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| no [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=31308#forumpost31308 usb devices detected] Geode GX1, 
|-
| CMD DU-A2 Silicon Image 0670 (pci AMD chipset)
| 0x1095
| 0x0670
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Silicon Image 0673 (pci AMD chipset)
| 0x1095
| 0x0673
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Nvidia Nforce2 USB
| 0x10de 
| 
| 
| &lt;!--Boots--&gt;{{Maybe|Bios options vary but does with Plop Boot}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Tested with 20th Aug 2012 improvement 
|-
| NEC µPD720100AGM 
| 0x1033
| 0x0035
| 0x 
| &lt;!--Boots--&gt;{{Unk}}
| &lt;!--Detects--&gt;{{Unk}}
| &lt;!--Works--&gt;{{Maybe|}}
| untested - Amiga Spider card with possible bottleneck issues at higher speeds 
|-
| NEC µPD720101AGM 720101GJ
| 0x1033
| 0x0035
| 0x43
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Mac mini, Belkin F5U219vea (2+1 ports), Belkin F5U220vea1 (4+1 ports), Adaptec 3100LP, BAFO BF-460, GWC UC-160, IOGear GIC250U, Keyspan U2PCI-5, O'toLink U2-C2B U2-C2A U2-P20N U2-P50, Ratoc PCIU5, USBWholesale UII-PCIP 
|-
| NEC µPD720102
| 0x1033
| 0x00
| 0x 
| &lt;!--Boots--&gt;{{Unk|untested }}
| &lt;!--Detects--&gt;{{Unk|untested }}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Opti 82C861 2-port 
| 0x1045
| 0xc861
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| no USB devices detected - Belkin F5U005, 
|-
| SIS 7001 OCHI 
| 0x1039
| 0x7001
| 0x0f
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 20th Aug 2012 - not booting stalls on GRUB word with Plop Boot 
|-
|}


UHCI USB 1.1 - Intel standard but since 2009 no hardware support as USB2 introduced virtual emulation of USB1 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| Intel 
| 0x8086 
| 0x
| 0x01 
| &lt;!--Boots--&gt;{{No|not in bios use AROS floppy disc boot}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Intel 82371AB EB MB PIIX4 
| 0x8086 
| 0x7112
| 0x01 
| &lt;!--Boots--&gt;{{No|none in bios use other booting options}}
| &lt;!--Detects--&gt;{{Maybe|Detects most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not RTL8187b WG111v3 blue led not on and does not work}}
|  
|-
| Intel 82801DB/DBL/DBM (onboard i830 mbd)
| 0x8086 
| 0x24c4 
| 0x01 
| &lt;!--Boots--&gt;{{Yes|but not from bios but floppy options}}
| &lt;!--Detects--&gt;{{Yes|}}
| &lt;!--Works--&gt;{{Yes|}}
| RTL8187b WG111v3 blue led on and although device has software failure and recoverable error IT STILL WORKS. Fresh start sometimes needs Network Prefs Saved to work. 
|-
| VIA MVP4 (onboard mbd)
| 0x1106
| 0x30
| 0x40 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not wireless options}}
| RTL8187b WG111v3 detected but blue led not on and does not work 
|-
| VIA VT82xx (onboard mbd)
| 0x1106
| 0x3038
| 0x40 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not wireless usb}}
| RTL8187b WG111v3 blue led on but does not work 
|-
| VIA VT6202 (VIA VT83C572)
| 0x1106
| 0x3038
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}} 
| &lt;!--Works--&gt;{{Maybe|}}
| A-Best USB-200, Cables N Mor USBPCI, CompUSA, D-Link DSB500, Digital/Research DRUSBCARD, Kouwell IOFlex 580, StarMount USB VIA, 
|-
| VIA VT6112 
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6212 (pci card)
| 0x1106
| 0x3038
| 0x61
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 2011 seems to have issues with other identical via based USB controller(s) present 
|-
| VIA VT6214L 
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
|}


=== USB 2.0 EHCI ===
The USB-IF insisted on only one implementation of EHCI but it creates 4 virtual hcd to cover USB1.1 support. The virtual HCD on Intel and VIA EHCI controllers are UHCI. All other vendors use virtual OHCI controllers. Hardware EHCI USB2.0 ended in most chipsets in 2014/5 and is now virtual through most newer USB3.0 chipsets 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| ALi Agere M5273 A1 Lucent USS-344 
| 
| 
| 
| &lt;!--Boots--&gt;
| &lt;!--Detects--&gt;
| &lt;!--Works--&gt;{{Maybe|}}
| {{N/A|untested}} belkin F5U006, 
|-
| Nvidia Nforce2 USB
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Intel 82801DB/DBM (onboard mbd)
| 0x8086 
| 0x24cd 
| 0x01 
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| NEC µPD720100AGM 
| 0x1033
| 0x00E0
| 0x 
| &lt;!--Boots--&gt;
| &lt;!--Detects--&gt;
| &lt;!--Works--&gt;{{Maybe|}}
| {{N/A|untested - Amiga Spider card}}
|-
| NEC 72101 GJ
| 0x1033 
| 0x00e0 
| 0x04
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Belkin F5U219 VEA1 (pci), 
|-
| SIS ECHI 
| 0x1039
| 0x7002
| 0x00
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|issues about which port is used if it works at all}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6202 
| 0x1106
| 0x3104
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6212 (pci card)
| 0x1106
| 0x3104
| 0x62
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes|detects}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
|}


=== USB 3.x SuperSpeed SS (Speed 5Gbit/s 3.1 gen 1) aka xHCI eXtensible ===

USB Attached SCSI (UAS or UASP) is a protocol used for high-speed data transfer between computers and external storage devices like SSDs, HDDs, and some flash drives. It provides up to 70% faster read/write speeds than traditional Bulk-Only Transport (BOT) by allowing multiple commands to run in parallel, rather than waiting in a queue

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Fresco Logic FL1000 FL 1000 
| &lt;!--Vendor ID--&gt;0x1B73
| &lt;!--Product ID--&gt;0x1000 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;link power management (LPM, USB 3.0 power saving) cannot be disabled so random connection issues  
|-
| &lt;!--Description--&gt;Fresco Logic FL1009-200 FL 1009 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1009 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;Orico PFU3-2P
|-
| &lt;!--Description--&gt;Fresco Logic FL1100-100 FL 1100SX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1100 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;LPM cannot be disabled so issues with disconnecting WD drives etc - CalDigit, ORICO PFU3-2P, FASTA-6GU3 Pro, inatech KTU3FR-2P 2 port USB 3.0,  and Inateck KT4004 (KTU3FR-4PA rev B2) for storage and hubs, etc 
|-
| &lt;!--Description--&gt;Fresco Logic FL1400 FL 1400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1400 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Fresco Logic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720200 uPD720200a chip
| &lt;!--Vendor ID--&gt;0x1d6b
| &lt;!--Product ID--&gt;0x0194
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{Maybe|no USB3 but seems to works like USB2}}
| &lt;!--Opinion--&gt;recognized but not supported for USB3 but works like USB2 - ORICO PRU3-4P 4 Port USB, early Dell Wyse zx0 thin client,  
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720201 uPD720201 chip
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x114 0x0115 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported 
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720202 uPD720202 chip
| &lt;!--Vendor ID--&gt;0x1912 
| &lt;!--Product ID--&gt;0x0015
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported 
|-
| &lt;!--Description--&gt;[http://www.ti.com/product/tusb7340 TI] tusb7340 TUSB732 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x8241
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported Koutech IO-PEU436 but only one with open docs 
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported - integrated since Ivybridge 
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Via Labs VL800 xHCI 0.96 support in VL800, VIA VL811 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x3432 0x3438 0x3515 and 0x9201
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{Maybe|}} 2.0 backwards support 
| &lt;!--Opinion--&gt;Anker 68UPPCIE-2S20PU 2 port, Plugable 4-Port, GA-z77x-ud5h rev. 1.1 mobo, 
|-
| &lt;!--Description--&gt;Via Labs VL811+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Via Labs VL812 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;xHCI 1.0 support in VL805 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
|}


USB 3.1 (power up to 100W and data 10Gbit/s USB 3.2 gen 2 - USB-A Full size plug - USB-B micro USB size - USB-C reversible) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Asmedia ASM1142 
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;Connector: USB Type C and  USB Type A x 1 - Ugreen USB C PCI Card 2 Port USB 3.1 Type C 
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[ Intel] Revision 1.8 1.9 Updated  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;AUKEY 4 Ports USB C , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;Startech - PEXUSB312C - 2-port Usb 3.1 10Gbit/s
|-
|}

USB 3.2 (power up to 100W and data 20Gbit/s gen 2x2 - USB-A Full size plug - USB-B micro USB size - USB-C reversible) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[ Intel] Revision 2.6 Update  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;
|-
|}

=== USB 4 (40Gbps thunderbolt, pcie 3.0 tunnelling, ) ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;AMD Ryzen7 6800U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;Intel Goshen Ridge JHL8440 Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
|  
|-
|}


== hid.class (Human Interface Device) ==

=== Keyboard ===

 Some multi-finger touchpad support works but not on all touchpads  

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;8BitDo Retro N C64 edition Keyboard, the super button accessory and optional N30 mouse
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 87 keys Kailh white}}
|-
| &lt;!--Description--&gt;8bitdo 108 Retro Mechanical Keyboard (white kailh) and two superbuttons (green) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Apple Pro Keyboard
| 0x05ac
| 0x0205 
| 0x0122
| {{yes|works (its two hub ports) but mouse scroll wheel issues}}
|-
| Apple Pro Keyboard
| 0x05AC
| 0x020B 
| 
| {{yes|works (two onboard ports also)}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Aigo K68 60% red switches, A68 A87 wireless 2G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=49&amp;products_id=973 AmigaOne Keyboard]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Akko TAC87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 80% TKL }}
|-
| &lt;!--Description--&gt;Akko MonsGeek FUN60 PRO&amp;MAX HE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 60% hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Akko 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 hall effect, good but expensive and software poor}}
|-
| &lt;!--Description--&gt;Akko 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ATTACK SHARK X98 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 98% maybe silent linear feel with Two-color PBT keycap}}
|-
| &lt;!--Description--&gt;ATTACK SHARK X68HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Azio Cascade 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Chilkey ND75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  good 75% expensive}}
|-
| &lt;!--Description--&gt;Chilkey ND104 (Wuque Studios) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 premium clicky (WS Blue) or silent (WS White) key options with Ansi and ISO formats also numpad and calculator, aluminum machined, tri mode, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2026 untested magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Corsair K65 Mech MX no numeric keypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair CH-9000045 K70 Blue MX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K95 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cherry G80 G80-3000L[x]C[yy]-[z] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cooler Master CM Storm Quickfire Rapid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K100 Air 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2025 okay low profile but expensive 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;Dell SK-8135 Dell USB Keyboard for Internet and Multimedia rev H for Dimension 4500, Dimension 8250, OptiPlex GX260n, OptiPlex GX60n, Precision 350 (R42232) 
| &lt;!--Vendor ID--&gt;0x413C
| &lt;!--Product ID--&gt;0x2010 
| &lt;!--Revision--&gt;0200 
| &lt;!--Opinion--&gt;{{Yes| usb1.1 keyboard hub 0x413C 0x1003 works as well - multimedia keys not mapped }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Deepcool KG722
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 65% }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Ducky Channel Zero DK2108 Mech Mechanical Cherry MX Red 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Ducky Shine 3 Brown or Blue (DK9087) MX keys 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Das Keyboard Model S Ultimate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Epomaker Cidoo V75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;epomaker rt100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 plastic build and no screws, numpad with small 0, mostly quiet seasalt switches, gimmick usb-c 1in screen}}
|-
| &lt;!--Description--&gt;EPOMAKER TH99  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} USB-C full numpad keyboard 
|-
| &lt;!--Description--&gt;eopmaker P75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;eopmaker p87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;epomaker x Leobog Hi75
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;epomaker x Feker Galaxy80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;epomaker x Galaxy100 gmk/via 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 96% }}
|-
| &lt;!--Description--&gt;epomaker Aula F75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 budget version good 75% choice of 4 leobog switches}}
|-
| &lt;!--Description--&gt;eopmaker Tide75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 75% and not too expensive}}
|-
| &lt;!--Description--&gt;Epomaker Ajazz AK820 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Epomaker Ajazz AK35I V3 MAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 104 keys - two models: wired and tri-mode connection - }}
|-
| &lt;!--Description--&gt;epomaker Aula F108 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pricy but okay 100% but only leobog graywood switches but hotswap available afterwards}}
|-
| &lt;!--Description--&gt;eopmaker Ajazz AK980 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 97 keys }}
|-
| &lt;!--Description--&gt;Epomaker G87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Epomaker RT82 RT85
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Epomaker RT100 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 96% }}
|-
| &lt;!--Description--&gt;epomaker x Galaxy100 lite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 good 96% }}
|-
| &lt;!--Description--&gt;Epomaker 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Filco Ninja Majestouch-2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Focus FK-760 Wireless Keyboard &amp; Trackball
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{yes|works}} but quality build issues raised 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;GMMK Tenkeyless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested  default Gateron Brown switches for Kailh Box Jades default Gateron Brown switches for Kailh Box Jades}}
|-
| &lt;!--Description--&gt;GK61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }}
|-
| &lt;!--Description--&gt;GMK67 GMK87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested budget good option}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Hengchangtong HCT Limeme gk103s Entry Keyboard
| &lt;!--Vendor ID--&gt;0xC0F4
| &lt;!--Product ID--&gt;0x0009
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{yes|half Keyboard left side only}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Hexgears M2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested hotswap kaihl green switches}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hexgears 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Iqunix mq80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2025 good 75% low profile keys
|-
| &lt;!--Description--&gt;Iqunix Magi65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested good 65% low profile keys }}
|-
| &lt;!--Description--&gt;iqunix ez60 ez80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 untested specific hall effect switches - actuation point, rapid trigger, etc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Jomaa YiChip Wireless 50% key with touchpad 
| &lt;!--Vendor ID--&gt;0x3151 
| &lt;!--Product ID--&gt;0x3000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|dongle detected, keys and pad not working - 2 AAA NM}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Keychron q0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 untested numpad only}} 
|-
| &lt;!--Description--&gt;Keychron q1 v1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 untested okay}} 
|-
| &lt;!--Description--&gt;Keychron Q6 Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested 75% with numeric numpad, barebones so choose switches and keycaps to suit }}
|-
| &lt;!--Description--&gt;Keychron q1 MAX V1 MAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }} 
|-
| &lt;!--Description--&gt;Keychron Lemokey P1 QMK 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested best option to customise switches and keycaps}}
|-
| &lt;!--Description--&gt;Keychron LemoKey X1 X3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested keycap swap only not switches}}
|-
| &lt;!--Description--&gt;Keychron K2HE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested okay}} wireless hall effect analogue on all keys 
|-
| &lt;!--Description--&gt;Keychron K4HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 untested hall effect but software }}
|-
| &lt;!--Description--&gt;Keychron K5 K17 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 untested okay low profile but }}
|-
| &lt;!--Description--&gt;Keychron Q5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Keychron K10 HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Kiiboom Breeze 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 good 75% }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;Meletrix Boog 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 magnetic hall effect, good but expensive and software poor}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;Melgeek O2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 low profile 75% but not repairable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;MOSART 2.4G Wireless 60% Keyboard Trackball 
| &lt;!--Vendor ID--&gt;0x062a
| &lt;!--Product ID--&gt;0x4105
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|dongle recognised HID, keys worked, roller worked, scroll wheel works and shoulders works but buttons around left, top and right hand side (RHS) do not work and plastic and 2 AA MN1500}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Mucai SiGma Micro MKA610 
| &lt;!--Vendor ID--&gt;0x1c4f
| &lt;!--Product ID--&gt;0x0084
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| unknown red keys - rgb backlighting - }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;[http://hjldemo.clsc.cn/ Guangzhou Zhentian Electronics Ltd] Perixx Periboard 505 Plus with Trackball 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|okay dome keyboard - poor trackball}}
|-
| &lt;!--Description--&gt;Guangzhou Zhentian Electronics Co., Ltd Perixx Periboard 706 Plus with Trackball Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|generally okay dome with good sized keys but piano black surround fingerprint magnet, occasional brief trackball freezes after no use, takes some time to get used to the trackball size}} 
|-
| &lt;!--Description--&gt;Perixx Periboard-716 Wireless (Chicony)
| &lt;!--Vendor ID--&gt;04f2:1013
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|okay dome keyboard and trackpad}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Description--&gt;Perixx Periboard-
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Perixx Periboard-
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Lenovo SK-8825 41A5327 SIL12-W07 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;works manufactured for 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lite-On USB NetVista Full Width Keyboard 
| &lt;!--Vendor ID--&gt;0x04b3
| &lt;!--Product ID--&gt;0x3025
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;works 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech K320 Wireless Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|The Logitech USB Unifying, Bolt, Lightspeed, or Nano receiver pairing}}
|-
| &lt;!--Description--&gt;Logitech K340 Wireless Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|The Logitech Unifying Receiver pairing}}
|-
| &lt;!--Description--&gt;Logitech K400
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt; [http://www.logitech.com/en-us/product/wireless-touch-keyboard-k400r Logitech Wireless Touch Keyboard k400]
| &lt;!--Vendor ID--&gt; 0x046D
| &lt;!--Product ID--&gt; 0xC52B
| &lt;!--Revision--&gt; 1201
| &lt;!--Opinion--&gt; {{yes|All (including multimedia) keys work. Some keys requires remapping with Trident. Touchpad works and acts as normal mouse. Presents itself in Trident as USB Receiver from Logitech with 3 HID bindings}}
|-
| &lt;!--Description--&gt;Logitech K400 Plus K400+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech K600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech TK820 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech TK830 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech G915 TKL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard TKL means no number pad}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lofree Lite84 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Lofree Flow Lite100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 silent switches and low profile keys}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;MACHENIKE K500 Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 94 keys untested Hot Swappable 94 Keys 90% Layout }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MechLands Vibe99 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 100 keys untested Gasket-mounted Wired/Bluetooth/2.4GHz Wireless Mechanical Keyboard}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft Comfortable Curve 2000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| recognized but not supported}}
|-
| &lt;!--Description--&gt;Microsoft Natural Ergonomic Keyboard 4000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|recognized but not supported}}
|-
| &lt;!--Description--&gt;Microsoft Wireless Media Desktop 1000 (1356)
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x00f9 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|working but not mouse part}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Niz Micro84 Duo82 X87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 electro capacitive }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;nuphy gem80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;nuphy kick 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 low profile 75% }}
|-
| &lt;!--Description--&gt;nuphy Air75 V3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  75% }}
|-
| &lt;!--Description--&gt;nuphy node 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 96% layout, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Qpad MK-50 MK-80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Qpad MK-90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Razer Chroma 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0203
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://openrazer.github.io/ Razer] Lycosa 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Blackwidow 2013 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razr Blackwidow Ultimate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Cynosa Lite V2 
| &lt;!--Vendor ID--&gt;1532
| &lt;!--Product ID--&gt;0x023f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer DeathStalker 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer HuntsMan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Ornata 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Orbweaver Chroma Keypad 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0207
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Tartarus Keypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested not hall effect and very expensive}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Redragon K668 RGB Gaming Keyboard Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested 108 Keys Mechanical Keyboard w/Extra 4 Hotkeys Upgraded Hot-swappable Socket，Red Switch}}
|-
| &lt;!--Description--&gt;Redragon K689 PRO Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested Gasket RGB Gaming Keyboard, 108 Keys Mechanical Keyboard w/Extra 4 Hotkeys, Upgraded Hot-swappable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Risophy 60
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 75% mechanical, hotswap so okay for price untested }}
|-
| &lt;!--Description--&gt;Risophy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Royal Kludge RK65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested cream switches }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;SINO WEALTH Gaming KB SkyLion K68 
| &lt;!--Vendor ID--&gt;0x258a
| &lt;!--Product ID--&gt;0x003a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| blue stalks with rgb lighting}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;SKYLOONG GK104 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested gateron }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;SteelSeries 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;TeckNet x300 2.4G Keyboard Mouse MosART 
| &lt;!--Vendor ID--&gt;0x062A
| &lt;!--Product ID--&gt;0x4101
| &lt;!--Revision--&gt;0312 
| &lt;!--Opinion--&gt;{{Yes|1 AAA for each and works well - mouse slightly better built than keyboard rubberised membrane}}
|-
| &lt;!--Description--&gt;TeckNet X331 HDE 2.4G Keyboard wireless RCMCU 
| &lt;!--Vendor ID--&gt;0x0C45
| &lt;!--Product ID--&gt;0x7000
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{Yes|wireless can be glitchy but few extra keys are mapped }}
|-
| &lt;!--Description--&gt;TeckNet X500 2.4G Keyboard Mouse MOSArt 
| &lt;!--Vendor ID--&gt;0x062A
| &lt;!--Product ID--&gt;0x2901
| &lt;!--Revision--&gt;0112 
| &lt;!--Opinion--&gt;{{Yes|works well especially large touchpad - usual rubber domed membraned keyboard mechanism }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tecware Specter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested good 75%}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Unicomp Model M USB 104 key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} IBM's and later Lexmark buckling spring switches 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varmilo Minilo Bluebell (prestige silent) and Eculapytus (violet tactile)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 75% plastic build no screws not great to mod}}
|-
| &lt;!--Description--&gt;Varmilo Sword 68 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}} 
|-
| &lt;!--Description--&gt;Varmilo 98 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 expensive but good and Kailh silent}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Weikav Velocifire Choice65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Weikav Velocifire Lucky65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Wobkey Crush80 Reboot Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 very good but expensive Aluminum Hotswap Wireless RGB}}
|-
| &lt;!--Description--&gt;Wobkey Rainy 75
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 75% but not as expensive CNC Aluminum HMX/JWK/Cocoa Switches}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wooting HE60 HE80 HE90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 hall effect but expensive with good software}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Womier WK61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2021 untested }}
|-
| &lt;!--Description--&gt;Womier Sk71 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;Womier Sk75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;Womier Sk75 TMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xenta White Wireless HK6718B+HM3302--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|works with Raspberry Pi untested on AROS native}}
|-
| &lt;!--Description--&gt;Xinmeng X87 MAGIC_REFINER 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 untested keycap swap but not hotswapable switches}}
|-
| &lt;!--Description--&gt;Yunzii AL66 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| milk switches, cherry PBT, }}
|-
| &lt;!--Description--&gt;Yunzi B75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 budget good with cocoa cream switches }}
|-
| &lt;!--Description--&gt;Yunzii AL75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|good budget option with  swappable switches,  }}
|-
| &lt;!--Description--&gt;Yunzii AL80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 switches }}
|-
| &lt;!--Description--&gt;Yunzi C75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 budget good with  switches }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

&lt;pre&gt;
linear  - creamy
tactile - thocky
clicky  - clacky 
&lt;/pre&gt;

&lt;pre &gt;
Cherry MX Black are linear switches (no feedback); good for gaming. 
Cherry MX Red are linear (less noise no click) but more squishy; 
Cherry MX Brown are in between Blue and Red in style and tactile; 
Cherry MX Clear switches have soft tactile feedback (with no click). 
Cherry MX Blue have tactile feedback with a click (noisy); good for typing. 

Gateron Yellows KS-3, KS-3x47 or better Pros have a milky top and black bottom and linear 

TTC Silent Frozen v2. Linear and dead silent 
Mouse the huano brown with yellow dot for silent mouse clicks
Kailh red dust proof encoder for smooth and close to silent scrolling
Boba U4 Silent Tactile switches
Husky linears

HMX 
&lt;/pre &gt;


=== Mouse ===

if the USB mouse is non-functional put a USB pendrive in before or add the following to user-startup in '''s''' drawer/folder/directory

 sys:prefs/trident NOGUI &gt; NIL:

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Brand
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; | Model
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| 3Dconnexion 
| 3D Mouse 
| &lt;!--Model--&gt;[http://www.3dconnexion.com/products/spacenavigator.html SpaceNavigator]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| 3D Mouse
| &lt;!--Model--&gt;SpacePilot Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| Mouse 
| &lt;!--Model--&gt;SpaceExplorer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| Wireless Mouse 
| &lt;!--Model--&gt;SpaceMouse 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;3D Optical 
| &lt;!--Description--&gt;Wired 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;0000:3825
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Belkin
| Combo mouse
|
| 0x05FE
| 0x0011
| Low 0100
| {{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Cytec
| &lt;!--Description--&gt;Wired Mouse Gaming 
| &lt;!--Model--&gt;R.A.T 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Dell
| Mouse
| MO56UC
| 0x413C
| 0x3200
|
| {{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;equatech / clone logitech  
| &lt;!--Description--&gt;wireless mouse
| &lt;!--Model--&gt;49779 / M185 
| &lt;!--Vendor ID--&gt; 3151:2020 later 3151:3020 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{Yes|detected and works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Hama
| RF Optical Mouse
| AM-6000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;M3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;M5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keycron 
| &lt;!--Description--&gt;Optical Wireless 
| &lt;!--Model--&gt;M6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1k polling and 16k dpi }}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical Wireless 
| &lt;!--Model--&gt;M7
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested barebones 1k polling and 16k dpi, great for small hands, loud clicks}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;LogiCAD 3D
| &lt;!--Description--&gt;3D Mouse
| &lt;!--Model--&gt;Magellan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Logitech
| Cordless Desktop Navigator 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|The Logitech Unifying Receiver pairing}}
|-
| Logitech Inc.
| First/Pilot Wheel Mouse
| N48/M-BB48 M-BE58 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested }}
|-
| Logitech
| Wireless mouse
| [http://www.logitech.com/en-roeu/mice_pointers/mice/devices/5484 M305]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{yes|works}}
|-
| Logitech
| Wireless RF Mouse
| MK710
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|The Logitech Unifying Receiver pairing}}
|-
| &lt;!--Brand--&gt;Logitech
| &lt;!--Description--&gt;Wireless Mouse 
| &lt;!--Model--&gt;MX Master Anywhere 2S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|untested}} micro USB charge port on front 
|-
| &lt;!--Brand--&gt;Logitech 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;M220 silent 
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|}}
|-
| &lt;!--Brand--&gt;Logitech Logi 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;MX Master 3S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|2021 untested usb-c bluetooth, inbuilt battery but muted clicks}}
|-
| &lt;!--Brand--&gt;Logitach
| &lt;!--Description--&gt;Optical
| &lt;!--Model--&gt;G502 X Plus 
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 very clicky}}
|-
| &lt;!--Brand--&gt;Logitech
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;MX Master 4 MXM
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Bluetooth usb-c dongle, inbuilt lithium battery}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Brand
| Description
| Model
| Vendor ID
| Product ID
| Revision
| Opinion--&gt;
|-
| &lt;!--Brand--&gt;Maxxter 
| &lt;!--Description--&gt;Wireless
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8566
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Maxxter 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8518
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;OrzerHome Maxxter 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8514
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1 aa with no on/off switch }}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Microsoft
| Wheel Mouse optical
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| Sidewinder Mouse 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| IntelliMouse Explorer USB optical
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| Wireless Optical Mouse 2000
|
| 0x045E
| 0x00F9 
|
| {{no|not working see keyboard Media Desktop 2000 above}}
|-
| &lt;!--Brand--&gt;Microsoft 
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;1461 1447 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|usb dongle matched to one mouse only no others}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Orochi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Mamba 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Naga
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 17 buttons 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB Optical
| &lt;!--Model--&gt;Naga Hex V2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} MOBA Gaming Mouse, Professional Grade 16,000 DPI Sensor - RGB lighting 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical 
| &lt;!--Model--&gt;DeathAdder 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Viper 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Basilisk V3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1k polling, 35k dpi, }} 
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Trust
| Slimline Lasermouse 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| SteelSeries 
| Tobii EyeX EyeMobile PCEye 
| Eye Tracking Control 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}} gaze interaction track technology for augment augmentative and alternative communication (AAC). 
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;The Eye Tribe Tracker 
| &lt;!--Description--&gt;Eye 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;USB Optical Mouse 
| &lt;!--Model--&gt;MV3000
| &lt;!--Vendor ID--&gt;0x192f
| &lt;!--Product ID--&gt;0x0916
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|}

=== Trackball ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;3Dconnexion SpaceBall 5000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}} Labtec designed and rolled into new company 3dconnexion 2001 by owners Logitech 
|-
| &lt;!--Description--&gt;ACCO Kensington Orbit optical F1233A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kensington Turbo Mouse 64210
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Clearly Superior Technologies. Model:CST 1000-RC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Trackman Marble Mouse Wired USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Cordless Trackman Wheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Optical Trackman T-RB22 - Cordless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech M570 wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Microsoft Trackball Mouse Optical 1.0 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Microsoft X05-87473 Trackball USB Optical 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== KVM ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;NanoKVM 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== Gamepad ===

Controllers have mostly decided that the left analog joystick is keyboard equivalent of WASD and right joystick is your mouse. You also have 2 bumpers above the triggers. Shoot could be right trigger (so it doesn't involve taking your thumb off the right joystick). Face buttons for reloading or jump or other non-critical functions. Crank up the sensitivity and practice. 

Testing can be done with the TRIDENT Prefs, [https://devicetests.com/controller-tester html5], [https://greggman.github.io/html5-gamepad-test/ html5], or [https://gamepad-tester.com/ Tester]


==== Dinput Poseidon Default Plugin - Playstation(TM) style ====

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Betop Betong Bat D2E BTP-BD2E XD4D2E
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  
|- 
| &lt;!--Description--&gt;Gravis Eliminator Gamepad Pro USB  
| &lt;!--Vendor ID--&gt;047d
| &lt;!--Product ID--&gt;4005
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A}}
| &lt;!--Opinion--&gt;2002 2d only 
|-
| Hama Black Force USB Gamepad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2003 psx clone look 
|- 
| &lt;!--Description--&gt;Jess Tech Game Elements Philips GGE909 PC Recoil Pad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| [http://www.youtube.com/watch?v=TCbAmIhj6P4 Logitech Wingman Precision USB] G-UC3B 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A| }} 
| 2002 no 3D but good for 2D retro games like Turrican II
|-
| &lt;!--Description--&gt;Logitech Wingman Action Pad G-UB3A 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untested }} 
| &lt;!--Opinion--&gt;2002 1 blue lucid translucent - thin analog stick N64 type - 
|- 
| Logitech Wingman RumblePad UB05B
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc20a
| 1.12
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untesed }} 
| 2000 twin blue analogue sticks N64 type - poor 2d controls with single molded blue piece - vibration feedback - single shoulder buttons with throttle control below right one 
|-
| Logitech Wingman Cordless RumblePad G-RA4A 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc211
| 1.12
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untested }} 
| 2001 twin blue analogue sticks N64 type - poor 2d controls with single molded black piece - vibration feedback - dual shoulder buttons L1 L2 R1 R2 with blue throttle control below right one - 4 aa mn1500 batteries; life not great - C-UD10A usb dongle - overall big and bulky 
|-
| &lt;!--Description--&gt;Logitech Precision Wired G-UG15
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 psx styling blue outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| &lt;!--Description--&gt;Logitech Cordless Precision G-X2E14A
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 ps2 styling blue outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| &lt;!--Description--&gt;Logitech G-X5C11A Cordless Precision Wireless Controllers
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 psx styling black outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| [http://www.testfreaks.co.uk/game-console-accessories-controls/logitech-dual-actiontm-gamepad/ Logitech Dual Action] 
* G-UD8 has no mode (2D only?) button and no rumble 
* G-UF13A later 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc2
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|[http://www.morphzone.org/modules/newbb_plus/viewtopic.php?topic_id=7018&amp;forum=12 G-UF13A tested only]}} 
| 2003 New body shape psx style - dual analog 3D sticks - 4 small travel shoulder triggers no 5,6,7,8 
|-
| Logitech RumblePad 2 G-UF13
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc218
| 1.00
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes| }} 
| 2006 light blue top/black base - twin analogues 3D along with dual short travel shoulder buttons - rumble present - 
|-
| &lt;!--Description--&gt;[Logitech RumblePad 2 Cordless] 
* G-RC?? OLD version that take FOUR batteries and RED Logitech logo 
* G-RC14 uses TWO batteries has an ORANGE logo - dongle C-UE10 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;0xc219
| &lt;!--Revision--&gt;0x0200
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|mostly}}
| &lt;!--Opinion--&gt;2008 may have to remove 1 battery - G-RC?? 5 + 7 buttons - G-RC14 use buttons 6 + 8 to reset sticks - replace battery and push large button on receiver - 
|- 
| &lt;!--Description--&gt;Logitech F310 Wired Dual Action G-U0001 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0xc21
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|D mode switch}} 
| &lt;!--Opinion--&gt;2010 dual analog 3D with pc-xbox/psx switch on back (only D works) - both rear shoulder RT LT buttons have excess travel - no rumble vibration - 
|-
| &lt;!--Description--&gt;Logitech F510 Wired G-UG0002 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0xc21
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }} 
| &lt;!--Opinion--&gt;2010 dual analog with dual xbox pc/psx X/D switched compatibility modes - 
|-
| Logitech F710 Wireless / Cordless RumblePad 2 G-R0001 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc219
| 3.05
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }} 
| When switch on top set to D and nano receiver for each controller to pair - 2 aa mn1500 batteries required - rumble support sometimes - rear back shoulder buttons excessive travel needed 
|- 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Megaworld 'TIME' USB pad
| &lt;!--Vendor ID--&gt;0x0735
| &lt;!--Product ID--&gt;0x9902
| &lt;!--Revision--&gt;Low 0100
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No |}}
| &lt;!--Opinion--&gt;2000 Poor quality
|-
| &lt;!--Description--&gt;Microsoft 
* SideWinder Precision Pro USB (1997)
* SideWinder Precision 2 (1998)
* Game Pad Pro (1999)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Microsoft Sidewinder Game Pad USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{yes| }}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{yes| }}
| &lt;!--Opinion--&gt;[https://www.arosworld.org/infusions/forum/viewthread.php?thread_id=1149&amp;rowstart=140&amp;pid=5934#post_5931 must setup first]
|- 
| &lt;!--Description--&gt;Microsoft Sidewinder Gamepad X04 Freestyle 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A }} 
| &lt;!--Opinion--&gt;{{N/A|untested}} 1998 might need USB adapter 
|-
| &lt;!--Description--&gt;Microsoft Sidewinder X05 63895 92626 Flight stick
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;{{Yes|2000 [https://ae.amigalife.org/index.php?topic=929.msg11309#new tested]}}
|-
| &lt;!--Description--&gt;Microsoft Sidewinder Flight Stick X08-58736 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Microsoft 
    Plug &amp; Play Game Pad (2000)
    SideWinder Joystick (2000)
    Game Pad 2.0 (2001)
    SideWinder Force Feedback 2 (2002)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2002 long-standing static buildup problem and Force Feedback 2 was the removal of the power brick 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| Saitek [http://www.testfreaks.co.uk/game-console-accessories-controls/saitek-ps1000/ PS1000 Cyborg V.1], [http://www.testfreaks.co.uk/game-console-accessories-controls/saitek-ps2700-rumble-pad/ PS2700] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2000 no rumble function 
|- 
| Saitek [http://www.youtube.com/watch?v=xG0v-hf6ZPA P2600] [http://compactiongames.about.com/od/hardware/tp/gamepads.htm P3600], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2000 no rumble function
|- 
| Saitek P2900 wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{N/A|untested but runs on 1 AA battery}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Sony Batoh PS3 mini USB Wired hookup [http://ps3.jim.sh/sixaxis/usb/ SIXAXIS] 
*PCB  Ribbon      Notes
*Protos ALPS MSU Rev3 M3 and the later CBEH-1019
*?    SA1Q135A 	  for sixaxis
*PP4  
*V2   
*V25  
*VX   SA1Q146A    first dualshock 3 model
*VX   SA1Q147A    CECHZC2U (USA)
*VX35 SA1Q159A 	  
*VX3  SA1Q160A 	  
*VX?  SA1Q188A    
*VX4  SA1Q189A    shipped with a CECH-2504 datecode 0C 
*VX5  SA1Q194A    changed design ALPS, PS button changes
*VX6  SA1Q195A    red case, 
*VX7  SA1Q222A    superslims 2 ribbons
*VX8  SA1Q224A    superslims 2 ribbons 
| &lt;!--Vendor ID--&gt;0x054c
| &lt;!--Product ID--&gt;0x0268
| &lt;!--Revision--&gt;1.00 
| &lt;!--Merge with USB on Digital Pad--&gt;{{No|}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|}}
| &lt;!--Opinion--&gt;Sometimes detected but no support - no sixaxis features detected - mini usb lead will have varying results - 
|- 
| &lt;!--Description--&gt;Sony PS4 
*JDM JDS 001 010 011 
*JDM 030 040 055 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Sony PS5 Dual Sense 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Speed Link Strike 2 FX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Thrustmaster Firestorm Dual Power 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|[http://www.morphzone.org/modules/newbb_plus/viewtopic.php?topic_id=7018&amp;forum=12 only 1 axis joystick only]}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Trust Predator GM-1500 GM-1520
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 M series Aluminum Metal Joystick Hitbox Controller Arcade Fighting Stick
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 T series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 G series Gamefinger G12 G13 G16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; plastic - 
|- 
| &lt;!--Description--&gt;Haute42 S series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  thinner and lighter than G series 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mad Catz sf2 fightstick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Datel Paewang Arcade Pro Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mayflash F300 Fighting Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mayflash F500 Fighting Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Pico Flatbox GP2040-CE Hot Swappable Mini Hitbox Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  default it is configured for PS4 but before plugging usbc cable in, X for Dinput, B Xinput, RT HID - plastic build case - Rev4 based on RP2040 chip and firmware is based on GP2040-CE (Community Edition) - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Shenzhen Onebitdo Tech 8bitdo Fighting stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Venom 8 button 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
|}


==== Xinput Xbox Style Plugin ====

2018 extension added originally called AROSx but later redacted. Latest [https://github.com/medusalix/xone linux driver] might be useful. 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;8bitdo Ultimate C Wired 82CB (Shenzhen ONEBITDO TECH - GWOWO) 
| &lt;!--Vendor ID--&gt;0x2dc8 
| &lt;!--Product ID--&gt;0x3106 
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2022 - 4 t6 torx screws - non hall effect so drifting issues - triggers go faulty often - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 2C Wired Controller 82CD 
| &lt;!--Vendor ID--&gt;0x2dc8 
| &lt;!--Product ID--&gt;0x310A
| &lt;!--Revision--&gt;0114
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - HID keyboard assigned - 4 t6 torx screws - hall effect analogs and triggers  - 1000Hz polling - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 2C wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024  - 400mw battery - hall effect 3d nubs and triggers - micro switch shoulder buttons - d-pad poor for retro games - 
|- 
| &lt;!--Description--&gt;8bitdo ULtimate Mini Wired Controller for Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect 
|- 
| &lt;!--Description--&gt;8BitDo Pro 2 
*Wired Controller 
*Wireless
*Bluetooth
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect - playstation style layout for pc - slide button for S-A-D-X switch, android, dinput or xinput -  
|-
| &lt;!--Description--&gt;8BitDo Pro 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025  tmr hall effect analogs, hall effect triggers and some microswitches - button swap - ps2 style layout - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2026  - mw battery - hall effect 3d nubs and triggers - micro switch shoulder buttons - d-pad  for retro games - 
|- 
| &lt;!--Description--&gt;8BitDo Pro 3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2026  hall effect analogs, hall effect triggers and some microswitches - button swap - ps2 style layout - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Ace Aurora 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect joysticks with no deadzone mode, gyro, linear rumble, trigger stops, back paddles, button swap, macro, turbo, RGB LED effects -  tri-mode connection - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Betop Beitong Spartan BTP-2270U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;  no hall effect 
|- 
| &lt;!--Description--&gt;Betop Betong Asura 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;  no hall effect - noble linear trigger potentiometer and alps shoulder LB/RB micro switch 
|- 
| &lt;!--Description--&gt;BEITONG ASURA 2 Pro+ Game Controller Wireless Gamepad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Beitong Zeus 2  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BebonCool Dinofire Model Number: Q218 / TP28
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2021  - triggers aren't progressive but ON/OFF - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;EasySMX X05 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect analog and triggers - tri mode connection - 
|- 
| &lt;!--Description--&gt;EasySMX Wireless Controller PC PS3, 9013pro ESM-9013PRO
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 linear hall effect but device sometimes will not connect tried multiple attempts with the dongle
|- 
| &lt;!--Description--&gt;EasySMX X10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;EasySMX X20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 ABXY MICRO SWITCH - Bumpers Tactile switch Hall Effect analog 
|- 
| &lt;!--Description--&gt;EasySMX X15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect analog and triggers - membrane buttons - 
|- 
| &lt;!--Description--&gt;EasySMX S10 Wireless Gamepad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 TMR Hall effect and compatible with Switch 2/PC/Phone/TV/Steam, NFC, Gyro, HD Rumble - 
|- 
| &lt;!--Description--&gt;EasySMX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;202
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Fantech World EOS Pro WGP15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect trigger and sticks,2 back paddles, motion controlling 
|- 
| &lt;!--Description--&gt;Fantech EOS PRO II S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 controller with TMR hall effect analogues, mechanical face buttons and D-pad, 63 input macro, back paddles, turbo - analog triggers with trigger stops - tri mode bt wifi and wired - slide switch on back for switch, macos/android and xinput - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Flydigi Apex 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023  luxury model 
|- 
| &lt;!--Description--&gt;Flydigi Vader Pro 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023 the Pro(Hall Effects) and Non-Pro (No Hall) 
|- 
| &lt;!--Description--&gt;Flydigi Direwolf 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023 hall effect sticks and triggers - poor wifi connection - 
|- 
| &lt;!--Description--&gt;Flydigi Apex 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024  luxury model 
|-
| &lt;!--Description--&gt;Flydigi Vader 4 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - hall effect, DInput mode (o+A hold) - 
|- 
| &lt;!--Description--&gt;Flydigi Direwolf 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 hall effect analog and triggers but membrane buttons with gold contacts - 800mhA battery - 
|- 
| &lt;!--Description--&gt;Flydigi Dunefox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 basic model hall effect analog and triggers but membrane buttons - 500mha battery - no gyros - 
|- 
| &lt;!--Description--&gt;Flydigi Vader 5 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2025 - hall effect stick with tension control, linear triggers, DInput mode (o+A hold) - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Gamesir T4K Keleid, T4C Cyclone wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2023 poor to ok switch 
|- 
| &lt;!--Description--&gt;Gamesir Nova 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no|| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2024 - switch type layout 
|- 
| &lt;!--Description--&gt;Guangzhou Chicken Run Network Tech Nova Lite GameSir-T4n LITE - Zikway HID gamepad
*[https://www.reddit.com/r/Gamesir/comments/1c185ve/psa_keep_gamesir_nova_lite_t4n_lite_firmware_at/ fw 4200 seems to be xbox so B then Home for Xinput (green LED), A then Home for HID BT Android (green/yellow LED), Y then Home for Switch Pro (Red LED)] or X then Home for Wifi and start and select to alternatively swap modes 
* and if on [https://www.reddit.com/r/Gamesir/comments/1c185ve/psa_keep_gamesir_nova_lite_t4n_lite_firmware_at/ fw 5700 ds4 so Home + B (blue LED), ]
* firmware 6900 
| &lt;!--Vendor ID--&gt;0x3537
| &lt;!--Product ID--&gt;0x1040 0x1041
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2024 - hall effect 3d nubs - no usb-c cable - rubber membrane analog trigger travel and bumpers shoulder buttons - wifi 2.4G and bluetooth - xbox layout so ab and xy might need to be swapped via m and a buttons for switch type [https://www.youtube.com/watch?v=po-nNuC5fps fixes video] - 250Hz polling - 600mah battery - rigid carry case - poor d-pad esp diagonals - gamesir settings software only on android 6+ or ios based only - 
|- 
| &lt;!--Description--&gt;Gamesir Nova 2 Lite  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir G7 SE Wired Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect 
|- 
| &lt;!--Description--&gt;GameSir G8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Gamesir TEGENARIA T3 Lite Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 playstation aesthetic hall effect analog and membrane buttons - X+Home button connects as an Xbox controller
|- 
| &lt;!--Description--&gt;GameSir Cyclone 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 TMR Joysticks with anti-friction rings and metal anti-friction rings around the stems, gyro, rumble, macro, turbo, 2 back paddles, hall analog triggers with micro-switch trigger - tri mode bluetooth, 2.4GHz wifi and wired, 1000hz polling rate - gamesir connect software - 
|- 
| &lt;!--Description--&gt;GameSir G7 Pro for Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 TMR hall effect - hall effect triggers, tri mode connection - gamesir nexus software - 
|-
| &lt;!--Description--&gt;GameSir Super Nova Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2026 hall effect sticks and triggers, 1000Hz polling, tri mode connectivity, 
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GuliKit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GuliKit KingKong 2 NS08 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;Electromagnetic Stick hall effect - hall linear triggers - Mechanical face buttons - wired and wireless - Built-in rechargeable lithium battery 
|-
| &lt;!--Description--&gt;GuliKit KingKong 2 PRO NS09
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;hall efect - wired and wireless - Mechanical face buttons - Built-in rechargeable lithium battery 
|-
| &lt;!--Description--&gt;GuliKit KingKong MAX 3 KK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;hall effect - wired and wireless - lithium battery - 
|-
| &lt;!--Description--&gt;Gulikit KK3 Max USB-c Bluetooth Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 Hall Joysticks and Triggers, Maglev/Rotor/HD Vibration, 1000Hz Polling Rate, 4 Back Buttons,  
|- 
| &lt;!--Description--&gt;GuliKit KK3 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 smaller version of KK3 MAX - hall effect analog and triggers, face buttons , maglev rumble, gyro, 4 back paddles - rigid case - 950mAh up to 8 hrs - 
|-
| &lt;!--Description--&gt;GuliKit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Hyperkin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Hori EX2 Turbo UHX3-45 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Machenike G1 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 Wireless Gaming Controller with 1K Polling Rate Hall Effect Trigger Joystick For Nintendo Switch PC iOS Android 
|- 
| &lt;!--Description--&gt;Machenike G5 Pro Wireless Gaming Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 ABXY Switch Membrane, Bumpers Tactile switch and hall effect analog 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;microsoft sidewinder precision pro 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| [https://pineight.com/mw/index.php?title=USB_game_controllers Xbox 360 Wired Controller]
| 0x045e
| 0x028e
| 0x
| &lt;!--Merge with USB Digital Pad--&gt;{{No|needs specific driver and has poor 2D control pad}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|- 
| Microsoft (R) [https://blog.tkjelectronics.dk/2012/12/xbox-360-receiver-added-to-the-usb-host-library/ Xbox 360] (TM) Wireless Receiver for Windows(R) Model 1086 and Controller 
| 0x045e 
| 0x0719, 0x or 0x0291
| 0x0100
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;{{No|separate standalone usb dongle detected and shows as 8 vendor interfaces but no class associated and so not working - may need new class from code from xpad or xboxdrv to work the controllor}}
|-
| &lt;!--Description--&gt;Xbox 360 Kinect [http://hackaday.com/2010/11/10/kinect-open-source-driver-demo-and-hacking/ Video] 
[http://git.marcansoft.com/?p=libfreenect.git;a=commit;h=7655fcf7239ba4907654089dba535a196685dbe5 GIT]
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007  proprietary 2.4GHz RF protocol, 
|- 
| &lt;!--Description--&gt;Xbox One Wired Controller 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Xbox One wireless controller newer model with the 3.5mm headphone jack 1537 1697 and microsoft adapter 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02d1 or 0x02dd
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2014 
|- 
| &lt;!--Description--&gt;Microsoft Elite Series 1
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02e3
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2016 ok - 
|-
| &lt;!--Description--&gt;Xbox later models 1708+ Xbox One and Series use 5GHz and use Bluetooth, 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02e0
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2017 
|- 
| &lt;!--Description--&gt;Xbox One S
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02ea 0x02fd
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2019
|- 
| &lt;!--Description--&gt;Microsoft Elite Series 2 Core 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02ff
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2022 ok - no hall - 125Hz polling - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Minisform MGP01 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;MOBAPAD N1HD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 has liquid silicone face buttons, hall effect analog, D-Pad swap, two back paddles, USB-A dongle, HD Rumble - 
|- 
| &lt;!--Description--&gt;Mobapad Huben 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 
|- 
| &lt;!--Description--&gt;Mobapad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON Gale 墨将 mòjiāng 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON Blitz PRO 2 TMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON now MOJHON AETHER 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect joysticks, hall effect triggers, mechanical bumpers, 1000hz polling rate, mechanical D-pad, membrane face buttons, mechanical back paddles, rumble, deadzone issues - tri mode 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;MSI FORCE GC20 GC30 V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2021 not hall effect 
|- 
| &lt;!--Description--&gt;MSI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mytrix Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;NACON GC-100XF Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 average 
|- 
| &lt;!--Description--&gt;PXN P5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect joysticks &amp; triggers, limited trigger stops, 1000hz polling rate on wired, 4 back paddles, 32 macro record, anti-deadzone mode, RAW mode, gyro, turbo, tri-mode connection - 
|- 
| &lt;!--Description--&gt;PXN P50L 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;PowerA 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD Stellar T5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD Junior E5 Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Razer Wolverine V3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024  hall 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;RetroFlag 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Speedlink XEOX Pro Analog Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;enclosed lithium battery? - xbox layout - switchable on back of controller to directinput (dinput) or xinput - USB dongle switchable to pc and ps3 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;SCUF Instinct Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2022 good 
|- 
| &lt;!--Description--&gt;SCUF Envision Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2023 good 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Steel Series Stratus Duo XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;usb adapter needed 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;[https://inputlabs.io/Inputlabs InputLabs Alpakka Open Source and build yourself] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;DIY it with 3d printer, pcb and components  - pi pico needed - 2 gyros for better accuracy - 
|- 
| &lt;!--Description--&gt;[https://inputlabs.io/kapybara Inputlabs kapybara] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;DIY one handed version wip 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Vilcorn Z03 BT Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - other Bluetooth modes (green, red, blue, purple, etc.) Select + M1 (or M2) - 400mAh - not great latency wired - 800mhz polling -  
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;zd ultimate legend 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;zd 0+ elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;zd 0+excellent
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
|}

&lt;pre&gt;
#ifndef AROSX_LIBRARY_H
#define AROSX_LIBRARY_H

#include &lt;exec/types.h&gt;

#define AROSX_CONTROLLER_TYPE_UNKNOWN  0x00
#define AROSX_CONTROLLER_TYPE_GAMEPAD  0x01

#define AROSX_GAMEPAD_DPAD_UP          0x0001
#define AROSX_GAMEPAD_DPAD_DOWN        0x0002
#define AROSX_GAMEPAD_DPAD_LEFT        0x0004
#define AROSX_GAMEPAD_DPAD_RIGHT       0x0008
#define AROSX_GAMEPAD_START            0x0010
#define AROSX_GAMEPAD_BACK             0x0020
#define AROSX_GAMEPAD_LEFT_THUMB       0x0040
#define AROSX_GAMEPAD_RIGHT_THUMB      0x0080
#define AROSX_GAMEPAD_LEFT_SHOULDER    0x0100
#define AROSX_GAMEPAD_RIGHT_SHOULDER   0x0200
#define AROSX_GAMEPAD_A                0x1000
#define AROSX_GAMEPAD_B                0x2000
#define AROSX_GAMEPAD_X                0x4000
#define AROSX_GAMEPAD_Y                0x8000

struct AROSX_GAMEPAD {
    ULONG   Timestamp;
    UWORD   Buttons;
    UBYTE   LeftTrigger;
    UBYTE   RightTrigger;
    WORD    ThumbLX;
    WORD    ThumbLY;
    WORD    ThumbRX;
    WORD    ThumbRY;
};

#define AROSX_EHMB_CONNECT    0x00
#define AROSX_EHMB_DISCONNECT 0x01
#define AROSX_EHMF_CONNECT    (1L&lt;&lt;AROSX_EHMB_CONNECT)
#define AROSX_EHMF_DISCONNECT (1L&lt;&lt;AROSX_EHMB_DISCONNECT)

struct AROSX_EventHook {
    struct Node         eh_Node;
    struct MsgPort     *eh_MsgPort;
    ULONG               eh_MsgMask;
};

struct AROSX_EventNote {
    struct Message      en_Msg;
    ULONG               en_Event;
    APTR                en_Param1;
    APTR                en_Param2;
};

#endif /* AROSX_LIBRARY_H */
&lt;/pre&gt;


=== Joystick ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;CH Products CombatStick 568 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Cyborg X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Extreme 3D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| [Logitech Attack 3 Joystick] 
| 0x0464
| 0xC214
| 0205
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;saitek X-52 x52 pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;saitek aviator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Speedlink Competition Pro USB 
| 
|
| 
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{maybe|works but games not working &quot;out of the box&quot;}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Trust Predator QZ 501
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust Predator TH 400
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust Predator GM-2500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust XK 100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

===[https://github.com/JacKeTUs/linux-steering-wheels Gaming Racing Steering Wheels]=== 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;40%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  [https://www.usb.org/sites/default/files/documents/pid1_01.pdf USB PID standard not supported], 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cammus C5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fanatec CSL Elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS4 and Xbox - belt driven wheel - 30cm wheel swapping 
|-
| &lt;!--Description--&gt;Fanatec Club Sport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; top belt $600 £500 system 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;FFBeast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Genius TRIO RACER F1 Racing Wheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Cheap and cheerful but not great - may need calibrating 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hama PC Racing Wheel Thunder V18 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Average 
|-
| &lt;!--Description--&gt;Hori Racing Wheel 3 with pedals 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS3 PC 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Logic3 PXU450 TopDrive GT450 Steering Wheel for PS3, PS4, XBox One and PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Logitech MOMO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Very good 
|-
| &lt;!--Description--&gt;Logitech Driving Force GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Logitech Drive Force Pro DFP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; wheel 900 degree - weighs in at 15&amp;nbsp;lbs
|-
| &lt;!--Description--&gt;Logitech Formula Force EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;200 degrees turn for the EX model is arcade-like driving - adds PS3 compatibility via the PSx/2 adaptor - weighs in at 9&amp;nbsp;lbs
|-
| &lt;!--Description--&gt;Logitech G25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;   - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G27 PC/PS3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; comes with gear shifter - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G29 PC PS3/PS4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  may need additional shifter - gear 900deg wheel / rumble - 3 peddle - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G920 PC XboxOne 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  may need additional shifter - gear 900deg wheel / rumble - 3 peddle - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G923 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft(R) SideWinder Precision Racing Wheel (1999)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R3
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R5
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R9
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R12
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://github.com/Ultrawipf/OpenFFBoard OpenFFBoard], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V12 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V12 Lite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simagic M10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; base direct drive $900 £800 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simplicity Simwheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; direct 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simxperience Accuforce V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SPEEDLINK Drift O.Z. Racing Wheel with Pedals and Gear Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SteelSeries Simraceway SRW-S1 Steering Wheel (PC) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Thrustmaster Nascar Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Thrustmaster Ferrari Challenge Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; Poor  
|-
| &lt;!--Description--&gt;Thrustmaster Ferrari FGT Rumble GT Experience 3-in-1 (PC/PS3)
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;b658
| &lt;!--Revision--&gt;0102
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Wheel and all buttons detected}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|}}
| &lt;!--Opinion--&gt;Not great - gear driven 240deg wheel rotation - no psu needed - 2 peddle - flappy gear change - rumble untested - red switch for PC PS3 selection 
|-
| &lt;!--Description--&gt;Thrustmaster F430 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Thrustmaster T500 RS Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; belt driven wheel/rumble for GT5 
|-
| &lt;!--Description--&gt;Thrustmaster T60 Challenge 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Thrustmaster T150 Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  gear / belt combo wheel / rumble - 2 peddle 
|-
| &lt;!--Description--&gt;Thrustmaster TMX Pro PC/XboxOne
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt; direct drive rumble - no manual gear shift included 
|-
| &lt;!--Description--&gt;Thrustmaster T80 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Base level and OK - PS4 - 270deg rumble - 2 peddle 
|- 
| &lt;!--Description--&gt;Thrustmaster T300 RS GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS3 PS4 - belt driven - 900deg rotation and modular 28cm wheel out - 2 peddles but 3 available 
|-
| &lt;!--Description--&gt;Thrustmaster TX Leather 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;TX Xbox version - 900deg rotation 
|-
| &lt;!--Description--&gt;Thrustermaster TS PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PC only belt wheel 
|-
| &lt;!--Description--&gt; TS XW Racer PC Xbox1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; top belt system 
|-
| &lt;!--Description--&gt;Thrustmaster T-GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS4 $700 £600 with T-DFB 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Tracer Zonda Racing Steering Wheel PC PS3 Vibration Feedback Pedals Gearbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


===Gamepad Joypad Adapters===

* Most adapters will work in most OS's without installing a driver. Special functions needing drivers will be noted. 
* Some adapters do not work with some [http://www.stepmania.com/wiki/Dance_Pads dance pads] because of voltage issues. Other adapters map the dancemat arrows as axes and not as buttons, causing problems.
* If using an adapters should be compatible with '''original''' PlayStation PS/Xbox Xbox/GameCube GC /Dreamcast DC/Sega Saturn SS gamepads. 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|- 
| &lt;!--Description--&gt;[http://www.maplin.co.uk/psx-usb-bridge-34887?tabid=3&amp;worldid=&amp;doy=21m9&amp;faqitem=playstation%20controller%20to%20pc%20adaptor Maplin] [http://www.rockfire.com.tw/ Padix Co. Ltd. Rockfire] PX-205 PSX/USB Bridge 
| &lt;!--Vendor ID--&gt;0x0583 
| &lt;!--Product ID--&gt;0x2050
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes}} but buttons mapped different from others 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|poor}}
| &lt;!--Opinion--&gt;Ok with dpads, but very poor support with analogue hack 
|-
| Boom PS Joy Converter adaptor 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| discontinued (2004/5). Hold Up, Start, and Select for three seconds. Very good [http://www.stepmania.com stepmania] recommendation. 
|-
| [http://www.hkems.com/m_main.htm EMS] [http://www.hkems.com/product/ps2/ps2-usb2.htm USB2] grey plastic box with 2 PSX ports, one on either side - UP and Select pressed for 3 seconds at the same time or the dance code (start+select+up) 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Tests/joystick shows the PS port works in digital mode on d-pad}}
| &lt;!--Analogue Hack with Analog Stick--&gt;
| Set in PC switch mode. Does not work when using 2 pads at the same time, likely higher power requirements. FPSE emu DualShock untested, Mat and Guitar untested but known lag involved 
|-
| Joytech (play.com) (EMS USB2 bad clone) Black box twin PSX
| 0x0b43
| 0x0003
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|buggy hardware}} 
| but poor on dance ddr mat and guitar hero as the left and right keys do not like being pressed together, Dual shock untested 
|-
| [ EMS Trio Linker ] 1 PSone connection at bottom
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX discontinued 2005 
|-
| [http://psxemulator.proboards.com/index.cgi?board=support&amp;action=display&amp;thread=421 EMS Trio Linker Plus] (blue box) 1 PSx at bottom
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX discontinued 
|-
| Gamtec [http://www.gamestone.co.uk/gradius/guides_usb_smartjoy_guide.php SmartJoy Plus] Lik Sang PS-&gt;USB converter Red 2005 
| 0x0925
| 0x0005
| Low 0110
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe|detected and digital dpad works with [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4138&amp;forum=2&amp;post_id=35952#forumpost35952 joystick and testjoystick tests] but  the second analog control is not mapping correctly in digital mode}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|Analogue Hack - hardware buggy not useable}} 
| Dual shock untested, Mat and Guitar untested. Nothing picked up upon plugging it in. Quite common, these items have grounding issues or feed voltage back into the USB host and freeze the host controller, preventing any plugins or removals being detected. 
|-
| Gamtec SmartJoy Plus Dual PS-&gt;USB converter Red 
| 0x0925
| 0x00
| Low 
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|buggy hardware}}
| 
|-
| [http://uk.gear.ign.com/articles/700/700334p1.html Lik-Sang Super SmartJoy PSX] 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX 
|-
| Soyo Kiki Kiky 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| eXcel PSX adaptor shaped a little like a stealth bomber with USB pass through 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| Venom 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| Dragon Plus (Radio Shack) Pantherlord GreenAsia USB to PS2/PS3 converter single black cable
| 0x0e8f
| 0x03
| 1.07
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes| }}
| 
|-
| Deal Extreme 2 PSX black cables from 1 USB port
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{N/A|untested }}
|- 
| &lt;!--Description--&gt;HDE 2014 Personal Communication Systems Inc 
| &lt;!--Vendor ID--&gt;0x0810
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;0106
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Same as single cable above but with black block midway along cable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
|- 
| &lt;!--Description--&gt;TigerGame Ltd Mayflash PC001 Super Joy Box 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| TigerGame Ltd Mayflash PC016 Super Joy Box arrowhead triangle twin PSX] Original was lack with RED Leds. Clones Dilong pu203, Blue HDE Neewer ShineData SD-APS2USB, Red Octane and Black PC Power Box (NS3454) '''embossed circle''' on top 
| 0x0810
| 0x0001
| 1.06
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Tests/joystick shows one PS port does not work with analog control at all but the other port does and maps correctly in digital mode}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|Analogue hack works }}
| Still available 2013, poor construction though, falls to pieces easily. Dual Shock untested, Mat and Guitar untested 
|-
| &lt;!--Description--&gt;TigerGame Ltd [http://www.mayflash.com/pc/pc038/pc038-1.htm Mayflash PC038 Super Joy Box Pro triangle twin PSX] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| TigerGame Limited Mayflash SuperJoy Box 5 PC006 long V-shaped 4 port PS/PS2 Game Controller Adapter  
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|- 
| &lt;!--Description--&gt;TigerGame Limited Mayflash SuperJoy Box 5 PRO PC039 PS/PS2 Game Controller Adapter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion 
|- 
| Boom PSX+N64 USB converter (purple or blue see through box) (2003/4) - red led for psx and green led for n64
| 0x6666
| 0x0667
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{No|not detected by Tests/joystick}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|Analogue hack }}
| Rumble Pak untested
|-
| [http://www.hkems.com/product/ps2/TrioLinkerPlus2.htm EMS Trio Linker Plus II] 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4753&amp;forum=24&amp;post_id=43102#forumpost43102 ]
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1DC 1GC 1PSX but not for ddr mat games 
|-
| TigerGame Mayflash PC043 clone HuiJia Black twin N64 converter for PC USB 
| 0x0e8f
| 0x3013
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{No|detected by Tests/joystick though two digital pads have their settings wrong}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|Analogue hack works well with middle handle/grip little joystick}}
| Rumble Pack untested 
|-
| TigerGame Mayflash PC MagicBox SuperBox 3 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| untested 1SS 1DC 1PSX }
|-
| &lt;!--Description--&gt;Lik Sang SmartJoy X 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x0285
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SmartJoy X2 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x0289
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| TigerGame Mayflash PC018 Super Joy Box 9 Xbox (NOT 360) 
| 0x05e3
| 0x060
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| does not work. Hub(s) 0x0288 detected but 0x0289 xbox1 joypads are not detected as hid let alone as [http://www.amiga.org/forums/archive/index.php/t-62940.html xpad] or [http://pingus.seul.org/~grumbel/xboxdrv/ linux xboxdrv driver] 
|-
| TigerGame Mayflash PC019 Super Joy Box 10 Xbox Twin ports (NOT 360) 
| 0x05e3
| 0x060
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| does not work with the big Fatty Duke or smaller S Akebono controller(s) 
|-
| TigerGame Ltd Mayflash PC020 Super Joy Box 11 Xbox Quad ports (NOT 360) 
| 0x05e3
| 0x0604
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| 
|- 
| &lt;!--Description--&gt;TigerGame Ltd Mayflash PC035 3 in 1 Magic Joy box PS GC Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;USB to NES [http://wiki.nesdev.com/w/index.php/Standard_controller SPI like protocol] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Buffalo Classic USB Pad SNES like 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash PC044 USB to SNES 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;USB to MEGADRIVE GENESIS Joypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;[http://www.retrousb.com/product_info.php?cPath=21&amp;products_id=70 USB to 9 pin ATARI RETROPORT style JOYSTICK PORT] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Atari RetroLink 9pin to SB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;SLS Sega Saturn USB pad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash PC050 Dual Saturn ports 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Guitar Hero for PC/Mac 
| &lt;!--Vendor ID--&gt;0x1430
| &lt;!--Product ID--&gt;0x474C
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Cronus Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BrookX One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Gamecube to USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Magic NS 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; WiiU 
|- 
| &lt;!--Description--&gt;Brook Converter WiiU P3 P4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;CooV Xbox One Converter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
|}


* [http://www.bemanistyle.com/forum/f6/best-metal-pad-19066/ Metal dance pads with LEDs] - My My Box Blue Shark (Nexen), Cobalt Flux (CF) (Let's Groove), Red Octane Afterburner, TX-2000, Logic3 (Dance Dance Dance), Gamerose (Stay Cool), 
* Hard foam mat - [http://www.mayflash.eu/3in1-deluxe-dansmat-ignition-foam-ps2xboxpc-p-5.html Mayflash] FutureMax Deluxe 3 in 1 Ignition, [http://www.gamerose.com/ Gamerose] (Stay Cool), TrinPad orange, 
* Soft foam mat - Logic3 (PS420N), [http://www.positivegaming.com/index.php?id=36 Positive Gaming Impact],  Gamerose Miss Daisys Naki (Stay Cool), Pelican, MadCatz

*PS1 PS2 PS3 PS4 flex ribbon big source of button/trigger issues with all controllers 
*PS2 Phat KSA1Q40A (Board), SA1Q33A (Membrane) SCHP-10010 H 
*PS2 SA1Q42A SCHP-10010 A 
*PS2 SA1Q43-A SCHP-10010 H


The primary axes are either the Control Pad or the left stick. Buttons come in a rough order: face buttons, then shoulder buttons, then Select and Start, then buttons under sticks, and finally Control Pad directions if not assigned to a hat. But the order and number of buttons within a category are unpredictable, as is which button the user expects to use for each action.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Joypad 
! width=&quot;5%&quot; | HATS 
! width=&quot;5%&quot; | Button 01
! width=&quot;5%&quot; | Button 02
! width=&quot;5%&quot; | Button 03
! width=&quot;5%&quot; | Button 04
! width=&quot;5%&quot; | Button 05
! width=&quot;5%&quot; | Button 06
! width=&quot;5%&quot; | Button 07
! width=&quot;5%&quot; | Button 08
! width=&quot;5%&quot; | Button 09
! width=&quot;5%&quot; | Button 10
! width=&quot;5%&quot; | Button 11
! width=&quot;5%&quot; | Button 12
! width=&quot;5%&quot; | Button 13
! width=&quot;5%&quot; | Button 14
! width=&quot;5%&quot; | Axes 1 
! width=&quot;5%&quot; | Axes 2 
! width=&quot;5%&quot; | Axes 3 
! width=&quot;5%&quot; | Axes 4 
! width=&quot;5%&quot; | Axes 5 
! width=&quot;5%&quot; | Axes 6 
! width=&quot;10%&quot; | Comment 
|-
| [https://pineight.com/mw/index.php?title=USB_game_controllers Xbox 360 Wired Controller]
| 
| A (down-green) 
| B (right-red) 
| X (left-blue) 
| Y (up-yellow) 
| LB (white) 
| RB (black) 
| Back
| Start
| Guide 
| L3
| R3
| 
| 
| 
| Left X 
| Left Y
| LT
| Right X
| Right Y 
| RT 
| Poor 2D, Good 3D 
|- 
| &lt;!--Description--&gt;Gravis GamePad / Original PlayStation Controller 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Red (Sqleft)
| Yellow X (X down)
| Green O (O right)
| Blue (Tri up)
| L1
| R1
| L2
| R2
| Select
| &lt;!--Button 10--&gt;Start
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;Stick X
| Stick Y
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; PlayStation 2 Older Adapters 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Blue X (down) 
| Red O (right) 
| Pink Sq (left) 
| Green Tri (up) 
| L1
| R1
| L2
| R2
| Select
| &lt;!--Button 10--&gt;Start 
| Stick 1
| Stick 2
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; PlayStation 2 Newer Adapters 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Up
| Right
| Down
| Left
| L2
| R2
| L1
| R1
| Select
| &lt;!--Button 10--&gt;Start
| Stick 1 (analogue Hack) 
| Stick 2 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; Wish Technologies N64 Adaptoid 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt; A
| C Down
| C Right
| B
| C Left
| C Up
| L
| R
| Start
| &lt;!--Button 10--&gt;Z
| Pad Up
| Pad Down 
| Pad Left
| Pad Right 
| &lt;!--Axes 1--&gt;Stick X
| Stick Y 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;
| 
| 
| 
| 
| 
| 
| 
| 
| &lt;!--Button 10--&gt;
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;
| 
| 
| 
| 
| 
| 
| 
| 
| &lt;!--Button 10--&gt;
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
|}

Just plug in your digital/analogue joystick or gamepad into USB port. The device will be handled by Poseidon USB stack. Poseidon is the USB stack with Trident adding a GUI (graphical user interface) prefs. 


the context sensitive page would come up right on pressing the help key inside the relevant window. The manual is in this archive, just in case it isn't in SYS:Locale/Help  


*How to change joystick mode to analogue?

By default a connected USB joystick emulates Amiga digital joystick. To change this behaviour so that the joystick is presented as analogue you need to use Trident preferences application (System:Prefs/Trident).

Open Trident and go to Devices on the left hand side (mouse click once on it). Select your controller from the list to the right and then click on Settings button below. This will open a new window. On the &quot;General&quot; tab find the &quot;Lowlevel Library Joypad Emulation&quot; section near the bottom. Find ports which are set to &quot;Merge with USB&quot; or &quot;Override with USB&quot; and change them to &quot;Analogue Hack&quot;. 

Please note that analogue joystick support is an extension of original Amiga functionality, thus an Amiga application must be explicitly written to use it. AROS SDL library uses this functionality, thus all SDL applications that use joystick, can use the analogue joystick feature.

The HID class has several options how to handle the input data: 

* Don't touch: The movement and button data for is not modified by the hid class. This is the default for the ports 0, 2, and 3. 

* Overwrite with USB: This will kill the  original  data  that  might  had  come  from  the internal  ports  and  overwrites it with the joypad data for this USB interface. Note well: If you have multiple  joypads  connected,  take care  which setting you have selected for each port, because only the last interface with this option will actually send the joypad data to the game. 

* Merge with USB: This option merges the input data of the  lowlevel.library  with  the USB  stream. This only works, if the connected device on the original Amiga  ports  is  NOT  a  mouse  (because  then   the   streams   are incompatible).  Merging  should  be  the preferred method, because it leaves the original joysticks working. 

* Disable: Turns off the port for the application.

* Analogue Hack: Tells Poseidon to force reporting  of  analogue  data  at  the  port. Please  note  that  this only works with programs that understand the analogue  data,  because  it's   an   extension   to   the   original lowlevel.library   standard   made  by  Commodore.  If  you  want  to incorporate this feature in your software, just contact me and I will send you the necessary information. 

* Rumble Port: As addition to the analogue data, the HID class  supports  applications and  games  that want to utilize a rumble pack or force feedback motors in the gamepads. This field selects to  which  lowlevel  port  the  hid device responds, when attempting to use the rumble pack. Normally, this corresponds to the port that has  been  set  in  the  actions  for  the joypad.


*How to change joystick port assignment?

The low  level  library  supports up to four ports. Port 0 is usually used by the mouse, port 1 is the standard port for joysticks/joypads. By default a connected USB joystick is present in Port 1. To change its location to Port 0 you need to use Trident preferences. 

Open Trident and go to Devices window. Select your controller from the list and then click on Settings button. This will open a new window. On the &quot;General&quot; tab find the &quot;Lowlevel Library Joypad Emulation&quot; section. Port 1 should be set as either &quot;Merge with USB&quot; or &quot;Override with USB&quot;. Change this setting to &quot;Don't touch&quot;. Change Port 0 setting to &quot;Merge with USB&quot;.

Go to &quot;Actions&quot; tab. In the &quot;Reports and collection&quot; select first entry named &quot;Joystick&quot;. in the &quot;Usage items&quot; select &quot;X axis&quot;. Go to &quot;Performed actions&quot; area. On the left there will be a list of triggers. Each of them should have (port1) in their params. Click on the first trigger and using buttons to the right of the list change port1 into port 0. Repeat this for all triggers and for all items on &quot;Usage items&quot; list.


*How to make joystick simulate keyboard keys?

With Poseidon it is possible to make the joystick simulate the keyboard pressings. This might enable using joystick for playing games which only have keyboard support. This feature is configured in Trident preferences.

Open Trident and go to Devices window. Select your controller from the list and then click on Settings button. This will open a new window. Go to &quot;Actions&quot; tab. On the right top window select X axis. On the left bottom list select an entry &quot;Digital Joystick, Push left(port 1)&quot;. On the panel to the right change &quot;Digital joystick&quot; into &quot;Raw Key&quot;. A list of keys will be displayed. Select key you wish to send. Repeat the same procedure for &quot;Digital Joystick, Release left (port 1)&quot; option but this time check &quot;Send key up even instead of key down&quot;. Open shell and move your joystick to the left - your selected letter should appear in the shell. 


*Analogue in Trident Prefs
* Open the Trident USB Prefs -&gt; Devices -&gt; Select your joypad -&gt; Settings button -&gt; Action TAB 
* See some &quot;axis&quot; listed under &quot;Usage items&quot; in the top right of the window. They are your analog stick(s) 
* Check [x] Track Incoming Events which is half way down the window on the left 
And you should see some axis activity in &quot;Usage items&quot; when you move the analog stick 


*Actions

HID class item -&gt; Settings -&gt; HID Class Window -&gt; Action Tab -&gt; Action handling area 

Reports and collections -&gt; Usage Items -&gt; Performed actions 


Qualifier keys are *special*. You don't only need to create the actual keypress but also modify the qualifiers.
Go to the keyboard panel and find the windows menu key by enabling key tracking and pressing the windows menu key. Then assign the right amiga key to it.

Go to the actions panel and find the right amiga key (it's called &quot;Keyboard right GUI&quot;). Remember the actions stored there, best write them down in exact order. Then delete them.
Find the windows menu item and add the missing qualifier action. Be sure the parameters are exactly the same and the order is right.

Set them to Raw, then assign an up and down button for each character, etc.
when you change the settings to RAW so you can assign keyboard strokes. it will always say, KEYDOWN or what ever on the left, it never provides and option for key release.

The problem still remains though that if I try to assign the Directional Pad (Hat) to Arrow Keys, that things will get screwed up and you either can not move with the directional PAD (HAT), or movements are assigned to the Left Analog, and do not work as they should, it's as if the right and down arrow keys are ALWAYS On, regardless of the fact that I did indeed assign a Key release command to each input.

check that by pressing analog directions and see the current values, and the thresholds configured in poseidon to bind them to left/right/up/down.

misconfigured too much stuff in the HID settings, you can always go in poseidon-&gt;config list entry and delete the config item related to your device (or the HID class setting itself), back to basics.


*Rumble in Trident Prefs
Open Trident Prefs and click on the Devices option in the left hand window. Click with the mouse once on your gamepad choice on the right hand side and again on the Settings button below. In the new window, select the '''General''' TAB and half way down on the right there is an &quot;Open Now&quot; button in the section &quot;HID output control window&quot;. Clicking on that button opens another window (HID Control) with sliders for the two rumble engines inside the controllers and you can test if they work. '''Sometimes clicking that button does nothing, other times it will open the window and say nothing is detected.''' The leftmost two sliders do nothing, the third one has a large rumble effect, and the fourth one has a small rumble effect.

===Graphic Drawing Tablet===

There is a standard in HID for tablets possibly mouse type. If the tablet is HID conforming in that sense, it should work. Aiptek does a fairly good job at this. The other competitor, Wacom, didn't pay too much attention to this and simply adapted their legacy serial protocol into HID in a very awkward way. Older Wacom tablets have worked with the special support in the HID class, but not the more recent ones. 

 to use graphic tablets fully, applications need to be written that make use of the AmigaOS NewTablet events (which AROS has) 


* Entry level - A6 (6x4) work area 
* Medium A5 (6x8) A4 (10x7) size   (recommended but only a few ie years 2000 to 2003 models supported) 
* Semi Pro A3 (12x9) 
* Pro  Cintiq


* 2005/6 Some support added for Wacom tablets  
* 2008 Wacom's patent on battery free pens expires


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Micrograf Tabby (late 1980s and early 1990s) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;podscat pt 3030 graphics tablet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Summagraphics 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Wacom IV compatible (Graphire, ArtPad, A3, A4, A5 and PenPartner CT-0405-P - Wacom intuos GD-0405-R) Waycom Digitiser II UD-0608-R
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Wacom Artpad II (KT-0405-R) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AceCad boards 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AipTek HyperPen 6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Calcomp 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AipTek HyperPen 8000 - Aldi/Medion MD 9310 and Aldi/Tevion LT 9310 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Tablet PC penabled 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based like x61t X60t NC4200 NC4400 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
* Wacom PenPartner
* PenPartner 2
* PenStation 2
| &lt;!--Vendor ID--&gt;0x056a
| &lt;!--Product ID--&gt;0x0000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Graphire - Wacom Tablet ET-0405-U UV1.1-1 (Slate Blue)  ET-0405UL (lime)  (orange)  (red)  (purple) 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0X0010
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{Yes|late 90s with A6 size - [Wacom Support] of X-axis 00000-10205  Y-AXIS 0000-7421 Tip Pressure 000-511 under Trident prefs. Air pen mouse type movements }}
|-
| &lt;!--Description--&gt;
* Grapphire 2 4x5  ET-0405A-U UV2.0-3 (Steel Blue) 
* Graphire 2 5x7 ET-0507A 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0011 and 0x0012
| &lt;!--Revision--&gt;0110
| &lt;!--Opinion--&gt;{{Yes|A6 and A5 versions - [Wacom Support] of X-axis 00000-10205  Y-AXIS 0000-7421 Tip Pressure 000-511. Air pen mouse type movements - mouse EC-120-0K tested}}
|-
| &lt;!--Description--&gt;Wacom Graphire 3
* cte-430/w 4x5 pearl   sapphire 
* cte 630 6x8 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0013 and 0x0014 
| &lt;!--Revision--&gt;0314
| &lt;!--Opinion--&gt;{{Yes|A6 and A5 size - [Wacom Support] Xaxis 0-10207 yaxis 0-7423 tip pressure 0-511 and the erase end appears to respond but avoid bluetooth BT versions }}
|-
| Wacom Graphire 4 
* cte-440/B Blue cte 440/s Silver 4x5
* cte-640 6x8 cte 640 u 0403 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0015 and 0x0016 
| &lt;!--Revision--&gt;403
| {{Yes|A6 and A5 work area detected [Wacom Support] x-axis 0000-10207 Y axis 0000-7423 Tip Pressure 000-511 and delete rub out end of the pencil seems detected but avoid bluetooth BT versions }}
|-
| &lt;!--Description--&gt;
* Wacom Intuos 4x5 GD-0405 
* Intuos 6x8    GD-0608
* Intuos 9x12    GD-0912
* Intuos 12x12  GD-1212-U 
* Intuos 12x18 GD-1218
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0020 0x0021 0x0022 0x0023 0x0024 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|detected and responses delivered back - x axis up to 30479 and y axis 31679, tip pressure up to 1023 and x and y tilt up to 127 - Wacom intuos GD-0912-A for Apple Macs NOT SUPPORTED}}
|-
| &lt;!--Description--&gt;
* Intuos 2 4x5 A6 - XD-0405-U 
* Intuos 2 6x8 A5 - xd 0608u uoc
* Intuos 2 9x12 XD-0912-U
* Intuos 2 12x12 XD-1212-U
* Intuos 2 12x18 XD-1218-U
| &lt;!--Vendor ID--&gt;0x056a
| &lt;!--Product ID--&gt;0x0041 0x0042 0x0043 0x0044 0x0045 
| &lt;!--Revision--&gt;0126
| &lt;!--Opinion--&gt;{{No|various sizes and recognised as [Wacom Support] but not working. x-axis 00000-20319 y-axis 00000-16239 tip presure 0000-1023 x-tilt y-tilt 000-127.  HID mouse xc-100-03 works but never could use it as a real tablet with pressure with TVPaint 3.6 }}
|-
| &lt;!--Description--&gt;
* Intuos 3 4x5 (PTZ-430) 
* Intuos 3 4x6   (PTZ-431W ) 
* Intuos 3 6x8   (PTZ-630 PTZ630) 
* Intuos 3 6x11 (PTZ-631W A3 wide)  
* Intuos 3 9x12 (A4 PTZ-930 PTZ930)  
* Intuos 3 
| &lt;!--Vendor ID--&gt;056a
| &lt;!--Product ID--&gt;0x00b0 0x00b1 0x00b2 0x00b3 0x00b4 0x00b5
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No}} Actions in HID setup window definitively locks the Pointer (mouse) reports settings and even after a clear and save, nothing changes, the configuration returns to default values.  &quot;[Wacom]&quot; reports don't see any events from the tablet, even with &quot;Pointer&quot; reports cleared and save, so is locked a in &quot;mouse&quot; state - but can send a special command to the tablet in order to put it into a special vendor mode. This mode enables Wacom specificities like pressure, tilt, absolute position, buttons, etc... you should send an HID report feature with ReportID=2 and data=2, the current HID class driver doesn't give a way to change that, even using the &quot;initial startup actions&quot; item in the extra collection. No listed features work 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Wacom Volito - Promethean FT-0405-U06 UV1.4-1 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0060
| &lt;!--Revision--&gt;0141
| &lt;!--Opinion--&gt;{{Yes|A6 work area with [Wacom Support] of x-axis 0000-5103 Y axis 0000-3711 Tip Pressure 000-511. Air and touch mouse movement - appears to be the budget option with some but limited features}}
|-
| &lt;!--Description--&gt;Wacom Volito 2 
* CTF-??? 2x3 
* CTF-420G CTF-420 V2.0-0 4x5
* Serif Penabled 6742 rebadge of CTF 420/020-B CTF-420/02
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0062
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{Yes|A6 work area with [Wacom Support] of x-axis 0000-5103 Y axis 0000-3711 Tip Pressure 000-511. Air and touch mouse movement - no erase function on the end of the pen - nylon nibs value option}}
|-
| &lt;!--Description--&gt;
* Wacom PL-400 LCD 
* PL-500
* PL-510
* PL-550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0030 0x0031 0x0032 0x0034 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
* PL-600
* PL-600 SX
* PL-700
* PL-710
* PL-800
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0033 0x0035 0x0036 0x0037 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Cintiq 21 UX and Cintiq Partner DTF-720
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Wacom PenTablet Bamboo (MTE), Bamboo Craft (CTH), Bamboo Fun (CTE), Bamboo Pen (CTL) and Bamboo Pen &amp; Touch (CTH) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Wacom Bamboo Fun Medium CTE-650 
| 
| 0x0018 
| 
| {{Maybe|[http://www.a1k.org/forum/showthread.php?t=11432 works on a1k forum]}}
|-
| &lt;!--Description--&gt;Bamboo Fun Small CTE-450 white 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0017 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Bamboo One CTF-430 V2.0-0 CTF 430/S
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0069
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{Maybe|A5 wired air pen and acts like a mouse only}}
|-
| &lt;!--Description--&gt;Wacom Intuos 4 
* Small PTK-440 PTK-540
* Medium - PTK-640 - PTK 540WL Wireless - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested  Intuos4 surface sheet was revised in October 2010 to reduce nib wear}}
|-
| &lt;!--Description--&gt;Wacom Intuos 5 Touch 
*
* Medium - PTH-650 - USB Wired and Wireless Kit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0027 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested work, however wireless may glitch or drag }}
|-
| &lt;!--Description--&gt;Wacom Intuos Pro Medium - PTH-651 - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Bamboo Small Pen Tablet - MTE 450 MTE-450A (MTE-450/k) - 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0065
| &lt;!--Revision--&gt;0116
| &lt;!--Opinion--&gt;{{Maybe|A6 work area - mouse movement but no pen detection except x-axis 2 to -2 and y-axis 2 to -2 - mini usb lead - 4 blue led lit buttons not detected as well as circular touch button??  }}
|-
| &lt;!--Description--&gt;Bamboo Pen CTL 460
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested all Bamboo versions were criticized for the drawing surface's roughness (which got smoother over time), which caused the small pressure-sensitive 'nib' to wear down, and become slanted or scratchy in the same way as pencil lead, albeit more slowly}}
|-
| &lt;!--Description--&gt;Wacom Bamboo Fun CTH-461/S wired 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x00D2
| &lt;!--Revision--&gt;0106
| &lt;!--Opinion--&gt;{{Maybe|A6 size - Pen tracking not working but finger touch works }}
|-
| &lt;!--Description--&gt;Wacom Bamboo Connect Pen Tablet CTL-470 CTL-470K 470-DE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;CTH 470K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom CTH 480/S wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} lithium battery for pad - 
|-
| &lt;!--Description--&gt;Wacom Intuos Pen Small CTL-480/S CTL 480 K wired 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x030E
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{No|A5 detected as Intuos PS  but not working although the RHS blue led responds to pen on tablet }}
|-
| &lt;!--Description--&gt;CTH 490 PK S Photo - CTH-490CK-S Comic - CTH-490AK-S Art 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested lower hovering height pen nibs wear fast and input lag/responsiveness}}
|-
| &lt;!--Description--&gt;Intuos Pen &amp; Touch Medium - CTH-680 - USB Wired and Wireless Kit work 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Intuos Pro (PTH-660 and PTH-860) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Waltop Media Tablet 10.6&quot;
    Genius G-Pen M609
    Genius G-Pen M609X
    iVista Media Tablet 10.6
    Aiptek MediaTablet 10000u

| &lt;!--Vendor ID--&gt;172f:0501
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Slim Tablet 12.1&quot;
| &lt;!--Vendor ID--&gt;0x172F
| &lt;!--Product ID--&gt;0x0034
| &lt;!--Revision--&gt;0x1105
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Waltop Media Tablet 12 by 9&quot; 
    Aiptek HyperPen 12000u T-12000U Tablet Series 
    Nisis T-12000u USB Tablet Series Version 1.05 (aiptek rebadged)

    Trust item #1535
    ADESSO Cyber Tablet 12000 Graphic design tablet
    iVista Media Tablet 12
    PENTAGRAM O'pen Wide P 2003
    Genius G-Pen M712
| &lt;!--Vendor ID--&gt;172f:0500, 0x08ca
| &lt;!--Product ID--&gt;0x0010
| &lt;!--Revision--&gt;0105
| &lt;!--Opinion--&gt;{{Yes|detected with Nisis/Aiptek functioning as a tablet, untested with others  - Puck (mouse) x axis 0000 to 6000 y axis 0000 to 6000 - stylus (pen) x axis 00000 to 12000 y axis 00000 to 12000 tip pressure 0000 to 1023 - 16 function keys - AAA battery needed for pen and another for the mouse}}
|-
| &lt;!--Description--&gt;Waltop Media Tablet 14.1&quot; v5.1e
    Genius G-Pen M714X
    Aiptek MediaTablet 14000u WMK-H141 
    Trust item #15358
    Adesso CyberTablet 14000 M14
    iVista Media Tablet 14.1
    PENTAGRAM O'pen Wide P 2004

| &lt;!--Vendor ID--&gt;0X172f
| &lt;!--Product ID--&gt;0X0500
| &lt;!--Revision--&gt;0114
| &lt;!--Opinion--&gt;{{Yes|detected with Nisis/Aiptek functioning as a tablet - Stylus (Pen) X 16838 Y 16838 Tip Pressure 1023 }}
|-
| &lt;!--Description--&gt;Waltop PID 0038
    Genius G-Pen F509
    Manhattan 177405

| &lt;!--Vendor ID--&gt;172f:0038
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop PID 0052
    Yiynova MSP19

| &lt;!--Vendor ID--&gt;172f:0052
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Q Pad
    Aiptek HyperPen Mini
    NGS Flexi Style
    VisTablet PenPad
    iVistaTablet Q Flex Pad
    Bravod Q-PD65-S
    Trust Flex Design Tablet (#16937)

| &lt;!--Vendor ID--&gt;172f:0037
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Sirius Battery Free Tablet
    VisTablet Muse
    PENTAGRAM Designer P 2700
    Princeton PTB-S1BK

| &lt;!--Vendor ID--&gt;172f:0502
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Slim Tablet 12.1&quot;
    Genius G-Pen F610
    Trust Slimline Widescreen Tablet (#16529)
    VisTablet Original 12&quot;
    Adesso CyberTablet Z12
    Adesso CT-Z12A
    PenPower Tooya Pro
    Aiptek Slim 12.1 Inch
    Aiptek SlimTablet 600u Premium II
    NGS Slim Proguess
    iVistaTablet Slim 12.1
    PENTAGRAM ThinType P 2006

| &lt;!--Vendor ID--&gt;172f:0034
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Slim Tablet 5.8&quot;
    Genius G-Pen F350
    Trust item #16485
    VisTablet Mini
    iVistaTablet Slim 5.8
| &lt;!--Vendor ID--&gt;172f:0032
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Venus S Tablet
    Trust eBrush Widescreen Tablet (#17939)

| &lt;!--Vendor ID--&gt;172f:0503
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Aiptek GmBH MediaTablet Ultimate II - 16:10 Professional Graphic Tablet Model 1400U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Hanvon Beijing HanWang HW Micro Drawing Tablet ET0504U 
| &lt;!--Vendor ID--&gt;0x0b57
| &lt;!--Product ID--&gt;0x8030
| &lt;!--Revision--&gt;01111
| &lt;!--Opinion--&gt;{{No|does not work - recognised as an HID mouse - no tablet extensions detected}}
|-
| &lt;!--Description--&gt;KYE EasyPen 340, Genius EasyPen 340 
| &lt;!--Vendor ID--&gt;0458:5014
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| Aiptek Hyper Pen 6000u PC Tablet APT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|detected but does not work - win98 era cordless 6in by 4.5in - }}
|-
| &lt;!--Description--&gt;nisis T-8000U APT-2 Aiptek rebadge 
| &lt;!--Vendor ID--&gt;0x08CA
| &lt;!--Product ID--&gt;0x0021
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|A5 detected but no responses }}
|-
| &lt;!--Description--&gt;Acecad Flair II GT-504 Init Fkt  Fkt 0x5ab450c0
AIPTEK HyperPen 10000 U
Aiptek HyperPen 10000U, 
AIPTEK Slim Tablet U600 Premium II
| &lt;!--Vendor ID--&gt;0x0460
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Ace Cad Enterprise Co., Ltd Tablet - 5x3.75 drawing area 
| &lt;!--Vendor ID--&gt;0x0460
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Bosto's 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} UCLogic Digitizer 
|-
| &lt;!--Description--&gt;Adesso CyberTablet Z7, Adesso CyberTablet 12000, Adesso CT-12000A  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;UC-Logic / Lapazz WP8060, UC-Logic / Lapazz PF1209, UC-Logic / Lapazz Artistic Tablet 5540,   Manhattan 8&quot;x6&quot;, Manhattan 3&quot;x4&quot;, Manhattan
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested but suspect not working}}
|-
| &lt;!--Description--&gt;DigiPro 5.5×4” Graphics Tablet
Digital Ink Pad (A4 format) 
DigiPro WP8060, DigiPro WP5540,  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius G-pen
G-Pen 4500
Genius Wizardpen
Genius Mousepen
Genius Easypen i405 M610 
Genius PenSketch 9x12, Genius MousePen i608, Genius MousePen 8x6, Genius MousePen / WizardPen 5x4, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius G-Pen F610
Genius G-Pen M610 
Genius G-Pen 340 (UC-LOGIC Tablet WP4030U)
Genius G-Pen 450 (UC-LOGIC Tablet WP5540U)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius
UC-LOGIC
iBall Tablet PF8060
iBall
Iball Pen Tablet 8060U, Iball Pen Tablet 5540U, Iball Pen Tablet 4030U, Iball Design Tablet PF1209,
NGS CADBOY (UC-LOGIC Tablet WP5540U)
Pentagram
QWare
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Trust TB-3100
Trust TB-5300 Trust 15356 
Trust TB-6300 Trust 15357  WP8060U  Slimline but bulky with metal backing A5 size 
Trust 16486, Trust 16447,  Sketch Design Tablet,
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|clashes with usb and crashes AROS }}
|-
| &lt;!--Description--&gt;UC-Logic Tablet WP1062
    Aiptek HyperPen 10000U
    Monoprice 10X6.25 Inches Graphic Drawing Tablet
    Pickle 10x6.25 Inch Graphic Drawing tabletguess

| &lt;!--Vendor ID--&gt;5543:0064
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| [ VTech KidiPhoto Art Studio] 
| 
| 
|  
| {{yes|works}}
|-
|}

Tablet has a squared lines of wires which induce a current into the pen which is then detected by the metal grid in the tablet pad. Tablets report pressure (and tilt on expensive models) and are absolute pointing devices (put the pen at the top left and the mouse pointer will go to the top left of the screen). Graphic drawing area, what keys, report rate, resolution lpi lpmm, accuracy, pressure levels (may come from the app), origin position,

Wacom tablets use electromagnetic resonance technology.  Since the tablet provides power to the pen through resonant inductive coupling, no power is required for the pointing device. As a result, no batteries are inside the pen (or the accompanying puck), making them lighter and slimmer.

Under the tablet's surface (or LCD in the case of the Cintiq) is a printed circuit board with a grid of multiple send/receive coils and a magnetic reflector attached behind the grid. In send mode, the tablet generates a close-coupled electromagnetic field (also known as a B-field) at a frequency of 531&amp;nbsp;kHz. This close-coupled field stimulates oscillation in the pen's coil/capacitor (LC) circuit when brought into range of the B-field. Any excess resonant electromagnetic energy is reflected back to the tablet. In receive mode, the energy of the resonant circuit’s oscillations in the pen is detected by the tablet's grid. This information is analyzed by the computer to determine the pen's position, by interpolation and Fourier analysis of the signal intensity.

In addition, the pen communicates information such as pen tip pressure, side-switch status, tip vs. eraser orientation and ID number (to differentiate between different pens, mice, etc.). For example, applying more or less pressure to the tip of the pen changes the value of the pen's timing circuit capacitor. This signal change can be communicated in an analog or digital method. An analog implementation modulates the phase angle of the resonant frequency, while a digital method is communicated to a modulator that distributes the information digitally. The tablet forwards this and other relevant tool information in packets, up to 200 times per second, to the computer.


If you disable (delete all of them except for one that needs to be set to &quot;no action&quot;, so that it will not be regenerated as default) the Extra Startup actions, the tablet should remain in relative mouse mode—you will not get pressure information in that mode though. [http://tech.groups.yahoo.com/group/highway_usb/message/2394]}}


=== Handheld Barcode Scanner Readers ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Farsun 9100 barcode scanner 0-12&quot; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola Symbol LS2203 CMOS 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Tysso 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Simple}} Code 11, Code 39, Code 93, Code 128, Coda Bar, UPC-A, UPC-E, EAN-8, EAN-13, MSI/Plessey, Telepen, Interleaved 2 of 5, Industrial 2 of 5, Matrix 2 of 5 
|-
| &lt;!--Description--&gt;Unitech MS320 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wasp WCS3905 CCD 1&quot; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Code 93, Matrix 2 of 5, Industrial 2 of 5, Code 39, UCC/EAN-128, ISBN, Code 32, EAN/JAN-8 , EAN/JAN-13 , UPC-A, UPC-E, Codabar, Code 128, Code 11, Interleaved 2 of 5, MSI-Plessey, China Post, IATA 2 of 5, ISSN, UK-Plessey 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Datalogic Touch 90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Intermec  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell Metrologic MK9540-32A38 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola LS2208 Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wasp WWS800 Laser 1D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Datalogic GD4130-BK-C066 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell 1202G-1USB-5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola / Symbol DS6707-DC20007ZZR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;DataMan 8000 2D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell Voyager 9520/40 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Metrologic MS1690 USB 2D Barcode Scanner  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} QR Code GS1 Databar PDF417
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Syscan GM800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

[http://www.scandit.com/2011/11/04/types-of-barcodes-choosing-the-right-barcode-type-ean-upc-code128-itf-14-or-code39/ Types of Barcode]

&lt;pre&gt;
UPC-A       Grocery most common 
Code 128    
EAN-13      Library Books ISBN &amp; ISSN, 
Code 39     
Codabar     blood bank,

2D barcodes such as 
Data Matrix 
PDF417e     
Maxicode    
Aztec       
QR Code     old Nokia handsets, 
MicroPDF417 
&lt;/pre&gt;


===TouchScreens===

Projected capacitive (PCAP) touch screen product, amongst many options the widely used are I2C and USB 

*USB host–device structure which dominates consumer and industrial electronics devices where higher bandwidth needed and user-friendly (multiswipes)
*I2C Inter-Integrated Circuit simple serial standard for LCD display in embedded systems because of cost and low power 
*SPI arduino and rpi single boards 

We cover the USB here 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| eGalax Touch 4a
| 0eef 
| 0001 
| 0001
| {{yes|2009 works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lilliput HDMI Monitors
669GL-70NP/C/T (7 inch)
869GL-80NP/C/T (8 inch)
FA1011-NP/C/T (10 inch)
FA1046-NP/C/T (10 inch)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Iilyama Prolite Monitors
PROLITE T1513SR-1 (15 inch)
PROLITE T1730 (17 inch)
PROLITE T1713SR-1 (17 inch)
PROLITE T1913SR-1 (19 inch)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Smart Display Company (SDC) Touchscreens TFT Monitors
TOUCH-TFT-TS07 (7 inch)
TOUCH-TFT-TS08 (8 inch)
TOUCH-TFT-TS10 (10 inch)
TOUCH-TFT-TS12 (12 inch)
TOUCH-TFT-TS15 (15 inch)
TOUCH-TFT-TS17 (17 inch)
TOUCH-TFT-TS19W (19 inch wide)
TOUCH-TFT-TS22W (22 inch wide)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;XENARC Monitors 7 inch models
700TSH
700TSU
700TSV
702TSV
705TSV
706TSA
700IDT
MDT-X7000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;XENARC 
8 inch models:
800TSV
805TSV

10 inch models:
1020TSV
1026TSA
1040TS

12 inch models:
1200TS
1200TR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Asus VT229H 21.5&quot;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;CUQI 7&quot; Monitor Touchscreen 1024x600 IPS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Espresso 15&quot; Portable Touchscreen Display Monitor
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hannspree HT225HPB 21.5 inch
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;WaveShare 13.3inch HDMI LCD (H) (with case)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


===GPS tracking, running, cycling, biking, walking, hiking, ORIENTEERING, boaters and mapping===

Support for OpenStreetMap but not for Ordnance Survey, Map Pilot or National Geographic's Topo maps data gdb,

Data output supported nmea 0183 V1.5 APA, V1.5 XTE and V2.1 GSA formats, gpx, kml/kmz, tracks from tcx files, geo: URIs,  
NMEA0183(which is RS232, voltages range from -15 volts to 15 volts, 4800 baud), or need NMEA sentences connected to your computer

other method that some units support is a special serial cable that actually emits raw RS232 NMEA. These usually take 10-&gt;30 volts input, can run the unit, and have full voltage I/O for RS232 (not like spanner mode, which effectively turns the unit into a USB-&gt;Serial adapter inside the case).

Equivalent apps - merkator, mapsource,

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Garmin gpsmap 180 GPS/chart plotter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;1992 GARMIN GPS 55 AVD Portable System 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin GPS V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - waas pinpoint within 3 metres - nmea - 4AA battery}}
|- 
| &lt;!--Description--&gt;Garmin GPS 12 12XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Legend C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin eMap 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|possibly through usbmodem rs232 connection nmea 0183 protocol}}
|-
| &lt;!--Description--&gt;Garmin eTrex 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} rs232 these older units supported it and would provide the stream in either the standard NMEA 0183 format or a proprietary Garmin format.
|-
| &lt;!--Description--&gt;Garmin GPS 75 AVD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS Map 7000 model 45006 (1994) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS Tracker
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan Pioneer Satellite Navigator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS 300 315 320 Mentor Receiver (2003) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Not for dedicated sat nav units like the Nuvi, TomTom, etc 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;NaviLock NL-402U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested u-blox 5 SuperSense® chipset with receivers for GPS, GLONASS, Galileo, BeiDou and QZSS}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;GM1-86UB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| U-BLOX UB-6010 GGA,GSA,GSV, RMC and support VTG, GLL, TXT ublox binary and NMEA Command Dynamic Condition }}
|-
| &lt;!--Description--&gt;NAVILOCK GPS NL-602U USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|works via usbmodem.device - ublox ag 6 chipset - 50 channel}}
|-
| &lt;!--Description--&gt;TOPGNSS ton Receiver &amp; Antenna GM702  u-blox 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|UBLOX7020 chip design bloc u-blox}}
|-
| &lt;!--Description--&gt;VK-162 G-MOUSE u blox 7 
| &lt;!--Vendor ID--&gt;0x1546
| &lt;!--Product ID--&gt;0x01a7
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{N/A|UBX G70xx with RMC VTG GSV TXT GLL GGA GSA}}
|-
| &lt;!--Description--&gt;VK-172 u-blox 7 G7020-KT gps gnss white pen stick receiver - over 1 inch long 
| &lt;!--Vendor ID--&gt;0x1546 
| &lt;!--Product ID--&gt;0x01a7
| &lt;!--Revision--&gt;0100 
| &lt;!--Opinion--&gt;{{N/A| detected as cdc controlled plug in device - 18x18x2mm patch antenna but can be slow to update - nmea 0183 and ublox binary protocol}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;GlobalSat BU-353 WaterProof USB GPS Receiver 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested SiRF Star III}}
|-
| &lt;!--Description--&gt;Haicom HI-206 USB GPS receiver with RS-232 interfaces, RJ11 and PS/II connector EB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|usb-serial prolific pl2303 detected but GSP3F SiRF Star IV technology not detected or bound}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;BT760Y, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 5 GPS chipset}}
|-
| &lt;!--Description--&gt;GM-65 USB GPS Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 6 GPS chipset - 65 channel}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 7 GPS chipset}}
|-
| &lt;!--Description--&gt;GM-65 USB GPS Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 8 GPS chipset - 167 channels}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Garmin Colorado 300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} USB 
|-
| &lt;!--Description--&gt;Garmin Geko 101 201 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} limited waas enabled only - waypoints - aaa battery 
|-
| &lt;!--Description--&gt;Garmin Edge 200 bike mount 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin ForeRunner 10 15 watch 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Montana 600
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Dakota 10 20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Map76s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Oregon 450T  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} USB nmea 0183 
|-
| &lt;!--Description--&gt;Garmin eTrex 10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - no nmea0183 sentences data stream output - configuration an option to set it to &quot;Garmin&quot; mode, or &quot;Mass Storage&quot; mode. Since the mass storage mode seems to be required for waypoint/track/etc data exchange, the 'Garmin' mode would be for this data stream. Yet putting it in that mode doesnt seem to produce anything.}}
|-
| &lt;!--Description--&gt;Garmin Oregon 650T 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin GPSMAP 64S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|untested}}
|-
| &lt;!--Description--&gt;GPSMap 78S or GPSMap 76CSX which has a NMEA port for talking to Nav equipment
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|untested}}
|-
| &lt;!--Description--&gt;Garmin eTrex Vista Cx GPS Receiver 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - 2AA battery}}
|-
| &lt;!--Description--&gt;Garmin GPSmap 276c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 2000 XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan Triton 300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} SiRFstarIII™, Antenna Type Multidirectional Patch with WAAS, EGNOS, MSAS support 
|-
| &lt;!--Description--&gt;Magellan Triton 400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


==massstorage.class (MSC/UMS - most cameras and mp3 players)==

=== USB Card Readers ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;15%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Installing
! width=&quot;15%&quot; |Booting
! width=&quot;30%&quot; |Opinion
|-
| A-Tec Model CR-362 
| 
| 
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{N/A|untested}}
|-
| [http://www.belkin.com/IWCatProductPage.process?Merchant_Id=&amp;Section_Id=200406&amp;pcount=&amp;Product_Id=179164 Belkin 15 in 1 Card Reader]
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Conrad CP440 60 in 1 
| 
| 
| 
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works on a1k forum}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Genesys Gtech Logic 19 in 1
| 0x05E3
| 0x0710
| High 0200
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Hama 19 in 1 Card Reader 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| Hama 35 in 1 Card Reader 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Integral Single Slot SD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kingston USB 3.0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lexar microsd adapter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} but wider than Sandisk version - could block other slot if below 
|-
| Pretec CardDriver 
|
|
| 
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{no|no driver}}
|-
| Sandisk MicroMate 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;Sandisk MobileMate SD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Sandisk MobileMate Micro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} has satisfying 'click' when microsd inserted 
|-
| &lt;!--Description--&gt;Sandisk MobileMate Duo MicroSD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} no 'click' insertion uses pressure so future wear and tear issues 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Serena metal cased microsd only 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|Maybe}} hit or miss on quality 
|-
| &lt;!--Description--&gt;Serena &quot;Sandisk MobileMate&quot; look-alike 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|Maybe}} hit or miss on quality 
|-
| SilverCrest 16in1 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;Transcend 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Transcend P5 8 in 1 TSRDP5K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Transcend P8 15 in 1 TSRDP8K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Zyxel integralmemory 8 in 1 
| 0x0aec
| 0x3260
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{no|not detected}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

=== USB Hard Drives ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Datel MaxDrive 
| 
| 
|  
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Inateck 2.5 Inch USB 3.0 Hard Drive Disk Enclosure/ Case (FE2001) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Full USB 3.0 port but plastic teeth keeping drive in place can snap 
|-
| &lt;!--Description--&gt;Inateck case (FE2002) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} full USB 3.0 port - updated design 
|-
| &lt;!--Description--&gt;Inateck case (FE3001) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} wider USB 3.0 port and no on/off switch  Jmicron JMS578 chipset
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Iomega Desktop Hard Drive 500GB, 3,5“, USB2.0 
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Samsung T3 SSD 
|
|
|
| {{N/A|untested}} USB 3.1 Gen 1 space grey / black metal/ plastic 
|-
| Samsung T5 SSD 
|
|
|
| {{N/A|untested}} USB 3.1 Gen 2 256GB 512GB alluring blue 1Tb 2Tb black unibody metal 
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Seagate
|
|
|
| {{N/A|untested}}
|-
| Seagate 
|
|
|
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Toshiba Canvio 1TB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|partition fat32 or sfs to 100GB max - ntfs partitions not detected out of the box - select usb drive in trident prefs and press disable to shutdown}}
|-
| Verbatim 160GB Smartdisk 
| 
| 
|  
| {{yes|works }}
|-
| Western Digital USB 
|
|
|
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;WD Essential 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;WD Passport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== USB DVD CD ROM Drives ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;12.5mm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;12.5mm enclosure mini-sata dvd-rw 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested needs sole usb3 port to power it}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;9.5mm enclosure ECD829 mini-sata dvd-rw with Initio Corporation INIC-1618L SATA 
| &lt;!--Vendor ID--&gt;0x13fd
| &lt;!--Product ID--&gt;0x0840
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested but probably needs sole usb3 port to power it}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|}


=== USB to NGFF NVMe SDD HDD DVD CD ROM Drives ===

The older Jmicron JMS539B seems to result in massive filesystem corruption given the amount of corrupted content. Prehaps always avoided Jmicron and opted for Asmedia even if it costed a bit more. Realtek seems to be working okay for me generally speaking and newer Jmicron chipsets are less buggy – but evidently not perfect. 

From [https://goughlui.com/2025/08/17/psa-validate-your-storage-jmicron-jms583-kioxia-bg4-series-ssd-issue/ thread] 

Here is a [https://forums.anandtech.com/threads/stable-nvme-usb-adapter.2572973/ very long thread] that discusses data corruption and stability issues with these bridges. The majority of the posts are complaining of dropouts, hangs and the like, which usually down to either a poor USB 3.x implementation (SuperSpeed connections are very picky as to cables, ports and trace routing) or problematic compatibility. Regardless, the [https://www.legitreviews.com/jmicron-jms583-controller-version-matters-for-portable-usb-drives_219422 JMS583 is known to have several versions] noting that the last revision (C) in that article is a 2021 release which should fix earlier stability and cable quality compatibility issues. 
JMS583-STD-Release-v00.02.01.04-Bus Power.bin is the latest JMS583 firmware as of August 2025. 

Early firmware RTL9210 seems to have issues as well 


* RTL9210B
* JMS583 rev1 with firmware A2 or A3  

* RTL9210A
* JMS583 firmware 2.0.9 
* Asmedia ASM2362

* RTL9201A


The reference Hardware ID for the JMS583 chipset from JMicron is:
VID_152D&amp;PID_0583&amp;REV_0209
where &quot;VID_152D&quot; identifies a JMicron product;
&quot;PID_0583&quot; is the generation chipset;
&quot;REV_0209&quot; is the firmware version installed.

In the same way, the reference Hardware ID for the RTL9210 from Realtek is:
VID_0BDA&amp;PID_9210&amp;REV_3100
&quot;VID_0BDA&quot; is for a Realtek product, &quot;PID_9210&quot; is referred to the chipset and &quot;REV_3100&quot; to the firmware.


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;ASM1153E / ASM1153 with firmware 140509_A1_82_40 or 141126_A1_EE_82. Both supports UASP and TRIM on USB 3.1 Gen.1 adapter
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|works with sabrent ec-uasp}}
|-
| &lt;!--Description--&gt;ASM235CM Ugreen aluminum bridging the USB3.2 Gen2x1 to Serial ATA host interface 
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;TI 9261 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;ASM225
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;JMicron JMS578 issues USB 3.1 Gen.1 adapter 
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0578
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;JMicron JMS576 issues USB 3 to usb-c adapter 
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0576
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|orico}}
|-
| &lt;!--Description--&gt;JMS562 JMicron Technology Corp
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0562
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;JMS561U
| &lt;!--Vendor ID--&gt;0x152d
| &lt;!--Product ID--&gt;0x1561
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|works with sabrent ec-uasp}}
|-
| &lt;!--Description--&gt;VL716Q4 Orico black meshed aluminum usb c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Asmedia ASM1053E 
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;ASmedia ASM1051E
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Asmedia ASM1053
| &lt;!--Vendor ID--&gt;0x174C
| &lt;!--Product ID--&gt;0x1536
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Asmedia ASM104x
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;0x1042 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Unknown Chinese version 
| &lt;!--Vendor ID--&gt;0x0bc2
| &lt;!--Product ID--&gt;0x2312 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|sometimes works}}
|-
| &lt;!--Description--&gt;JMicron N5321 gr
| &lt;!--Vendor ID--&gt;0x152d
| &lt;!--Product ID--&gt;0xa583
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Initio Corp INIC-1618L mini slimline sata 6 + 7 pins to usb2 adapter 
| &lt;!--Vendor ID--&gt;0x13FD
| &lt;!--Product ID--&gt;0x0840
| &lt;!--Revision--&gt;0114
| &lt;!--Opinion--&gt;{{maybe|sometimes works mini sata to usb2 detects 201x laptop DVD as MassStorage(CD/DVD) but may need powered USB hub}}
|-
| &lt;!--Description--&gt;Unknown mini sata to usb3 adaptor 
| &lt;!--Vendor ID--&gt;0x01F75
| &lt;!--Product ID--&gt;0x0621
| &lt;!--Revision--&gt;0036 
| &lt;!--Opinion--&gt;{{maybe|sometimes works mini sata to usb3 detects 201x notebook DVD drive as MassStorage(SCSI) but 5V 1.5Amp needs powered hub to burn }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|}


=== External Floppy ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;[http://techtravels.org/amiga/amigablog/ Amiga Floppy Project]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;[http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=842 Catweasel Mk4]
| 0xE159
| 0x0001
| 0x00
| {{yes|[http://archives.aros-exec.org/index.php?function=browse&amp;cat=driver/storage works]}}
|-
| &lt;!--Description--&gt;[http://hxc2001.free.fr/floppy_drive_emulator/ HxC Floppy Emulator]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;[http://www.softpres.org/glossary:kryoflux KyroFlux]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;Samsung SFD-321U/EP USB Floppy
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}} 
|-
| &lt;!--Description--&gt;[http://www.cbmstuff.com/proddetail.php?prod=SCP SuperCard Pro] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://www.facebook.com/groups/greaseweazle Greaseweazle STM hardware], [https://cowlark.com/fluxengine/index.html Greaseweasel support], [https://github.com/keirf/Greaseweazle/wiki software], [https://amigakit.amiga.store/greaseweazle-p-91279.html buy], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FL-2501 USB Portable Diskette Drive  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2009 usb - [https://amiga.robsmithdev.co.uk/ Drawbridge] [https://github.com/RobSmithDev/ArduinoFloppyDiskReader software] ribbon cable compat with p/n 19308801-19 and s/n U356244 - model ASM P/N 27l4226 and FRU P/N 05k9283 - 
|-
| &lt;!--Description--&gt;Dell Floppy Drive Module USB External 3.5&quot; - Teac FD-05PUB 1.44mb 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2004 usb 1.1 
|-
| &lt;!--Description--&gt;USB FLOPPY DISK DRIVE (USB External Floppy Disk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://github.com/SukkoPera/OpenFlops OpenFlops] with [https://github.com/keirf/flashfloppy FlashFloppy] Gotech clone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://github.com/hmerrett/HenryFlops HenryFlops reworked OpenFlops] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


==ptp.class (PTP and MTP - other cameras and mp3 players)==

=== Cameras ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Canon EOS 20D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004  }}
|-
| &lt;!--Description--&gt;Canon 350D (also known as the Digital Rebel XT/Kiss Digital N) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 DIGIC II processor 8-megapixel }}
|-
| &lt;!--Description--&gt;Canon PowerShot A430 A560 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 }}
|-
| &lt;!--Description--&gt;Canon EOS 400D (XTi) digital SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;Canon EOS 1000D also known as Rebel XS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10.2mp 720p  }}
|-
| &lt;!--Description--&gt;Canon 450D aka Rebel Xsi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 12.2mp }}
|-
| &lt;!--Description--&gt;Canon PowerShot S90 S95 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 2010 720p video - 10Mpixel }}
|-
| &lt;!--Description--&gt;Canon Powershot SD960 IS Digtal ELPH 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 Still Image: Exif 2.2 (JPEG), Movie: MOV (Image: H.264; Audio: Linear PCM) Lithium-ion Battery Pack NB-4L }}
|-
| &lt;!--Description--&gt;Canon EOS 500D aka Rebel  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 1080p 15.1MP Lithium  }}
|-
| &lt;!--Description--&gt;Canon EOS 550D 600D aka Rebel T2i T3i DSLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010-2011 1080p 18MP Lithium LP-E8 }}
|-
| &lt;!--Description--&gt;Canon Powershot S100 S110 S120  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011-2013 720p-1080p video 12.1MP and above versions - }}
|-
| &lt;!--Description--&gt;Canon EOS 1100D DSLR Camera aka Rebel T3 SLR, EOS Kiss X50 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p 10Mpixels Lithium  }}
|-
| &lt;!--Description--&gt;Canon EOS 650D 700D aka Rebel T4i T5i T6i SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2013 1080p 18Mpixels Lithium LP-E8 articulating flip out twistable screen }}
|-
| &lt;!--Description--&gt;Canon ELPH 300 HS (IXUS 220 HS) 230 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 blogging camera }}
|-
| &lt;!--Description--&gt;Canon PowerShot N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013  12.1 MP CMOS, DIGIC 5 Wifi Lithium Battery Pack NB-9L }}
|-
| &lt;!--Description--&gt;Canon Powershot G7 X, G7X-II 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014-2016 1080p video 12.1MP and above versions - }}
|-
| &lt;!--Description--&gt;Canon EOS 1300D DSLR Camera aka Rebel T6 SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 1080p 16Mpixels Lithium  }}
|-
| &lt;!--Description--&gt;Canon Powershot G7x G5X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| G7X flip up and G5X flip out - same batteries - no external microphone input - }}
|-
| &lt;!--Description--&gt;Canon EOS M3 M5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| flip out - same batteries - }}
|-
| &lt;!--Description--&gt;Canon EOS 60D 70D 80D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 6D 7D 8D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;Canon 5D Mark II III IV DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji FinePix A850
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;FujiFilm Finepix F100fd
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji FinePix F810
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xf1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| pocketable exr cmos 12mp }}
|-
| &lt;!--Description--&gt;Fuji xt1  x-t1  x10 x-t10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 1080p }}
|-
| &lt;!--Description--&gt;Fujifilm x100 x100s x100t 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xPro1 xPro2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xt2 / x-t2 x-t20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4K video }}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;GoPro HERO 3 HERO4 HERO 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon D100, D60
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 Compact flash storage - non interchangeable lenses up to 12.3MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D50, D50x 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005  storage - 6.1MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D70, D80, D90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 Compact flash storage - 10MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D40, D40x 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007  storage -  10MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D300, D700
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008  storage -  12.3MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D2Xs, D2Hs, D3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006-2008  storage - sensor }}
|-
| &lt;!--Description--&gt;Nikon D3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 720p video }}
|-
| &lt;!--Description--&gt;Nikon D5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 720p video unlike D3000 }}
|-
| &lt;!--Description--&gt;Nikon D6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 16mpixel}}
|-
| &lt;!--Description--&gt;Nikon D7000  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 16.2mp 720p video }}
|-
| &lt;!--Description--&gt;Nikon L26 L27 L28 L29 L31 Coolpix compact cameras 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p video - 2 AA - pocket sized }}
|-
| &lt;!--Description--&gt;Nikon D3100   
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p video 14.2mp}}
|-
| &lt;!--Description--&gt;Nikon D5100 DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 16.2mp  720p}}
|-
| &lt;!--Description--&gt;Nikon L810 L820 L830 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2014 720p video }}
|-
| &lt;!--Description--&gt;Nikon D4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012  storage - sensor }}
|-
| &lt;!--Description--&gt;Nikon D7100 D7200  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2014 up to 24.2mp 1080p video }}
|-
| &lt;!--Description--&gt;Nikon D3200  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 1080p 24MPixel}}
|-
| &lt;!--Description--&gt;Nikon D5200 D5300  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 24.1MP 1080p }}
|-
| &lt;!--Description--&gt;Nikon D800 D600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 1080p video sd card storage - dust/oil issue at start}}
|-
| &lt;!--Description--&gt;Nikon D3300 DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24.2MP 1080p  }}
|-
| &lt;!--Description--&gt;Nikon D500, a high-performance DX-format (APS-C) DSLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 }}
|-
| &lt;!--Description--&gt;Nikon D5500 D5600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016-2018 24.1MP 1080p }}
|-
| &lt;!--Description--&gt;Nikon D810 D610 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 1080p video sd card storage }}
|-
| &lt;!--Description--&gt;Nikon D7300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4K UHD video }}
|-
| &lt;!--Description--&gt;Nikon D900 D850 D820 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4k 46MP }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Olympus C-370 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 3.2mp }}
|- 
| &lt;!--Description--&gt;Olympus Camedia C-725 Ultrazoom
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 3mp aa batteries, }}
|-
| &lt;!--Description--&gt;Olympus Evolt E-500
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 8mp  }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Olympus Evolt E-410 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007  }}
|- 
| &lt;!--Description--&gt;Olympus Evolt E-510
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 10MP Live MOS sensor with TruePic III processor,  }}
|-
| &lt;!--Description--&gt;Olympus E-420
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10mp, compactflash and xD cards,  }}
|-
| &lt;!--Description--&gt;Olympus E-520
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10mp, compactflash and xD cards,  }}
|- 
| &lt;!--Description--&gt;Olympus E-620
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 12.3mp, compactflash, xD and microdrive cards,  }}
|- 
| &lt;!--Description--&gt;Olympus E-30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  }}
|- 
| &lt;!--Description--&gt;Olympus E-450 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 10mp,  }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Pentax * ist DS DSLR camera
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 6.1mp  }}
|- 
| &lt;!--Description--&gt;Pentax K10D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 10.2mp APS-C CCD no video and older manual Pentax K-mount lenses}}
|-
| &lt;!--Description--&gt;Pentax K20D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2008 14.6MP APS-C but no video recording mode }}
|-
| &lt;!--Description--&gt;Pentax K30 K-5 II 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2012 16MP full HD (1080p) recording at 24/25/30 fps}}
|-
| &lt;!--Description--&gt;Pentax K-3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24MP 1080p  }}
|-
| &lt;!--Description--&gt;Pentax K-3 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 24MP  }}
|-
| &lt;!--Description--&gt;Pentax K-3 III
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 25.7MP BSI CMOS sensor  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix LZ10 LZ20 DMC-LZ30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 720p video }}
|-
| &lt;!--Description--&gt;Panasonic TZ1 TZ5  TZ9 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix GH1 GH2 like the DMC-GH2HEB-K - GH3 DMC-GH3HEB-K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| Four Thirds (GH2)  MFT Micro Four Thirds (GH3) limited to 29mins recording }}
|-
| &lt;!--Description--&gt;Panasonic AF series AF100 AF101 AF102 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix DMC-G2 DMC-G3 G5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic TZ60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic DMC LX7 10 LX15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic GF7 GX8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic G80 G85 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| micro 4/3 }}
|-
| &lt;!--Description--&gt;Panasonic GH4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| micro 4/3 - shooting in MOV or MP4 formats recording limited to sd card size but split files because the FAT32 file system only supports files up 4GB in size, which amounts to around 5 minutes of 4K (100mbps) footage - GH4 appears to create 4GB files as a rule, regardless of whether the memory card’s file system supports larger files or not - }}
|-
| &lt;!--Description--&gt;Panasonic GH5 gx80 gx85 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| Effective: 20.3 Megapixel 5184 x 3888 - 2 sd card slots compatible with high-speed, high capacity UHS-II - sd card v rating like the v90 should record at 60MB/s to be compatible with the GH5 in the All-I format - possible file corruption with .mdt files - new firmware 2.0 update, the Panasonic GH5 becomes the first 5K - }}
|-
| &lt;!--Description--&gt;Panasonic FZ2000 FZ2500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung WB100 WB1100 WB150 WB2200 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 16MP }}
|-
| &lt;!--Description--&gt;Samsung NX11 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung  NX200, NX20, NX1000 and NX210
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 20.3Mp APS-C sized CMOS image sensor }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sanyo Xacti CG65
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sanyo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 6.1MP }}
|-
| &lt;!--Description--&gt;Sony Cyber-shot DSC camera models W110 W220 H300 H400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10.2MP }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A230
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 10.2MP }}
|-
| &lt;!--Description--&gt;Sony Cybershot HX20V HX30V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 18mp 720p  - steady shot unit / optical block can cause buzzing noise and/or jumping image in lcd / viewfinder - dots are dirt and this voids the warranty }} 
|-
| &lt;!--Description--&gt;Sony Cybershot HX50V HX60V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 20.2MP 1080p  - steady shot unit / optical block can cause buzzing noise and/or jumping image in lcd / viewfinder - dots are dirt and this voids the warranty }} 
|-
| &lt;!--Description--&gt;Sony A77 A99 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 }}
|-
| &lt;!--Description--&gt;Sony WX100 WX150 wx220 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 2014 }}
|-
| &lt;!--Description--&gt;Sony NEX-6 Sony NEX-7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 16 to 24MP }}
|-
| &lt;!--Description--&gt;Sony NEX-3N Sony NEX-5N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 16MP }}
|-
| &lt;!--Description--&gt;Sony α58 Sony α68 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 20.1 MP  2014 24mp }}
|-
| &lt;!--Description--&gt;Sony rx100 mk III 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 20.1MP 1.0-type back-illuminated Exmor R CMOS sensor, often after boot-up, the motor starts running for no reason for first versions' -  }}
|-
| &lt;!--Description--&gt;Sony α5000 a5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 20.1 Megapixel APS-C Exmor APS HD CMOS 1080p Sony E-mount [https://github.com/ma1co/Sony-PMCA-RE hack] using [https://www.youtube.com/watch?v=8M4hR9HiOzM this] }}
|-
| &lt;!--Description--&gt;Sony α6000 a6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24MP APS-C sensor }}
|-
| &lt;!--Description--&gt;Sony α7 A7S a7r a7c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 mirror less - more compact }}
|-
| &lt;!--Description--&gt;Sony α77 II, α99 II, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 24.3 MP,  2016 42.4mp   }}
|-
| &lt;!--Description--&gt;Sony rx100 mk IV V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 2016 }}
|-
| &lt;!--Description--&gt;Sony RX0 RX zero, RX0 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 2017 }}
|-
| &lt;!--Description--&gt;Sony α6500 a6500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 24.2MP APS-C sensor 4K }}
|-
| &lt;!--Description--&gt;Sony α7 Alpha 7 II E-mount interchangeable lens mirrorless camera 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 24.2mp,  }}
|-
| &lt;!--Description--&gt;Sony α7 A7Sii a7r a7c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 mirror less - more compact }}
|-
| &lt;!--Description--&gt;Sony a7 III α77 ILCE7M3/B Full-Frame Mirrorless Interchangeable-Lens Camera
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 24.2mp,  }}
|-
| &lt;!--Description--&gt;Sony ZV-1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 24mm optical zoom, }}
|-
| &lt;!--Description--&gt;Sony ZV-1F
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 entry-level vlogging, 1-inch 20.1MP, ultra-wide 20mm f/2 prime lens}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}

&lt;pre &gt;
Lens Mounts

Canon EF EF-S
Nikon F 
Panasonic 
Olympus OM 
Pentax DA, FA, F, A, M, and K series
Fujifilm X mount 
&lt;/pre &gt;

&lt;pre &gt;
Sensors

APS-C 
S35 
Full Frame 
43 Four Thirds 
M43 MFT Micro four thirds 
&lt;/pre &gt;


=== Digital Voice Recorder Dictaphone Dictation Machine Handheld ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-7000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2011 }}
|-
| &lt;!--Description--&gt;Olympus VN-7200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested 2012 no usb }}
|-
| &lt;!--Description--&gt;Olympus VN-7500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2012 }}
|-
| &lt;!--Description--&gt;Olympus VN-7600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2013 }}
|-
| &lt;!--Description--&gt;Olympus WS-100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested usb}}
|-
| &lt;!--Description--&gt;Olympus VN-7700 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-8600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-711PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-712PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-731PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus WS-811
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested slide out usb-a - aaa battery - ok recordings }}
|-
| &lt;!--Description--&gt;Olympus VN-540PC Olympus VN-541PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Philips DVT1250
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX470
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX560
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX570 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


=== USB eBooks Readers drm free EPUB version 2.0.1 (2007), 3.0 (2011), 3.1 (2015) or [https://www.w3.org/TR/epub-33/ 3.3 (2024)] [https://github.com/thansen0/sample-epub-minimal epub examples] formats access ===

EPUB file format is an open standard based on XHTML for content and XML for metadata, contained in a zip file archive 

PDF v2.0 in 2017, 2009 takeover by ISO Org, 1.7 in 2006 , 1.6 in 2005, 1.4 in 2001, 1.3 in 1999, 1.0 in 1993 


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Access
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Barnes and Noble Nook Simple Touch NST BNRV300 
| &lt;!--Vendor ID--&gt;0x2080
| &lt;!--Product ID--&gt;0x0003
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;when finding the right micro usb cable that works, internal nook memory not accessible but sd card fat32 readable and writable outside 
| &lt;!--Opinion--&gt;{{N/A|2011 6in 600x800 e-ink 16 grayscale .jpg}} battery remove sd card and Torx T5 back top for Cameron Sino CS-BNR003SL - USA 1.2.2 md5sum 351e26527e80156183e74be2da2ce89f *nook_1_2_update.zip - 1.2.1 UK fdba3981f7f221cc5143db6329645bc2 *nook_1_2_update.zip - skip registration, Turn on the device, but do NOT start setting it up. Hold down the top right button on the front of the device and slide your finger from left to right across the top of the E Ink screen. A ‘Factory’ button should appear in the top left corner of the screen. Press it. Once in the Factory menu, hold down the top right button on the front of the device and tap the bottom right corner of the screen should now see a ‘Skip Oobe’ button. Tap that and the Nook should finally load the home screen. Poor battery management - 
|-
| &lt;!--Description--&gt;Barnes and Noble Nook Simple Touch with Glowlight 
*2012 Nook Simple Touch with GlowLight BNRV350 
*2013 Nook GlowLight BNRV500
| &lt;!--Vendor ID--&gt;0x2080
| &lt;!--Product ID--&gt;0x0004 0x0007 
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2012 untested }} perform a hard reset: Turn off the nook completely, turn it on, as soon as you see the screen flash begin holding the bottom page turn buttons until the screen flashes with a message asking reset, press the 'n' key twice to start the reset - Poor battery management - 
|-
| &lt;!--Description--&gt;Nook Glowlight 4 Plus 7.8-inch screen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Poor battery management - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
*NOOK 1st Edition (2009-2018) BNRZ100
*NOOK Color (2010-2024) BNRV200
*NOOK Tablet (8GB/16GB) (2011-2024) BNTV250A / BNTV250
*NOOK HD (2012-2024) BNTV400 
*NOOK HD+ (2012-2024) BNTV600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Elonex 511EB 
| &lt;!--Vendor ID--&gt;045e:ffff
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2009 untested Preferences-&gt;advanced-&gt;debug device detection}}
|-
| &lt;!--Description--&gt;[https://jaforeck.wordpress.com/2012/08/05/ready-to-meet-viktor-navorski-gained-access-to-elonex-621ebs-terminal-52/ Elonex 621EB] eBook 
| &lt;!--Vendor ID--&gt;0x1f85
| &lt;!--Product ID--&gt;0x1688
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;unlocked ootb 
| &lt;!--Opinion--&gt;{{N/A|2010 untested usb mini charging 6&quot; diagonal eInk Screen - 800 x 600 pixels, 8 Level 166dpi Paperlike screen, Embedded 1GB Flash NAND, full SD Card Slot up to 16GB - WAV, MP3, JPG, PNG, BMP, GIF support and ePub and PDF(with reflow) (TXT, HTML) support}}
|-
| &lt;!--Description--&gt;Elonex 700eb 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2011 untested adjust screen blanking by menu then settings then device standby, you can then turn it off}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;iRiver Story HD eBook 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} freescale imx.508 arm mcimx508cvkbb cpu with 2gb samsung nand, m13892aj charging chip, eb07_main_mp1_110321 mobo, mini usb, atheros ar61026 wifi - 
|-
| &lt;!--Description--&gt;iRiver Story 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Rakuten Touch A/B	kobo3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Touch C, Kobo Mini, Kobo Glo N613, Kobo Aura HD N514 N204	kobo4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Aura, Kobo Aura H2O, kobo5
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2013 6in untested }}
|-
| &lt;!--Description--&gt;Kobo Aura H2O Edition 2 v1, Kobo Glo HD, Kobo Touch 2.0, Kobo Aura ONE N709, Kobo Aura ONE Limited Edition, Kobo Aura Edition 2 v1 N236,	kobo6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Aura H2O Edition 2 v2, Kobo Aura Edition 2 v2, Kobo Nia, Kobo Clara HD, Kobo Forma, Kobo Libra H2O	kobo7
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Elipsa, Kobo Sage	kobo8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
*Kobo Libra 2  kobo9, Kobo Clara 2E	kobo10, Kobo Elipsa 2E	kobo11
*Kobo Libra Colour	kobo13, Kobo Clara BW, Kobo Clara Colour	kobo12
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pandigital Personal eReader aka? Papyre 6.2 very similar to BQ Avant Firmware
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2011  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PRS 300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PRS 350 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2009 epub bbeb cbz untested }}
|-
| &lt;!--Description--&gt;Sony PRS-650
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle K1 D00111 - Main Menu=: Settings: Menu=: Device Info shows S/N 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0002
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;256mb 
| &lt;!--Opinion--&gt;{{N/A|2007 untested Marvell Xscale PXA255}}
|-
| &lt;!--Description--&gt;Kindle K2, D00511 170-1012-00, D00701 D00801 S11S01B  
* k2 means K2 US
* k2i means K2 GW
* dx means KDX US
* dxi means KDX GW
* dxg means KDX Graphite 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0003
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb unless jb 
| &lt;!--Opinion--&gt;{{N/A|2010 untested Freescale i.MX31 }} the Kindle is a small computer running Linux 2.6 on an ARM processor
|-
| &lt;!--Description--&gt;AMAZON Kindle D00901 3rd Gen with keyboard - Menu, Settings for S/N and then Menu again to choose Update 
* S/N starts B006 means k3g aka K3 3G US 
* S/N starts B008 means k3w aka K3 WiFi 
* S/N starts B00A means k3gb aka K3 3G UK EU 
 - debug mode with ;debugON and ~help
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;{{yes|4Gb internal no access until jailbroken JB}} 
| &lt;!--Opinion--&gt;2010 with mobi and azw3 formats only - micro usb 5v 0.85a - freescale i.mx35 ARM soc with 12bit parallel interface with epson e-ink cpu, 256MB synchronous dynamic RAM, 4GB eMMC internal memory only but no sd slot, MC13892 PMIC - atheros wifi 54mbit pci-e a e keyed wifi - ?? later models wm96103 audio codec - display has 2Mbit serial memory ic on ribbon cable with 4bpp inverse grayscale display not touchscreen - 3g module - screen replacement really annoying - 4 test points near T07 = TX RX GND ? - as of 2025, JB v0.13.N, MKK2014, MKK2025, KUAL, KoReader Legacy2025, and maybe later SS v0.47.N, Python 0.14.N, Fonts v5.16.N, USBNet v0.57.N - USB-downloader mode when Vol+ is pressed during startup - Shift + Alt + M for Minesweeper - 
|-
| &lt;!--Description--&gt;Amazon Kindle 4th Generation k4 D01100 two buttons, square movement and two buttons at bottom 
*B00E 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0005
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb unless jb with USB MS, USBMS aka also known as USB MSC or UMS
| &lt;!--Opinion--&gt;{{N/A|2012 untested }} plastic back clipped in but taped down to battery cover, use Torx T5 to remove battery cover screws - battery glued down S2011-001-A 515-1058-01 DR-A015 MC-265360 - Freescale i.MX508 SOC, 2Gb eMMC storage, 256MiB of LPDDR1, MC13892 PMIC - vendor modified u-boot imximage based on u-boot v2009.08 - USB-downloader mode press the fiveway down button during startup resetmykindle - as of 2025 upgrade firmware from 4.1.x and to 4.1.4, sign into account and copy jb.1.8 bits, mkk-2014, mkk-2025, kual and then uninstall kual, koreader2025 - 
|-
| &lt;!--Description--&gt;Kindle Touch WiFi (Kindle 5th Gen) D01200 K5, KT
*Once signed into an Amazon Account get S/N under Settings -&gt; Device Options
*B00F 	Kindle Touch 3G + WiFi (Kindle 5) (U.S. and Canada) [Mostly]
*B011 	Kindle Touch WiFi (Kindle 5)
*B010 	Kindle Touch 3G + WiFi (Kindle 5) (Europe) 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0006
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;4gb unless jb 
| &lt;!--Opinion--&gt;{{N/A|untested }}  touchscreen i.MX508 SOC, 256MiB of LPDDR1 and USB-downloader mode by the SOC microcode when a specific key is pressed during startup: the home button on model D01200 - update firmware 5.3.2 to 5.3.7.3, access account, 
|-
| &lt;!--Description--&gt;Kindle PaperWhite 3G + WiFi (U.S.) [Mostly] PW 
&lt;pre&gt;
B024 	Kindle PaperWhite WiFi 
B01B 	Kindle PaperWhite 3G + WiFi (U.S.) [Mostly]
B020 	Kindle PaperWhite 3G + WiFi (Brazil) 
B01C 	Kindle PaperWhite 3G + WiFi (Canada)
B01D 	Kindle PaperWhite 3G + WiFi (Europe)
B01F 	Kindle PaperWhite 3G + WiFi (Japan)
&lt;/pre&gt;
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0007
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb 
| &lt;!--Opinion--&gt;{{N/A|untested Freescale i.MX508 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0008
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle PaperWhite 2 (2013) PW2 
*B0D4, 90D4 WiFi (U.S., Intl.) 
*B05A, 905A WiFi (Japan)
*B0D5, 90D5 3G + WiFi (U.S.) [Mostly]
*B0D6, 90D6 3G + WiFi (Canada] 
*B0D7, 90D7 3G + WiFi (Europe)
*B0D8, 90D8 3G + WiFi (Russia)
*B0F2, 90F2 3G + WiFi (Japan)
*B017, 9017 WiFi (4GB) (U.S., Intl.)
*B060, 9060 3G + WiFi (4GB) (Europe)
*B062, 9062 3G + WiFi (4GB) (U.S.) [Mostly]
*B05F, 905F 3G + WiFi (4GB) (Canada)
*B061, 9061 3G + WiFi (4GB) (Brazil) 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0009
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb or 4gb 
| &lt;!--Opinion--&gt;{{N/A|untested }} PW2 uses Freescale/NXP i.MX6 SoloLite 
|-
| &lt;!--Description--&gt;Kindle Paperwhite 3 PW3 i.e. Kindle 7th gen 
*G090G1 (2015) WiFi 
*G090G2 (2015) 3G + WiFi (U.S.) [Mostly] 
*G090G4 (2015) 3G + WiFi (Mexico)
*G090G5 (2015) 3G + WiFi (Europe, Australia) 
*G090G6 (2015) 3G + WiFi (Canada)
*G090G7 (2015) 3G + WiFi (Japan) 
*G090KB (2015) WiFi 
*G090KC (2015) 3G + WiFi (Japan) 
*G090KE (2016) 3G + WiFi (International) White 
*G090KF (2016) 3G + WiFi (International) White 
*G090LK (2016) WiFi, 32GB (Japan) 
*G090LL (2016) WiFi, 32GB (Japan) White 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x000A
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;4gb 
| &lt;!--Opinion--&gt;{{N/A|untested }} ease up glued down front bezel rim panel gently, remove 11 screws underneath and lift screen up from bottom end - battery underneath - 
|-
| &lt;!--Description--&gt;Kindle PaperWhite 4 (2018) PW4
*G000PP, G8S0PP WiFi, 8GB
*G000T6, G8S0T6 WiFi, 32GB
*G000T1  WiFi+4G, 32GB
*G000T2  WiFi+4G, 32GB (Europe)
*G00102  WiFi, 8GB (India)
*G000T3  WiFi+4G, 32GB (Japan)
*G0016T, G8S16T WiFi, 8GB Twilight Blue
*G0016Q, G8S16Q WiFi, 32GB Twilight Blue
*G0016U  WiFi, 8GB Plum
*G0016V, G8S16V WiFi, 8GB Sage 
*G00103  WiFi, 32GB (India) 
*G0016R  WiFi, 32GB Plum
*G0016S  WiFi, 32GB Sage 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x000B
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;8gb or 32gb
| &lt;!--Opinion--&gt;{{N/A|untested Freescale/NXP i.MX6 SoloLite }}
|-
| &lt;!--Description--&gt;Kindle Oasis 2 and 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 32gb
| &lt;!--Opinion--&gt;{{N/A|untested NXP i.MX7D  }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 16gb
| &lt;!--Opinion--&gt;{{N/A|untested MediaTek MT8110  }}
|-
| &lt;!--Description--&gt;Kindle 11 Scribe 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 16gb
| &lt;!--Opinion--&gt;{{N/A|untested MediaTek MT8113 }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;16gb or 32gb
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite Gen 11 and 12 - Signature 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;16Gb or 32Gb 
| &lt;!--Opinion--&gt;{{unk|2024 account not blocked,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://github.com/Modos-Labs Modos Labs] open source e-ink 60Hz 75Hz caster controller and glider monitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xteink X3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.xteink.com Xteink X4] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;2025 4.3in 220ppi no touchscreen so [https://www.youtube.com/watch?v=R7RuokaVauo buttons navigation] - 650mAh battery - micro-sd slot up to 512Gb covering epub, txt, and jpg in directories with [https://github.com/crosspoint-reader crosspoint reader] esp32 cpu custom rom firmware using [https://xteink.dve.al/ Flash website] on usb-c but no ecosystem store 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;15%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Access
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Amazon D01400 Kindle Fire (1st Generation) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{No|2010 too old }} android 2.3 and touchscreen digitizer fails often, battery SWE P/N 1002000004742 Model KC1 (EU) QP01 (US) 16.28whr, ti 257epl9l omap 4430 with elpida 88164b3pf-10-f88164b3pf or hynix,  mobo ??,, DAOKC1MB8F0 Rev F, ti aic3110 audio codec, 
|-
| &lt;!--Description--&gt;Amazon Fire 7in X43260 X43Z60 2nd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 untested FireOS Android 4 omap 4460 and PowerVR SGX540}}
|-
| &lt;!--Description--&gt;Amazon Kindle Fire HD (3rd Gen) P48WVB4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 untested }}
|-
| &lt;!--Description--&gt;Amazon 
*Amazon Fire HD10 (2015) 
*Amazon Fire HD8 (2015)	
*Amazon Fire HD7 (2015)	(5th Generation) 7 inch 8GB SV98LN 
*Amazon Fire HD7 (2014)	
*Amazon Fire HD6 (2014) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|untested android 5.1 max}}
|-
| &lt;!--Description--&gt;
*Amazon Fire 10 (2017) 
*Amazon Fire 8 (2017) 7th Gen 8 inch SX034OT 
*Amazon Fire 7 (2017) (7th Generation) 7 inch 16GB (SR043KL) 
*Amazon Kindle Fire 7 (7th Generation) 7 inch 8GB WIFI Tablet (SR043KL) 
*Amazon Fire HD8 (2016)	
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| Android 5.1 max 7in screen resolution of 1024 x 600, }}
|-
| &lt;!--Description--&gt;
*Amazon Fire 10/10+ (2021) 
*Amazon Fire 8/8+ (2020) 
*Amazon Fire 10 (2019) 
*Amazon Fire 7 (2019) 
*Amazon Kindle Fire 7 9th Gen 16GB M8S26G 
*Amazon Fire 8 (2018) 8th Gen 8 inch 32GB L5S83A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| android 9 max}}
|-
| &lt;!--Description--&gt;Amazon 
*Amazon Fire HD 10 (2023)	
*Amazon Fire Max 11 (2023)	
*Amazon Fire 8 (2022)	
*Amazon Fire 7 (2022)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| android 11 max}}
|-
| &lt;!--Description--&gt;Amazon Kindle Scribe 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;Amazon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Minimal Phone, Mudita Kompakt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| eink }}
|-
| &lt;!--Description--&gt;Bigme B751C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 android untested }}
|-
| &lt;!--Description--&gt;Bigme B7 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;Bigme B6
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android based color eink small - 300dpi b/w 150ppi color -}}
|-
| &lt;!--Description--&gt;Bigme 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| e-ink }}
|-
| &lt;!--Description--&gt;Bigme Hibreak Pro, Hisense A9
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| e-ink}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;iFlyTech AINote 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;iFlyTech AINote 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Meebook 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Page Palma 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 android untested }}
|-
| &lt;!--Description--&gt;Onyx Boox Leaf3C
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Go Color 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 untested 7in e-ink e-reader android tablet }}
|-
| &lt;!--Description--&gt;Onyx BooxTab Ultra X C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Note Max Air4 C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Leaf5C
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Poke6S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Go 10.3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox MC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| color e-ink 13.3in }}
|-
| &lt;!--Description--&gt;Onyx Boox Go 10.3 (Gen 2) Lumi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 b/w eink with front light, no EMR annd capacitance pen,  }}
|-
| &lt;!--Description--&gt;Onyx Moaan Pantone 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;reMarkable 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2021 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable Paper Pro Move 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 untested but subscriptions needed for some features}}
|-
| &lt;!--Description--&gt;reMarkable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Supernote A5 X2 Manta
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;Supernote A6 X2 Nomad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2023  }}
|-
| &lt;!--Description--&gt;Supernote 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tolino Vision 2 3 4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tolino Epos2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viwoods AI Paper and AI Paper Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


==printer.class - PostScript 3 and internal ghostscript drivers==


As the only printer driver that AROS supports natively is Postscript, our focus is on applications that generally output postscript formatted data for printing purposes and since the general Joe Public finds postscript capable printer very expensive, postscript interpreters (eg ghostscript) have been developed aas a cheaper option which sit in between postscript data streams and non postscript (HP PCL?) printers.

Set up Printer Prefs for Postscript and set the print to file option.


Ghostscript has internal printer drivers

 gs -h

and with something like

 gs -sDEVICE=stcolor -r300 -sOutputFile=RAM:tempfile gs813:examples/tiger.ps
 copytopar ram:tempfile

It checks if in RAM: exists a outputfile (Cinnamon can export to PS postscript) then it sends this via copytopar to the printer. There was only support for parport (parallel) but Terminillis added support for USB and ethernet. A big issue with using ghostscript for drivers is that data has to originate as postscript (.PS) file.

 gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=ljet4 -sOutputFile=RAM:tempfile RAM:file.pdf

the ljet4 output device generates PCL

also the pxlmono driver, which generates more generic PXL (PCL 6)

 gs -q -sstdout=%stderr -sDEVICE=pswrite -sOutputFile=- -dBATCH -dNOPAUSE -dPARANOIDSAFER testpage-a4.ps &gt; test.pdf

 gs -q -sstdout=%stderr -sDEVICE=pxlmono -sOutputFile=- -dBATCH -dNOPAUSE -dPARANOIDSAFER test.pdf &gt; test.pxl


Printers supported by ghostscript...Explanation [http://freebooks.by.ru/view/RedHatLinux6Unleashed/rhl6u151.htm here] or [http://www.gnu.org/software/ghostscript/devices.html here] and [http://pages.cs.wisc.edu/~ghost/doc/printer.htm here]

&lt;pre&gt;
bit            cljet5          ljet4d          pjxl300         pxlcolor
bitcmyk        cljet5c         ljetplus        pkm             pxlmono
bitrgb         deskjet         nullpage        pkmraw          stp
bj10e          djet500         pbm             pksm            tiff12nc
bj200          epswrite        pbmraw          pksmraw         tiff24nc
bjc600         faxg3           pcx16           png16           tiffcrle
bjc800         faxg32d         pcx24b          png16m          tiffg3
bmp16          faxg4           pcx256          png256          tiffg32d
bmp16m         ijs             pcxcmyk         pnggray         tiffg4
bmp256         jpeg            pcxgray         pngmono         tifflzw
bmp32b         jpeggray        pcxmono         pnm             tiffpack
bmpgray        laserjet        pdfwrite        pnmraw          uniprint
bmpmono        lj5gray         pgm             ppm             x11
bmpsep1        lj5mono         pgmraw          ppmraw          x11alpha
bmpsep8        ljet2p          pgnm            psgray          x11cmyk
cdeskjet       ljet3           pgnmraw         psmono          x11gray2
cdj550         ljet3d          pj              psrgb           x11gray4
cdjcolor       ljet4           pjxl            pswrite         x11mono
cdjmono
&lt;/pre&gt;

=== Internal Ghostscript support ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| Canon BJ10e
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested with Ghostscript drivers }}
|-
| Canon BJ200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested with Ghostscript drivers }}
|-
| Epson Stylus Color 600 parport inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - internal ghostscript support}}
|-
| &lt;!--Description--&gt;HP Deskjet 500 Parallel Port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| HP1220C/PS USB Inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - PS3 emulation only}}
|-
| HP 1700PS USB Inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - PS3 emulation only}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| &lt;!--Description--&gt;LJ-III
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested HP PostScript Cartridge Plus (C2089A) a.. Press &lt;ON LINE&gt; (and take machine off line)
b.. Press &lt;Plus &amp; Minus&gt;, and while holding, press &lt;ALT&gt; and &lt;RESET&gt; together and watch the LCD and let go when the desired mode is displayed.}} 
|-
| &lt;!--Description--&gt;HP Laserjet 4 4M 4MP (1992)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested PS2 emulation HP 4 with optional ps cartridge - HP 4M and 4M+ built in}} 
|-
| &lt;!--Description--&gt;HP Laserjet 4L Parport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{no|PCL5 HP 4L only - no postscript}} 
|-
| &lt;!--Description--&gt;HP Laserjet 5M (1995) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS2 emulation
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested you can try the ljet4 for the various lj5 drivers which produce various flavours of PCL. The 4, 4+ and 5 only really had one issue that plagued them, and it's hardly an issue at all. You would get accordian jams at the exit. A lot of people worked through this by pulling the sheet out before it got caught. Easily fixed by opening back door and scrubbing grime off of rubber rollers. }}
|-
| HP Laserjet 5L Parport (1997) (C3906A bk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;{{N/A}}
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{no|PCL5 support only.}}
|-
| HP Laserjet 5P 6P (1995) (C3906A bk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested HP 5p, 6p - Less tiny, slightly less slow. They are pretty bullet proof for low volume best to get postscript module though }}
|-
| HP Laserjet 2100 2100N 2100TN (1999) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested PS2 emulation }}
|-
| HP Laserjet 4000 Series Parport (1998) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|PS3 emulation only (4200 and 4600 have issues)}}
|-
| HP Laserjet 4050 Parport (1999) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|works }}
|-
| HP Laserjet 5000 Parallel Port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|}}
|-
| HP LaserJet 6M, 1200, 1300, 2100, 2200, P2050 (and P2055) P3005, M3025, M3027, 3050, 3300, 4000, 4050, 4100, 4200, 4300, M4345, P3005, P3015, P4010, P4410, M5025, M5035, 5100, 5200, 8000, 8100, or 9000 series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation optional only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{untested }}
|-
| &lt;!--Description--&gt;HP Color LaserJet 2550, 3700, 4650, 8500 and 8550 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lexmark Optra C, T, and W series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Xerox Phaser 850, 860 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

=== USB Monochrome ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| &lt;!--Description--&gt;Brother HL-1270N
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRScript
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL-3070CW Printer USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|BR-Script3 (PS3) untested}}
|-				
| &lt;!--Description--&gt;Brother HL5240 HL5240L 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRScript (PostScript Level 2) 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL-7050N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR3
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother MFC-7860DW Monochrome B/W BW 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR-Script BRScript (PostScript Level 3) 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL4570CDWT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Epson EPL-6200 Laser Printer USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|cheap to buy but untested - running cost unknown}}
|-		
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kyocera FS-1370DN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| HP LaserJet CP1515n USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|cheap to buy but untested - running cost unknown}}
|-
| &lt;!--Description--&gt;Lexmark Optra E312 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;built in? 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== USB Color ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother hl-3075cw
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR-Script 3 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother MFC-9120CN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRS3 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;HP Color LaserJet 2500L (2003) USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| HP Color LaserJet 2550L 2550Ln (2004) USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| HP Color LaserJet CP1218, 2605, 3700, 4500, 4600, or 4650 series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Konica Minolta Magicolour 4650EN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| Kyocera FS-1010 FS-1010N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| Kyocera FS-C5200DN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Kyocera Mita FS-1030D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kyocera FS-C5150DN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Lexmark C540n 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| Lexmark [http://www1.lexmark.com/products/view/Printers/Lexmark%20C780n/catId=cat10006-category&amp;prodId=3907-product C780n]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;{{yes|works PS3 emulation only}}
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| OKI C3600 Color Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Samsung CLP-315
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;untested 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Xerox 618x Color Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

See [http://www.irseesoft.de/tp_drive7.htm here] for compatibility with TP7 (TurboPrint 7) Last update 2004. Not tested under emulation. Janus-UAE, Emumiga, 

OS3.x support via [http://aminet.net/package/comm/tcp/NetPrinter NetPrinter] and [http://www.os4depot.net/index.php?function=browse&amp;cat=driver/printer OS4 drivers] and [http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=33955&amp;forum=27#622365 experiences].

usbparallel.device

untested with USB-&gt;Centronics - The printer.class is rather 'clever'. It remembers to which unit the printers were connected (until you reboot). So if you first plug in Printer1, it gets unit 0, and Printer2 gets unit 1. If you now remove both printers and replug Printer2, it still will get unit 1 and not 0. This is used not to confuse the programs using the different units (moreover, if some program uses the usbparallel.device unit of an USB printer, and the printer is unplugged, the device unit cannot be freed immediately as the application still keeps it open). Sticking to the same units is generally a good idea I think (and therefore this mechanism is also used with all other classes creating exec.devices).

You may not send a short packet (packet less than maxpktsize == 64) nor zero byte packets until the very last byte of your printout. Otherwise the printer will silently ignore the data you sent. Some printer drivers print very short sequences that never fill the endpoint buffer, so printer ignore them. Bufferize all printer driver writes in the ieee1284.device and send them by epsize packets. So my hppsc2210 works fine with a classic HP560C driver, on a classic A2000 subwayized :)


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Beige cream D shape centronics end (Prolific chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Belkin F5U002v1 centronics end (chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Belkin F5U002VEA v2 centronics end (Prolific PL2305L chipset) 
| 
| 
| 
| {{N/A|untested}}
|-
| DYNAMODE USB-C-PP-1284 USB to 36pin (Prolific 2305 chipset) 
| 0x067b
| 0x2305
| 0x02
| {{N/A|untested but similar to BAFO below}}
|-
| IOGear GUC1284B 
| 
| 
| 
| {{N/A|untested}}
|-
| My-Link (raised ellipse on centronics plastic end) (unknown chipset) 
| 
| 
| 
| {{N/A|untested but more expensive }}
|-
| NEWLink (Prolific chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Targus PA096E centronics end (chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| TRENDnet ware TU-P1284
| 
| 
| 
| {{N/A|untested}}
|-
| True PnP (Prolific chipset 2305) cheap 36pin Centronics (series of ridges along both short sides) 
| 0x067b
| 0x2305
| 2.00
| {{N/A|untested on BAFO BF-1284 but reports of poor quality and lack of support on other OSs }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| Transparent See Through Blue 
| 
| 
| 
| {{N/A|untested but possible poor quality build }}
|-
| Dynamode USB-PARALLEL 25pin female (prolific) 
| 0x067b
| 0x2305 
| 0x02 
| {{N/A|untested}}
|-
| FDL USB to 25pin 
| 
| 
| 
| {{N/A|untested}}
|-
| PlusKom USB to 25pin female connector for printer (IEEE 1284) 
| 
| 
| 
| {{N/A|untested}}
|-
| QinHeng Electronics (CH340S chipset) 
| 0x1a86
| 0x7584
| 
| {{N/A|untested curvy sides - flat top }}
|-
| StarTech 
| 
| 
| 
| {{N/A|untested}}
|-
| Syba SD-USB-DB25 
| 
| 
| 
| {{N/A|untested}}
|-
|}


==rawwrap.class - some old flatbed scanners supported==

Scandal is the MUI frontend to [http://www.ppa.pl/bugtracker/ Betascan Bugtracker] and [http://aminet.net/search?query=betascan Search for Betascan scanner drivers] derived from [http://www.sane-project.org/sane-backends.html sane backends] 


[http://www.sane-project.org/sane-backends.html#S-EPSON2 Epson2] 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Expression 1600 1640XL 1680 10000XL
| 0x04b8
| 0x0107 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Prefection 1200U, 1200 Photo, 
| 0x04b8
| 0x0104
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 1240U
| 0x04b8
| 0x010b
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{[https://amigaworld.net/modules/newbb/viewtopic.php?topic_id=45760&amp;forum=25 works]|Needs 24V 0.8A psu but in Trident, click on &quot;Classes&quot;, then on &quot;rawwrap.class&quot;, then on &quot;Configure&quot;. There, under &quot;Global&quot;, activate the Option &quot;Bind to Vendor/Unknown Interfaces&quot;. Now go to the second tab &quot;Default Interface&quot; and select/enter these values: 
Default usbraw.device Unit: 0
Exclusive access: Yes
Out NAK Timeout: 20000ms
In NAK Timeout: 20000ms
In Buffer Mode: No buffering
Buffer Size: 36 KB
Short Reads Terminate: Yes
Now click on &quot;Use as Default&quot; and select &quot;Devices&quot; on the left. There, click on your scanner and click on &quot;Class Scan&quot;. Now close Trident by clicking on &quot;Save&quot;. }}
|-
| Perfection 1640SU Photo
| 0x04b8
| 0x010a
| 0x0104
| {{yes|works, even the transparency unit}}
|-
| Perfection 1650 Photo, 1660 Photo, 3200 Photo
| 0x04b8
| 0x011c
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 2400 Photo, 2450 Photo 
| 0x04b8
| 0x011b 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 4870 Photo, 4990 Photo, 
| 0x04b8
| 0x0128
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection V700 V750 Photo
| 0x04b8
| 0x012c
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Stylus CX2800 2900 3200 3500 3600 3650 3700 3800 3900

Stylus CX4100 4200 3500 4600 4700 4800 4900 500 5100 5200 5300 5400 5900
| 0x04b8 
| 0x0802 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Stylus Office BX300F USB 
| 0x04b8
| 0x0848
| 
| {{yes| works with good scan quality}}
|-
|}


[http://www.meier-geinitz.de/sane/gt68xx-backend/ gt68xx] scanners based on the Grandtech GT-6801 and GT-6816 &quot;System-On-Chip&quot; scanner chipsets 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Artec Ultima 2000 and e+, Trust Flat Scan USB 19200 (ePlus2k.usb / Gt680xfw.usb) 
| 0x05d8
| 0x4002
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Genius Colorpage Vivid3x 4x 1200x
| 0x0458
| 0x2011 to 0x201f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (ccd548.fw)}}
|-
| &lt;!--Description--&gt;Lexmark	X70	also X73 [http://subfusion.net/drivers/oslo3071b2.usb OSLO3071b2.usb]
| &lt;!--Vendor ID--&gt;0x043d
| &lt;!--Product ID--&gt;0x002d
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Medion/Lifetec/Tevion/Cytron MD/LT 9375 and Artec Ultima 2000, MD LT 9385 Gt680xfw.usb 
| &lt;!--Vendor ID--&gt;0x05d8
| &lt;!--Product ID--&gt;0x4002
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| BearPaw 2448 CS and TA Plus [http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/A2Nfw.usb A2Nfw.usb]
| 0x055f
| 0x021a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  }}
|-
| Mustek BearPaw 1200 CS 
| 0x055f
| 0x021e
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/A1fw.usb A1fw.usb])}}
|-
| &lt;!--Description--&gt;Mustek 1200 CU Plus Scanner [http://www.meier-geinitz.de/sane/gt68xx-backend PS1Dfw.usb / SBSfw.usb]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2000 }}
|-
| Mustek ScanExpress 1200 UB plus, Trust Compact Scan USB 19200, ScanMagic 1200 UB Plus
| 0x05d8
| 0x4002 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/sbfw.usb sbfw.usb])}}
|-
| Mustek ScanExpress 1248 UB aka PC-World PC Line PCL-3000 
| 0x055f
| 0x021f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/SBSfw.usb SBSfw.usb])}}
|-
| Mustek BearPaw 2400CS TA aka Goodmans GSC 12/24
| 0x055f
| 0x0218
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| (Transparency adapter untested) }}
|-
| BearPaw 2400 CS aka TA Plus
| 0x055f
| 0x0219
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (Transparency adapter) }}
|-
| Packard Bell Diamond 1200 Plus
| 0x055f
| 0x021c or 0x021b 
| 0x0
| {{yes|works - [http://www.meier-geinitz.de/sane/gt68xx-backend/ firmware required] but slow usb 1.1 speed with poor quality output (scanner fault not scandal)}}
|-
| Packard Bell Diamond 2400 Plus aka BearPaw 2400 CU Plus [http://www.meier-geinitz.de/sane/gt68xx-backend/ PS2Dfw2.usb firmware rename to PS2Dfw.usb]
| 0x055f
| 0x021d 
| 1.00
| {{yes|works slow usb 1.1 speed with ok quality output (scanner fault not scandal)}}
|-
| Plustek OpticPro 1248U
| 0x07B3
| 0x0400 0x0401
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| (ccd548.fw)}}
|-
| Plustek OpticSlim 2400
| 0x07b3
| 0x0422
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (cis3R5B1.fw)}}
|-
| Visioneer OneTouch 7300
| 0x04a7
| 0x0444
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (Cis3r5b1.fw)}}
|-
| &lt;!--Description--&gt;Mustek ScanEpress 1200 UB (Plus) clone [http://www.meier-geinitz.de/sane/ use mustek_usb backend]
| &lt;!--Vendor ID--&gt;0x055f
| &lt;!--Product ID--&gt;0x0006
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Lexmark - needs testing
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Lexmark X1110 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1140
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1150 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1170 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1180 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1185
| 0x043d
| 0x007c
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Lexmark X12xx 
| 
| 
| 
| {{N/A|untested in USB1.1, not fully tested in USB2.0}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Dell A920 
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


HP - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| HP ScanJet 4100C
| 0x03f0 
| 0x0101
| 
| {{no|no driver}}
|-
| HP ScanJet 5200C
| 0x03f0 
| 0x0401
| 
| {{no|no driver}}
|-
| HP ScanJet 62X0C
| 0x03f0 
| 0x0201
| 
| {{no|no driver}}
|-
| HP ScanJet 63X0C
| 0x03f0 
| 0x0601
| 
| {{no|no driver}}
|-
| HP  
| 0x03f0
| 0x0102, 0x0105, 0x0205, 0x0305, 0x0405
| 
| {{no|no driver}}
|-
| HP
| 0x03f0
| 0x0705, 0x0805, 0x0901, 0x0a01
| 
| {{no|no driver}}
|-
| HP
| 0x03f0
| 0x1205, 0x1305, 0x2005, 0x2205
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Plustek [http://www.sane-project.org/sane-backends.html#S-PLUSTEK LM983x] - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Plustek OticPro U12 UT12 UT16 U24 UT24
| 0x07B3
| 0x0010 to 0x0017
| 
| {{no|no driver}}
|-
| KYE/Genius Colorpage HR6-V2 HR6A HR7 HR7LE HR6X
| 0x0458
| 0x2008 to 0x2016 
| 
| {{no|no driver}}
|-
| Hewlett-Packard ScanJet 2100C and 2200C
| 0x03F0
| 0x0505 and 0x0605
| 
| {{no|no driver}}
|-
| Mustek BearPaw 1200 and 2400 
| 0x0400 	
| 0x1000 and 0x1001
| 
| {{no|no driver}}
|-
| UMAX 3400/3450 and 5400 	
| 0x1606
| 0x0050, 0x0060 and 0x0160 
| 
| {{no|no driver}}
|-
| Epson Perfection 1250 and 1260
| 0x04B8
| 0x010f and 0x011d
| 
| {{no|no driver}}
|-
| CANON CanoScan N650/656U N1220U D660U N670/676U N1240U LIDE20 LIDE25 LIDE30
| 0x04A9
| 0x2206 to 0x2220
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


[http://snapscan.sourceforge.net/ SnapScan] - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Acer Benq 310U, 320U, 340U
| 0x4a5
| 0x0
| 
| {{no|no driver}}
|-
| Acer Benq 620U, 620UT, 640U, 640UT
| 0x4a5
| 0x20
| 
| {{no|no driver}}
|-
| Acer Benq 1240 3300 4300
| 0x4a5
| 0x020
| 
| {{no|no driver}}
|-
| Agfa SnapScan e10 e20 e25 e26 e40 e42 e50 e52
| 0x06bd
| 0x20
| 
| {{no|no driver}}
|-
| Epson Perfection 660
| 0x04b8
| 0x0114
| 
| {{no|no driver}}
|-
| Epson Perfection 1270 1670
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Epson Perfection 2480 2580
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Epson Perfection 3490 3590
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Mitsubishi
| 0x0
| 0x0
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}

==hub.class (self-powered and external ac powered hubs)==

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Dynamode USB-H41 4 ports 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Belkin 4 Port 
| 
| 
| 
| {{yes|works}}
|-
| Conrad
| 
| 
| 
| {{yes|[http://www.a1k.org/forum/showthread.php?t=11432 works on a1k forum] }}
|-
| DLink DUB-H4 AC Adapter 
| 0x05e3
| 0x0608
| High 0200
| {{maybe|WARNING Genesys Logic Hub Broken - Will cause failures with USB}}
|-
| [http://service.targa.co.uk/faq.php?lang_id=2&amp;baseid=178&amp;artdesc=SilverCrest+USB+Hub+2040&amp;artid=760&amp;artpic=silvercrestHUB2040.jpg SilverCrest 4-port slim USB 2.0 HUB - HUB2040 (40775) - Targa GmbH]
| 0x05e3
| 0x0608
| 0901
| {{yes|works  Genesys Logic, Inc., [http://service.targa.co.uk/dokumente/USB_HUB_2040_0109_manual_EN.pdf Manual]}}
|-
| Skymaster
| 0x05e3
| 0x0605
| 060B
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| No Name active 4-port
| 0x1a40
| 0x0101
| 0111
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Thinkpad USB 3.0 Dock DU9019D1 
| &lt;!--Vendor ID--&gt;0x17e9
| &lt;!--Product ID--&gt;0x4302
| &lt;!--Revision--&gt;0014
| &lt;!--Opinion--&gt;{{Maybe|works a bit}} classed as dfu.class with two further USB 2.0 hubs - USB 3.0 ports detected and work (2.0 backwards compatibility) - DisplayLink DL-3900 with VIA VL811 chipset - usb ethernet not working - two dvi not working - 20V psu 2a (40w) with a 5.5 - 2.5mm tip (no bus power) - data through a-b printer/scanner usb lead - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


==Internet==

===rndis.class USB Tethering ===

The rndis class provides support for Ethernet access over Remote NDIS. Most USB based devices should be supported including smartfones.

Before opening Network Prefs, activate USB Tethering on the Smartfon, on Network prefs, type in usbrndis.device and tick &quot;Start Network during system boot&quot; and saved the configuration, the Connection is immediate no reboot is needed.

When restart AROS my Smartphone deactivates the connection and to access the network again, have to reactivate it before starting the browser.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Alcatel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| Huawei U8800
| 0x12d1
| 0x1039
| 
| {{yes|works}}
|- 
| &lt;!--Description--&gt;Huawei
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| HTC (Android phone)
| 0x0bb4
| 0x0ffe
| 
| {{Yes|any android phone with usb tethering option}}
|- 
| &lt;!--Description--&gt;Nokia 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;Oppo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;Samsung Galaxy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
|- 
| &lt;!--Description--&gt;iPhone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Microsoft winPhone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


===USB &amp;rarr; ethernet lan adaptor===

*2002 playstation 2 usb1.1 era - a little support but very old and slow 
*2006 wii asix era - a little support but very much miss than hit 
*2026 usb0: or eth0: of CDC Ethernet protocol (cdcether) with Ethernet Control Model (ECM) and [https://www.usb.org/document-library/class-definitions-communication-devices-12 others like Wireless Mobile Communication Devices WMC] and later CDC EEM (Ethernet Emulation Model) and NCM (Network Control Model) are USB Communication Device Class (CDC) protocols packing more Ethernet traffic over every USB bundle. For CDC Ethernet - NCM is better than EEM is better than ECM 


* USB1.1 Up to 010 meg broadband (1.25MBytes/s) - ADM8511, DM9601 poor speeds 
* USB2.0 Up to 400 meg broadband (60MBytes/s) - MCS7830, AX88772 a little especially the 2010 apple version but buy many as very very poor odds of working one 
* USB3.0 Over 400 meg broadband (60+MBytes/s) - not supported at the moment 


SANA (Standard Amiga Network Architecture) to usb 

ADMtek Infineon ADM8511 Pegasus II (USB 1.1 and 10Mbit/s - Sony PlayStation 2 network adapter) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| 3Com 3c460b 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| Abocom UFE1000 / Abocom DSB650TX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Accton USB320-EC / Accton SpeedStream Ethernet
| 0x083a
| 0x0320
| &lt;!--Revision--&gt;
| {{unk|2002 }}
|-
| AEI USB Fast Ethernet / Allied Telesyn AT-USB100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2002 }}
|-
| ATEN UC-110T
| 0x0557
| 0x4000
|
| {{unk|2001 }}
|-
| BAFO USB To Ethernet Adapter BF-310
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| Belkin F5D5050 v1 1101 
| 0x050D
| 
| &lt;!--Revision--&gt;
| {{maybe|2002 sometimes works from old amiga.org post which is now removed}}
|-
| Belkin F5D5050 v2 2101
| 0x050D
| 0x0121
| &lt;!--Revision--&gt;
| {{no|2006 does not works}} 
|-
| Belkin F5U122-PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Billionton USB-100 / Billionton USBLP-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Billionton USBEL-100 / Billionton USBE-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Compex LinkPort/UE202A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DSB-H3ETX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DSB-650 / D-Link DSB-650TX / D-Link DSB-650TX-PNA
| 0x2001
| 0x4000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DU-E10 / D-Link DU-E100
| 0x2001
| 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Edimax USB Ethernet Adapter EU-4201 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Elsa AG MicroLink USB2 Lan Ethernet adapter
| 0x05cc
| 0x3000
| &lt;!--Revision--&gt;1.01
| &lt;!--Opinion--&gt;{{unk| }}
|-
| GetNet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| GIGABYTE GN-BR402W Wireless Router
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Goodway Fellowes USB UE-120 REV:V1 UE120 ADMTek 1011594 HO2419741 
| &lt;!--Vendor ID--&gt;0x07a6
| &lt;!--Product ID--&gt;0x0986
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{maybe|2001 USB Specification 1.1 compliant}} 
|-
| GWC Tech USB Ethernet Adapter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Hawking UF100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| HP HN210E / I/O DATA USB ETTX / Kingston KNU101TX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Jinco USB Ethernet Adapter 10/100 Base-T UE-110
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Kouwell USB to Ethernet 588A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Linksys USB10T / TA / TX
| 0x066b
| 0x2202
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested - possible peg1/peg2}}
|-
| Linksys (Cisco) USB100TX / H1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitec LAN-TX/U1 H2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| [http://www.mayflash.com/psps2/ps2024/ps2024.htm Mayflash PS2024] Playstation2 compatible clone of Proxim/Farallon NetLine?
| 0x07a6
| 0x8511
| &lt;!--Revision--&gt;1.01
| &lt;!--Opinion--&gt;{{maybe|works with DHCP router option on old 32bit distros but not on newer 64bit, best to go asixeth apple 2010 but buy many of them as poor success rate i.e. a lottery}}
|-
| Netgear FA101
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Philips CPWUE01/00 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Planet UE-9500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| PlayStation 2 SCPH-10000 50000 models 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Proxim (formerly Farallon) NetLine USB PN796-650
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Siemens SpeedStream USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| SOHOware NUB100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| SMC EZNET-USB 2202USB/ETH / SMC 2206USB/ETH
| 0x0707
| 0x0100 0x0200 0x0201
| &lt;!--Revision--&gt;
| {{unk|untested but should work very well }}
|-
| Surecom EP-1427X 100/10M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Target USB to 10/100M Fast Ethernet Converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Trendnet TU-ET100C
| 0x07a6
| 0x8511 
| &lt;!--Revision--&gt;0x0
| {{yes| sometimes works well, very stable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Digitus USB NIC DN-3016-A 
| 0x07a6
| 0x8513
| 1.01
| {{unk|untested new chipset }}
|-
| Digitus lanusb ADM8515
| 0x07a6
| 0x8515
| 1.01
| {{unk|untested because new chipset }}
|-
| VE285 usblan ADMtek 8515 
| 0x07a6
| 0x8515
| 1.01
| {{no|not working as new chipset }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Davicom DM9601 eth (USB 1.1 and up to 10Mbit/s) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Davicom USB-100 see clone below 
| 0x0a46
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| [http://wiki.maemo.org/USB_to_ethernet_networking chinese translucent transparent crystal blue] but variants are also found in clear, white and black. Just over 6&amp;nbsp;cm long. 
| 0x0a46
| 0x9601
| 0x0
| {{yes|2002 success can be sporadic so technically okay, but lacking in reliability. Out of 4 tested by me, only 2 worked. One case cracked open. }}
|-
| Corega FEther USB-TXC
| 0x07aa
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Dynamode USB-NIC-1427-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Hirose USB-100
| 0x0a47
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| KY-RS9600
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585358&amp;postcount=12 works] }}
|-
| ShanTou ST268 USB NIC
| 0x0a46
| 0x0268
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| ZT6688 USB NIC 
| 0x0a46
| 0x6688
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ICS Advent DM9601 USB 2.0 10/100M Ethenet Adaptor JP1081B 
| &lt;!--Vendor ID--&gt;0x0FE6
| &lt;!--Product ID--&gt;0x9700
| &lt;!--Revision--&gt;0101
| &lt;!--Opinion--&gt;{{No|only USB 1.1 10M ethernet support but will plug into an usb 2.0 port}} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


MosChip MCS7830 (USB 2)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Digitus DN-10050
| 0x9710
| 0x7830
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 }}
|-
| Edimax [http://www.edimax.co.uk/images/Image/datasheet/USB/EU-4206/EU-4206.pdf EU-4206]
|
| 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 }}
|-
| Speed Dragon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| STLabs 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| StarTech Compact USB2105S [http://www.kustompcs.co.uk/acatalog/info_6790.html USB2106S]
| 0x9710
| 0x7830
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| Sunrich Technologies [http://www.st-lab.com/admin/upfile/UploadFile/manual/manual(u-250).zip U-250]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 }}
|-
| Syba 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;MCS 7832 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2008 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


* USB2 [https://www.asix.com.tw/en/product/USBEthernet Asix Ethernet] AX88178A, AX88772C, AX88772B, AX88772A (wii), AX88172A 
* USB3 AX88179A, AX88179  

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| AirLink101 AGIGAUSB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  AX88172}}
|-
| ATEN UC210T 
| 0x0557
| 0x2009
| 0x
| &lt;!--Opinion--&gt;{{unk| AX88172}}
|-
| &lt;!--Description--&gt;Billionton Systems USB2AR
| &lt;!--Vendor ID--&gt;0x08dd
| &lt;!--Product ID--&gt;0x90ff
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;Buffalo LUA-U2-KTX
| &lt;!--Vendor ID--&gt;0x0411
| &lt;!--Product ID--&gt;0x003d
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;corega FEther USB2-TX
| &lt;!--Vendor ID--&gt;0x07aa
| &lt;!--Product ID--&gt;0x0017
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| }}
|-
| D-Link DUB-E100 up to rev A4
| 0x2001
| 0x1a00
| 
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;D-Link DUB-E100 rev B1 onwards 
| 0x07d1 or 0x2001 
| 0x3c05
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|AX88172 works on Deneb with [http://amigax.com/2010/02/21/usb-ethernet-speed-test-amigaos-4-0-classic/ Amiga OS4 Classic] and [http://www.a1k.org/forum/showthread.php?t=11432 on a1k] }}
|-
| &lt;!--Description--&gt;goodway corp USB gwusb2e
| &lt;!--Vendor ID--&gt;0x1631
| &lt;!--Product ID--&gt;0x6200
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hawking UF200 
| 0x07b8
| 0x420a 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[Linksys USB200M] 
| 0x077b
| 0x2226
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585601&amp;postcount=20 works] }}
|-
| &lt;!--Description--&gt;Netgear FA120 
| 0x0846 
| 0x1040
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2002 10/100 Rev.B1&quot; is silkscreened on the board of the device populating this entry (S/N: FA12254CB100409, date code 0508). This device may be manuf. by [http://www.cameo.com.tw/ Cameo] &quot;AX88172 L&quot;, &quot;F05040157&quot;, and &quot;ED3&quot; Chip1 ASIX AX88172  Chip2 Realtek RTL8201BL}}
|-
| &lt;!--Description--&gt;Intellinet
| 0x0b95 
| 0x1720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;JVC MP-PRX1 Port Replicator
| &lt;!--Vendor ID--&gt;0x04f1
| &lt;!--Product ID--&gt;0x3008
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ST Lab USB Ethernet
| &lt;!--Vendor ID--&gt;0x0b95 
| &lt;!--Product ID--&gt;0x1720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Sitecom LN-029 &quot;USB 2.0 10/100 Ethernet adapter&quot;
| &lt;!--Vendor ID--&gt;0x6189
| &lt;!--Product ID--&gt;0x182d
| &lt;!--Revision--&gt;0
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;Surecom EP-1427X-2
| &lt;!--Vendor ID--&gt;0x1189
| &lt;!--Product ID--&gt;0x0893
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v2
| 0x07b8
| 0x420a 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|version 2}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;A-LINK NA1GU 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 88772}}
|-
| &lt;!--Description--&gt;AirLink101 ASOHOUSB Wii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AirLive EtherWe-1000U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;APPLE AX88772 Model No. A1277 MC704LL/A P/N 825-7098-A 
| &lt;!--Vendor ID--&gt;0x05ac 
| &lt;!--Product ID--&gt;0x1402
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2008  usb2, }}
|-
| &lt;!--Description--&gt;APPLE Model No. A1277 (MB442Z/A 0885909217434) MC704ZM/A PN 825-7579-A 
| &lt;!--Vendor ID--&gt;0x05ac 
| &lt;!--Product ID--&gt;0x1402
| &lt;!--Revision--&gt; 
| &lt;!--Opinion--&gt;{{Maybe|2010 model, usb2 and controller AX88772 where prehaps 1in3 units working with owb - really poor odds i.e. a lottery, could be situation where various ethernet phy chipsets are used - press Use in network prefs after Save initial setup typing in usbasixeth.device, }}
|-
| &lt;!--Description--&gt;ASIX AX88772 bulbous casing 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{maybe|2008 works on 32bit and 64bit though setup can take a few attempts but may have issues with phy ethernet chip changing,  }}
|-
| &lt;!--Description--&gt;Datel Wii Lan Adapter DUS0204 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;EdiMax EU-4207 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;Goodway HE2230 Maplin ASIX 88772 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;Intec LAN G5626 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;LevelOne USB-0202
| 0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;LevelOne USB-0301
| 0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{unk|2009 }}
|-
| &lt;!--Description--&gt;Linksys USB200M Rev 2
| &lt;!--Vendor ID--&gt;0x13b1
| &lt;!--Product ID--&gt;0x0018
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|2008 sparsely randomly working AX88772 or with &quot;Sana-II Meter Tool 37.11&quot; network monitoring program, showing continuous &quot;Bad Packet&quot; errors which could means &quot;CRC&quot; errors}}
|-
| &lt;!--Description--&gt;Linksys USB300M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|2009 AX88772  }}
|-
| &lt;!--Description--&gt;Mayflash W001 or clones Lupo/PEGA S-Wii-0680 light gray rectangular with third of one top 45 degree angled slope
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{unk| may have randomly changed phy ethernet chips, }}
|-
| &lt;!--Description--&gt;Max Value MVF00446 ASIN B006EG568A 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{Maybe|Trident prefs recognises as AX88772 sometimes works on 32bit and 64bit}} 
|-
| &lt;!--Description--&gt;NEWLink N14050 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;NEWLink Wii-ETH USB2.0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nintendo Wii LAN Adaptor 2110566 and clones 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{Maybe|Poseidon recognises as AX88772 with usbasixeth.device sometimes works seems different ethernet phy chips can be matched affecting compatibility}} 
|-
| &lt;!--Description--&gt;Nyko Wii Net Connect 87024
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585624&amp;postcount=22 works] }}
|-
| &lt;!--Description--&gt;0Q0 cable ethernet
| &lt;!--Vendor ID--&gt;0x1557
| &lt;!--Product ID--&gt;0x7720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB2-E100 (2009/2010) Bulbous housing 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{Maybe|Trident prefs recognises it as ax88772A and typing in usbasixeth.device sometimes works}}
|-
| &lt;!--Description--&gt;Sabrent KINAMAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SpeedLink SL-3401-SGY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;UGreen 20254 USB2 to 10/100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| AX88772}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Afunta Apple-style White USB2.0 I/O Crest SY-ADA24005 ASIX Electronics Corp. AX88772A Fast Ethernet Adapter 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{no|usbasixeth.device accepted by network prefs but does not work}}
|-
| &lt;!--Description--&gt;Amazon Basics USB 2.0 AX88772A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Digitus DN-10050-1
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;0x0 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Edimax EU-4230  
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sabrent KINAMAX NT-USB20 AX88772A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt; AX88772B USB 2.0 to 10/100M 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EdiMax EU-4208 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt;0x772b
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{No|Detected but not working}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB2100 ASIX AX88772C 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.asix.com.tw/en/product/USBEthernet/High-Speed_USB_Ethernet/AX88772D AX88772D]
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.asix.com.tw/en/product/USBEthernet/High-Speed_USB_Ethernet/AX88772E AX88772E]
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;AX88178 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2004 }} 
|-
| &lt;!--Description--&gt;Plugable USB2-E1000 i.e. USB 2.0 to Gigabit Ethernet 10/100/1000 LAN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 ASIX AX88178 Controller and Realtek RTL8211CL PHY}}
|-
| &lt;!--Description--&gt;AX88178A USB 2.0 to 10/100/1000M Gigabit Ethernet controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2005 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AmazonBasics USB3.0 adapter [https://github.com/nothingstopsme/AX88179_178A_Linux_Driver AX88179] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cable Matters SuperSpeed USB 3.0 RJ45 adapter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hori Nintendo Switch 1 USB3 ethernet AX88179 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 AX88179 not binding to asixeth.class }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB3-E1000  
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2020 ASIX AX88179 not binding to class, USB 3.2 Gen1 to Gigabit Ethernet controller with integrated 10/100/1000Mbps Gigabit Ethernet PHY}}  
|-
| &lt;!--Description--&gt;Plugable AX88179 = [https://plugable.com/products/usb3-e1000-deal USB3-E1000] before mid-2023 or USB3-E1000; AX88179A = USBC-E1000 after mid-2023
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022  controller is AX88179 phy is ??, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000SPTW ax88179 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| AX88179 not binding to asixeth.class, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000NDS AX88179 USB-A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech US1GC301AU AX88179 USB-c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech US1GC30B2 AX88179A USB-c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB32000SPT AX88179A USB-c Rev 1 (AX88179) Rev 2 (AX88179A) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;USB32000SPT the Lot code sticker will have a bar code accompanied by a 10 digit number. The 5th and 6th digits of this lot code number would signify the revision. (Ex. xxxx02xxxx which would indicate rev. 2)
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SYBA SY-ADA24029 Gigabit AX88179 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} may depend on the PHY chip connected to the controller chipset
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TP-Link UE306 AX88179 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TeckNet® Orico UL677G 10/100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TeckNet® UL688G USB 3.0 10/100/1000 Base-T Ethernet port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;AX88179 178A 
|-
| &lt;!--Description--&gt;Tecknet UL699G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v6 
| &lt;!--Vendor ID--&gt;0x07b8
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|no support }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;uGreen 50922 USB3-A to 100/1000 dark grey rounded barrels 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| ax88179 not binding to asixeth.class, }}
|-
| &lt;!--Description--&gt;UGreen USB3-C to 100/1000 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;uGreen CR111 20256 usb3 a black plastic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| AX88179}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;  AX88179A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB3-E1000 USBC-E1000 after mid-2023 i.e. AX88179A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000SPTB 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  AX88179A USB-A, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;  AX88179B
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


==USB  &amp;rarr; SerialPort Converter==

*2002 some support for early revisions of PL2303 
*2005 Prolific PL2303H PL-2303X and Pl-2303HX (same usb ids as pl2303) no support 
*2025 FTDI 232R [https://www.arosworld.org/infusions/forum/viewthread.php?thread_id=1135&amp;highlight=232r&amp;rowstart=20 work in progress] 
*2026 CDC-ACM i.e. Serial port over USB standard 

serialpl2303.class make sure you specify serialpl2303.device or Echo &quot;Test&quot; &gt;SER1: 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| ATEN UC-232A 
| 0x0557 
| 0x2008 
| Full 0x0300
| {{N/A|untested}}
|- 
| IOGear GUC232A 
| 0x0557  
| 0x2008 
| Full 0x0110
| {{N/A|untested}}
|- 
| Alcatel 
| 0x11f7 
| 0x02df 
|
| {{N/A|untested}}
|- 
| BAFO BF-810 
| 0x067B  
| 0x2303 
| 0x0
| {{N/A|untested}}
|- 
| Belkin F5U103 
| 0x
| 0x
| 0x0
| {{N/A|untested}}
|- 
| Davibe SP611 
| 0x067B 
| 0x2303 
| 0x0 
| {{N/A|untested}}
|- 
| Dcu10 
| 0x0731
| 0x0528
| 
| {{N/A|untested}}
|- 
| Elcom 
| 0x056e
| 0x5003
| 
| {{N/A|untested}}
|- 
| IOData 
| 0x04bb 
| 0x0a03 
| 0x0
| {{N/A|untested}}
|- 
| Itegno 
| 0x0eba
| 0x1080
| 
| {{N/A|untested}}
|- 
| Nokia CA42 
| 
| 
| 
| {{N/A|untested}}
|- 
| Radioshack 
| 0x1453
| 0x4026
| 
| {{N/A|untested}}
|- 
| Ratoc 
| 0x0584
| 0xb000
| 
| {{N/A|untested}}
|- 
| Samsung 
| 0x04e8
| 0x8001
|
| {{N/A|untested}}
|- 
| Siemens DCA-510 
| 0x067B 
| 0x2303 
| 0x0 
| {{N/A|untested}}
|- 
| Sitecom CN104
| 0x6189
| 0x2068
|
| {{N/A|untested}}
|- 
| Sitecom CN116 
| 0x6189
| 0x2068
|
| {{N/A|untested}}
|- 
| Some Cut Ma620 
| 0x0df7
| 0x0620
| 
| {{N/A|untested}}
|- 
| Speed Dragon Multimedia MS3303H 
| 
| 
| 
| {{N/A|untested}}
|- 
| Syntech 
| 
| 
| 
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Tripp 
| 0x2478
| 0x2008
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Airlink101 AC-USBS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Belkin F5U103v
| 0x067B  
| 0x2303 
| 0x0
| {{no|no driver }}
|- 
| Dynamode U232-P9
| 0x067B
| 0x2303
| 300
| {{no| no driver [http://koti.mbnet.fi/lonnberg/pl2303x.html linux patch] and using lsusb -v -d 067b:2303 gave bMaxPacketSize as 64 - pl2303x }}
|- 
| Konig CABLE-146/2 USB to RS232 
| 0x067b
| 0x2303
| 400
| {{no|no driver }}
|-
| MANHATTAN 205146 USB to Serial Converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|- 
| Sabrent SBT-USC1M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Trendnet TU-59
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Unbranded black case and lead USB 232 Converter
| &lt;!--Vendor ID--&gt;0x067B
| &lt;!--Product ID--&gt;0x2303
| &lt;!--Revision--&gt;0300
| &lt;!--Opinion--&gt;{{No| }}
|-
|}


[http://www.ftdichip.com/index.html Future Technology Devices International Ltd FTDI]-FT232R.class [https://ftdichip.com/software-examples/code-examples/c-builder/ FTProg src], [http://rtr.ca/ft232r/ ft232r src], [https://ftdichip.com/wp-content/uploads/2020/08/DS_FT232R.pdf FT232R datasheet], [], 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt;0x6001 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} [https://www.youtube.com/watch?v=1GE-gKgHxZI beware of cheap clones fake with s/n A50285BI SN]
|-
| &lt;!--Description--&gt;Lynx Astro FTDI 
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232R 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Sabrent CB-FTDI
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver TTL-232R cables use FTDI's [http://n1mm.hamdocs.com/tiki-index.php?page=USB+Interface+Devices FT232RQ ic device] }}
|-
| &lt;!--Description--&gt;Startech.com 1 Port FTDI USB to Serial RS232 DB9M Adapter Cable with COM Retention ICUSB2321F 
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232RL Chipset
|-
| &lt;!--Description--&gt;StarTech.com 2 Port FTDI USB to Serial RS232 Adapter Cable ICUSB2322F
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FTDI FT2232D Chipset
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232RL is the SSOP-28 and the FT232RQ is the QFN-32 package option 
|}


[https://www.onetransistor.eu/2017/08/ch341a-mini-programmer-schematic.html ch341a.class] 

*I2C EEPROMS (3.3V and 5V) compatible and also SPI FLASH memories (3.3V devices) making sure 1.8V is covered  
*each having their own [https://winraid.level1techs.com/t/guide-how-to-use-a-ch341a-spi-programmer-flasher-with-pictures/33041 4x2 connection blocks] using [https://github.com/flashrom/flashrom flashrom] 

 sudo flashrom --programmer ch341a_spi -r backup.bin
 sudo flashrom --programmer ch341a_spi -w &lt;new bios name&gt;

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Jiangsu QinHeng Ltd CH341A emulate UART communication, standard parallel port, memory parallel port and synchronous serial (I2C, SPI) 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x5512
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;QinHeng USB2.0-Serial HL-340 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x7523
| &lt;!--Revision--&gt;0252
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|}


==simplemidi.class and CAMD==

Currently support includes 

* simplemidi.class SimpleMidi maps some keyboard keys to corresponding computer keys as used by music trackers to emulate a musical keyboard 
* camdusbmidi.class follows the rules of the m68k implementation of Commodore's CAMD midi specification and usb class compliant 

for 

* usb host like a computer 
* usb device controllers - keyboards, drum machines, djay turntables, grooveboxes, etc 
* interfaces - cables or boxes which convert usb to 5pin DIN plug midi 


What is needed is a fully class-compliant '''brand name''' USB MIDI keyboard, especially manufactured in the last 10 years are best 

*Arturia
*Novation
*M-Audio
*Akai

Plugging this in one of your USB ports, the camd.library will make the keyboard's MIDI IN/OUT ports available in the system. 

Then select the keyboard's MIDI IN port (known as a &quot;cluster&quot; in CAMD) for input, and the software instrument's cluster as output 


ShowCluster (shows midi ports available in and out)

MidiWatch (usually port usbmidi.in.0 less often usbmidi.out.0) (Ctrl-C to end output stream) 
 usbmidi.in.0 Message on channel 01, NoteOn  90  39  08  00
 usbmidi.in.0 Message on channel 01, NoteOff 80  39  00  00

MidiThru (forwards messages from one port to another)
 run &gt;nil: c:midithru usbmidi.out.0 usbmidi.out.2 

MidiSendC (sends a middle C to a specific port)


Midi Controller + Sound Module (together aka as a synth) -&gt; Audio Output 


The difference between midi and midi over USB is that in old school Midi the transmitter transmits whenever it wants and the receiver always has to be prepared to receive data. Easy to do at the rate of a 1990's modem speed these days.

USB over midi.. turns midi into a polled protocol.. So the USB host (typically the computer) has to ask &quot;do you have anything for me&quot; before the remote will send. If the USB host gets busy doing other things or there is a lot of things on the USB bus to get polled, you can get delays.

For its age midi is still a great protocol for music

* [https://www.usb.org/sites/default/files/midi10.pdf USBIF's &quot;USB Device Class Definition for MIDI Devices&quot; document, version 1.0 from Nov 1, 1999]
* [https://www.usb.org/sites/default/files/USB%20MIDI%20v2_0.pdf MIDI v2.0 from 2020 which AROS still needs, adds support for MIDI 2.0, MIDI-CI, and Universal MIDI Packet] 

Nearly all synthesizers now use the 16 MIDI channels available on a MIDI bus in one instrument alone, requiring multiple MIDI busses in a typical setup with more than
one MIDI instrument. In addition, by handling multiple &quot;virtual&quot; cables, USB offers a solution to go beyond MIDI's 16-channel limit. 

MIDI data is transferred over USB using 32-bit USB-MIDI Event Packets. These packets provide an efficient method to transfer multiple MIDI streams with fixed length messages. The 32-bit USB-MIDI Event Packet allows multiple &quot;virtual MIDI cables&quot; routed over the same USB endpoint. This approach minimizes the number of required endpoints. It also makes parsing MIDI events easier by packetizing the separate bytes of a MIDI event into one parsed USB-MIDI event. 


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Computer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{Yes|which acts as USB midi host to get all usb devices talking together}} 
|-
| &lt;!--Description--&gt;Hobbytronics usb host standalone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;bomebox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;raspberry pi with several midi interface(s) and linux scripting 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Kenton MIDI USB Host mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acorn Instruments Masterkey 49 device 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 untested usb powered 5V regulated - similar keybed to keystation 49es but unplug then re-plug the USB cable while it is powered the device might reconnect 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Akai SynthStation 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 - sticky rubber keys - usb 
|-
| &lt;!--Description--&gt;Akai MPK Mini Laptop Production Keyboard 
| &lt;!--Vendor ID--&gt;0x09e8
| &lt;!--Product ID--&gt;0x007c
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected and camd usb to use, not tested with apps}}
| &lt;!--Opinion--&gt;2010 25 mini key self powered by mini USB lead - sustain port - no top left corner joystick - tested icaros 2.3 -  
|-
| &lt;!--Description--&gt;Akai LPK25 LPK37 LPK49 Laptop Production Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }}
| &lt;!--Opinion--&gt;2012 untested velocity sensitive mini keys with synth action - weak mini USB port - latency issues -  
|-
| &lt;!--Description--&gt;Akai Professional APC Key 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;Akai MPK49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2012 untested 49 key 49-key full-sized, semi-weighted keyboard with aftertouch - 
|-
| &lt;!--Description--&gt;AKAI Max25 MAX49 control keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }} 
| &lt;!--Opinion--&gt;2014 usb compliant 
|-
| &lt;!--Description--&gt;Akai Professional MPK249 MPK261 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}} 
| &lt;!--Opinion--&gt;2015 USB2 USB-b - full keys semi-weighted aftertouch - midi in out - sustain and peddle port 
|-
| &lt;!--Description--&gt;Akai Professional Advance 49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 
|-
| &lt;!--Description--&gt;Akai MPK Mini MKII MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2017 untested USB2 USB-b midi connection only - 4 way thumb joystick top left - 25 tiny keys - velocity drum pads - plastic build quality - 
|-
| &lt;!--Description--&gt;AKAI Professional APC Key 25 MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| driver}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;Akai MPK Mini Play
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 untested USB2 USB-b midi connection only - synth basic samples - class compliant? - small led display top centre - 25 mini keys - press and hold the &quot;Prog Select&quot; button then use the &quot;Program&quot; knob to assign a MIDI channel - 
|-
| &lt;!--Description--&gt;Akai MPK Mini 3 MKIII MK3 
| &lt;!--Vendor ID--&gt;0x09E8
| &lt;!--Product ID--&gt;0x1049 
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class -  - midi in out untested - }}
| &lt;!--Opinion--&gt;2021 USB2 USB-b midi controller connection no 5pin legacy - small led display top centre - 25 mini keys goofy uneven feel of the akai keyboards - press and hold the &quot;Prog Select&quot; button and press pad 1 to 8 to assign a MIDI channel - tested on AROS One 2.4 usb
|-
| &lt;!--Description--&gt;Akai Force / MPC One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Akai Pro MPK Mini Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2023 untested 37 mini keys - class compliant device - usb-b bus powered only with 5pin midi in and out - Shift and Global for Midi Ch - 
|-
| &lt;!--Description--&gt;Akai Pro Ableton Push Mk 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Akai Professional MPC Key 37 49 61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2023 untested USB2 usb-b
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Alesis Photon PH-25 X25 Midi &amp; USB keyboard/synth
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2005 midi keyboard controller  
|-
| &lt;!--Description--&gt;Alesis Q25 Q49 Q61 Q88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2014 untested 
|-
| &lt;!--Description--&gt;Alesis Coda Pro Portable 88-Key Digital Piano USB MIDI Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 
|-
| &lt;!--Description--&gt;Alesis V25 V49 V61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;Alesis V Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Alesis VI49 VI61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Alesis VX49 VX61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 1 5-pin MIDI input, 1 5-pin MIDI output, 1 USB port,
|-
| &lt;!--Description--&gt;Alesis Q25 Q49 Q61 Mk2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Alesis Recital 88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;Alesis V25 V49 V61 MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022
|-
| &lt;!--Description--&gt;Alesis Qmini portable 32-key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;audiothingies MicroMonsta 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested synth - 
|-
| &lt;!--Description--&gt;audiothingies MicroMonsta 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019  synth - 
|-
| &lt;!--Description--&gt;Arturia Analog Experience “The Player” USB MIDI Master Keyboard Model APE25
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 usb-b bus powered - 
|-
| &lt;!--Description--&gt;Arturia MiniLab Mk1
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2013 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia MiniLab MkII Mk2
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia Keystep 32 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2016 untested 32 mini keys  usb compliant 
|-
| &lt;!--Description--&gt;Arturia KeyLab 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2017 untested hammer-action Fatar keybed - reset Press and hold Oct + and Oct – buttons then insert the USB cable - 
|-
| &lt;!--Description--&gt;Arturia MiniLab mkII
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt;0x2209 
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class -  - midi in out untested - }}
| &lt;!--Opinion--&gt;2017 USB2 usb-b bus power - metal base heavier than most - Shift and press a key to select the MIDI Channel - To reset to original factory, unplug the USB cable, hold down the Oct- and Oct + buttons, plug the USB cable back in and continue to hold the buttons until the pads turn white - need software to change parameters like velocity sensitive assistance - 
|-
| &lt;!--Description--&gt;Arturia KeyLab MK2 MKII 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }}
| &lt;!--Opinion--&gt;2017 untested hammer-action Fatar keybed 
|-
| &lt;!--Description--&gt;Arturia MicroFreak
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019 hybrid digital/analog synthesis, 
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=PeYIAfn3UMs Arturia Minilab 3] [https://www.youtube.com/shorts/chj1WgMupGw ]
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2020 untested usb-c bus powered - 25 mini keys semi - 
|-
| &lt;!--Description--&gt;Arturia Keystep Pro 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;Arturia MiniLab 3 Mk3
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2022 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia MiniFreak
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2022 
|-
| &lt;!--Description--&gt;Arturia KeyLab Essential 49 61 88 mk3 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested usb-c and 1 midi out - lack of aftertouch - 
|-
| &lt;!--Description--&gt;Arturia AstroLab 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;Arturia KeyLab MK3 MKIII 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2025 untested hammer-action Fatar keybed 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer UMX61
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe|untested}}
| &lt;!--Opinion--&gt;2007 
|-
| &lt;!--Description--&gt;Behringer U-Control UMX490 UMX610 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Behringer U-Control 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer Swing 32-Key
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer MOTOR 49 - 49-Key USB/MIDI Master Controller Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Creative EMU Xboard 25 E-MU X-Board 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|untested}}
| &lt;!--Opinion--&gt;2008 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;CME M-Key Mkey 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2008 stops sending MIDI on a regular basis. The simplest &quot;fix&quot; is to flip it off and on via the power switch at the back
|-
| &lt;!--Description--&gt;CME Ukey U-Key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2009 
|-
| &lt;!--Description--&gt;CME Xkey 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 low-profile aluminium  full size pressure sensitive with polyphonic aftertouch but keys make too much noise and that they can be too sensitive to velocity - low power draw 25ma 
|-
| &lt;!--Description--&gt;CME M-Key 49 V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 simplified version of the U-key Mobiltone 
|-
| &lt;!--Description--&gt;CME XKEY AIR 37
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019
|-
| &lt;!--Description--&gt;cme xkey 37 le
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Donner Spaceline DMK-25 Donnerdeal Rantion 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Donner DMK25 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;  25 mini velocity keys with limited aftertouch - usb-c powered - 8 drum pads - 3.5mm &quot;midi out&quot; socket - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Digitakt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 expensive later midi usb class compliant with since 1.5 Update
|-
| &lt;!--Description--&gt;Elecktron Digitone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Digitone Keys 37-key Digital FM Synthesizer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2018 expensive 
|-
| &lt;!--Description--&gt;Elektron Analog Four MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Octatrak MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 49+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 25xt
| &lt;!--Vendor ID--&gt;0x2702 
| &lt;!--Product ID--&gt;0x2702
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected and usb driver working}}
| &lt;!--Opinion--&gt;2011 bus powered or 12v 0.5a dc in - metal base so heavy - midi out 5pin - sustain pedal port - modulation slider - rubber coated knobs becomes sticky - 
|-
| &lt;!--Description--&gt;ESI keycontrol 49xt 61xt 88xt 
| &lt;!--Vendor ID--&gt;0x2702
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected}}
| &lt;!--Opinion--&gt;2011 12v 0.5a center pin +ve external psu required - USB i/o and 1 legacy 5pin out - full sized keys - heavy aluminium case keyboard metal base - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Evolution MK-125 MK-149
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2000 9v 
|-
| &lt;!--Description--&gt;Evolution MK-225C MK-249C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 9v 
|-
| &lt;!--Description--&gt;Evolution USB/Midi Controller MK-425C MK-449C MK-461C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|25, 49, 61 keys -  }}
| &lt;!--Opinion--&gt;2006  9V or 12V - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 37 full keys 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys Pro Mobile
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 25 or 37 mini keys 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 mini velocity keys no aftertouch - 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 2 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 full velocity keys no aftertouch - 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Kawai VPC 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; weighted keys - heavy build - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Keith McMillen Instruments K-Board
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; omni class compliant to all channels? each keypad makes them velocity, pressure, and location sensitive but  not really suited for piano playing 
|-
| &lt;!--Description--&gt;Keith McMillen  BopPad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; omni class compliant to all channels? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg NanoKontrol 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;mini usb
|-
| &lt;!--Description--&gt;Korg Prophecy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;KORG microKONTROL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010
|-
| &lt;!--Description--&gt;Korg microKEY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2011 velocity-sensitive Natural Touch keys but  joystick is an alternative to the common pitch/modulation wheel design - power draw - 
|-
| &lt;!--Description--&gt;Korg nanoKey nanoPad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 
|-
| &lt;!--Description--&gt;Korg Taktile 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg microKEY2 25 37 49 61 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|2015 untested}}
| &lt;!--Opinion--&gt;2015 USB powered - semi weighted - 
|-
| &lt;!--Description--&gt;Korg MiniList 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg MinKey nanoPad nanoPad 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Nautilus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Kurzweil PC3 7 series - Artis 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}} 
| &lt;!--Opinion--&gt;fatar TP-8 semi-weighted action  
|-
| &lt;!--Description--&gt;Kurzweil PC1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Kurzweil PC3 A8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Line 6 Mobile keys 25
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Line 6 POD Studio KB37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Line 6 Tone Port KB37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Midiman (later M-Audio) Oxygen8 Ozone Ozonic 25 32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|not class compliant - untested 5pin legacy }}
| &lt;!--Opinion--&gt;2002 2004 untested - 25 full keys - slider/fader to left of lcd display - 
|-
| &lt;!--Description--&gt;m-audio oxygen keystation (61 key) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;M-Audio eKeys 37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;M-Audio Axiom 25, 49, 61
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 bus powered and 12v psu - if sliders/faders are on right - legacy midi 5pin - chunky unit -
|-
| &lt;!--Description--&gt;M-Audio Oxygen 8v2, 49, 61 (silver) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 full size velocity sensitive 12v psu - sending random pitchbend info - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 37e 49e, 61e MK1 MKI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 - ok key action - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 37es 49se 61es, 88es MK1 MKI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 - 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25/49/61/88 (blue) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 [https://m-audio.com/products/view/oxygen-25-legacy advised Class-compliant and GM/GM2/XG SysEx messages] with full size velocity sensitive 12v psu - sending random pitchbend info - 
|-
| &lt;!--Description--&gt;M-Audio Axiom 25, 49, 61 (2nd Gen) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 semi-weighted mini keys - bus powered and 9v psu for 25/49 and 12v for 61 - if sliders/faders are on left - legacy midi 5pin - chunky unit - 
|-
| &lt;!--Description--&gt;M-Audio Axiom Pro 25, 49, 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 poor construction 
|-
| &lt;!--Description--&gt;MAudio Axiom AIR 25 M-Audio Axiom Air Mini 32
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25 III (3rd Gen) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 untested - usb only - rubber keys sticky - 
|-
| &lt;!--Description--&gt;MAudio Keyrig 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Keystation Mini 32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 - mini usb - plays a few notes and then stops responding randomly - try plugging it into port 1 or 2 on your pc - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 49 MK2 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 USB port and class compliant
|-
| &lt;!--Description--&gt;M-Audio Keystation 61 MK3 MKIII MIDI keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 usb compliant untested 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25 IV
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2016  choice 
|-
| &lt;!--Description--&gt;M-Audio CTRL-49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;M-Audio ProKeys 88, 88sx 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Keystation Mini 32 MK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019 mini usb - some power or incompatibility issue with the native USB ports of the laptop, plugged in a passive USB 2.0 HUB (not USB 3.0, not powered)
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=3328SvuJsLw M-Audio Oxygen25 MKV]
| &lt;!--Vendor ID--&gt;0x0763
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;0023
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class  - midi in out untested}}
| &lt;!--Opinion--&gt;2020 25 full size semi keys - USB2 usb-b but no 5pin classic plugs - channel select SHIFT button and CHANNEL on keybed - plastic build - holding down both the Octave + and - for factory reset -  more limited in what you can do with it than IV 4th one - tested on AROS One 2.4 usb
|-
| &lt;!--Description--&gt;M-Audio Oxygen Pro 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 untested semi full keys 
|-
| &lt;!--Description--&gt;M-Audio Oxygen Pro Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested - 32 smaller keys - not endless encoders - usb only - 
|-
| &lt;!--Description--&gt;M-Audio Hammer 88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Moog 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Moog Minitaur 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-VAVE SMK-25mini 25key MIDI Control Keyboard Y6I0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Native Instruments NI Primus A25 JamMate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2008 not compliant, 
|-
| &lt;!--Description--&gt;Native Instruments Maschine MK1 MKI
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2009 not compliant uses snd-usb-caiaq module, 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol S88 S61 S49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 - weighted keys - 
|-
| &lt;!--Description--&gt;Native Instruments Maschine MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe compliant, 
|-
| &lt;!--Description--&gt;Native Instruments Maschine Micro Mikro MK2 MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe? 
|-
| &lt;!--Description--&gt;NI Komplete Kontrol S49 S61 S88 MkII MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 all MK2 MK3 power up the keyboard using USB, it will set the keyboards MIDI port to computer MIDI only without any option to set it to use the MIDI DIN, meaning you cannot connect the keyboard to hardware and power from USB, you MUST power with the power adapter and physically unplug from any USB connection - 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol A25 A49 A61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe compliant,  
|-
| &lt;!--Description--&gt;[https://github.com/sikorak666/maschine-mikro-mk3-driver Native Instruments Maschine Micro Mikro Plus MK3 MKIII]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol M32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 untested 32 smaller keys - no drum pads - USB only - 
|-
| &lt;!--Description--&gt;NI Komplete Kontrol S49 S61 S88 MkIII MK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;NI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2025 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Neusonik iBoard 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nektar Impact LX25+ LX49+ LX61+ LX88+ SE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 budget full-size velocity-sensitive synth-action keyboard - 
|-
| &lt;!--Description--&gt;Nektar Impact GX49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; USB port - 
|-
| &lt;!--Description--&gt;Nektar Panorama P4 P6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  USB &amp; USB Micro B, 5-pin MIDI out, 2 x TRS inputs with 49 semi-weighted, velocity sensitive with aftertouch
|-
| &lt;!--Description--&gt;Nektar SE25 SE49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; mini keys - micro usb bus powered - velocity and sustain button 
|-
| &lt;!--Description--&gt;Nektar Panorama P6 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nektar Panorama T6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nord Stage 3 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; sysex 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Novation ReMote 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 lhs XY touchpad and the joystick -
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 49 61 88 Mk1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 not USB class compliant 
|-
| &lt;!--Description--&gt;Novation 49 61 SL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 semi-weighted Fatar TP-8 or TP-9 keybed
|-
| &lt;!--Description--&gt;Novation ReMote 25SL 49SL 61SL soft label 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 - two long top liquid-crystal display LCD strips - XY touchpad and the joystick - 
|-
| &lt;!--Description--&gt;Novation ReMOTE 25LE 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;0001
| &lt;!--CAMD--&gt;{{Yes|detected, usb driver in devs/midi for camd to use}}
| &lt;!--Opinion--&gt;2007 USB-b powered, 9v center pin positive or 6 MN1500 AA batteries - X/Y touchpad and the combined pitch and modulation joystick - no aftertouch but can use both the legacy MIDI OUT and USB port simultaneously 
|-
| &lt;!--Description--&gt;Novation Nocturn 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Unk| }} 
| &lt;!--Opinion--&gt;2008 untested sending random pitchbend info
|-
| &lt;!--Description--&gt;Novation 49 61 SL MkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 semi-weighted Fatar TP-8 or TP-9 keybed 
|-
| &lt;!--Description--&gt;Novation MiniNova 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2013 
|-
| &lt;!--Description--&gt;Novation Impulse 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 velocity aftertouch‑sensitive semi-weighted keyboards and eight backlit pads -  USB, 5-pin MIDI out - 
|-
| &lt;!--Description--&gt;Novation Circuit Tracks / Rhythm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 untested 
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 49 61 88 MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 USB class compliant - full keys - 
|-
| &lt;!--Description--&gt;Novation Launchpad Mini MK2 MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested 8x8 buttons with 16 backlit
|-
| &lt;!--Description--&gt;Novation LaunchKey Mini MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 untested - 25 soft mini keys - 2 rotary wheels lhs - 
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 37 49 61 88 MK3 MKIII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 USB class compliant choice - full keys - 
|-
| &lt;!--Description--&gt;Novation LaunchKey Mini MK3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested - 25 soft mini keys - 2 sliders lhs -  
|-
| &lt;!--Description--&gt;Novation 61SL Mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Nymphes Dreadbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; 6 voice analog synth
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Oberheim MC 2000 EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 88 keys fully weighted - very heavy - 
|-
| &lt;!--Description--&gt;PreSonus ATOM SQ Hybrid MIDI Keyboard/Pad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://polyend.com/tracker/ Polyend Tracker]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland ED PC-300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2002 USB MIDI keyboard controller 49-key
|-
| &lt;!--Description--&gt;Roland EDIROL PCR-M30 PCR-M50 PCR-M80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;Roland Edirol PCR-30 PCR-50 PCR-80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 untested 32 key - 
|-
| &lt;!--Description--&gt;Roland PC-50 PC-80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 
|-
| &lt;!--Description--&gt;Roland PCR-500 PCR-800
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 61 velocity-sensitive keys with aftertouch 
|-
| &lt;!--Description--&gt;Roland A-88 a-49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 USB port - weighted keys velocity no aftertouch - class compliant with press FUNCTION so it is lit. Press the key labelled &quot;ADV.&quot;, Press the &quot;+&quot; button so it is lit - 
|-
| &lt;!--Description--&gt;Roland PC-200 mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 some had fatar keys 
|-
| &lt;!--Description--&gt;Roland MC-707 Groovebox
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 
|-
| &lt;!--Description--&gt;Roland MC-101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 untested 
|-
| &lt;!--Description--&gt;Roland A-500 A500Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Roland A-300 A300Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Roland JUNO DS, FA, Fantom, JUPITER X / Xm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 (be sure that USB driver is set to &quot;Generic&quot; - requires device rebooting) 
|-
| &lt;!--Description--&gt;Roland A-88 a-49 MKii MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 expensive with USB-c port - hammer-action keyboard weighted keys - Class-compliant if  USB-C enables bus power - MIDI 2.0 later - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ROLI Seaboard RISE 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Samson Graphite 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Samson Carbon 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Sequential TAKE 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic VMK-161 and VMK-161 Plus Organ version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;TP-8O action is the unweighted, organ-style waterfall keybed - usb midi in out - 9v psu - 
|-
| &lt;!--Description--&gt;Studiologic SL990XP midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic VMK176 Plus
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;USB and midi connectivity
|-
| &lt;!--Description--&gt;Studiologic SL880 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic SL73 SL88 Studio midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; hammer-action Fatar TP semi-weighted keys 
|-
| &lt;!--Description--&gt;Studiologic Numa Organ 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 73 key TP-8O action is the unweighted, organ-style waterfall keybed used in nearly all clonewheels 
|-
| &lt;!--Description--&gt;Studiologic Numacompact 2/2x, Numa X Piano
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero CommandKey49 CommandKey25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero SZ-MiniCommand Mini-Command USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero SPC61 MIDI Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; bus powered - 5 octave 
|-
| &lt;!--Description--&gt;SubZero ControlKey49S 49 Key Slim MIDI Controller Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Synido TempoKey K25
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 25 mini keys - usb-c powered 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Worlde Panda 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha KX8 KX49 KX61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2008 not compliant 
|-
| &lt;!--Description--&gt;Yamaha CMC-PD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Yamaha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 not class compliant 
|-
| &lt;!--Description--&gt;Yamaha P45B P-45 Digital Piano 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2011 not compliant 
|-
| &lt;!--Description--&gt;Yamaha P-115 midi controller  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested weighted keys - USB midi port 
|-
| &lt;!--Description--&gt;Yamaha MX49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 should compliant untested 
|-
| &lt;!--Description--&gt;Yamaha Montage, CP73/88, YC, MODX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi keyboard controller 
|-
| &lt;!--Description--&gt;Yamaha PSR-E353, PSR-E443
PSR-S670, PSR-S770, PSR-S970, PSR-A3000, TYROS-5
NP-12, NP-32
DGX-650, DGX-660
P-105, P-115, P-255
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha MX49 II V2 Black Blue 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;DJM V10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; dj 
|-
| &lt;!--Description--&gt;Native Instruments Kontrol DJ Pro midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; detected but untested 
|-
| &lt;!--Description--&gt;Numark Mixtrack Pro II USB DJ Controller Djay 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;older generation pioneer DDJ-SX2 dj 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Alyseum AL-22 AL22c  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alyseum AL-88 Schneidersladen AL88c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alyseum U3-88c Midi Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; no CopperLan support Midi network using a UTP Ethernet patch cable) 
|-
| &lt;!--Description--&gt;Behringer BCF2000 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[http://www.behringer.com/EN/home.aspx Behringer] BCR2000 1in 2out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer B-CONTROL DEEJAY BCD3000 DJ Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer UMD404 UMD202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Creative EMU 0404/USB midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;DigiDesign / Focusrite Command 8 Control Surface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005 supports MIDI continuous controller (CC) and note data. SysEx dumping and loading is also supported  
|-
| &lt;!--Description--&gt;Digidesign Digi 002
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006   firewire only 
|-
| &lt;!--Description--&gt;Digidesign Digi 003
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2009   firewire only 
|-
| &lt;!--Description--&gt;emagic m4 2x4 AMT8 Unitor 8 Mk2  8x8 
| &lt;!--Vendor ID--&gt;0x00d0
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;0x010 0x0103
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2000 offers MTS (Midi Time Stamping) - 12v 2a psu centre pos - usb mini with rs232 and rs422 serial ports - 16 channels (8-in / 8-out), this rack-mountable unit - 
|-
| &lt;!--Description--&gt;Evolution U-Control UC-16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| detected}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Focusrite Saffire 6 USB 1.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Guillemot Maxi Studio ISIS Vintage Sound Card MIDI Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;1998 
|-
| &lt;!--Description--&gt;[http://www.ucapps.de/mbhp_usb.html MidiBox] Hardware Platform USB Module
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Mackie Control Universal Pro XT with One Two Extenders 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2008 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Audiophile USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Midisport UNO old version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio MidiMan 1x1 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004  [http://sourceforge.net/projects/linux-hotplug/ firmware update]
|-
| &lt;!--Description--&gt;M-Audio Midisport 2x2 yellowy green blue, green or silver chassis plastic box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|MIDISPORT 2x2 or 4x4 interfaces from previous production series (blue, green or silver chassis) are not class-compliant}}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;MAudio Audiosport Quattro USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant as [http://usb-midi-fw.sourceforge.net/ firmware required and that is buggy], 
|-
| &lt;!--Description--&gt;M-Audio UC-33
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Midisport 1x1 2x2 4x4 Anniversary Edition, black box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe class compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;[http://www.amiga.org/forums/showthread.php?t=52920 Mark of the Unicorn Motu Fastlane] 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|[http://www.amiga.org/forums/showpost.php?p=560852&amp;postcount=8 not working on OS4]}} 
| &lt;!--Opinion--&gt; not class compliant, 
|-
| &lt;!--Description--&gt;Motu Micro Lite 1x1 and MOTU microlite 5x5 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt; good unit but poor just plug in support and not class compliant - USB2 usb-b - 
|-
| &lt;!--Description--&gt;Motu MIDI Express 128 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;poor support serial port only - offers MTS (Midi Time Stamping) A serial port based MIDI interface or a USB interface without MTS will have a MIDI slop of up to 2ms on record and playback. MTS provides accuracy for record and playback to around .3ms - five times more accurate than serial or non-MTS.&quot; 
|-
| &lt;!--Description--&gt;MOTU.com MIDI Express XT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;2008 for many USB should have octocoupled connection to reduce groundloop humm, usually the timing is off 
|-
| &lt;!--Description--&gt;MOTU MIDI Timepiece AV 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt; not class compliant is one of the best multi-port MIDI interfaces ever made as USB model connects to the computer as an 8x16 interface
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Native Instruments GmbH Audio 8 DJ, 4 DJ, 2 DJ
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|needs dedicated driver}}
| &lt;!--Opinion--&gt;2006 not class compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Qcon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Roland Edirol UA-100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|did not match to camdusbmidi.class USB audio midi with onboard DSP}}
| &lt;!--Opinion--&gt;1998 
|-
| &lt;!--Description--&gt;Roland Corp Edirol UM-2 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0005
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{no|is not bound via camdusbmidi.class }}
| &lt;!--Opinion--&gt;1999 not bound to any midi class - 2x2 - tested Aros One USb 2.4 
|-
| &lt;!--Description--&gt;Roland Edirol UA-100G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;1999 USB audio midi with onboard DSP 
|-
| &lt;!--Description--&gt;Roland Edirol UM-880 8x8 midi interface 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2000 under poseidon but could work with run &gt;nil: c:midithru out.0 &quot;EDIROL UM-880.out.2&quot;
|-
| &lt;!--Description--&gt;Roland Edirol UM-1 blue plastic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Unk| bound??? via camdusbmidi.class - untested midi in out}}
| &lt;!--Opinion--&gt;2000 UM-1 -  1-in/1-out (16 channels) 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1S
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2000 1-in/1-out (16 channels)
|-
| &lt;!--Description--&gt;Roland Edirol UM-2E
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2000 
|-
| &lt;!--Description--&gt;Roland Edirol UM550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1X midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|do not have the Advanced Driver Switch on them}}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1SX
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0052
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{No|do not have the Advanced Driver Switch on them}}
| &lt;!--Opinion--&gt;2003 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-2C - 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-1G 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-2G 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;[https://github.com/spotify/linux/blob/master/sound/usb/usbquirks.h Roland Edirol UA20 UA-20] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;Roland UM-1EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005
|-
| &lt;!--Description--&gt;Roland Edirol UM-2EX 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005  adds a second MIDI OUT
|-
| &lt;!--Description--&gt;Roland Cakewalk UM-3G - 3x3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Roland Cakewalk ua-25excw 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2009 not class compliant mode 
|-
| &lt;!--Description--&gt;[https://alsa.opensrc.org/Edirol_UA-25EX Roland Edirol UA55 UA-55 Cakewalk UA25 EX] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2011 not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Sonuus B2M Bass MIDI Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Sonuus G2M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Steinberg CMC Series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Subzero SZ-MB44 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Swisssonic MIDI1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2012 AmigaOS there is no output at midichannel one and two but if play a midi file there is only output on some channels and if pressed stop the prog freezes or the whole system crashes
|-
| &lt;!--Description--&gt;Teac Tascam US-428 US-422 midi interface 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 2000 not compatible 
|-
| &lt;!--Description--&gt;Teac Tascam [http://web.archive.org/web/*/http://www.tascam.com/Products/US-224.html US-224]
| &lt;!--Vendor ID--&gt;0x1604
| &lt;!--Product ID--&gt;0x8004
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 2002 does not bind to any class
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-1x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }} 
| &lt;!--Opinion--&gt;2002 
|-
| &lt;!--Description--&gt;Teac Tascam US-122 MKII midi interface 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt;0x8021
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{No|not detected / binding to camdusbmidi.class on AROS 2.4 usb }} 
| &lt;!--Opinion--&gt;2004 detected but not working 2-in/2-out USB two XLR microphone preamps with phantom power for condenser microphones 
|-
| &lt;!--Description--&gt;Teac Tascam US-200 US-400 US-600 US-800 US-1200 US-1800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|no driver}}
| &lt;!--Opinion--&gt;2010 may not be totally usb compliant 
|-
| &lt;!--Description--&gt;Yamaha UX-16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|no driver}}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Akai EIE and Pro version midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 dc 6v power - 3 USB hubs, midi in out , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alesis I/O2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 powered USB hub required, not compliant 
|-
| &lt;!--Description--&gt;Alesis IO2 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 usb compliant?
|-
| &lt;!--Description--&gt;Alesis IO4 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Behringer XTouch 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; psu needed 
|-
| &lt;!--Description--&gt;Behringer X-Touch Compact
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant?
|-
| &lt;!--Description--&gt;Behringer X-Touch Mini
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant?,  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Behringer U-Phoria UMD404HD UMD202HD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe class compliant - volume low, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;CME U2 MIDI Pro 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; current model 
|-
| Creative EMU XMIDI 1X1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 early versions with sysex checksum errors 
|-
| &lt;!--Description--&gt;Creative E-MU Xmidi 1x1 Tab (V3) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 tab version class compliant but report that when transferring 'System Exclusive' messages (SysEx) the unit could not handle the highest data rate leading to data corruption 
|-
| Creative EMU XMIDI 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 sysex errors 
|-
| &lt;!--Description--&gt;Digidesign Mbox 2 Mini now Avid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 USB powered but not compliant 
|-
| &lt;!--Description--&gt;Digidesign Mbox II Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 USB powered but not compliant 
|-
| &lt;!--Description--&gt;Engl Z7 MIDI Interface (E660/E610/E360/E930)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; guitar?
|-
| &lt;!--Description--&gt;Elektron TurboMidi TM-1 1in 1out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI MidiTerminal M4U 4x4 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;supposedly class compliant - USB bus powered - 
|-
| &lt;!--Description--&gt;ESI MidiTerminal M8U 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI MidiTerminal M4U XL 4x4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; ploytec chipset 
|-
| &lt;!--Description--&gt;ESI MidiTerminal M8U XL 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; no hardware routing e.g. x on input 5 to synth y on output 7 - ploytec chipset 
|-
| &lt;!--Description--&gt;ESI MidiMate 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; supposedly class compliant - USB bus powered 
|-
| &lt;!--Description--&gt;ESI MidiMate II 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI ROM I/O
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2005 romio version 
|-
| &lt;!--Description--&gt;ESI M4U XT
| &lt;!--Vendor ID--&gt;0x2573
| &lt;!--Product ID--&gt;0x0002
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Maybe|is bound via camdusbmidi.class AROS One 2.4  - untested midi in out}}
| &lt;!--Opinion--&gt;2010  - 
|-
| &lt;!--Description--&gt;ESI M8U XT 8in 8out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 discontinued 2018 
|-
| &lt;!--Description--&gt;ESI M8UEX USB3.0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 current model 
|-
| &lt;!--Description--&gt;ESI M4U eX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 current model 
|-
| &lt;!--Description--&gt;ESI MidiMate eX midi interface 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 curent model, well liked and might class compliant?? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;icon midiport 2x2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;iCON CubeMi 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant? 
|-
| &lt;!--Description--&gt;iConnectivity 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;iConnectivity mio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 class compliant but reported issues with sending System Exclusive (SysEx) MIDI messages and MIDI signals getting cut off 
|-
| &lt;!--Description--&gt; iConnectMidi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;iCM2 iCM4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;iConnectivity iConnectMIDI4+ L
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 class compliant?? 
|-
| &lt;!--Description--&gt;iConnectivity MioXL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;IK Multimedia iRig MIDI 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant 
|-
| &lt;!--Description--&gt;iRig Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton Electronics pro solo mk2 midi to cv converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton Midi Thru-25 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Keytech MT18E 8 Way Midi Thru box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 9 to 12v psu required 
|-
| &lt;!--Description--&gt;MidiPlus Midi 2x2 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;MidiPlus Midi 4x4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; supposedly class compliant - USB bus powered 
|-
| &lt;!--Description--&gt;MidiTech MIT-00151 Midiface 4x4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;MidiTech Midiface 4x4 8x8 16x16 thru merge 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Miditech Midilink mini 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;M-Audio Midisport UNO only if box is labeled Class Compliant and latest MIDISPORT 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Fast Track Ultra (6 in 6 out) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 not usb compliant, - 
|-
| &lt;!--Description--&gt;M-Audio Midiman Midisport 2x2 Anniversary Edition [https://gearspace.com/board/electronic-music-instruments-and-electronic-music-production/1133862-why-there-hardly-any-midi-interfaces.html not stable enough] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 USB2 usb-b - does not need firmware and supposedly plug and play - 
|-
| &lt;!--Description--&gt;M-Audio Midisport 4x4 Anniversary Edition
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; rumored does not need firmware - supposedly plug and play -  issues with its firmware for some and lacks configurable routing
|-
| &lt;!--Description--&gt;Maudio Fast Track Ultra 8R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Audio 6 Mk1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 maybe usb compliant but bus powered, 
|-
| &lt;!--Description--&gt;Nektar Midiflex 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 class compliant and usb-b powered - used as a 1 in / 3 out, 2 in / 2 out or 4 out 5pin sockets - 
|-
| &lt;!--Description--&gt;Neusonik IM-One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Peavey Xport
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; guitars only 
|-
| &lt;!--Description--&gt;Roland UM-ONE UM-1 mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 USB class compliant if switch to TAB for class compliant mode rather than the COMPUTER mode 
|-
| &lt;!--Description--&gt;Squarp Hermid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Steinberg Midex 8x8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant?  supporting MIDI Time Stamping protocol
|-
| &lt;!--Description--&gt;Swissonic MidiConnect 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Tapco LiNK.midi USB 4x4 (Loud technologies) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|dedicated driver}}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-2x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt; 2014 5v dc power, midi out in, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-4x4
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;Teac Tascam US-16x08 US-20x20
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;Zoom U-24
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi to 5pin interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi to 5pin interface 
|-
| &lt;!--Description--&gt;Unbranded cable 
| 0x552d
| 0x4348
| F110 
| &lt;!--CAMD--&gt;{{Maybe|detected but no usb driver in devs/midi for camd to use}}
| &lt;!--Opinion--&gt;detected but not working the USB-MIDI conversion functionality of the cheapo USB MIDI &quot;cable&quot; interface is simply lacking, possibly being incapable of handling MIDI strings longer than 3 bytes long SysEx strings (e.g. SysEx dumps) - tested in Icaros 2.3 - 
|-
| &lt;!--Description--&gt;USB2.0-MIDI Unbranded cable with clear braided underneath leads 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x752D 
| &lt;!--Revision--&gt;0254 
| &lt;!--CAMD--&gt;{{Maybe|detected binding to camdusbmidi.class but untested midi in / out}}
| &lt;!--Opinion--&gt;untested but better to get a branded version - tested AROS One 2.4 usb
|-
| &lt;!--Description--&gt;LogiLink USB to Midi In-Out 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|}}
| &lt;!--Opinion--&gt;untested cheap cable version but issues with latency on other systems 
|-
| &lt;!--Description--&gt; gm5 USB midi chip  DIY option only
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Doremidi LEKATO MIDI USB C Interface 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Thomann Midi USB 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;   Prodipe made 
|-
| &lt;!--Description--&gt;Prodipe MIDI 1i/1o 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|}


Classic 5pin DIN controllers for above interfaces 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Akai s5000 s6000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi digital samplers 
|-
| &lt;!--Description--&gt;Akai AX80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Casio CZ-5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Casio CZ-3000 CZ-1000 CZ-101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Cheetah MS6 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|untested}}
| &lt;!--Opinion--&gt;2000 multi-timbral, six-voice (twelve-oscillator), analogue synthesiser module is loaded with CEM 3396s 
|-
| &lt;!--Description--&gt;Ensoniq ESQ1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Integra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Wavestation Ex A/D SR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1986 ex has piano and drum sounds 
|-
| &lt;!--Description--&gt;Korg DW-8000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg DW-6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Poly 800 MK1 Poly-800ii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  all plastic and can run on batteries - 49 keys non-velocity dco synt analogue filter 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland D-50
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|1987 untested greater concern would be moisture and wear}}
|-
| &lt;!--Description--&gt;Roland A50 (76) A80 (88) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|1989 untested}}
|-
| &lt;!--Description--&gt;ROLAND JUNO-D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Roland Juno 106 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;80s kx73 or kx88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Roland ED PC-160A PC-180A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} legacy DIN5 MIDI port only - 6 AA batteries or 9v psu - One regular source of failure for me were emty batteries (even with red control light still active). Another source was a bad MIDI cable - unplug then re-plug the USB cable while it is powered the device might reconnect 
|-
| &lt;!--Description--&gt;Roland M1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland S-550 S-760 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; digital samplers kontakt replaced these? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha DX7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1983 12bit 
|-
| &lt;!--Description--&gt;Yamaha DX7S DX72IID DX7IIFD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1987 16bit versions 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
|}


The MIDI standard was published in August 1983. The inventors, Kakehashi and Smith finally received a Technical Grammy Award in 2013 for their work. 

The MIDI files that contained just the note data, velocity and timing meant you could transfer an entire studio session from one place to another on one floppy disk and it could control all the synths and drum samplers. Pass-thru meant that one computer could run an entire bands worth of instruments. 

It's bulletproof too. MIDI never goes wrong, it's always a bug in software that causes any issue - you can absolutely rely on it to go gigging with, take your synths, controllers and computers and not crash an entire gig at your 100,000 person venue. 

The MIDI hardware specification is very simple (voltage, polarity, screening, protection and a fast enough opto-isolator), it assumes that the data it sends and receives between MIDI devices is to the MIDI data standard and just passes it on. The microprocessor in the hardware does all the work.

The minimum for a computer/MIDI interface is that it meets the MIDI hardware specification. It is attached to the computer bus and handles the electrical conversions required. To meet the MIDI hardware specification, to be class compliant as a USB device all it has to do is report itself properly when plugged in.

The other half of the equation is the MIDI data standard, and for a computer MIDI interface the main issue is the speed of data transmission. The bus speed of the computer is faster than the speed of the MIDI standard so it can generate and send MIDI data faster than a MIDI device can receive it. The MIDI standards have nothing to say on that bottleneck at all. MIDI was designed to be very simple and very open, it just defines a standard for the messages and leaves it up to manufacturers to implement them in the way they want. That's what makes it so powerful a tool, and also what makes it so confusing and frustrating at times.

For midi, the hardware/software combination at various connection points handles the translation to/from midi (or other protocols). Drivers would be needed for midi, including clock and SysEx signal (actually claiming to handle ALL midi quirks transparently

All the important MIDI data types can be sent (CC, NRPN, RPN, MMC, Note On/Off, program change)

There is no official way to solve the data bottleneck. Early software sequencers and librarians tried to solve it by having an option to buffer SYSEX data in software and transmit it at the MIDI data rate. The downside is that hogs the bus and can hit computer performance. Interface manufacturers would add a hardware buffer which would take all the MIDI data from the PC bus and feed it into the MIDI at the slower data rate, but that added cost and created timing issues.

Things have moved on since then, but the principles remain the same. You can buffer in the hardware or in software, whether that is in the application or the interface driver. SYSEX will work perfectly well with that budget cable if your software handles the buffering. And while the cables with hardware buffers make SYSEX easier, they still have potential problems because of the limitations of the MIDI data rate. Your MIDI clock doesn't like being interrupted with a big program dump 

The serial / parallel ports were a direct connection, so faster. Now, everything in the computer is virtual and the only thing connected to the hardware is the kernel, hence everything is by default bottlenecked and jittery, regardless of which connection. So by the time the interface gets the information it's already too late. 

Ethernet network cable to transport MIDI over large distances, connect 2 MIDI In and 2 MIDI Out ports to patch, remap, filter and merge MIDI flows on a fine channel basis for tight MIDI throughput, latency and jitter 

Possibilities for DAWs of the future including a kind of sync reference for timing reference which an interface could sync to, hence all the timings then would be locked between the grid on the DAW screen and the MIDI info. 

Preemptible, low latency and accuracy are essential for good communication.  

One of the first things you need to do, is make sure your MIDI software sets the interface to the same MIDI channel as your keyboard (usually 1) 


Do you want to send just your master keyboard to other synths or to be able to use any keyboard with any synth?

1st option is relatively simple. Just need to send midi from your master keyboard into a midi splitter that redistributes the signal onto your synths. Each synth will be set up to receive midi on a specific channel so the only challenge is to find a way to select to which channel you are sending midi. Some master keyboards can do that although not many that have a dedicated knob or switch on the panel and most require a bit of menu diving. Could use a midi box that offers channel selection but usually this is not very workflow friendly. The software route would require using the mouse. 

2nd option is a bit more complex but superior workflow by sending midi messages into a merge box, from there into a hardware sequencer that allows to select midi channel, then on to a midi interface that distributes the signal to the synths. 

Master keyboard MIDI-in to computer. External hardware sampler MIDI-out from computer. Audio-out from sampler to audio-in on computer/device. 


Blue Ribbon Soundworks Bars &amp; Pipes Professional (1993/4) 

GM (1984), GS (1987), XG level 1-3 (1994-1997), GM level 2 (1999) 	

GM GM1 imposes several requirements beyond the MIDI 1.0 specification. While MIDI 1.0 by itself provides a communication protocol which ensures that different instruments can interoperate at a fundamental level e.g sound modules. GM goes further in two ways. First, GM requires that all compliant MIDI instruments meet a certain minimal set of features, such as being able to play at least 24 notes simultaneously (polyphony). Second, GM attaches specific interpretations to many parameters and control messages which were left unspecified in the MIDI 1.0 specification. A minimum of 128 MIDI Program Numbers (conforming to the GM 1 Instrument Patch Map) and 47 percussion sounds (conforming to the GM 1 Percussion Key Map). Support for controller number 1, 7, 10, 11, 64, 100, 101, 121 and 123; support for channel pressure and pitch bend controllers. 

General MIDI Level 2 or GM2 is a specification for synthesizers which defines several requirements beyond the MIDI standard and is based on General MIDI (GM) and Roland GS extensions. It was adopted in 1999 by the MIDI Manufacturers Association (MMA).

* Number of Notes: 32 simultaneous notes
* MIDI Channels: 16
* Simultaneous Melodic Instruments – up to 16 (all Channels)
* Simultaneous Percussion Kits – up to 2 (Channel 10/11)

Program and bank change events
General MIDI 2 compatible synthesizers access all of the 256 instruments by setting cc#0 (Bank Select MSB) to 121 and using cc#32 (Bank Select LSB) to select the variation bank before a Program Change. Variation bank 0 contains the full GM (General MIDI 1) sound set. Variations using other bank numbers are new to General MIDI 2, and correspond to variation sounds introduced in Roland GS. 


[https://www.youtube.com/watch?v=CluuHrr7HG4 Major WWHWWWH, Minor WHWWHWW scale], [https://www.youtube.com/watch?v=Jjm7Ti-iwz0 Chords], 


==usb audio==

 AROS currently does not support natively any USB audio interface for recording audio 

USB audio is only available for limited Amiga like OSs, independent of the USB protocol version USB1.x USB2, USB3.x, which are not backwards compatible. 

*Introduced 2000 and from 2014 USB Audio 1 UAC1 16bit 44.1kHz
*Introduced 2006 and from 2014 USB Audio 2 [https://www.usb.org/document-library/usb-device-class-definition-audio-devices-release-20-errata-and-ecn-through-april UAC2] 24bit 192kHz
*Introduced 2016 and from 2024 USB Audio 3 [https://www.usb.org/documents UAC3] 32bit 384kHz 

USB group decided to rewrite the audio standard, so [https://os4depot.net/?function=showfile&amp;file=audio/record/usbaudio2.lha UAC2] and [https://archive.fosdem.org/2019/schedule/event/linux_and_usb_audio_class_3/attachments/slides/3345/export/events/attachments/linux_and_usb_audio_class_3/slides/3345/Linux_and_USB_Audio_Class_3___FOSDEM_2019.pdf UAC3]. They added clock selection and control, timing domains and others. Part of the changes included changing many of the descriptors that an audio device uses to describe itself to the machine. 

PsdErrorlog/PsdDevlister? The AHI driver generated only supports mono/stereo at any bit rates between 8 and 32 bit per sample, but not multichannel modes and only rates up to 65KHz (because AHI uses a 16-bit word for frequencies). If the soundcard does not offer such a PCM 8-32 bit mode at frequencies lower than 65 KHz, there's nothing much that can be done about it on the computer side other than revising and expanding the AHI standard. Most cheap USB soundcards do though. 

AHI does not support six channel playback. It only supports mono, stereo and multichannel (8 channels). Due to the multichannel mode not being used by any application so far, the usbaudio.class does not support multichannel playback, especially not &quot;upchannelling&quot; stereo to six or more channels. If this USB device does not support a two channel mode, you can't use it under AHI.

Untested but most likely to work, at least 2 mic inputs (low impedance) &amp; instruments (high impedance) and made in the last 10 years 
*[https://www.youtube.com/watch?v=gMuA-2FbJxE Entry level &lt;100Euro]   BOMGE U202, Behringer UMC, Presonus Studio, 
*[ Next tier &lt;200Euro]   Audient iD, Solid SSL2 and SSL2+, Lewitt, Focusrite Scarlett, Arturia MiniFuse, 
*[ Prosumer &lt;300Euro]   Focusrite Clarett+, 
*[ Professional &lt;500Euro]   RME Babyface, 
*[ Studio &gt;500Euros]    

Bands may need 4 or more mic inputs 

[http://forum.xda-developers.com/showthread.php?p=38364030 XDA Forum thread],

&lt;pre&gt;
                                            &lt;- Computer 
                                            &lt;- Mobile Phone / Tablet (OTG)
                                            &lt;- Digital Cameras 
                            &lt;- Video        &lt;- Webcams 

Base Computer &lt;-&gt; OBS like  &lt;- Audio Mixer  &lt;- Microphone(s) 

                            -&gt; Internet     -&gt; Youtube &amp; Chat 

&lt;/pre&gt;

USB AUDIO CARDS - UAC Compliant 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; |Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |Playback
! width=&quot;10%&quot; |Records 
! width=&quot;30%&quot; |Opinion
|-
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| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Arturia Mini Fuse 1
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant, okay pre amp 1 combi input, cirrus logic cs4272 ad converter, 
|-
| &lt;!--Description--&gt;Arturia MiniFuse 2
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant usb-c with usb2.0, okay pre amps with good dynamic range 110dB, cirrus logic cs4272 ad converter, two combi inputs for mic, line or guitar, 
|-
| &lt;!--Description--&gt;Arturia MiniFuse 4 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, okay 110dB dynamic range, -129dB EIN, 
|-
| &lt;!--Description--&gt;Arturia AudioFuse 16Rig 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audient iD44 mk1 mki 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2018 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Audient evo4 EVO8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Audient iD4 mk2 mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Audient id14 mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Audient iD24 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 maybe usb compliant and usb-c bus powered, good, , 0-in/14-out audio interface with ADAT expandability, balanced inserts
|-
| &lt;!--Description--&gt;Audient iD44 Mk2 Mkii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC22 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC202HD 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps ein -129 dBu, 24bit ADC, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC404HD 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps, 24bit adc, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC204HD 192 Empower Tribe 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt;0x0508
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 maybe usb compliant, okay, midas pre-amps
|-
| &lt;!--Description--&gt;Behringer UMC1820 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2016, bus complaint?, okay midas pre amps, adc, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UM2 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, poor zenyx pre-amps with high noise floor, plastic build no rf shielding, latency issues, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Focusrite Saffire 6 USB 1.1
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, , , midi, strictly NEC USB 2.0, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 8i6 Gen 1 MOSC0001 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, but 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 1 MOSC0003 
*TP1 - 3.3V, tested ok
*TP2 - U4 control signal, 3.3V present at all time.
*TP4 - Ground
*TP6 - 48V, tested ok
*TP7 - Ground
*TP8 - Ground
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 usually avoid early Gen 1, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2021/08/75-focusrite-scarlett-2i4-1st-gen.html Focusrite Scarlet 2i4 Gen 1 (slide toggles) MOSC0004] 
*TP1 - 3.3V, tested 3.22v
*TP2 - U4 control signal, 3.3V present 
*TP4 - Ground
*TP6 - measure 47.72v 
* AKM 4384ET (VDD 5v)
* Cirrus Logic CS4272-CZZ (VA 4.94v/ VD 3.2v/ VL 3.2v)
* all four HC4066 (VCC 4.96v)
* XMOS XS1-L01A-TQ128-C5 (all VDD 1.08v/ all VVDIO 3.23v/ PPLAVDD 0.99v/ PCU-VDDIO 3.23v)
2i4S
*TP1 seems to be 0V
*TP2 should be 5V
*TP3 should be 
*TP6 should be 48V
*TP8 should be 3.3V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, pre amps JRC NJM2122 and NJM4565, [https://statics.cirrus.com/pubs/proDatasheet/CS4272_F1.pdf CS4272 adc], [https://pdf.datasheet.live/e5e5fd1c/akm.com/AK4384.pdf AK4384 output pair], Xmos XS1-L8A-64-TQ128 processor and firmware in Winbond 25X40CL 4Mbit, an SMSC Microchip USB3343 interface and a Microchip PL611 clock generator - two Intersil / Renesas ISL97519A for the phantom power rail, two OnSemi NCP1521B for the 3.3V (digital) and 1V (Xmos core) rails - 
|-
| &lt;!--Description--&gt;Focusrite iTrack Solo USB Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2012 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 1st Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, , Cirrus CS4272, 
|-
| &lt;!--Description--&gt;[http://wiki.linuxaudio.org/wiki/current_audio_gear Focusrite ] Scarlett 4i4 Gen  MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, , Cirrus CS4272, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 6i6 Gen1 MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, , , 12v psu, the headphone outs mirror the outs on the back panel, so that's six independent outs. 4 independent analog output paths, plus two over spdif, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2019/03/38-focusrite-scarlett-18i8-gen1-teardown.html Focusrite Scarlett 18i8 1st Gen MOSC0008]
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, JRC NJM4565 provide most of the opamps, pair of JRC NJM2122's for inputs 1 and 2, [http://www.mouser.com/ds/2/76/cs4272_f1-43250.pdf Cirrus CS4272], 12v 1a +central psu to a pair of National Semiconductor LM2672 for 3.3V rail and the +6.9V rail, Xmos XS1–L16A–128 dual-row QFN package, firmware a Winbond 25X40C 4Mbit SPI Flash and an SMSC USB3343 interface chip, the two headphone outs are completely independent so 6 independent analog output paths, plus two over spdif, 
|-
| &lt;!--Description--&gt;Focusrite Clarett+ 8Pre 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 great, expensive, maybe usb compliant?  
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 2 (slide toggles) MOSC0006 
*TP6 should be 48V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8202
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, USB-b bus powered, good preamps ein equivalent input noise -128 dBu, 24-bit 192kHz CS4272 as well as an additional AKM AK4384ET for the second stereo output pair, 4 screws under bottom rubber,  
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2021/07/focusrite-scarlett-2i4-2nd-gen-teardown.html Focusrite Scarlett 2i4 Gen 2 (slide toggles) MOSC0014]
*TP6 should be 48V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, USB-b bus powered, good preamps NJM2122's, NJM4565's and CMOS switches (HEF4053 and HEF4066), CS4272 and a AKM AK4384ET, Xmos XU208-256-TQ64-C10 with firmware stored in a Macronix MX25L8006E 8Mbit flash memory, clocking by a Cirrus Logic CS2100, an MP1542 boost converter creates +6V and -6V rails, powering the opamps and the rest of the analog circuitry, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 6i6 Gen2 MOSC0016
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 2nd Gen MOSC0019
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2024/03/focusrite-scarlett-18i8-gen2-teardown.html Focusrite Scarlett 18i8 2nd Gen MOSC00]
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 3rd Gen MOSC0024
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant usb-c but usb2, preamps, ad/dc 24bit 192kHz, most Focusrite gen3 interfaces have encrypted processors, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i6 Gen3 MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, USB2 class compliant device, but with custom mixer interface
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 3 (push in switches) MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8210
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, USB-c bus powered, good preamps ein equivalent input noise -128 dBu, 24-bit 192kHz Cirrus Logic xfr002c and cs4272 chips, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 3rd gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i8 3rd Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8214
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, , , no screws under the rubber pads on the bottom, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo Studio Mk3 USB Audio Interface MOSC0030 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2020
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 4i4 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Studio 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 4th Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 4th Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Lewitt Connect 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Lewitt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Motu UltraLite AVB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt; usb not compliant? 
|-
| &lt;!--Description--&gt;MOTU M2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt; maybe not usb compliant?, usb-c, good pre amps, ad/dc, 
|-
| &lt;!--Description--&gt;MOTU M4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;MOTU U2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;  maybe not usb compliant, good but latest had hardware revision 
|-
| &lt;!--Description--&gt;MOTU UltraLite-mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;2010 not usb compliant, great 
|-
| &lt;!--Description--&gt;MOTU UltraLite-mk5
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 not usb compliant, great 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nuemann MT48 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, okay 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Presonus AudioBox USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe not usb compliant, usb1.1 usb-b bus powered, okay pre-amps, 24bit ADC 48Khz max, 
|-
| &lt;!--Description--&gt;Presonus Audiobox 1818VSL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Presonus AudioBox 44VSL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 may not be usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;PreSonus AudioBox 22VSL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 2|4 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, usb-b, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 2|6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 6|8 USB Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe compliant, needs ext psu, 
|-
| &lt;!--Description--&gt;PreSonus Studio 24c 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, good, adc, 
|-
| &lt;!--Description--&gt;PreSonus Studio 26c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, 
|-
| &lt;!--Description--&gt;PreSonus® Studio 68c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, 
|-
| &lt;!--Description--&gt;PreSonus AudioBox USB 96 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, high preamp noise, 
|-
| &lt;!--Description--&gt;Presonus Quantum ES2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, okay, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Prism 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Prism Lyra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe not usb compliant, great 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Platane UP1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant usb- UAC2 asynchronous protocol, 64dB Low-noise Mic amplifier, 32Bit High End ADC and DAC, 16dBu High-power ti headphone amplifier
|-
| &lt;!--Description--&gt;Platane UP2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Platane 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;RME Babyface/UC/UFX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant, good 
|-
| &lt;!--Description--&gt;RME Fireface UCX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 might be able to put into class compliant cc although a firewire device, pre amps, adc,  
|-
| &lt;!--Description--&gt;RME Babyface Pro FS  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe not usb compliant, good 
|-
| &lt;!--Description--&gt;RME Fireface UCX II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 might be class compliant usb-b, pre amps, adc,  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Solid State Logic SSL2 SSL2+ Mk1 1st Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, good, adc, 
|-
| &lt;!--Description--&gt;Solid State Logic SSL12 SSL18 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, bus powered, good pre-amps, up to 32-bit 192kHz AD/DA converters, 12-in 8-out, 
|-
| &lt;!--Description--&gt;Solid State Logic SSL2 SSL2+ MkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, good pre amps ein -130 dBu, ad/dc, okay latency, 
|-
| &lt;!--Description--&gt;Solid State Logic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Topping E1x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;Topping Pro E2x2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;UAD UA Apollo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;UA apollo 2nd Gen twin X (Duo/Quad), X4, X6, X8, X8P, and X16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 bus compliant?, usb-
|-
| &lt;!--Description--&gt;UA apollo twin x quad 3rd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 bus compliant?, usb-
|-
| &lt;!--Description--&gt;Universal Audio Volt 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;|Universal Audio Volt 276 2|76 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Universal Audio Volt 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;Akai EIE Pro AI01 Electromusic Interface Expander - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 4-in/4-out USB 2.0 audio interface with a built-in USB hub and MIDI I/O, up to 24-bit/96kHz 
|-
| &lt;!--Description--&gt;Akai EIE Pro AI02 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;|Alesis io2 io|2, io14 io|14, io26 io|26 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 bus powered but not usb compliant, okay pre-amps, 2, 4 or 8 mics respectively, 
|-
| &lt;!--Description--&gt;Alesis iO2 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010  not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Alesis Core 1 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe cc, mini usb, poor latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Apogee Duet 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 firewire only, not usb compliant micro-usb with most features, , ,  two‑channel two‑in, two‑out, 
|-
| &lt;!--Description--&gt;Apogee Ensemble 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 firewire, not usb compliant micro-usb with most features, , ,  two‑channel 
|-
| &lt;!--Description--&gt;Apogee One USB 1st Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant micro-usb for basic features, , , single‑channel up to 48kHz
|-
| &lt;!--Description--&gt;Apogee One USB 2nd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant usb- and maybe aa batteries, 
|-
| &lt;!--Description--&gt;Apogee Duet 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c with most features, , , 
|-
| &lt;!--Description--&gt;Apogee One USB 3rd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Apogee Ensemble Thunderbolt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe not usb compliant micro-usb with most features, , ,  two‑channel 
|-
| &lt;!--Description--&gt;Apogee Boom 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c, , , 
|-
| &lt;!--Description--&gt;Apogee Duet 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c with most features, , , 
|-
| &lt;!--Description--&gt;Apogee 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ART PRO Audio Usb Mix 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant bus powered, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 1 USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt;01000
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2002 mbox original was usb1 and not a usb class compliant device, and had the much hated &quot;focusrite designed&quot; mic preamps, light blue front plate and the sticky out feet 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 midi not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Pro USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Mini USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Micro USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not usb compliant 
|-
| &lt;!--Description--&gt;AVID MBox 3rd gen Mini or Standard but Pro is Firewire 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2010 maybe usb compliant, 
|-
| &lt;!--Description--&gt;behringer u-control uca202 
| &lt;!--Vendor ID--&gt;0x8bb
| &lt;!--Product ID--&gt;0x2902
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, draws a lot of power - dac ti burr-brown - no microphone pre-amp - 
|-
| &lt;!--Description--&gt;Behringer U-CONTROL UCA 222 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 maybe usb compliant,  - no microphone pre-amp - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Black Lion Audio 2x2 evolution 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant but , okay with 109dB range - poor noise floor, 24-bit 192kHz Cirrus Logic CS4272, average latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Bomge 11s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 
|-
| &lt;!--Description--&gt;Bomge 22s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 
|-
| &lt;!--Description--&gt;Bomge BMG22 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 usb-c, 24bit 192kHz but only use much lower, may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge U202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-c, 32bit 192kHz but only use much lower, may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge U204 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-c, 32bit 192kHz but only use much lower , may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;TI Burr-Brown PCM2702E PCM2704 PCM2704C Muse Audio Mini USB DAC board 
| &lt;!--Vendor ID--&gt;0x08bb 
| &lt;!--Product ID--&gt;0x2704
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, no mic input - goodish quality
|-
| &lt;!--Description--&gt;TI Burr-Brown PCM2900 PCM2902 PCM2906 USB DAC board 
| &lt;!--Vendor ID--&gt;0x08bb
| &lt;!--Product ID--&gt;0x2900
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, no mic input - goodish quality 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Depusheng MD22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-b powered, 24bit 192kHz though is 96kHz, 
|-
| &lt;!--Description--&gt;Depusheng USB Audio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 usb-b powered, 24bit 192kHz though is 96kHz, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;|Emagic emi 2|6 em2|6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2002 not uac 
|-
| &lt;!--Description--&gt;|Emagic emi 6|2m 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 not uac 
|-
| &lt;!--Description--&gt;|Emagic emi 6|2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 not uac 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Ego Systems, Inc. in Korea (ESI) joining with RIDI GmbH 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2006 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;esi Mixvibes U46 Mk II USB audio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 not usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;ESI ESU22
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2008 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;esi U24XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, 24 bits, 2 analogue inputs and outputs with 6.3 mm jack connection, Output L can be used as a headphone output, S / PDIF digital input - 
|-
| &lt;!--Description--&gt;esi U46XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;ESI Originals, Inc ESIO MAYA22USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;ESI MAYA44USB+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, usb-b powered,  xlr, 
|-
| &lt;!--Description--&gt;ESI Originals, Inc ESIO MARA22XTU 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;ESI U22XT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb class compliant
|-
| &lt;!--Description--&gt;ESI Gigaport Ex
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 usb compliant?, usb-c usb3.1, , , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;iConnectivity iConnectAUDIO2+ icaudio-02 USB audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;LexiconPro - Omega 8x4x2 (USB-1.1)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2003 not usb complaint 
|-
| &lt;!--Description--&gt;Lexicon Alpha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;Lexicon Lambda
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 may not be compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Line 6 Toneport UX1 and Tone Port UX2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2004  not usb compliant, 
|-
| &lt;!--Description--&gt;Line 6 TonePort UX8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 maybe not class compliant, 
|-
| &lt;!--Description--&gt;Line 6 POD Studio UX1 UX2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2006  not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Lokchonk UX22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=ljSiNmudMm0 Lokchonk UX44HD] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 usb-b , , , 2in 2out only, average latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mackie Onyx Artist 1·2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 maybe not usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;Mackie Onyx Producer 2X2 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b midi 
|-
| &lt;!--Description--&gt;Mackie Onyx Blackjack
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 USB powered but maybe not usb compliant, Two Onyx Preamps, 2-in, 2-out which are combo Neutrik-type connectors to handle XLR, instrument or line level 
|-
| &lt;!--Description--&gt;Mackie 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, , , 
|-
| &lt;!--Description--&gt;Media Assistance USB-One
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not uac cc comliant, 
|-
| &lt;!--Description--&gt;M-Audio Fast Track USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2004 maybe not usb compliant, - guitar 
|-
| &lt;!--Description--&gt;M-Audio Fast Track Ultra (6 in 6 out) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2008 maybe usb cc providing 24-bit/96kHz audio capabilities but requires manual configuration of the mixer settings 
|-
| &lt;!--Description--&gt;M-Audio M-Track 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 usb compliant?, okay - guitar and vocal mainly 
|-
| &lt;!--Description--&gt;[https://htyp.org/M-Audio/Fast_Track_Ultra/Linux M-Audio FastTrack Ultra] and Ultra 8R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe usb compliant, low round-trip latency, okay octane pre amps, adc, 
|-
| &lt;!--Description--&gt;M-Audio M-Track 2x2M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb compliant? usb-c - okay pre-amps, , 
|-
| &lt;!--Description--&gt;M-Audio M-Track (MkII) 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb compliant? usb-c - okay pre amps, , 
|-
| &lt;!--Description--&gt;M-Audio M-Track Solo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 usb compliant? - okay but issues, MJN4580C opamps (lower gain 55 dB at volume 9-10), ti PCM2900C ADC 16bit means there is a hard noise floor at -96 dB, plastic build no rf shielding, 
|-
| &lt;!--Description--&gt;M-Audio M-Track DUO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 usb compliant? - okay but issues, MJN4580C opamps (lower gain 55 dB at volume 9-10), ti PCM2900C ADC 16bit means there is a hard noise floor at -96 dB, plastic build no rf sheild, 
|-
| &lt;!--Description--&gt;M-Audio Air
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, okay 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;NI AK1 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, 
|-
| &lt;!--Description--&gt;[https://www.pogo.org.uk/~mark/linuxdj/ Native Instruments Traktor Audio 8 DJ], [ Traktor Audio 4 DJ], [ Traktor Audio 2 DJ], 
| &lt;!--Vendor ID--&gt;0x17cc
| &lt;!--Product ID--&gt;0x1978, 0x0839, 0x041C 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not usb compliant uses snd-usb-caiaq module, [https://mixxx.discourse.group/t/problems-with-native-instruments-audio-8-dj-on-linux/14719/2 Audio 8 device has 4 subunits which are not recognized correctly], Cirrus Logic DACs spec'd at 24-bit/96KHz over a USB2, 
|-
| &lt;!--Description--&gt;NI Komplete Audio 6 Mk1 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, pre amps, 24bit 96kHz adc, ocassional dropouts, plastic build top with metal around 3/4, 
|-
| &lt;!--Description--&gt;Native Instruments NI Komplete Audio 1 and 2 USB 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, good pre amp ein -129.5 dBu, ad/dc, 
|-
| &lt;!--Description--&gt;[https://support.native-instruments.com/hc/en-us/articles/360014683497-Apple-Silicon-Compatibility-News Native Instruments Komplete Audio 6 Mk2] 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, pre amps, 24bit 192kHz adc, black aluminum glass build, 
|-
| &lt;!--Description--&gt;[ Native Instruments Traktor Pro] 
| &lt;!--Vendor ID--&gt;0x17cc
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Novation AudioHub 2x4 NOVHUB01 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, no xlr, focusrite sounds inside, 
|-
| &lt;!--Description--&gt;Novation AudioHub 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Prodipe Studio 22 Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland Edirol UA-3 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1998 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-30 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;1999 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA1A UA-1D Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-5 Audio Capture (Roland)
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-1000 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-1EX, Cakewalk UA-1G  
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2005 not usb compliant driver also supports ASIO (Steinberg Audio Stream I/O Interface), noisy 
|-
| &lt;!--Description--&gt;Roland Duo Capture UA-11 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland QUAD-CAPTURE Analog 2x2 Digital 2x2 USB 2.0 4in/4out
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2005 not usb compliant, usb-b powered 
|-
| &lt;!--Description--&gt;[https://wiki.debian.org/DebianEdu/Documentation/Manuals/Rosegarden/Setup Roland Edirol UA-101 and UA-1000 (Clemens Ladisch driver)]
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;[https://github.com/mmueller-kaffeeschluerfercom/UA-25-Firmware-Modification Roland Edirol ua-25]
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2007 maybe usb compliant 16bit 44.1kHz sampling without MIDI but not USB class complient when in Advanced mode for 24bit or midi 
|-
| &lt;!--Description--&gt;Edirol by Roland USB AudioCapture UA-25EX 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x00e6, 0x00e7
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant if ADVANCED DRIVER switched to OFF might play and record at 44.1kHz and 16-bit samples 
|-
| &lt;!--Description--&gt;Roland Audio Interface V-Studio 20 VS-20 Cakewalk
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;Roland Edirol UA55 UA-55 Quad Cakewalk 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x012f
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2011 not USB class compliant, 
|-
| &lt;!--Description--&gt;Roland DUO-CAPTURE EX UA-22 USB Audio
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0159
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant but not be used with a USB 3.0 port that is not compatible with USB 2.0 specification, vs pre amps, adc, three AA batteries in base, or an AC adapter psb-1u 9V 2A - 
|-
| &lt;!--Description--&gt;Roland Rubix series Roland Rubix22 USB 2.0 Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Roland Rubix series Roland Rubix24 USB 2.0 Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Roland 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant 
|-
| &lt;!--Description--&gt;Steinberg MI2, Steinberg MI4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 not usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg (2004 Yamaha buys) MIDI interface hardware including the CC like CC121 CC-121 and CI1 CI2 series.
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2008 not usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg UR12 UR22
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR44 usb audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR242 audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 maybe usb compliant, usb powered or 5v psu, okay pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR22mkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, okay pre-amps ein -123 dBu, ad/dc, 
|-
| &lt;!--Description--&gt;Steinberg UR-RT 2 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, usb2.0 usb-b, pre-amps, ad/dc, 
|-
| &lt;!--Description--&gt;Steinberg UR44C (USB3) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg URX22C UR22C  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, preamps okay but little noisy, ad/dc. 
|-
| &lt;!--Description--&gt;Steinberg UR22 MkIII UR series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant usb-c, okay pre-amps, adc, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Tapco LiNK.USB 2x2 (Loud technologies WA, USA) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 maybe not compliant, usb-b, poor pre-amps hum, latency issues, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://git.alsa-project.org/?p=alsa-tools.git;a=blob;f=usx2yloader/README;hb=3843634ef0310a952b256bcb6a4ddd0ad4ebe396 Teac Tascam US-422 US-428 US2XYloader] 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Tascam US-122 US-224 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2003 not usb compliant, needing firmware usx2yloader/us122fw.ihx for audio sound card - Tascam US-122 and US-122L are not the same - 
|-
| &lt;!--Description--&gt;Tascam US-122L 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt;0x800e
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2006 not usb compliant, obsolete needs tascam_loader.ihx and us122fw.ihx firmware loaded each time unless automated 
|-
| &lt;!--Description--&gt;Tascam US122 US-122 Mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant although USB2 downgrade so using USB1.1 UHCI, tascam units suffer from high round-trip latency as do most typical USB units
|-
| &lt;!--Description--&gt;Tascam US144 US-144 Mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 maybe usb compliant although USB2 downgrade so using USB1.1 UHCI, tascam units suffer from high round-trip latency as do most typical USB units
|-
| &lt;!--Description--&gt;Teac TASCAM US-200 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac US-366 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac TASCAM US-600 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac TASCAM US-800 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 may not be totally usb compliant 
|-
| &lt;!--Description--&gt;Teac Tascam iU2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2012 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-2x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 usb compliant?, 5v dc power, midi out in, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-4x4
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; usb compliant?, 
|-
| &lt;!--Description--&gt;Teac Tascam US-16x08 US-20x20
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;teyun q12 Q-12, q22 Q-22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant - unknown pre amp, unknown ad/dc, 
|-
| &lt;!--Description--&gt;Teyun q26 Q-26, q24 Q-24 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant - unknown pre amp, unknown ad/dc, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha UW500
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2000 not class compliant, 
|-
| &lt;!--Description--&gt;Yamaha Audiogram 3 USB Digital Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 maybe usb compliant, okay pre amp, 16bit 44kHz adc no advanced features without dedicated asio driver, 1 xlr, 1 instrument, 
|-
| &lt;!--Description--&gt;Yamaha Audiogram 6 USB Digital Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;2013 maybe usb compliant, okay, 2 xlr, 2 instrument, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Zoom UAC-232 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;Zoom UAC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;[http://www.arcam.co.uk/products,rseries,usb-dacs,rPAC.htm Arcam rPac] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audioquest Dragonfly 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audioengine D1 Premium 24-bit DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Beresford TC-7520 (Burr Brown PCM 1716) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Beresford TC-7520 + Burson Buffer + MK3 JKSPDIF
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[http://epiphany-acoustics.co.uk/products-page/dacs/e-dac-24bit-miniature-usb-dac/ Epiphany E-DAC 24bit] ES9023 DAC chip 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Firestone Audio FUBAR II Mk2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Firestone Audio iLoveTW 24Bit USB DAC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO D5 ta2020 chip amp 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO E07K Andes 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO E17 Alpen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Magnum 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Martini-U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Vulcan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Halide Design DAC HD (Wolfson WM8716) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;HRT Steamer II USB DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;John Kenny JKDAC uses a 24-bit/192&amp;nbsp;kHz Sabre ES9022 DAC or better JKDAC32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt; iBasso D12  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Leckerton UHA-6S MKII  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;MyST 1866 PortaDAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Objective DAC ODAC+O2  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Rega DAC (Wolfson WM8742) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;[http://www.henryaudio.com/open-source.php Henry Audio USB DAC 128 also known as QNKTC AB-1.2 open source DAC] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Henry Audio mkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;AKM4430 DAC chip comes from Asahi Kasai 
|-
| &lt;!--Description--&gt;DevilSound USB DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Zoom U series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;KingRex UD-01 SE (Burr-Brown PCM 2702E) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SuperPro 24/192 USB DAC (24bit 192&amp;nbsp;kHz, CS-4398 D/A chip) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| CMedia CM108 7.1ch emulation I2S in and out
| 0x1926
| 0x0003
| 0x0100
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| [http://www.lindy.co.uk/usb-2-audio-adapter/42961.html Lindy USB 2.0] (Chipset CM108)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| Speed-Link SL-8850-SBK Vigo ([http://mightyohm.com/forum/viewtopic.php?p=1036#p1030 CMedia CM108])
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Dynamode USB SOUNDCARD 2.0 
| &lt;!--Vendor ID--&gt;0x0003
| &lt;!--Product ID--&gt;0x1130
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Dynamode Virtual 7.1 USB-SOUND7 (C-Media )
| 0x0d8c
| 0x000c 0x000e
| 1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Generic White box with very little red led and white USB lead (CMedia )
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt; 0c000e
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| CM109 CiT SC-U119 5.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| CMedia CM1197.1ch I2C MCU port Penguin 
| 0x0D8C
| 0x0000
| 0x010
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;Sweex 7.1 Startech External USB, WMA Blue metal box SYBA SD-AUD20040, Sabrent USB-SND8, Sewell Vantec NBA-200U (C-Media CM6206 CM106 like) 
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x0102
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;50/50 if the item is detected but does not work 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative Labs SoundBlaster X-fi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative X-Fi Go 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative X-Fi 5.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative Sound Blaster Play! USB sound adapter (SB1140) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; working with [http://www.amiga.org/forums/showpost.php?p=646431&amp;postcount=15 Deneb on OS3] 
|-
| &lt;!--Description--&gt;Asus Xonar U1 (ASUS UA100 USB Audio Chip) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Asus Xonar U3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Griffin iMic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Transit
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Icemat Siberia (steel series) (Cmedia chipset) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;JMTek HY554, ZyXEL NSA-220, Logilink (Tenx Technology TP6911 and SSS-1623 headphone set) 
| 0x0C76 0x1130
| 0x1605 0x1607  0xf211
| 0x
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt; reports on other OS not good 
|-
| &lt;!--Description--&gt;
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| &lt;!--Description--&gt;Plantronics &quot;DSP Adapter-01&quot; (or &quot;USB Adapter-02&quot;) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Description--&gt;Rocksmith Real Tone Cable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
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| &lt;!--Description--&gt;RSA Intruder Predator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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|-
| &lt;!--Description--&gt;StarTech ICUSBAUDIO7
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x000c
| &lt;!--Revision--&gt;1.00
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| &lt;!--Description--&gt;
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| &lt;!--Description--&gt;Stoner Acoustics UD100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Description--&gt;Teac UDH01-B  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
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| &lt;!--Description--&gt;
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| &lt;!--Description--&gt;Terratec Aureon 5.1 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Description--&gt;Terratec Aureon 5.1 USB MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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|-
| &lt;!--Description--&gt;TerraTec Electronic GmbH Aureon Dual USB
| 0x0ccd
| 0x0077 
| &lt;!--Product ID--&gt; 
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| &lt;!--Description--&gt;Terratec Phase26
| &lt;!--Vendor ID--&gt;
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| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Description--&gt;
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| &lt;!--Description--&gt;Trust 510 EX 5.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Description--&gt;
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| &lt;!--Playback--&gt;{{unk| }}
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|-
| &lt;!--Description--&gt;Logitech A-5572A USB 2.0  to 3.5mm jacks Virtual 7.1 Surround Sound Adapter or accessory of Logitech Clearchat pro USB or Logitech USB Headset H530 
| &lt;!--Vendor ID--&gt;0x0003 
| &lt;!--Product ID--&gt;0x046D
| &lt;!--Revision--&gt;
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| &lt;!--Description--&gt;
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|-
| &lt;!--Description--&gt;Trumix TM-10 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
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| &lt;!--Opinion--&gt;2024  maybe cc 
|-
| &lt;!--Description--&gt;Trumix TM-12 USB-C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Opinion--&gt;2024 maybe cc usb compliant, 
|-
| &lt;!--Description--&gt;
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| &lt;!--Description--&gt;Turtle Beach Audio Advantage Amigo Micro II USB Sound Card &amp; Headset Adapter 
| &lt;!--Vendor ID--&gt;0x10F5
| &lt;!--Product ID--&gt;0x0211
| &lt;!--Revision--&gt;0100
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| &lt;!--Description--&gt;
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| &lt;!--Description--&gt;Vantec NBA-100U 7.1 Channel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
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| &lt;!--Description--&gt;
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|}

 Companies including Access, Alesis, Allen&amp;Heath, American Audio, CME, ESI, Infrasonic, Lexicon, Numark, Presonus, Reloop, SIMS, Sound Devices, Steinberg, Swissonic, Tascam, Terrasoniq, Terratec, Yamaha and Yellowtec decided to license and bundle this driver. So fully functional custom drivers are available for Access Virus TI, Access Virus TI snow, Alesis Multimix 8 USB2.0, Alesis Multimix 16 USB2.0, Allen&amp;Heath XONE:2D, Allen&amp;Heath XONE:3D, Allen&amp;Heath XONE:4D, Allen&amp;Heath XONE:DX, Allen&amp;Heath XONE:DB4, American Audio Versa Port, CME XCORPIO, ESI ESU1808, ESI Gigaport AG / DG, ESI Maya 44 USB, Infrasonic Amon, Lexicon I-ONIX U22, Lexicon I-ONIX U42S, Lexicon I-ONIX U82S, Mindprint DI-MOD USB, Numark DJ IO, Numark NS6, Numark NS7, Numark Omni Control, Numark V7, Presonus Audiobox USB, Reloop Digital Jockey, SIMS Primus, Sound Devices USB pre, Steinberg MI2, Steinberg MI4, Swissonic Easy USB, Tascam M-164UF, Tascam US-122L, Tascam US-144, Tascam US-Tascam US-144mkII 122mkII, Tascam US-200, Tascam US-600, Tascam US-1641, Tascam US-1800, Tascam US-2000, Terratec Area 61, Terrasoniq Phase X64, Terratec Phase 26 USB, Yamaha UW10, Yamaha UW500, Yellowtec PUC2 and many others.

Well, those companies are using the same driver framework because all of those interfaces use the same microprocessor/firmware architecture to communicate with the USB bus. Just like almost all FireWire audio interfaces use the same TC Dice or BridgeCo chipsets. Usually it does not make sense for companies to develop their own USB1.1/USB2/FW framework for a product they are going to sell for &lt;$500.

However, that isn't the end of the story. The companies who develop audio interfaces implement different features into their devices and must update the driver and firmware to accommodate those features. That is where things can go wrong. Sometimes there is miss-communication about how things are coded, sometimes the developer who started a project leaves without transferring his knowledge to his successor, etc. You have to keep in mind that there are no &quot;big&quot; computer audio companies. Even the companies that seem big in the scale of the market, probably have fewer employees than you'd think.

A very well made interface that is designed from scratch from the ground up would be a very expensive device, regardless of whether it's USB, FW, PCIe or whatever.

Round-trip latency is the sum of the following:
&lt;pre&gt;
    ASIO input buffer
    ASIO output buffer
    A/D D/A converter latency
    The driver's hidden safety buffer
&lt;/pre&gt;
At a 64-sample ASIO buffer size/44.1k, Tascam units yield ~18ms total round-trip latency.

Typical USB audio interfaces use a large hidden safety buffer.
This helps ensure glitch-free playback... even under less than ideal circumstances. But... this comes at the expense of much higher round-trip latency. Short of doubling the sample-rate, there's no means of mitigating the higher round-trip latency.
If you have no plans of ever monitoring in realtime thru software based EFX/processing (ie: playing/monitoring DI bass thru an AmpSim plugin as you're playing), then this may not matter to you.
If you want the ability this play/monitor in realtime thru software based EFX/processing, make sure to get an audio interface that yields low round-trip latency.

As a point of reference the best PCI/e audio interfaces yield about 5ms total round-trip latency at a 64-sample ASIO buffer size/44.1k
The best Firewire and USB units yield 5.5-5.6ms total round-trip latency at those same settings.
Typical USB and Firewire units (that use a large hidden safety buffer) yield 12-18ms total round-trip latency at those same settings.

Anything above ~6ms starts to feel sluggish.
Anything above ~10ms feels like playing thru molasses.


USB Microphones 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;C-Media Electronics, Inc. CM108 Audio Controller Mic
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x013c 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato WaveMic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato Wave:1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 no driver }}
|-
| &lt;!--Description--&gt;Elgato Wave:3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 no driver lightweight }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;hyperx solocast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver}}
|-
| &lt;!--Description--&gt;hyperx quadcast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sennheiser CC510 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Alesis USB-Mic microphone podcasting kit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio-Technica AT2020 (AT202) AT4040
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio-Technica AT2035 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Behringer B1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Blue Microphones Snowball 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Blue Microphones Snowball iCE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| cardioid only }}
|-
| &lt;!--Description--&gt;Blue Microphones Yeti 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|can pick up a lot of background noise but not sure if right mode used }}
|-
| &lt;!--Description--&gt;Blue Microphones Yeti Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| can pick up a lot of background noise but not sure if right mode used }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MXL 2001A/600 Studio Microphone Pack / MXL 2003A Studio Condenser
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft LifeChat LX-3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Namtai SingStar(TM) PS2 SCEH-0001 USBMIC 
| &lt;!--Vendor ID--&gt;0x1415
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;0.01
| &lt;!--Opinion--&gt;{{unk| mono microphones }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Neumann 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Razer Seiren X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Razer Seiren Mini USB Condenser Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rockband USB Mic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rode NT1A VideoMic Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rode Podcaster 2 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| RODECaster Pro usb audio compatible}}
|-
| &lt;!--Description--&gt;Rode NT1A NT2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  NT2 better }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Roland R-07
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samson Go Mic - Portable USB Microphone for Recording 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| mini usb r.h.s. and clip on the bottom left hand side}}
|-
| &lt;!--Description--&gt;Samson Go Mic Clip On USB Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| switch to choose between Cardiod, Omni and -10&amp;nbsp;dB modes, a 3.5mm headphone socket and a USB socket}}
|-
| &lt;!--Description--&gt;Samson C01U  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| cardoid only}}
|-
| &lt;!--Description--&gt;Samson C03U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Shure MV7 USB Podcast Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;SONY PCM-D50 handy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb 5V, }}
|-
| &lt;!--Description--&gt;Sony PCM-M10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out 5V, }}
|-
| &lt;!--Description--&gt;SONY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out, }}
|-
| &lt;!--Description--&gt;SONY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out, }}
|-
| &lt;!--Description--&gt;TASCAM DR-1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008, one mini usb out, lithium battery}}
|-
| &lt;!--Description--&gt;Tascam DR-07 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009, one mini usb out, aa battery}}
|-
| &lt;!--Description--&gt;Tascam DR05 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011, one mini usb port for file transfer and charging the AA batteries }}
|-
| &lt;!--Description--&gt;Tascam DR-40
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011  mini usb aa battery }}
|-
| &lt;!--Description--&gt;Tascam DR-07mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 , one mini usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-05X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-07X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-40X
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb 3 aa battery }}
|-
| &lt;!--Description--&gt;Tascam DR-05XP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c , }}
|-
| &lt;!--Description--&gt;Tascam DR-07XP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c , }}
|-
| &lt;!--Description--&gt;Tascam DR-40XP
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c, }}
|-
| &lt;!--Description--&gt;Tascam DR-100mkIII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| , usb , }}
|-
| &lt;!--Description--&gt;Tascam 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| , usb , }}
|-
| &lt;!--Description--&gt;Zoom H4 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H2 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;0x0095
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 no driver, mini usb 5V audio i/f USB Card and USB Audio; press the Record button when USB Audio is displayed. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H4n 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H1 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;0x0120
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 no driver, mini usb 5V and display will alternate between USB Card and USB Audio; press the Record button when USB Audio is displayed. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H2n 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 no driver, mini usb 5V audio i/f press the Record. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H4n PRO 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H6 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 untested, 2xlr, 5v mini usb, }}
|-
| &lt;!--Description--&gt;Zoom H5 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 no driver, 5v mini usb, 2 xlr, }}
|-
| &lt;!--Description--&gt;Zoom H1n-vp handy 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H6studio 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 untested}}
|-
| &lt;!--Description--&gt;Zoom 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|no driver}}
|-
| &lt;!--Description--&gt;Zoom Q3
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 untested usb a cord, no hdmi, 480p}}
|-
| &lt;!--Description--&gt;Zoom Q3HD Handy Video Recorder 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 untested, built in usb-a cord, mini hdmi, 1 hour on 2 AA batteries, H.264 movies 480p }}
|-
| &lt;!--Description--&gt;Zoom Q2HD Handy 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 untested, up 720p but no stablisation, mini usb cord, 1 hour on 2 AA batteries}}
|-
| &lt;!--Description--&gt;Zoom Q4
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 untested, li-ion battery}}
|-
| &lt;!--Description--&gt;Zoom Q4N 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 untested, li-ion battery}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio Technica ATR4697-USB Boundary Microphone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;CAD Audio CAD USB Condenser Boundary Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MXL AC-44 Boundary Conferencing Mic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samson Audio SAUB1 Boundary Microphone (USB)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


USB Speakers 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Focal XS 2.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


USB Headset Wired/Wireless 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Logitech Vantage Wired (came free with PS2 Socom3)
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech G330 
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech Premium USB Stereo Headset 350
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Plantronics DSP-300 
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Plantronics GameCom 777
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech G-930 Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| [http://www.makeuseof.com/tag/set-usb-wireless-earphones/ Plantronics Audio 995 Wireless RF] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Sennheiser  Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


[https://www.youtube.com/watch?v=Be1e0QPIPK0 Mixers]

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;ALESIS MULTIMIX 4 CHANNEL USB MIXER
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Alesis - MultiMix 8 USB FX (USB 1.0)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2010 usb compliant?, up to 16-bit/48kHz, 18v 500mA - 
|-
| &lt;!--Description--&gt;Alesis - MultiMix 8 USB 2.0 FX (USB 2.0)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2012 usb compliant?, up to 16-bit/48kHz, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Allen&amp;Heath MixWiz16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Allen and Heath ZED Power 1000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 8 xlr, usb-b out, }}
|-
| &lt;!--Description--&gt;Allen &amp; Heath ZEDi-10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Behringer XENYX 302USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 5-Input Mixer/Audio Interface - 1 xlr - }}
|-
| &lt;!--Description--&gt;Behringer Xenyx Q502USB Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|no driver}} Behringer 2*18.5V 250ma psu - 1 xlr - phanton power - 
|-
| &lt;!--Description--&gt;Behringer Xenyx Q802USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} Behringer 2*18.5V 250ma psu - 2 xlr - phanton power - 
|-
| &lt;!--Description--&gt;BEHRINGER XENYX 1204USB 8-Channel 2-Bus Mixer USB/Audio Interface Studio/Live
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} iec kettle psu lead - can develop constant background hiss over time 
|-
| &lt;!--Description--&gt;Behringer XENYX X1222USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver - 12-Channel Analog Mixer with USB Interface and Effects}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Depusheng HT-7 HT7USB 7 Channel Audio Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2023 cheap no driver, USB MP3 player to work, format your USB stick Fat32 as a Logical drive - not primary}}
|-
| &lt;!--Description--&gt;Depusheng XT7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2025 cheap no driver}}
|-
| &lt;!--Description--&gt;Depusheng DT8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2025 cheap no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Spirit soundcraft Folio FX8 with Lexicon Effects Processor
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} unusual power connector - [https://github.com/lack/soundcraft-utils usb routing] -  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Weymic Professional F7 7-Channel 2-Bus Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2022 no driver, cheap mixer with 3pin ac input (introduces noise) and 1 usb-a port}}
|-
| &lt;!--Description--&gt;Weymic Professional F7-Pro 7-Channel 2-Bus Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2022 no driver}}
|-
| &lt;!--Description--&gt;Weymic A80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2024 no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Yamaha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


Mixer no hardware usb 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;ALTO Lynx MIX82FX Audio Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Alto L16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer MXUL5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer MX602A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB502
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 17.5V 3pin psu needed}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB802 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 2 xlr,}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1002 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 2 xlr,}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 4 xlr, }}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1602 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer RX1602 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer 802 XENYX 8-Input 2-Bus Mixer Small Format Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} Behringer 18.5V ???ma psu - 2 xlr - phanton power - 
|-
| &lt;!--Description--&gt;Behringer Xenyx 502 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer Xenyx 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;IMG stage Line MMX-122 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, 4 xlr, iec cable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Mackie 802VLZ4 Mackie 802-VLZ4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb , psu}}
|-
| &lt;!--Description--&gt;Mackie 1202-VLZ Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, mains iec}}
|-
| &lt;!--Description--&gt;Mackie Mix5 Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}} 18v 300mA psu - 5 Channel - 
|-
| &lt;!--Description--&gt;Mackie Mix8 Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}} 9v x2 600mA psu - 
|-
| &lt;!--Description--&gt;Mackie MIX12FX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, 4 xlr, 9v 500mA x2 psu, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;[https://www.soundcraft.com/en/product_documents/en/owners_manual Soundcraft] Spirit Folio F1 Fader 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} 16 Channel Mixer - 
|-
| &lt;!--Description--&gt;Soundcraft EPM6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Soundcraft EPM8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Harman Soundcraft EPM 12 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} iec kettle power lead - 
|-
| &lt;!--Description--&gt;Soundcraft EPM 16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Soundcraft Notepad 8FX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Soundcraft Notepad UI12
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; connect via wifi 
|-
| &lt;!--Description--&gt;Soundcraft Notepad UI16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; connect via wifi 
|-
| &lt;!--Description--&gt;Soundcraft Notepad 124FX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection, 14.8V x2 3 pin psu}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;t.mix xmix 1402fx mp usb
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection, mains iec, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
|}


==Webcameras==

A USB camera has two dedicated chips: a controller or bridge and an image sensor.

There was no Commodore support for video interfaces. The only commercial, now discontinued application that defined some sort of standard was VHI Studio by iospirit.

===OLD standards===

See [http://www.e3b.de/usb/main_supported_e.html support pages] and [http://www.e3b.de/usb/main_faq_e.html here] and some [http://webcam-osx.sourceforge.net/cameras/index.php?orderBy=status further compatibility]


Pencam STV680
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| AIPTEK stv680 
| 0x0553 
| 0x0202 
| 
| {{N/A|untested}}
|-
| Konica e-mini 
| 0x04c8 
| 0x0722 
|
| {{N/A|untested }}
|-
| DigitalDream l'espion XS 
| 0x1183 
| 0x0001 
|
| {{N/A|untested}}
|-
| [http://reviews.cnet.com/webcams/creative-webcam-go/1707-6502_7-1446174.html Creative WebCam Go mini] 
| 0x041e 
| 0x4007 
|
| {{N/A|untested}}
|-
|}


SonixcamTool (Sonix webcams and derivates)

'''Note [http://amigadev.free.fr/sonix/ some] Sonix Webcams with a Sonix SN9C1xx controller ''and'' a pas106b or tas5110c1b sensor support bulk mode which works even with pciusb.device!'''
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Macally IceCam II
| 0x0c45
| 0x05d8
| 
| {{N/A|untested}}
|-
| Sweex MiniCam 100K 
| 0x0c45 
| 0x6005 
| 
| {{N/A|untested - sensor tas5110c1b}}
|-
| Macally IceCam Portable 
| 0x0c45
| 0x6007
| 
| {{N/A|untested - sensor tas5110d}}
|-
| Sweex 100K 
| 0x0c45 
| 0x6009 
| 0x0101
| {{yes|bulk works - sensor pas106b}}
|-
| [http://www.epinions.com/pr-Chicony_TwinkleCam_Webcam/display_~full_specs Chicony Twinkle DC-2110A] 
| 0x0c45
| 0x600d
| 
| {{no|no}}
|-
| Unknown
| 0x0c45
| 0x601e
| 
| {{no|no}}
|-
| USB PC Camera (SN9C102)
| 0x0c45 
| 0x6028
| 
| {{no|no - sn9c10x + pas202b}}
|-
| Trust SpaceC@m 120 and 150
| 0x0c45 
| 0x6029
| 
| {{N/A|untested - sensor pas106a}}
|-
| HiRes Webcam Live
| 0x0c45 
| 0x602c
| 
| {{no|no - sensor ov7630}}
|-
| [http://www.sweex.com/en/assortiment/sound-vision/webcams/JA000020 Sweex USB Webcam 300K]
| 0x0c45
| 0x608f
| 
| {{no|no - sensor ov7630}}
|-
| Speedlink Sphere Webcam SL-6820, 350K
| 0x0c45
| 0x613c
| 0x0101
| {{N/A|untested - sensor HV7131R}}
|-
| WB-3250P
| 0x0c45
| 0x613e
| 
| {{no|no - sensor ov7630}}
|-
| Unknown
| 0x0c45 
| 0x6207
| 
| {{no|no}}
|}

&lt;pre&gt;
micromaxx USB Camera 	STM 	1363 	514 	works 	---
USB Tower 	Lego 	1684 	1 	works 	need NCQ
Trust Spycam 100plus 	STM 	1363 	514 	works
&lt;/pre&gt;


ov51x.class - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| D-Link VGA Webcam (640x480) 
| 0x05a9
| 0x8519
| 
| {{no|no driver}}
|-
| Sony PS2 EyeToy Logitech/Logicool Black (ov519) SCEH-0004 
| 0x054c
| 0x0154
| 
| {{no|no driver}}
|-
| Sony PS2 EyeToy Namtai Silver (ov519) SLEH-00031 SLEH-00030
| 0x054c
| 0x0155
| 
| {{no|no driver}}
|-
|}


===UVC.class - [https://www.usb.org/document-library/video-class-v15-document-set USB Device Class Definition for Video Devices or USB Video Class]===

 AROS needs realtime isochronous transfers in EHCI and XHCI, then a usb uvc.class which might create a virtual UVC.VHI type device driver for use by AROS apps 

since 2019 the market is filled with UVC Compliant USB HDMI Capture

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acasis 4K30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Acasis 4K60 HD VS009
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|4k 60hz ok for chat streams}}
|-
| &lt;!--Description--&gt;Acasis 4K60 HDMI HDR Game Live Video Capture
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| for chat streams }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AJA U-tap HDMI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;ASUS TUF CU4K30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ATEN CAMLIVE HDMI to USB-C UVC Video Capture adapter UC3020 HDMI (F) TO USB-C M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 possibly UVC and UAC standard support allows up to 1080P @ 60}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Avermedia Live Streamer Cap 4K - BU113 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 uvc usb3}}  
|-
| &lt;!--Description--&gt;AVerMedia GC515 video capturing device 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.2 Gen 1 (3.1 Gen 1)}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra GC553
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 usb3 powered by Type C USB cable and 4K HDMI cable}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra S GC553PROW 302AGC553DL2 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1553
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 powered by good quality type C USB3 cable and 4K HDMI 2.0 cable}}
|-
| &lt;!--Description--&gt;AVermedia Live Gamer Mini GC311 302AGC311DG9 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1311
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 uvc compliant up to 1080p 60fps capture and supports internal hardware H.264 encoding }}
|-
| &lt;!--Description--&gt;AVerMedia Ez Recorder 330 (ER330) 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 designed to work independently and is generally not compatible as a plug-and-play UVC capture card }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer extreme3 GC551G2 (LGX3) 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x3551
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc compliant for intensive gaming streams, some vrr but no hdr with maximum recording resolution of 4K30/1080p60 from fully wired usb3 compatible cable - passing through 4K60/1080p120 Game Capture video capturing device HDMI}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra Pro GC553Pro 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 usb3 }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra 2.1 GC553G2 61GC553G20BV video capturing device 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 USB 3.2 Gen 1 (3.1 Gen 1)}}
|-
| &lt;!--Description--&gt;AVerMedia GC575
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 usb3 powered by Type C USB cable and 4K HDMI cable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AVMatrix 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ClonerAlliance Flint 4KP Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;DIGITNOW U600 video capture card 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc uac  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Epiphan AV.io HD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Epiphan AV.io 4K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato Cam Link 4K 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 uvc }}
|-
| &lt;!--Description--&gt;[https://github.com/elgatosf/capture-device-support Elgato HD60 S+]
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt;0x006C, 0x006E
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 4K 30FPS capture, 1080p 60FPS uvc}} 
|-
| &lt;!--Description--&gt;Elgato HD60 X 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc }}
|-
| &lt;!--Description--&gt;Elgato Cam Link 4K HDMI video capture card 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 uvc compliant but can have usb disconnects}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EVGA XR1 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.0 device with 1080/60 capture and 4K/60 passthrough}}
|-
| &lt;!--Description--&gt;EVGA XR1 lite USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 USB 3.0 device }}
|-
| &lt;!--Description--&gt;EVGA XR1 Pro USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.0 device with 1080/60 capture and 4K/60 passthrough}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EZcap Game Link Raw - ezcap321 usb3.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 2160p30, 1080p120 and 1440p60 HDMI input and pass-through. - 1080p120, 2160p30 and 1440p60 recording. - Latency less than 50ms uvc}} 
|-
| &lt;!--Description--&gt;EZCap GameDock Ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 record at 4K30, 1440p60, and 1080p120}}
|-
| &lt;!--Description--&gt;EZcap 360 Game Capture Extreme 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 USB 3.0, 4K 60FPS passthru and 1080p 240FPS}}
|-
| &lt;!--Description--&gt;EZCAP 364 GameDock Extreme 2.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Genki ShadowCast 1 &amp; 2, the Pro version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HAUPPAUGE HD PVR Pro 60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021  4K in/Out 1080P 60fps Capture and Streaming PC Connected and Stand Alone }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kondor Blue 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nanjing Magewell Electronics Co ltd USB 3.0 XI100DUSB-HDMI Pro Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 }}
|-
| &lt;!--Description--&gt;Magewell USB3.0 Silver HDMI Full HD Video Capture Device 1080p 32011 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 usb audio extract HDMI embedded audio output via headphones}}
|-
| &lt;!--Description--&gt;Magewell USB capture HDMI PLUS 2K 32040 320400000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 captures video up to 1920×1200, 1920×1080 or 2048×1080 at 60 fps over an HDMI capture from devices such as game consoles in up to DCI 4Kp60 4:2:0 input resolution, and it automatically upscales/downscales the signal to 2K for recording or streaming}} 
|-
| &lt;!--Description--&gt;Magewell USB capture HDMI Gen2 32060 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 1080p gets hot, 165M HDMI receiver, max input 2048x1080 60fps 4:4:4, RGB/YUV 4:4:4 8/10/12-bit, YUY 4:2:2 12-bit, up to 8-channel 24-bit HDMI-embedded audio at 192kHz, HDMI 1.4a, output from 480p to 1080p, YUY2/UYVY/RGB24/RGB32 support video cropping, up/down scaling, de-interlacing, aspect ratio conversion, color format conversion, frame rate conversion, flip and mirror, up to 2-channel IEC60958 audio streams, 5V 0.5A 2.5W, }}
|-
| &lt;!--Description--&gt;Magewell USB Capture 4K Plus 32090 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 limited by the bandwidth of USB 3.0, the maximum frame rate can only reach 30 fps when capturing}}
|-
| &lt;!--Description--&gt;Magewell USB Capture 4K PRO
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Magewell Pro Convert IP to USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Captures one network eth NDI® High Bandwidth, NDI® HX2, NDI® HX3 sources or H.264/H.265 video source into software at resolutions up to 1080p60}}
|-
| &lt;!--Description--&gt;Magewell USB Fusion 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|versatile USB video capture device that allows users to switch between two HDMI inputs and one USB webcam input for live presentations}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ROLAND UVC-01 USB Video Capture
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sunplus Innovation Technology Inc. MiraBox HSV321 ARX321 Video Capture device 
| &lt;!--Vendor ID--&gt;ox1bcf
| &lt;!--Product ID--&gt;0x2c99
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc uac  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;UGREEN CM716 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| uvc uac but disable HDCP on your source device (PS4/PS5, Xbox) }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;VisionTek UVC HD60 Capture Card
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acer Aspire Crystal Eye AOA110 AOA150 0.3M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2008 webcam }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;AVerMedia Live Streamer CAM 313 (PW313) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2019 uvc 1080p/30 webcam}}
|-
| &lt;!--Description--&gt;AVerMedia Live Streamer DUO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2021 uvc 1080p/60 webcam}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;[http://reviews.cnet.co.uk/webcams/creative-live-cam-optia-af-review-49294183/ Creative Live Cam Optia AF] 2.0M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| {{no|2008 }}
|-
| &lt;!--Description--&gt;DSLR macro extensions + a cheap 50mm E-Series lens + some PVC tubing and a negative holder 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes| if uvc camera chosen}}
|-
| &lt;!--Description--&gt;DSLR scanning using a macro lens, for the adapter, for a 3d printed negative holder) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes| if uvc camera used }}
|-
| &lt;!--Description--&gt;Logitech C270 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;0x0825
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|720p }}
|-
| &lt;!--Description--&gt;Logitech C910 C920 HD Pro 5Megapixels 720p 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Output mjpg 1080p}} 
|-
| &lt;!--Description--&gt;Logitech C920s c922 HD Pro 5Megapixels 1080p 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Output mjpg 1080p}} 
|-
| &lt;!--Description--&gt;Logitech 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Logitech Brio 100 300 500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}} 1080p 
|-
| &lt;!--Description--&gt;Logitech MX Brio 4k 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|4k}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Microsoft's LifeCam HD-3000 HD-5000 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt; 0x0779
| &lt;!--Revision--&gt;1.06
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Microsoft LifeCam Cinema 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Microsoft LifeCam Studio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} sony imx179 1080p 
|-
| &lt;!--Description--&gt;Pi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} 1/2.8” Sony IMX291 image sensor, it's a 2MP, UVC-compliant, ultra-wide-angle, low light, high-speed USB 2.0 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} OV5648 
|-
| &lt;!--Description--&gt;razer kiyo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} 4 megapixel sensor 1080p 30fps 720p 60fps - 12 led ring light adjustable 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;TeckNet C068 1.3mpixel HTD USB2.0 Camera Vimicro Z-Star Corp 
| &lt;!--Vendor ID--&gt;0x0AC8
| &lt;!--Product ID--&gt; 0x3420 
| &lt;!--Revision--&gt;0x01FA
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;YEALINK(XIAMEN) NETWORK UVC50 is compatible with the UVC 1.1 protocol CP960-UVC50 and CP960-UVC80 kits PTZ, CP960-UVC30 Kit is UVC 1.5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Amcrest ProHD 1080P WiFi Wireless IP Security Camera - 1080P (1920TVL), [https://www.ispyconnect.com/man.aspx%3Fn%3DAmcrest IP2M-841] nvr 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} h264/rtsp, motion detection, features Sony image sensor and Ambarella processor - rtsp://[username]:[password]@[IPaddress]:[port]/cam/realmonitor?channel=[channel]&amp;subtype=[stream] - [username] - username to login to the DVR or NVR, [password] - password, [IPaddress] - IP address of the device. If you are not on the same local network, this should be the external IP address of the device's network, [port] - port number, [channel] - channel number of the stream, [stream] - view the Main or Sub stream. (main stream is 0, sub stream is 1) , eg. rtsp://admin:admin@192.108.1.108:80/cam/realmonitor?channel=1&amp;subtype=1 - utilizing RTSP ( rtsp://user:pass@ipcam1 )  
|-
| &lt;!--Description--&gt;Axis all modern ones 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} RTSP/RTP + H264/mjpeg or MJPEG over HTTP
|-
| &lt;!--Description--&gt;PTZ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;DLink DCS-5222 5222L network camera 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} camera streams H.264 over RTP controlled by RTSP 
|-
| &lt;!--Description--&gt;Dlink DCS900 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Wansview 1080p [http://marc.merlins.org/perso/linuxha/post_2013-11-10_Reviewing-IP-Webcams-for-Linux-and-Zoneminder_Dlink-DCS900_-Ubnt-Aircam_-Foscam-FI8904W-FI8910W_-FFI9820W_-FI9821W_-Wansview-NCB541W_-and-Zavio-F3210.html#NCM625GA NCM625GA] IP Camera WiFi Wireless IP Security Camera , Full HD Plug n Play Home Surveillance / Baby Monitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} RTSP/RTP + H264/mjpeg - play its HD stream without problem with vlc rtsp://ip/live/ch0 and getting  jpegs http://ipaddr/mjpeg/snap.cgi?chn=0 - methods involve transcoding h.264 video from the camera into jpeg's, which is cpu intensive - able to pull images manually, using http://username:password@ip/mjpeg/snap.cgi - 
|-
| &lt;!--Description--&gt;Wansview NCB541W
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;Avermedia Game Capture HD C281 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2011 standalone h.264 recording of up to component cable not hdmi but not uvc}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Avermedia GL310 Live Gamer Portable (LGP Lite)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 not working usb2 and USB Lite no uvc}} 
|-
| &lt;!--Description--&gt;Avermedia AVerMedia Live Gamer Portable ([https://github.com/Trouffman/octv_gears_lgp Model C875])  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 usb2 no uvc}}   
|-
| &lt;!--Description--&gt;AVerMedia LGX Live Gamer extreme GC550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2015 but [https://github.com/ChrisAJS/lgx2userspace driver]}}
|-
| &lt;!--Description--&gt;AVerMedia LGX2 Live Gamer extreme2 gc550 plus gc551 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 but [https://github.com/ChrisAJS/lgx2userspace driver]}}
|-
| &lt;!--Description--&gt;Avermedia ExtremeCap UVC - BU110 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 maybe not uvc and uac}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Portable 2 Plus GC513 Micro-USB Capture Box LGP2 Plus
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1513
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 powered by a standard Micro-USB cable, video capture output up to 1080p60 capture to hdmi in, standalone sd card recording on exFAT or FAT32 of .MOV, 2160p pass-through hdmi out to tv - no vrr - [https://www.avermedia.com/uk/support/download#ans_part firmware latest 2.1.7.13, 2.1.7.14], SN74AVC8T245 8bit, DRV604 stereo, iTE IT6663FN hdmi 2.0 splitter, TLV320DAC3101 DAC, CS42L73 audio codec, CDCE913 PLL clock, W29N01HVSINA nand bios, I-Catch V35MA SOC CPU 32bit MIPS24K, ADV7480 hdmi mhl, }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer 4K LG4K GC573 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2018 not uvc but [https://github.com/derrod/lg4k-linux drivers here], }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Blackmagic intensity Extreme Capture Card
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2011 not uvc }}
|-
| &lt;!--Description--&gt;BlackMagic Intensity Pro 4k 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2015 }}
|-
| &lt;!--Description--&gt;Elgato Video Capture (1VC108601000)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Elgato Game Capture HD60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc, }}
|-
| &lt;!--Description--&gt;Elgato Game Capture HD GCHD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc https://github.com/tolga9009/elgato-gchd needs firmware mb86h57_h58_idle.bin and mb86h57_h58_enc_h.bin}}
|-
| &lt;!--Description--&gt;Elgato HD60S Elgato Game Capture 4K60 S+ Video Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|non uvc, }}
|-
| &lt;!--Description--&gt;August EZCap.tv model 116 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} poor audio recording 
|-
| &lt;!--Description--&gt;E-SDS Diamond Maplin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Hauppauge 1212 HD PVR 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} analog and component only - PlayStation (.m2ts), AVCHD (ts), or XBox(.mp4) recording formats - switched the component output from the default YPbPr to RGB. 
|-
| &lt;!--Description--&gt;Hauppauge 1431 1445 HD PVR Gaming Edition HDMI Capture 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 not working, can get warm}}  
|-
| &lt;!--Description--&gt;Hauppauge HD Rocket 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;Hauppauge HD-PVR2 (model 145210 Rev E4) 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xE502
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Hauppauge 1480 1482 HD PVR 2 GE Gaming Edition HDMI Capture green LED - 1498 1503 1504 Plus version with Mac support 
| &lt;!--Vendor ID--&gt;0x2040 
| &lt;!--Product ID--&gt;0xe514 0xe524
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| can get warm - [https://ez.analog.com/video/w/documents/581/adv7482-design-support-files ADV7482] [https://patchwork.kernel.org/patch/9201075/ video chip] with Magnum DXT H.264 encoder blob, IDR keyframe generation poor - best for model 157210 and not 157221 and Game Edition Plus (model 157320) 2040:E505 E505-00-00AF1234 [http://www.hauppauge.com/site/support/linux.html#tabs-3 ]}} 
* HDMI: 1920x1080p50/60, 1920x1080i50/60, 1280x720p50/60, 720x480i, 720x576i, 640x480p60.
* Component: 1920x1080p50/60, 1920x1080i50/60*, 1280x720p50/60, 720x480p60, 720x480i, 720x576i.
* Composite: 720x480i and 720x576i 
* Audio Inputs : HDMI PCM and RCA support with Adjustable Bitrate Quality 2 Channel AAC/AC3 audio codec 
|-
| &lt;!--Description--&gt;Hauppauge 1512 HD PVR 2 PC blue LED with optical in input on the back 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xe525
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} can get quite warm - IR Blaster added - 
|-
| &lt;!--Description--&gt;Hauppauge Colossus2 E585-00-00AF4321 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xe585
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Ion SLIDES2PC 35mm Portable Slide &amp; Film Scanner 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Ion Pics 2 PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;ION PowerScan USB film and slide scanner
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2011 not uvc }}
|-
| &lt;!--Description--&gt;Koolertron Sunny 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;FilmScan35 35mm Film Negative Scanner 1304 marks spencer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;U3 HD Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Razer Ripsaw HD - Game Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}} put in usb2 slot and use video BGR3 (Emulated) and OpenRazer drivers 
|-
| &lt;!--Description--&gt;Razer Ripsaw HD USB HDMI Capture Card 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0x0d01
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| not uvc compliant}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Silvercrest 35mm Photo Slide Scanner 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc but not great quality}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Z-Star Microelectronics Corp. Traveler TV 6500 SF Dia-scanner
| &lt;!--Vendor ID--&gt;0x0ac8
| &lt;!--Product ID--&gt;0x3370
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2010 not uvc and poor scans}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
|}


=== AR VR XR Headset ===

 AROS needs realtime isochronous transfers in EHCI and XHCI, then an usb based uvc.class to vhi type driver for virtual display and maybe more 

The primary engineering challenge of VR is motion sickness caused by a mismatch of visual and inner ear information, which is extremely well established as causing people to throw up in a wide range of contexts outside of VR. The experiences that make some people sick are low framerate. Foveated rendering doesn't solve vergence accommodation. Your eye will still be focused at infinity regardless of where you are looking, you'll just have the illusion that the foreground or background are out of focus. Eye tracking plus dynamic lenses (perhaps liquid lenses) or real light fields are necessary. 

First start with apps that have simple static features at first, then advance to dioramasa and teleportation options for 10, 20 minutes and then gradually upgrade over a timespan of four weeks to train your brain. Avoid smooth motion stuff like rollercoaster or mountain heights until much later. Even with this preparation, VR makes 40% of people seasick nausea. If so, you may be able to use VR glasses just to watch videos and some slow moving apps [https://www.emuvr.net/ emuVR] instead.

*2014-2019 1st Gen, low resolution, 
*2020-2025 2nd Gen, higher resolution, 
*2026-

Most hardware typically has a 1-3 year retail lifespan with 1-3 years of updates after. Really need &quot;right&quot; tethered PCVR rather than wireless. 
The advantage to being tethered to a PC is processing power. Any standalone headset is going to be running purely off of batteries.

VR and AR are known as XR

Technology will get immersed enough so not making people sick. Higher resolution, faster frame rates, and [https://github.com/opentrack/opentrack better tracking]. 
Eventually, hyper reality brings VR, AR and MR digital layers together as a less chaotic, optic tracking with no delay, agents understanding, experiences with objects 

3Dgs 4Dgs gassian splats bullet time slice photo snaps .ply for WebXR 

[https://lvra.gitlab.io/docs/hardware/ ], 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Big Screen Beyond 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 pcvr 2560 x 2560, fixed IPD,  }}
|-
| &lt;!--Description--&gt;bigscreen Beyond 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pcvr oled 5120 x 2560 @75Hz 2688x2688 @90Hz over pancake lenses, 116 FOV, virtual screens, custom facial plate from iphone app, streamvr 2.0 basestations and controllers not included, no passthrough, 107g-196g, }}
|-
| &lt;!--Description--&gt;bigscreen Beyond 2e 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 pcvr oled 5120 x 2560 total up to 90Hz pancake lens 116 FOV adjustable IPD app needed for adjustment, eye tracking, custom face mask cushion, streamvr 2.0 basestations and controllers not included, seperate head strap and speaker modules extra costs, 110g-300g }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Dpvr P1 Pro 4k Ultra Vr Headset 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 wireless snapdragon, }}
|-
| &lt;!--Description--&gt;DPVR P2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Play for Dream MR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android modular 3840x3552 uoled per eye 90Hz or qled mura issues, Arm snapdragon XR2+ Gen 2, eye tracking and 11 cameras 7 sensors 22 ir leds 14ms latency and foveated rendering, 1.5hrs battery, }}
|-
| &lt;!--Description--&gt;Play for Dream GravityXR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 ultralight head gear gx100 3w }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} 
|-
| &lt;!--Description--&gt;[https://lvra.gitlab.io/docs/community/ Valve Index HMD] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 tethered PC VR headset 1440 x 1600 120Hz, 108° and 104° FOV, fresnel lenses, SteamVR2 compatible tracking ir basestations, controllers aka Knuckles, dp 1.2 and usb3 cable proprietary cable end, no battery, }}
|-
| &lt;!--Description--&gt;Valve Steam Frame (Valve Deckard / Valve’s Index 2) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 - 2160 x 2160 up to 144Hz pancake lens, 108° and 96° FOV, wifi 6 fovelated streaming, Qualcomm Snapdragon 8 Gen 3 with [https://github.com/FEX-Emu/FEX fex] arm-to-x86 x64 translation layer, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PSVR2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 PCVR with adapter, two, one for each eye, 2000 x 2040 resolution OLED panels from 90Hz 120Hz refresh rates,  fresnel lenses, 116° and 102° FOV, sony proprietary headset cable end, needs additional comfort options, }}
|-
| &lt;!--Description--&gt;VisionPro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Goertek glasses 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive ?
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| 2016 2x 1080x1200 needs external power supply, }} 
|-
| &lt;!--Description--&gt;HTC Vive Original 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 108° and 96° FOV}}
|-
| &lt;!--Description--&gt;HTC Vive Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 , uvc, at least 2 powered steamvr basestations so 3 to 5 wall warts in total, proprietary cable end, }}
|-
| &lt;!--Description--&gt;HTC Vive Pro 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 dual 1440x1600 oled displays, 116° and 100° FOV - steamvr 2.0 basestation 2 for 5m2 area 4 for 10m2 - steamvr 2.0 joypads - low latency wireless later - type USB-c headphone adapter required, [https://github.com/CertainLach/VivePro2-Linux-Driver Rust on Linux] with [https://github.com/santeri3700/vive-pro-2-on-linux Shell], proprietary cable end, }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lynx R1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 android Qualcomm Snapdragon XR2 Gen 1, }}
|-
| &lt;!--Description--&gt;Lynx R2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2026 company liquidated, 2 x 2312x2160 110 FOV pancake lenses, LynxOS android Qualcomm Snapdragon XR2 Gen, openxr 1.1, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Oculus Rift prototype development kit [https://www.virtual-boy.com/forums/t/the-oculus-rift-dk1-thread/ DK1] with [https://www.youtube.com/watch?v=X_T4DJyy2Bo wired razer hydra controllers]
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2013 pcvr LCD 1280 × 800 resolution 640 × 800 per eye up to 110° FOV, and 3DoF rotational tracking via a 1000Hz 9-axis IMU (Accelerometer, gyroscope, and magnetometer), no positional optical tracking either inside-out or outside-in, 380g, nausea issues, , }}
|-
| &lt;!--Description--&gt;Oculus Rift prototype development kit [https://github.com/facebookarchive/RiftDK2/tree/master DK2], [https://www.ifixit.com/Teardown/Oculus+Rift+Development+Kit+2+Teardown/27613 ifixit teardown] 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 pcvr, 5.7&quot; Super AMOLED display with a resolution of 960 x 1080 per eye 100° field of view, 1 usb Positional Tracker DK2 camera, lots of wires}}
|-
| &lt;!--Description--&gt;Facebook [https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter Oculus Rift CV1] [https://noraisin.net/diary/?m=202201 some Linux support] [] [https://github.com/OpenHMD/OpenHMD/issues/330 AMD usb issues] [https://github.com/OpenHMD/OpenHMD/wiki/Xorg ] [https://github.com/Doc-Ok/OculusRiftCV1Camera Live Video] [https://www.youtube.com/@thaytan Youtube] [https://github.com/Fredrum/riftOnLinux Pi] [https://github.com/OhioIon/riftDriverPi ], but not quite there with the [https://www.youtube.com/watch?v=DSsCN6HFkWc consumer CV1], [https://forum.dcs.world/topic/142259-cv1-not-working-in-dcs/#comment-2878168 orange led could be HDMI Signal is not within HDMI Spec and might be Overclocked or usb3 not getting enough power frustrating],  
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x3031, 0x2031, 0x0031 and 0x0211 for 3p-a basestations lighthouses, 0x045e 0x02e6 for xbox wireless adapter 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2016 powered run from your PC maybe uvc via wired dual PenTile OLED 2160x1200 (1080x1200 per eye) @ exactly 90Hz but screen door effect (space between pixels), 87 FOV, IPD from 58mm to 72mm, good 3D audio and okay mic, constellation headset 6DOF (3-axis rotational tracking + 3-axis positional tracking) with up to 3 usb infrared basestation (1 in front and 2 behind pointing upwards) on usb3 and usb2 to your PC but the tracking can be fragile so set it up on a weekly basis, wired only HDMI 1.3, USB 3.0 bus powered with proprietary plug in headset, 470g 1lb front heavy, 2 robust 1st Gen touch controllers with external sensors i.e. outside-in - 1 aa alkaline over rechargable battery each , press occulus and B buttons for 2 secs to connect, headset traps air so gets very warm inside and random disconnects due to twisting action on the top of the headset and/or cables, t4 torx screws }} 
|-
| &lt;!--Description--&gt;Facebook Occulus Go 32Gb 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2018 discontinued 2020 android based, 1280x1440 per eye 60Hz LCD, not gaming, no inside-out and limited self tracking, }} 
|-
| &lt;!--Description--&gt;Facebook Oculus Rift S [https://noraisin.net/diary/?m=202201 some Linux support] 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x0051 headset (cdc, audio, tracking data), 0x2052 usb hub, 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 PCVR wired dual LCD 1080 by 1200, 88 horizontal FOV, display port (fibre optic strands) and annoying USB3 copper cables (power, audio and other data) but proprietary port in the headset, cameras on the headset (&quot;inside-out&quot;) tracking so no base stations, non removeable head band and cushions and ipd hard to set, requires specific fragile Rift S/Quest1 2nd Gen Touch controllers which has a ring of translucent plastic with leds inside - t5 torx to disassemble for sticks drifting}} 
|-
| &lt;!--Description--&gt;Facebook Occulus Quest 1 
*032Gb
*064Gb
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x0183 (single adb boot), 0x0
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 android standalone wireless, 1440 x 1600 72Hz oled, front heavy though, play area 2m x 2m or bigger, low clocked Qualcomm Snapdragon 835 (MSM8998) (4x Kryo 280 Gold cores ARM Cortex-A73) + (4x Kryo 280 Silver A53), 2 to 3 hrs play time, 575g, 2nd Gen touch controllers, }}
|-
| &lt;!--Description--&gt;Meta Oculus Quest 2 KW49CM aka Codename Del Mar [https://www.meta.com/en-gb/help/quest/967070027432609/ fragile 3rd Gen Touch controllers] [https://www.youtube.com/watch?v=Cgejky8ZeoM internal battery] and selling over 20 million, more than all other quest headsets combined 
*064Gb 
*128Gb (110Gb free) 
*256Gb 
Setup continuous wifi, create Meta Oculus account, [https://developers.meta.com/horizon/ verify dev account, click on My apps], [ create Organization -&gt; My Organization Groupings], [https://www.youtube.com/watch?v=QPInS5xxF-0 finally, meta quest mobile app to switch on adb], 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x5010 (), 0x0083 (massstorage), 0x0086 (), 0x0186 (adb and xrsp [https://github.com/shinyquagsire23/xrsp_tests tests]), 0x0090 (composite adb), 0x0081 (), 
| &lt;!--Revision--&gt;0419
| &lt;!--Opinion--&gt;{{unk|2021 android stand alone, lcd 1832x1920 per-eye 90Hz refresh rate, 97 FOV, fresnel lenses, 6DOF (degrees of freedom), 58-63-68 IPD settings, low clocked Arm snapdragon xr2 gen 1 apps with Meta Link cable USB-C usb3.2 pcvr maybe, b/w but no color passthrough, 6 t2 torx and 5 ph00 screws in headset (long bit), discontinued December 31, 2024, feature updates until December 2026, critical bug fixes and security updates until December 2027, 470g, Oculus + B button on right controller (move) and Menu + Y button on left controller (click) for about 3 seconds, 10W 5v 2a, RTL8153 chipset usb support, 
*V60 unable to 
*V77 pcvr issues 
*V79 unable to }}
|-
| &lt;!--Description--&gt;Facebook Occulus Quest Pro aka Codename Seacliffe 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 android standalone wireless 1440 x 1600 72Hz oled, 106° and 96° FOV mini lcd local dimming, pancake lenses, limited eye tracking, play area 2m x 2m or bigger, higher clocked snapdragon xr2 gen 1 arm cpu Arm apps, 1 to 2 hrs play time, new pro controllers with 3 cameras each, battery at rear, wireless charging, color passthrough, 9V 3A or 5V 3A, 
*v77 capped wifi }}
|-
| &lt;!--Description--&gt;Meta Oculus Quest 3 aka Codename Eureka [ Air Light ALVR] or [ WiVRn] with fragile touch plus q3 controllers 
*128Gb
*512Gb
streaming from PC with [https://github.com/alvr-org/Monado-ALVR ALVR], runtime of [https://monado.freedesktop.org/ Monado steamvr alternative openxr openVR], with Envision GUI, 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 standalone, pancake lenses on lcd 2064 x 2208 res panel per eye 1200ppi - 104° and 96° FOV - up to 120Hz, Arm snapdragon xr2 gen 2 apps,  foveated rendering, Meta Link cable USB-C 3.2, headstrap clamshell or halo style, speaker arms fragile, color passthrough, 510g, 18W 9v 2A or 15W 5V 3A, 
*v74 ok }}
*v76 pcvr issues }}
|-
| &lt;!--Description--&gt;Meta Quest 3S aka Codename Ventura 
*128Gb
*256Gb
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 Arm snapdragon xr2 gen 2 cpu, lcd 1832 x 1920 fresnel lenses, 97 FOV, headphone arms fragile, better air flow, no promixity sensor inside, Meta Link cable USB-C 3.2, passthrough, }}
|-
| &lt;!--Description--&gt;Meta Boba 3 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 ultra-wide 180° x 120° FOV, snapdragon XR2 G2,  }}
|-
| &lt;!--Description--&gt;Meta Tiramisu 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027  µOLED displays with 90 pixels per degree,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pimax 5K Super Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 }}
|-
| &lt;!--Description--&gt;Pimax 8K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020  }}
|-
| &lt;!--Description--&gt;Pimax 8K-X 8KX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021  }}
|-
| &lt;!--Description--&gt;Pimax Crystal Light 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tethered to PC with 2160 x 2160 4k 120Hz, 115° and 96° FOV, inside-out tracking, no battery, display port cable, variable qc and customer service, }}
|-
| &lt;!--Description--&gt;Pimax Crystal Super 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tethered to PC with 3640 x 3640 4k 90hz, 116°+ and 100° FOV,  eye tracking, inside-out tracking, no battery, display port cable, }}
|-
| &lt;!--Description--&gt;Pimax Dream Air with Lighthouse(s)  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 tethered 3840 by 3552 @90Hz micro oled with pancake lens, 100 HFOV 96 VFOV but FOV IPD changes in app, link box for headset 2 split y cables, removable face gasket, 290g, steamVR2 bases and controllers, eye tracking, }}
|-
| &lt;!--Description--&gt;Pimax Dream Air SLAM 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026  Simultaneous Localization and Mapping (SLAM) tracking inside-out so no base stations,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://somniumspace.com/ Somnium VR One VR1] [https://portal.vrgineers.com/user-guide/software/ open source] VR headset
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pcvr 2880 x 2880 per eye @90 @120Hz, 125° horizontal 100° vertical FOV, 2 x SteamVR 2.0 bases, passthrough, 900g }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero VR-1 Headset 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 psu needed, 2 x Mini LED binocular of 150 nits, 2880x2720 per, 90Hz, FOV 102° horizontal, 73° vertical, 720g with headstrap, 2 x SteamVR 2.0 basestations, no speakers/mic, hdmi and usb3.0}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero XR-3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero XR-4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Camelo La Melaza Music Shield 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2026 no usb only bluetooth ,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;InAir 2 elite suite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar  nits 46FOV , , 4h battery life, 80g, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Oakley Vanguard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;RayNeo Air 3s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 100in 46FOV 650nits, usb-c 79g  }}
|-
| &lt;!--Description--&gt;RayNeo Air 3S Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 135in virtual display 46FOV 1200nits, usb-c 80g }}
|-
| &lt;!--Description--&gt;RayNeo Air 4 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 AR oled vision 4000 processing, HDR10, 47 FOV }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rokid Max 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 147in 50 FOV 650nits, usb-c back left, 76g, }}
|-
| &lt;!--Description--&gt;Rokid AI Spatial with Station 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 600nits 147in 50FOV  75g, }}
|-
| &lt;!--Description--&gt;Rokid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| ar ai smart glass}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viture Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 135in 46 FOV 1000nits, magnetic connector, 77g, }}
|-
| &lt;!--Description--&gt;VITURE XR Luma 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 147in 1200p 50 FOV, }}
|-
| &lt;!--Description--&gt;Viture Luma Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 152in 52 FOV 1000nits 1200p, 3dof, , 79g, }}
|-
| &lt;!--Description--&gt;Viture Luma Ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 in  FOV, 2 cameras, 3dof 6dof,  }}
|-
| &lt;!--Description--&gt;[https://github.com/wheaney/XRLinuxDriver Viture Luma Pro] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viture Beast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 1250nits 58FOV 174in, magnetic,  88g,  }}
|-
| &lt;!--Description--&gt;VITURE Beast X Glasses models (Immersive 3D Moonlight) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 based 2D to 3D conversion with support DP Alt Mode (DisplayPort over USB-C), 1200p, 3df tracking, practic lenses 58deg POV, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xreal One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 600nits, 50FOV, 3dof, usb-c 84g,  }}
|-
| &lt;!--Description--&gt;XReal One Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 700nits 57FOV 171in, usb-c, x1 3dof, }}
|-
| &lt;!--Description--&gt;Nreal now Xreal Air 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , micro-oled 1080p, audio, virtual uvc ar displays, }}
|-
| &lt;!--Description--&gt;Nreal now Xreal Real3D 1S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 AI based 2D to 3D conversion 57 FOV, , virtual uvc ar displays not vr, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xiami XR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xtal 8k
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Apple Vision Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 tethered AR mixed reality glasses,   3300ppi, 800g, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Google XR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive Focus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 standalone }}
|-
| &lt;!--Description--&gt;HTC Vive Focus Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 android with 2 1440 x 1600 75Hz amoled, inside-out, durable motion controllers, Vive port,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive Pro EYE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 dual-OLED displays 2880 x 1600 combined resolution), SteamVR 2.0 tracking, foveated rendering, Tobii, it enables gaze-based menu navigation with avatar eye contact, proprietary cables, }}
|-
| &lt;!--Description--&gt;HTC Vibe Cosmos 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2018  poor tracking and lifespan on controllers,  }}
|-
| &lt;!--Description--&gt;HTC Vibe Cosmos Elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2020 1440x1700 per eye resolution, 90 Hz refresh rate, 6 DoF tracking, 2880 x 1700 combined pixel resolution, 97° FoV, two controllers and two base stations. Lighthouse tracking, }}
|-
| &lt;!--Description--&gt;HTC Vive Focus Vision Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;HTC Vive Focus 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 per-eye resolution of 2448×2448 at 90 Hz, a 120-degree field of view, Qualcomm Snapdragon XR2 Gen 1,  }}
|-
| &lt;!--Description--&gt;HTC Vive XR Elite VR Headset Deluxe Pack 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 snapdragon xr2 gen 1, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pico Goblin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 android based, 2.5K 1280x1440 per eye @70Hz, 92° FoV, and 3DoF (three degrees of freedom) tracking (Orientation tracking only—yaw, pitch, roll), single controller, snapdragon 820, ipd adjustment 54-71 mm, 600g,  }}
|-
| &lt;!--Description--&gt;ByteDance Pico G2 4K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 android standalone VR headset, 3840 x 2160 (4K) LCD screen, Snapdragon 835 processor, 3DoF so rotational movement (looking around, pointing) rather than positional movement (walking, leaning), does not support hand or eye tracking, 800g }}
|-
| &lt;!--Description--&gt;ByteDance Pico NEO 2 EYE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 6DoF 360g snapdragon 845 display 4k 75Hz tracking inside-out - magnetic field for controllers - pico software on android 8 - eye tracking }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 Snapdragon XR2 Gen, 4K 3664 x 1920 90Hz lcd, battery at rear, displayport, Pico apparently emulates Oculus controllers, }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 Link 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;ByteDance Pico 4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 2160x2160 panel per eye 75Hz 90Hz 105 FOV, Arm snapdragon xr gen 1, }}
|-
| &lt;!--Description--&gt;ByteDance Pico 4 ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 2160 x 2160 @90 105 FOV, snapdragon XR2 G2, streaming from PC with alvr, wireless streaming from PC with WiVRn, Pico apparently emulates Oculus controllers, not plug and play, }}
|-
| &lt;!--Description--&gt;ByteDance Pico 5 aka Project Swan aka Vision Pro Competitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 micro-oled BOE 3840 x 3840 4000ppi per eye, MLA pancake lenses, custom pico arm cpu, pico os 6 android, eye and hand tracking, 300g,  }}
|-
| &lt;!--Description--&gt;ByteDance Pico  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung Galaxy XR VR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 3552 x 3840 @60-90 109 FOV , Arm snapdragon XR2+ Gen 2, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Shiftall MeganeX 8K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 android  }}
|-
| &lt;!--Description--&gt;[https://en.shiftall.net/products/meganex8k MeganeX Superlight 8K] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android (3552 x 3840 pixels) into pixel count yields 27.27MP 10-bit HDR-compatible 4K resolution micro OLED panels @90Hz, pancake lenses 94 FOV, SteamVR™ tracking, 180g, 5V 2A, }}
|-
| &lt;!--Description--&gt;[https://en.shiftall.net/products/meganex8kmk2 MeganeX 8K Mk2 MkII] [https://github.com/sboys3/CustomHeadsetOpenVR community] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 pcvr linux, 4K per eye (1.35inch micro OLED 3552x3840 10 bit HDR) 27MP @90Hz 75Hz 72Hz pancake, upto 108 hor 100 vert FOV, usb-c and dp cables to breakout box, 5V 2.1A, 200g}}
|-
| &lt;!--Description--&gt;Shiftall 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 }}
|-
| &lt;!--Description--&gt;Shiftall 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Acer Windows(TM) MR AH101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 Dual 2.89” LCD panels 2880 x 1440 combined (1440 x 1440 per eye) Up to 90Hz (HDMI 2.0), or 60Hz (HDMI 1.4), Field of View FOV 95, Tracking Inside-out, lots of light leak, }} 
|-
| &lt;!--Description--&gt;Acer H7001 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 wmr 1440 x 1440 per-eye resolution @90Hz refresh rate, and 100-degree field of view FOV, inside-out tracking with front-mounted cameras so no external sensors, flip-up visor design but has a &quot;screen door effect,&quot; subpar foam padding, win10 to win11 24H2,  }}
|-
| &lt;!--Description--&gt;Dell Visor Mixed Reality VRP100 VR118
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 2x 1440x1440 a bit of nose light leak }}
|-
| &lt;!--Description--&gt;Fujitsu 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 cheap and lots of light leak }}
|-
| &lt;!--Description--&gt;[https://github.com/HadesVR HadesVR] with [https://github.com/ManoloMancelli/Persephone-Classic-Controller Persephone Controller]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=HFaVjB1uNOM Persephone 3 Pro DiY 6Dof SteamVR Headset], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HP Reverb G1 VR1000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 WMR 2160 x 2160 @90Hz, 115 FOV, , hp proprietary headset cable end, 2 camera tracking but poor and controllers can be unresponsive, 500g front heavy, flight sims rather than gaming,  }}
|-
| &lt;!--Description--&gt;HP 1440p Spatial Computing 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 dim display }}
|-
| &lt;!--Description--&gt;[https://forums.x-plane.org/forums/topic/294764-vr-in-linux-without-steam/ HP Reverb G2] WMR VR3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 2 2160 x 2160 90Hz, needs Windows10 or Win 11 24H2, 4 camera tracking, controllers can be unresponsive, hp proprietary headset cable end, , }} 
|-
| &lt;!--Description--&gt;HP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Mirage Solo is a Standalone VR headset
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 Qualcomm Snapdragon 835, 1280x1440 per eye resolution, 75 Hz refresh rate, }}
|-
| &lt;!--Description--&gt;Lenovo Explorer VR2511N (G0A2) VR windows mixed reality (WMR) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 LCD 2.89&quot; 1440 x 1440 per eye @90Hz, 6 DOF position tracking, 400g, }}
|-
| &lt;!--Description--&gt;[https://github.com/relativty/relativty open source relativty] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung MHD Odyssey XE800ZAA WMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 9V 500mA oled screens 2x 1440x1600 with usb3 and hdmi cables but bluetooth dongle required }}
|-
| &lt;!--Description--&gt;Samsung MHD Odyssey+ Plus WMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 dual 3.5-inch AMOLED displays 2880 x 1600 total @90Hz, 6DOF inside-out tracking with usb3 and hdmi cables but bluetooth dongle required, use only win10 or win11 24H2,  }}
|-
| &lt;!--Description--&gt;Sony PSVR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2016 2x 1080x960 up to 120Hz, lots of cables and computation brick, sony camera needed for tracking, ps4 or move controllers, }} 
|-
| &lt;!--Description--&gt;Virtuality 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|1992 , , Amiga 3000 with TI chips, }}
|-
| &lt;!--Description--&gt;Virtuix Omni 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 VR treadmill changed course to commercial VR and pivotted back again 2020, }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


=== HDMI CEC transmitter and receiver ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


=== TV Remote Control MCE IR transmitter and receiver ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Compro K100 K300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|need extra software support}}
|-
| &lt;!--Description--&gt;Elitegroup Computer Systems
| &lt;!--Vendor ID--&gt;0x1019
| &lt;!--Product ID--&gt;0x0f38
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;GMYLE MCE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|acts as usb-hid with limited keyboard like controls }}
|-
| &lt;!--Description--&gt;Hauppauge WinTV-PVR kit
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested}}
|-
| &lt;!--Description--&gt;Logitech Harmony 300 i300 600 650 800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|need extra software support}}
|-
| &lt;!--Description--&gt;Microsoft MCE Commander 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2005 need extra software support}}
|-
| &lt;!--Description--&gt;Microsoft 1039 rev 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2005 home top of square shape direction keys}}
|-
| &lt;!--Description--&gt;Microsoft 1039 rev 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2006 home under circle spaced direction keys}}
|-
| &lt;!--Description--&gt;Microsoft 1069 SMK Manufacturing, Inc
| &lt;!--Vendor ID--&gt;0x0609
| &lt;!--Product ID--&gt;0x0334 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2007 untested}}
|-
| &lt;!--Description--&gt;Philips RC1974506/00 
| &lt;!--Vendor ID--&gt;0x0471
| &lt;!--Product ID--&gt;0x0815
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE10E PC REMOTE CONTROL VGN-AR21M VGX-XL100 VGN-AR21B/AR21S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE20E PC REMOTE CONTROL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE30E PC REMOTE CONTROL VGN-AW21XY VGX-TP3E VGX-TP3G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE50E PC REMOTE CONTROL VGC-LA2R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;TSDX-IR14 USB MCE Media Center External Infrared IR Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;chipsets support CIR (consumer IR) Winbond W83977F/AF, SMC IrCC 2.0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|technical reasons it's not possible to use USB IrDA dongles}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Zotac RC2604323/01G Zbox Media Remote Control with IR USB Receiver OVU710
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Anycubic Cobra 2 Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Bambu Labs A1 Mini 3D printer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 EMS proprietary slicer app and cloud use, eSUN}}
|-
| &lt;!--Description--&gt;Bambu Labs X2D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality K1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality K2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lulzbot 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Prusa 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Qidi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Snapmaker U1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tool changer  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sovol SV08 Max
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| open source voron model, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


==ethwrap.class - Host Data Link &quot;Cable Bridge&quot; for data transfer==

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Advance USBNET (eTEK design)
| 0x0525
| 0x9901
| 
| {{N/A|untested}}
|-
| ALi Uli M5632 (chip)
| 
| 
| 
| {{N/A|untested}}
|-
| Aten (Ali Corporation) UN201
| 0x0402
| 0x5632
| 
| {{maybe|force binding from rawwarp to ethwrap}}
|-
| Belkin (eTek design see below)
| 0x050d
| 0x0004
| 
| {{N/A|untested}}
|-
| Digitus DN-3004 - USB Host Link
| 
| 
| 
| {{yes|works}}
|-
| EPSON USB client
| 0x0525
| 0x2888
| 
| {{N/A|untested}}
|-
| eTEK
| 0x056c
| 0x8100
| 
| {{N/A|untested}}
|-
| KC-190
| 0x050f
| 0x0190
| 
| {{N/A|untested}}
|-
| GeneSys GL620USB
| 
| 
| 
| {{no|no driver the half-duplex GL620USB is NOT supported, products using it include the Inland Pro USB Quick Link}}
|-
| GeneSys GL620USB-A
| 
| 
| 
| {{N/A|untested}}
|-
| Laplink Gold (uses NetChip 1080)
| 
| 
| 
| {{N/A|untested}}
|-
| Prolific 2301/2302 (Jaton USB ConNET) (BAFO DirectLinq) 
| 0x067b
| 0x0000 and 0x0001
| 0x0004
| {{maybe|detected but untested}}
|-
| Xircom PGUNET (uses AnchorChips 2720)
| 0x0547
| 0x2727
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}

==cdcacm.class - USB modem==

The CDC ACM driver exposes the USB modem as a virtual serial modem or a virtual COM port to the operating system. The driver enables sending both data and AT commands, either through ACM (separating data and AT commands over different channels) or through Serial Emulation (passing the AT commands as is and as part of the data stream).

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Alcatel OT-I650 
| 0x1bbb
| 0x0003
| 
| {{N/A|untested}}
|-
| Acatel Dymamode/Dynamite
| 0x06b9
| 0xa5a5
| 
| {{N/A|untested Zyxel Prestige 630-13 - untested PROLiNK Hurricane 8000 external link }}
|-
| AnyData ADU-100A ADU-E100A ADU-E100D ADU-E100H D10
| 0x16d5
| 0x6501
| 
| {{N/A|untested}}
|-
| AnyData ADU-310
| 0x16d5
| 0x650
| 
| {{N/A|untested}}
|-
| AnyData ADU-500A ADU-510A ADU-510L ADU-520A
| 0x16d5
| 0x6502
| 
| {{N/A|untested}}
|-
| AnyData ADU-610 ADU-620
| 0x16d5
| 0x650
| 
| {{N/A|untested}}
|-
| BT On-Air USB MODEM 
| 0x079b
| 0x000f
| 
| {{N/A|untested}}
|-
| Conexant USB MODEM CX93010 
| 0x0572
| 0x1321
| 
| {{N/A|untested}}
|-
| Conexant USB MODEM RD02-D400 
| 0x0572
| 0x1324
| 
| {{N/A|untested}}
|-
| Conexant Chipset 
| 0x06ea
| 0x0002
| 
| {{N/A|untested AUS N367 Roadster II 56 USB (Model AM5050R3) - untested }}
|-
| [http://accessrunner.sourceforge.net/ Conexant AccessRunner]
| 0x0586
| 0x330a
| 
| {{N/A|untested }}
|-
| Creative Modem Blaster USB DE5670
| 0x1690
| 0x0101
| 
| {{N/A|untested}}
|-
| FIREFLY, MediaTek Inc
| 0x0e8d
| 0x0003
| 
| {{N/A|untested}}
|-
| Huawei E122
| 0x12d1
| 0x1446
| 
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=49126#forumpost49126]
|-
| Huawei E160, E160E, E160G
| 0x12d1
| 0x1003
| 
|{{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=51888#forumpost51888] (Chipset: Qualcomm MSM6246)
|-
| Huawei E169 also known as Vodafone K3715 and Huawei K3715 
| 0x12d1
| 0x1001
| 
|{{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4941&amp;forum=4&amp;post_id=44683#forumpost44683] (Chipset: Qualcomm MSM7200)
|-
| Huawei E220 &quot;Vodafone EasyBox II&quot; &quot;T-Mobile wnw Box Micro&quot; also known as Huawei K3565 
| 0x12d1
| 0x1003
|
| {{yes|works, see E169 above (Chipset: Qualcomm MSM6280)}}
|-
| Huawei E1750
| 0x12d1
| 0x1001
| 
| {{N/A|untested (Chipset: Qualcomm MSM6290)}}
|-
| Huawei E170, E172, E176 
| 0x12d1
| 0x1003
| 
| {{N/A|untested (Chipset: Qualcomm MSM7200)}}
|-
| Huawei E180
| 0x12d1  
| 0x1406
| 
| {{yes|Works (Chipset: Qualcomm MSM7200)}}
|-
| KYOCERA AH-K3001V 
| 0x0482
| 0x0203
| 
| {{N/A|untested}}
|-
| LG CU515
| 
| 
| 
| {{N/A|untested}}
|-
| MediaTek Inc GPS 
| 0x0e8d
| 0x3329
| 
| {{N/A|untested}}
|-
| Metricom GS Modem 
| 0x0870
| 0x0001
| 
| {{N/A|untested}}
|-
| Motorola MOTOMAGX phones 
| 0x22b8
| 0x6425
| 
| {{N/A|untested}}
|-
| Motorola Q Phone 
| 0x22b8
| 0x7000
| 
| {{N/A|untested}}
|-
| Hummingbird huc56s (Conexant) 
| 0x0572
| 0x1329
| 
| {{N/A|untested}}
|-
| Netcomm Roadster II 128 ISDN
| 
| 
| 
| {{N/A|untested}}
|-
| Nokia n70 N95 HSDPA
| 
| 
| 
| {{yes|works - see [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=4415&amp;viewmode=flat&amp;order=ASC here]}}
|-
| OGO
| 0x045E
| 0x0079
| 0090
| {{no|no driver}}
|-
| Olitec ADSL Modem V2 
| 0x08e3
| 0x0100 / 0x0102
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;Onda PT502HS 
| &lt;!--Vendor ID--&gt;0x19D2
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| Radicom V92HU-E2
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;Samsung i8510 Innov8 Symbian smartphone
| 0x04e8
| 0x6651
| &lt;!--Revision--&gt;
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=5552&amp;viewmode=flat&amp;order=ASC&amp;type=&amp;mode=0] 
|-
| Samsung Tocco Lite (aka GT-S5230)
| 0x04e8
| 0x6795
| &lt;!--Revision--&gt;
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=5552&amp;viewmode=flat&amp;order=ASC&amp;type=&amp;mode=0] 
|-
| Shiro / Aztech USB MODEM UM-3100 
| 0x0572
| 0x1328
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM 
| 0x0ace
| 0x1602
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM 
| 0x0ace
| 0x1608
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM - new version 
| 0x0ace
| 0x1611
| 
| {{N/A|untested}}
|-
| Zoom Telephonics Model 3095F USB MODEM 
| 0x0803
| 0x3095
| 
| {{N/A|untested}}
|-
| Ugobe Pleo
| 0x6962
| 0x0100
| 0x0100
| {{Yes|Works}}
|}


==Misc==

palmpda.class - no [http://aminet.net/package/util/libs/PdaLinkPoseidon pdalink.library and tools] in AROS 

 Palm PDA (discontinued) synchronisation requires a port of pdalink.library and its tools through virtual usbpalm.device.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Palm IIIx (OS3.1) serial rs-232 only
| 
| 
| 
| {{no|no }}
|-
| Palm IIIc (OS3.5)
| 
| 
| 
| {{no|no }}
|-
| Palm V
| 
| 
| 
| {{no|no }}
|-
| Palm m100
| 
| 
| 
| {{no|no }}
|-
| Palm m125 first USB - last with aaa batteries
| 
| 
| 
| {{no|no }}
|-
| Palm m500 (OS4)
| 
| 
| 
| {{no|no }}
|-
| Tungsten T (OS5) first arm cpu 
| 0x
| 0x
| 0x
| {{no|no }}
|-
| Zire 31 (OS 5.28) color arm-based
| 
| 
| 
| {{no|no }}
|-
| [[:w:Handspring (company)|Handspring Visor]] – USB support out of box
|
|
|
| {{no|no }}
|-
| Handspring Treo 600 – last one for [[:w:Handspring (company)|Handspring]] 
| 
| 
| 
| {{no|no }}
|-
| Treo 700w
| 
| 
| 
| {{no|no }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


bluetooth.class - needs Bluetooth (Viking King Harald &quot;Bluetooth&quot; Gormsson (Old Norse: Haraldr Blátǫnn Gormsson; Danish: Harald Blåtand Gormsen) stack to work (not written due to licensing fees to use the symbol merging the Younger Futhark runes for H (ᚼ) and B (ᛒ), representing Harald's initials)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


ccid.class - Chip/Smart Card Interface Devices (not implemented)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;cyberJack RFID basis
| &lt;!--Vendor ID--&gt;0x0C4B
| &lt;!--Product ID--&gt;0x9102
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


dfu.class - DFU firmware upgrade
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;iPhone 3, 4, 5, 5c 
| &lt;!--Vendor ID--&gt;0x05ac
| &lt;!--Product ID--&gt;0x1290 0x1292 0x1294
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 32bit use with caution could cause damage}}
|-
| &lt;!--Description--&gt;iPhone 5s, 6, 7, 8, X 
| &lt;!--Vendor ID--&gt;0x05ac
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 64bit use with caution could cause damage}}
|-
| &lt;!--Description--&gt;M-Audio/Midiman USB audio
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;iPad 1, iPad 2 A1395 A1430, iPad 3, ipad mini A1432, iPad A1458 4th Gen (MD512LL/A),  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2008-2013 32bit A4, A5 up to Apple A6X, iOS 1 to 10, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;iPad Air (1st generation) A1474, A1475, A1476, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2014-2015 [https://github.com/AsahiLinux 64bit], A7, iOS 11 up to 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2015 64bit A8, A8X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2016 64bit A9, A9X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2017 64bit A10, A10X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2018 64bit A11 
|-
| &lt;!--Description--&gt;iPad Air 3rd Gen A2153, A2123, A2154, iPad Mini 5th Gen, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2019 64bit A12 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


RocketTool (USB Rocket Launchers - Toy missile launchers)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;3px&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Original Launcher and StrikerII (includes laser)
| 0x1130
| 0x0202
| 
| {{yes|works }}
|-
| Dream Cheeky USB Missile Launcher or USB Cirus Cannon
| 0x1941
| 0x8021
| 
| {{no|no driver }}
|-
| Dream Cheeky USB Webcam Missile Launcher
| 0x1941
|
| 
| {{no|no driver }}
|-
| Rocket Baby
| 0x0a81
| 0x0701
| 
| {{no|no driver }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|}


DRadioTool (FM Radios - USB radio devices D-Link/Gemtek)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| D-Link DSB-R100 USB 
| 0x04b4
| 0x1002
| 0x0410
| {{yes|works }}
|-
| [http://www.neoseeker.com/forums/383/t257009-link-usb-dru-r100-radio/ GemTek USB FM Radio 21]
| 0x04b4
| 0x1002
| 
| {{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|}


UproarTool (Valencia MPX mp3 player and others)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;3px&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Korean D Square Valencia MPX-Player
| 0x04e8
| various
| 
| {{N/A|untested }}
|-
|}


[https://www.youtube.com/watch?v=vIuT7rJgc8w with unlocked android bootloader], 

&lt;pre&gt;

Kill and restart the server a few times

 sudo adb kill-server
 sudo adb start-server 

And finally type in

sudo adb devices

adb devices                 Lists connected devices              

adb shell                   Opens a terminal shell on the device hollywood:/ $
su 
id
df -h
top
ls -la
ls sdcard
ls sdcard/Android
ls sdcard/Oculus
wm size 

cd ..
cd data/system              look inside bad Corejava folder 
cd data/system/etc/init     look 
cd data/system/app
cd /data
cd /dev/block


 adb shell 
 pm disable-user --user 0 com.oculus.nux.ota


adb shell am start -a android.intent.action.VIEW -d com.oculus.tv -e uri com.android.settings/.DevelopmentSettings com.oculus.vrshell/.MainActivity

Don't change your Oculus account password after doing the FB account bypass. You'll break the log-in session, and have to factory-reset and start over 

adb shell 'setprop debug.oculus.cpuLevel 5 &amp;&amp; setprop debug.oculus.gpuLevel 5 &amp;&amp; setprop debug.oculus.adaclocks.force 0 &amp;&amp; setprop debug.oculus.phaseSync 1 &amp;&amp; settings put global always_finish_activities 1 &amp;&amp; settings put global wifi_scan_throttle_enabled 1 &amp;&amp; settings put global window_animation_scale 0.25 &amp;&amp; settings put global transition_animation_scale 0.25 &amp;&amp; settings put global animator_duration_scale 0.25 &amp;&amp; sync'


 settings list --user 0 secure or global or system 
   user_setup_complete=0

 adb shell 
 screenrecord

 adb shell reboot


 adb install &lt;path_to_apk&gt;   Installs an app like adb install -g -r alvr_client_android.apk or adb install -r app.apk 

 memtester 

 lsmod 

 
adb command to enable hand tracking, possible, but root access is required 
 adb root
 oculussetting --set hand_tracking_opt_in 1 hand_tracking_enabled 1 

adb push &lt;local&gt; &lt;remote&gt;   Copies files to the device
adb pull &lt;remote&gt; &lt;local&gt;   Copies files from the device 

pull them using CFB, extract original apk using LL 

adb forward tcp:9943 tcp:9943 (Used for advanced, such as ALVR streaming)

 adb shell pm disable-user --user 0 com.oculus.partnercustomization  Enterprise versions 

adb reboot                       Performs a standard system restart
adb reboot bootloader            Restarts the device into fastboot/bootloader mode
adb reboot recovery              Restarts the device into recovery mode
adb reboot download              Reboots Samsung devices into Download Mode
adb reboot fastboot              Directly enters fastboot mode

[https://gist.github.com/pantasio/3d0eb4bb03a1e696aae8696f60730859#file-enable-usb-debug-adb usb dev debug adb]

&lt;/pre&gt;


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{{ArosNav}}


==Host Adapter Protocol USB1 OHCI UHCI USB2 EHCI USB3.0 USB3.1 xHCI ==

Please let us know any mistakes or any information to be added, use Prefs/Trident to confirm Vendor and Product IDs 
Please chat at [https://www.arosworld.org/index.php AROS World]

*1996 USB1.0
*1998 USB1.1
*2000 USB2.0
*2008 USB3.0
*2013 USB3.1
*2017 USB3.2

[https://github.com/aros-development-team/AROS/tree/master/rom/usb AROS has these USB transfers] 

*Control     - 
*Bulk        - Midi 1.0 ( 'send my data when you can' )
*Interrupt   - Midi 2.0
*Isochronous - USBAudio, Webcams, etc (wip) 

Isochronous is the starting point of modern types of multimedia creativity. IsoChronous isoc code is already in place in poseidon.library and '''scheduled''' transfers are queued to be later rerouted in the host driver code (needs to be written for each host protocol e.g. OCHI, UCHI, EHCI and [https://cdrdv2-public.intel.com/625472/625472_xHCI_Rev1_2b.pdf#:~:text=Page%203.%20Document%20Number:%20625472%2C%20Revision:%201.2b.%203. XHCI rev1.2], [https://www.intel.com/content/www/us/en/content-details/868296/extensible-host-controller-interface-for-universal-serial-bus-xhci-requirements-specification-r2-0.html rev2], etc). There seems to be 2 types of isoc transfers, one is just the normal isoc transfer and the other is realtime implementation of isoc transfer. 

For isoc transfer there needs to be a scheduler that makes sure no isoc transfers are dropped (in or out) and that they happen at the right time. It all gets difficult as the device making use of the isoc transfer may be at any point on the device tree. One needs to calculate the USB bandwidth for the packet based periodic transfers that are initiated by the host which have fixed but guaranteed bandwidth. Host controllers guarantee this bandwidth by planning a schedule of transfers ahead of time to ensure there is enough time reserved on the bus.

[https://www.intel.co.uk/content/www/uk/en/products/docs/io/universal-serial-bus/ehci-specification.html EHCI] [https://www.thegoodpenguin.co.uk/blog/understanding-why-usb-isochronous-bandwidth-errors-occur/ bus-bandwidth] vs payload-bandwidth and the algorithm of the EHCI scheduler. 
The bandwidth of the endpoint in terms of payload data (stuff we put in a packet) and the protocol overhead, signalling imposed bit stuffing, host delays etc. 

Poseidon controls the driver and device tree and it provides an API to communicate with the USB devices. Poseidon really doesn't care much about what sort of transfer pipe is opened or used, it only provides the means to do so and forwards the iorequests to the correct driver. Poseidon code is the higher level code for USB communication and drivers are of course the lower level one.


[[File:Psd.svg|220px|right]]


; Best Hardware - NEC Chipset (OHCI + EHCI), Intel Chipset (UHCI + EHCI), 
; Early support - [https://github.com/aros-development-team/AROS/commit/03c5252d962941a56c816a9f2315134362089349 XHCI USB3.0, USB3.1 &amp; gen 2 Type-A Type-B Type-C] 
; Next Best Set - General OHCI, SIS (OHCI + EHCI), 
; Buggy Chipset - [ Early AMD OHCI], ALi OHCI, VIA UHCI, Nvidia OHCI &amp; EHCI, 


=== USB1.1 ===
OHCI USB 1.1 - USB-IF sanctioned standard but hardware physical form removed with USB2.0 and replaced with virtual emulation of USB1 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device 
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| ALi Agere M5273 A1 M5237 Lucent USS-312 
| 
| 
| 
| &lt;!--Boots--&gt;{{Maybe}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| StarTech PCI425USB, CompUSA Iogear GIC220U-b, Nvidia 220 mobo, USBA2041P, ALi SU2A-PS, 
|-
| AMD 756 Chipset (onboard motherboard) 
| 0x1022 
| 0x740c 
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| no [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=31308#forumpost31308 usb devices detected] Geode GX1, 
|-
| CMD DU-A2 Silicon Image 0670 (pci AMD chipset)
| 0x1095
| 0x0670
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Silicon Image 0673 (pci AMD chipset)
| 0x1095
| 0x0673
| 0x06
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Nvidia Nforce2 USB
| 0x10de 
| 
| 
| &lt;!--Boots--&gt;{{Maybe|Bios options vary but does with Plop Boot}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Tested with 20th Aug 2012 improvement 
|-
| NEC µPD720100AGM 
| 0x1033
| 0x0035
| 0x 
| &lt;!--Boots--&gt;{{Unk}}
| &lt;!--Detects--&gt;{{Unk}}
| &lt;!--Works--&gt;{{Maybe|}}
| untested - Amiga Spider card with possible bottleneck issues at higher speeds 
|-
| NEC µPD720101AGM 720101GJ
| 0x1033
| 0x0035
| 0x43
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Mac mini, Belkin F5U219vea (2+1 ports), Belkin F5U220vea1 (4+1 ports), Adaptec 3100LP, BAFO BF-460, GWC UC-160, IOGear GIC250U, Keyspan U2PCI-5, O'toLink U2-C2B U2-C2A U2-P20N U2-P50, Ratoc PCIU5, USBWholesale UII-PCIP 
|-
| NEC µPD720102
| 0x1033
| 0x00
| 0x 
| &lt;!--Boots--&gt;{{Unk|untested }}
| &lt;!--Detects--&gt;{{Unk|untested }}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Opti 82C861 2-port 
| 0x1045
| 0xc861
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{No}}
| &lt;!--Works--&gt;{{Maybe|}}
| no USB devices detected - Belkin F5U005, 
|-
| SIS 7001 OCHI 
| 0x1039
| 0x7001
| 0x0f
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 20th Aug 2012 - not booting stalls on GRUB word with Plop Boot 
|-
|}


UHCI USB 1.1 - Intel standard but since 2009 no hardware support as USB2 introduced virtual emulation of USB1 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| Intel 
| 0x8086 
| 0x
| 0x01 
| &lt;!--Boots--&gt;{{No|not in bios use AROS floppy disc boot}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Intel 82371AB EB MB PIIX4 
| 0x8086 
| 0x7112
| 0x01 
| &lt;!--Boots--&gt;{{No|none in bios use other booting options}}
| &lt;!--Detects--&gt;{{Maybe|Detects most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not RTL8187b WG111v3 blue led not on and does not work}}
|  
|-
| Intel 82801DB/DBL/DBM (onboard i830 mbd)
| 0x8086 
| 0x24c4 
| 0x01 
| &lt;!--Boots--&gt;{{Yes|but not from bios but floppy options}}
| &lt;!--Detects--&gt;{{Yes|}}
| &lt;!--Works--&gt;{{Yes|}}
| RTL8187b WG111v3 blue led on and although device has software failure and recoverable error IT STILL WORKS. Fresh start sometimes needs Network Prefs Saved to work. 
|-
| VIA MVP4 (onboard mbd)
| 0x1106
| 0x30
| 0x40 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not wireless options}}
| RTL8187b WG111v3 detected but blue led not on and does not work 
|-
| VIA VT82xx (onboard mbd)
| 0x1106
| 0x3038
| 0x40 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|most devices}}
| &lt;!--Works--&gt;{{Maybe|most devices but not wireless usb}}
| RTL8187b WG111v3 blue led on but does not work 
|-
| VIA VT6202 (VIA VT83C572)
| 0x1106
| 0x3038
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}} 
| &lt;!--Works--&gt;{{Maybe|}}
| A-Best USB-200, Cables N Mor USBPCI, CompUSA, D-Link DSB500, Digital/Research DRUSBCARD, Kouwell IOFlex 580, StarMount USB VIA, 
|-
| VIA VT6112 
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6212 (pci card)
| 0x1106
| 0x3038
| 0x61
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 2011 seems to have issues with other identical via based USB controller(s) present 
|-
| VIA VT6214L 
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
|}


=== USB 2.0 EHCI ===
The USB-IF insisted on only one implementation of EHCI but it creates 4 virtual hcd to cover USB1.1 support. The virtual HCD on Intel and VIA EHCI controllers are UHCI. All other vendors use virtual OHCI controllers. Hardware EHCI USB2.0 ended in most chipsets in 2014/5 and is now virtual through most newer USB3.0 chipsets 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| ALi Agere M5273 A1 Lucent USS-344 
| 
| 
| 
| &lt;!--Boots--&gt;
| &lt;!--Detects--&gt;
| &lt;!--Works--&gt;{{Maybe|}}
| {{N/A|untested}} belkin F5U006, 
|-
| Nvidia Nforce2 USB
| 
| 
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| Intel 82801DB/DBM (onboard mbd)
| 0x8086 
| 0x24cd 
| 0x01 
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| NEC µPD720100AGM 
| 0x1033
| 0x00E0
| 0x 
| &lt;!--Boots--&gt;
| &lt;!--Detects--&gt;
| &lt;!--Works--&gt;{{Maybe|}}
| {{N/A|untested - Amiga Spider card}}
|-
| NEC 72101 GJ
| 0x1033 
| 0x00e0 
| 0x04
| &lt;!--Boots--&gt;{{Yes}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| Belkin F5U219 VEA1 (pci), 
|-
| SIS ECHI 
| 0x1039
| 0x7002
| 0x00
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Maybe|issues about which port is used if it works at all}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6202 
| 0x1106
| 0x3104
| 
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
| VIA VT6212 (pci card)
| 0x1106
| 0x3104
| 0x62
| &lt;!--Boots--&gt;{{No}}
| &lt;!--Detects--&gt;{{Yes|detects}}
| &lt;!--Works--&gt;{{Maybe|}}
| 
|-
|}


=== USB 3.x SuperSpeed SS (Speed 5Gbit/s 3.1 gen 1) aka xHCI eXtensible ===

USB Attached SCSI (UAS or UASP) is a protocol used for high-speed data transfer between computers and external storage devices like SSDs, HDDs, and some flash drives. It provides up to 70% faster read/write speeds than traditional Bulk-Only Transport (BOT) by allowing multiple commands to run in parallel, rather than waiting in a queue

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Fresco Logic FL1000 FL 1000 
| &lt;!--Vendor ID--&gt;0x1B73
| &lt;!--Product ID--&gt;0x1000 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;link power management (LPM, USB 3.0 power saving) cannot be disabled so random connection issues  
|-
| &lt;!--Description--&gt;Fresco Logic FL1009-200 FL 1009 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1009 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;Orico PFU3-2P
|-
| &lt;!--Description--&gt;Fresco Logic FL1100-100 FL 1100SX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1100 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;LPM cannot be disabled so issues with disconnecting WD drives etc - CalDigit, ORICO PFU3-2P, FASTA-6GU3 Pro, inatech KTU3FR-2P 2 port USB 3.0,  and Inateck KT4004 (KTU3FR-4PA rev B2) for storage and hubs, etc 
|-
| &lt;!--Description--&gt;Fresco Logic FL1400 FL 1400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x1400 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Fresco Logic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720200 uPD720200a chip
| &lt;!--Vendor ID--&gt;0x1d6b
| &lt;!--Product ID--&gt;0x0194
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{Maybe|no USB3 but seems to works like USB2}}
| &lt;!--Opinion--&gt;recognized but not supported for USB3 but works like USB2 - ORICO PRU3-4P 4 Port USB, early Dell Wyse zx0 thin client,  
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720201 uPD720201 chip
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x114 0x0115 
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported 
|-
| &lt;!--Description--&gt;NEC Renesas xHCI µPD720202 uPD720202 chip
| &lt;!--Vendor ID--&gt;0x1912 
| &lt;!--Product ID--&gt;0x0015
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported 
|-
| &lt;!--Description--&gt;[http://www.ti.com/product/tusb7340 TI] tusb7340 TUSB732 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x8241
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported Koutech IO-PEU436 but only one with open docs 
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;recognized but not supported - integrated since Ivybridge 
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Via Labs VL800 xHCI 0.96 support in VL800, VIA VL811 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x3432 0x3438 0x3515 and 0x9201
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{Maybe|}} 2.0 backwards support 
| &lt;!--Opinion--&gt;Anker 68UPPCIE-2S20PU 2 port, Plugable 4-Port, GA-z77x-ud5h rev. 1.1 mobo, 
|-
| &lt;!--Description--&gt;Via Labs VL811+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Via Labs VL812 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;xHCI 1.0 support in VL805 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
|}


USB 3.1 (power up to 100W and data 10Gbit/s USB 3.2 gen 2 - USB-A Full size plug - USB-B micro USB size - USB-C reversible) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Asmedia ASM1142 
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;Connector: USB Type C and  USB Type A x 1 - Ugreen USB C PCI Card 2 Port USB 3.1 Type C 
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[ Intel] Revision 1.8 1.9 Updated  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;AUKEY 4 Ports USB C , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;Startech - PEXUSB312C - 2-port Usb 3.1 10Gbit/s
|-
|}

USB 3.2 (power up to 100W and data 20Gbit/s gen 2x2 - USB-A Full size plug - USB-B micro USB size - USB-C reversible) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;AMD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Intel xHCI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[ Intel] Revision 2.6 Update  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{unk| }}
| &lt;!--Detects--&gt;{{unk|}}
| &lt;!--Works--&gt;{{unk|}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
| &lt;!--Opinion--&gt;
|-
|}

=== USB 4 (40Gbps thunderbolt, pcie 3.0 tunnelling, ) ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Boot from USB
! width=&quot;10%&quot; |Detect USB device
! width=&quot;10%&quot; |USB device works 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Marvell 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;AMD Ryzen7 6800U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;Intel Goshen Ridge JHL8440 Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{No| }}
| 
|-
| &lt;!--Description--&gt;VLI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Boots--&gt;{{N/A}}
| &lt;!--Detects--&gt;{{N/A|}}
| &lt;!--Works--&gt;{{N/A|}}
|  
|-
|}


== hid.class (Human Interface Device) ==

=== Keyboard ===

 Some multi-finger touchpad support works but not on all touchpads  

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;8BitDo Retro N C64 edition Keyboard, the super button accessory and optional N30 mouse
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 87 keys Kailh white}}
|-
| &lt;!--Description--&gt;8bitdo 108 Retro Mechanical Keyboard (white kailh) and two superbuttons (green) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Apple Pro Keyboard
| 0x05ac
| 0x0205 
| 0x0122
| {{yes|works (its two hub ports) but mouse scroll wheel issues}}
|-
| Apple Pro Keyboard
| 0x05AC
| 0x020B 
| 
| {{yes|works (two onboard ports also)}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Aigo K68 60% red switches, A68 A87 wireless 2G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=49&amp;products_id=973 AmigaOne Keyboard]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Akko TAC87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 80% TKL }}
|-
| &lt;!--Description--&gt;Akko MonsGeek FUN60 PRO&amp;MAX HE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 60% hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Akko 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 hall effect, good but expensive and software poor}}
|-
| &lt;!--Description--&gt;Akko 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ATTACK SHARK X98 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 98% maybe silent linear feel with Two-color PBT keycap}}
|-
| &lt;!--Description--&gt;ATTACK SHARK X68HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Azio Cascade 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Chilkey ND75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  good 75% expensive}}
|-
| &lt;!--Description--&gt;Chilkey ND104 (Wuque Studios) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 premium clicky (WS Blue) or silent (WS White) key options with Ansi and ISO formats also numpad and calculator, aluminum machined, tri mode, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2026 untested magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Corsair K65 Mech MX no numeric keypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair CH-9000045 K70 Blue MX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K95 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cherry G80 G80-3000L[x]C[yy]-[z] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cooler Master CM Storm Quickfire Rapid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Corsair K100 Air 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2025 okay low profile but expensive 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;Dell SK-8135 Dell USB Keyboard for Internet and Multimedia rev H for Dimension 4500, Dimension 8250, OptiPlex GX260n, OptiPlex GX60n, Precision 350 (R42232) 
| &lt;!--Vendor ID--&gt;0x413C
| &lt;!--Product ID--&gt;0x2010 
| &lt;!--Revision--&gt;0200 
| &lt;!--Opinion--&gt;{{Yes| usb1.1 keyboard hub 0x413C 0x1003 works as well - multimedia keys not mapped }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Deepcool KG722
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 65% }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Ducky Channel Zero DK2108 Mech Mechanical Cherry MX Red 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Ducky Shine 3 Brown or Blue (DK9087) MX keys 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Das Keyboard Model S Ultimate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Epomaker Cidoo V75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;epomaker rt100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 plastic build and no screws, numpad with small 0, mostly quiet seasalt switches, gimmick usb-c 1in screen}}
|-
| &lt;!--Description--&gt;EPOMAKER TH99  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} USB-C full numpad keyboard 
|-
| &lt;!--Description--&gt;eopmaker P75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;eopmaker p87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;epomaker x Leobog Hi75
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;epomaker x Feker Galaxy80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;epomaker x Galaxy100 gmk/via 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 96% }}
|-
| &lt;!--Description--&gt;epomaker Aula F75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 budget version good 75% choice of 4 leobog switches}}
|-
| &lt;!--Description--&gt;eopmaker Tide75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 75% and not too expensive}}
|-
| &lt;!--Description--&gt;Epomaker Ajazz AK820 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Epomaker Ajazz AK35I V3 MAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 104 keys - two models: wired and tri-mode connection - }}
|-
| &lt;!--Description--&gt;epomaker Aula F108 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pricy but okay 100% but only leobog graywood switches but hotswap available afterwards}}
|-
| &lt;!--Description--&gt;eopmaker Ajazz AK980 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 97 keys }}
|-
| &lt;!--Description--&gt;Epomaker G87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Epomaker RT82 RT85
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Epomaker RT100 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 96% }}
|-
| &lt;!--Description--&gt;epomaker x Galaxy100 lite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 good 96% }}
|-
| &lt;!--Description--&gt;Epomaker 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Filco Ninja Majestouch-2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Focus FK-760 Wireless Keyboard &amp; Trackball
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{yes|works}} but quality build issues raised 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;GMMK Tenkeyless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested  default Gateron Brown switches for Kailh Box Jades default Gateron Brown switches for Kailh Box Jades}}
|-
| &lt;!--Description--&gt;GK61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }}
|-
| &lt;!--Description--&gt;GMK67 GMK87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested budget good option}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Hengchangtong HCT Limeme gk103s Entry Keyboard
| &lt;!--Vendor ID--&gt;0xC0F4
| &lt;!--Product ID--&gt;0x0009
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{yes|half Keyboard left side only}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Hexgears M2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested hotswap kaihl green switches}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hexgears 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Iqunix mq80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2025 good 75% low profile keys
|-
| &lt;!--Description--&gt;Iqunix Magi65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested good 65% low profile keys }}
|-
| &lt;!--Description--&gt;iqunix ez60 ez80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 untested specific hall effect switches - actuation point, rapid trigger, etc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Jomaa YiChip Wireless 50% key with touchpad 
| &lt;!--Vendor ID--&gt;0x3151 
| &lt;!--Product ID--&gt;0x3000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|dongle detected, keys and pad not working - 2 AAA NM}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Keychron q0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 untested numpad only}} 
|-
| &lt;!--Description--&gt;Keychron q1 v1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 untested okay}} 
|-
| &lt;!--Description--&gt;Keychron Q6 Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested 75% with numeric numpad, barebones so choose switches and keycaps to suit }}
|-
| &lt;!--Description--&gt;Keychron q1 MAX V1 MAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested }} 
|-
| &lt;!--Description--&gt;Keychron Lemokey P1 QMK 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested best option to customise switches and keycaps}}
|-
| &lt;!--Description--&gt;Keychron LemoKey X1 X3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested keycap swap only not switches}}
|-
| &lt;!--Description--&gt;Keychron K2HE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested okay}} wireless hall effect analogue on all keys 
|-
| &lt;!--Description--&gt;Keychron K4HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 untested hall effect but software }}
|-
| &lt;!--Description--&gt;Keychron K5 K17 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 untested okay low profile but }}
|-
| &lt;!--Description--&gt;Keychron Q5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Keychron K10 HE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Kiiboom Breeze 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 good 75% }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;Meletrix Boog 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 magnetic hall effect, good but expensive and software poor}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;Melgeek O2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 low profile 75% but not repairable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2025 }}
|-
| &lt;!--Description--&gt;MOSART 2.4G Wireless 60% Keyboard Trackball 
| &lt;!--Vendor ID--&gt;0x062a
| &lt;!--Product ID--&gt;0x4105
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|dongle recognised HID, keys worked, roller worked, scroll wheel works and shoulders works but buttons around left, top and right hand side (RHS) do not work and plastic and 2 AA MN1500}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Mucai SiGma Micro MKA610 
| &lt;!--Vendor ID--&gt;0x1c4f
| &lt;!--Product ID--&gt;0x0084
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| unknown red keys - rgb backlighting - }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;[http://hjldemo.clsc.cn/ Guangzhou Zhentian Electronics Ltd] Perixx Periboard 505 Plus with Trackball 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|okay dome keyboard - poor trackball}}
|-
| &lt;!--Description--&gt;Guangzhou Zhentian Electronics Co., Ltd Perixx Periboard 706 Plus with Trackball Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|generally okay dome with good sized keys but piano black surround fingerprint magnet, occasional brief trackball freezes after no use, takes some time to get used to the trackball size}} 
|-
| &lt;!--Description--&gt;Perixx Periboard-716 Wireless (Chicony)
| &lt;!--Vendor ID--&gt;04f2:1013
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|okay dome keyboard and trackpad}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Description--&gt;Perixx Periboard-
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Perixx Periboard-
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Lenovo SK-8825 41A5327 SIL12-W07 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;works manufactured for 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lite-On USB NetVista Full Width Keyboard 
| &lt;!--Vendor ID--&gt;0x04b3
| &lt;!--Product ID--&gt;0x3025
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;works 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech K320 Wireless Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|The Logitech USB Unifying, Bolt, Lightspeed, or Nano receiver pairing}}
|-
| &lt;!--Description--&gt;Logitech K340 Wireless Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|The Logitech Unifying Receiver pairing}}
|-
| &lt;!--Description--&gt;Logitech K400
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt; [http://www.logitech.com/en-us/product/wireless-touch-keyboard-k400r Logitech Wireless Touch Keyboard k400]
| &lt;!--Vendor ID--&gt; 0x046D
| &lt;!--Product ID--&gt; 0xC52B
| &lt;!--Revision--&gt; 1201
| &lt;!--Opinion--&gt; {{yes|All (including multimedia) keys work. Some keys requires remapping with Trident. Touchpad works and acts as normal mouse. Presents itself in Trident as USB Receiver from Logitech with 3 HID bindings}}
|-
| &lt;!--Description--&gt;Logitech K400 Plus K400+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech K600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech TK820 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech TK830 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard}}
|-
| &lt;!--Description--&gt;Logitech G915 TKL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Unk|okay keyboard TKL means no number pad}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lofree Lite84 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 }}
|-
| &lt;!--Description--&gt;Lofree Flow Lite100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 silent switches and low profile keys}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;MACHENIKE K500 Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 94 keys untested Hot Swappable 94 Keys 90% Layout }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MechLands Vibe99 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 100 keys untested Gasket-mounted Wired/Bluetooth/2.4GHz Wireless Mechanical Keyboard}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft Comfortable Curve 2000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| recognized but not supported}}
|-
| &lt;!--Description--&gt;Microsoft Natural Ergonomic Keyboard 4000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|recognized but not supported}}
|-
| &lt;!--Description--&gt;Microsoft Wireless Media Desktop 1000 (1356)
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x00f9 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|working but not mouse part}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Niz Micro84 Duo82 X87 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 electro capacitive }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;nuphy gem80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}}
|-
| &lt;!--Description--&gt;nuphy kick 75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 low profile 75% }}
|-
| &lt;!--Description--&gt;nuphy Air75 V3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  75% }}
|-
| &lt;!--Description--&gt;nuphy node 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 96% layout, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Qpad MK-50 MK-80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Qpad MK-90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Razer Chroma 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0203
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://openrazer.github.io/ Razer] Lycosa 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Blackwidow 2013 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razr Blackwidow Ultimate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Cynosa Lite V2 
| &lt;!--Vendor ID--&gt;1532
| &lt;!--Product ID--&gt;0x023f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer DeathStalker 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer HuntsMan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Ornata 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Orbweaver Chroma Keypad 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0207
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Razer Tartarus Keypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested not hall effect and very expensive}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Redragon K668 RGB Gaming Keyboard Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested 108 Keys Mechanical Keyboard w/Extra 4 Hotkeys Upgraded Hot-swappable Socket，Red Switch}}
|-
| &lt;!--Description--&gt;Redragon K689 PRO Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested Gasket RGB Gaming Keyboard, 108 Keys Mechanical Keyboard w/Extra 4 Hotkeys, Upgraded Hot-swappable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2027 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Risophy 60
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 75% mechanical, hotswap so okay for price untested }}
|-
| &lt;!--Description--&gt;Risophy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Royal Kludge RK65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested cream switches }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;SINO WEALTH Gaming KB SkyLion K68 
| &lt;!--Vendor ID--&gt;0x258a
| &lt;!--Product ID--&gt;0x003a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| blue stalks with rgb lighting}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;SKYLOONG GK104 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested gateron }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;SteelSeries 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;TeckNet x300 2.4G Keyboard Mouse MosART 
| &lt;!--Vendor ID--&gt;0x062A
| &lt;!--Product ID--&gt;0x4101
| &lt;!--Revision--&gt;0312 
| &lt;!--Opinion--&gt;{{Yes|1 AAA for each and works well - mouse slightly better built than keyboard rubberised membrane}}
|-
| &lt;!--Description--&gt;TeckNet X331 HDE 2.4G Keyboard wireless RCMCU 
| &lt;!--Vendor ID--&gt;0x0C45
| &lt;!--Product ID--&gt;0x7000
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{Yes|wireless can be glitchy but few extra keys are mapped }}
|-
| &lt;!--Description--&gt;TeckNet X500 2.4G Keyboard Mouse MOSArt 
| &lt;!--Vendor ID--&gt;0x062A
| &lt;!--Product ID--&gt;0x2901
| &lt;!--Revision--&gt;0112 
| &lt;!--Opinion--&gt;{{Yes|works well especially large touchpad - usual rubber domed membraned keyboard mechanism }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tecware Specter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested good 75%}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Unicomp Model M USB 104 key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} IBM's and later Lexmark buckling spring switches 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varmilo Minilo Bluebell (prestige silent) and Eculapytus (violet tactile)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 75% plastic build no screws not great to mod}}
|-
| &lt;!--Description--&gt;Varmilo Sword 68 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| expensive but good}} 
|-
| &lt;!--Description--&gt;Varmilo 98 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 expensive but good and Kailh silent}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Weikav Velocifire Choice65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Weikav Velocifire Lucky65 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Wobkey Crush80 Reboot Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 very good but expensive Aluminum Hotswap Wireless RGB}}
|-
| &lt;!--Description--&gt;Wobkey Rainy 75
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 good 75% but not as expensive CNC Aluminum HMX/JWK/Cocoa Switches}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wooting HE60 HE80 HE90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 hall effect but expensive with good software}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;Womier WK61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2021 untested }}
|-
| &lt;!--Description--&gt;Womier Sk71 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;Womier Sk75 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024  }}
|-
| &lt;!--Description--&gt;Womier Sk75 TMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  hall effect }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xenta White Wireless HK6718B+HM3302--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|works with Raspberry Pi untested on AROS native}}
|-
| &lt;!--Description--&gt;Xinmeng X87 MAGIC_REFINER 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 untested keycap swap but not hotswapable switches}}
|-
| &lt;!--Description--&gt;Yunzii AL66 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| milk switches, cherry PBT, }}
|-
| &lt;!--Description--&gt;Yunzi B75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 budget good with cocoa cream switches }}
|-
| &lt;!--Description--&gt;Yunzii AL75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|good budget option with  swappable switches,  }}
|-
| &lt;!--Description--&gt;Yunzii AL80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 switches }}
|-
| &lt;!--Description--&gt;Yunzi C75 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 budget good with  switches }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2028 magnetic hall effect software should be better and surpasses mechanical}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

&lt;pre&gt;
linear  - creamy
tactile - thocky
clicky  - clacky 
&lt;/pre&gt;

&lt;pre &gt;
Cherry MX Black are linear switches (no feedback); good for gaming. 
Cherry MX Red are linear (less noise no click) but more squishy; 
Cherry MX Brown are in between Blue and Red in style and tactile; 
Cherry MX Clear switches have soft tactile feedback (with no click). 
Cherry MX Blue have tactile feedback with a click (noisy); good for typing. 

Gateron Yellows KS-3, KS-3x47 or better Pros have a milky top and black bottom and linear 

TTC Silent Frozen v2. Linear and dead silent 
Mouse the huano brown with yellow dot for silent mouse clicks
Kailh red dust proof encoder for smooth and close to silent scrolling
Boba U4 Silent Tactile switches
Husky linears

HMX 
&lt;/pre &gt;


=== Mouse ===

if the USB mouse is non-functional put a USB pendrive in before or add the following to user-startup in '''s''' drawer/folder/directory

 sys:prefs/trident NOGUI &gt; NIL:

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Brand
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; | Model
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| 3Dconnexion 
| 3D Mouse 
| &lt;!--Model--&gt;[http://www.3dconnexion.com/products/spacenavigator.html SpaceNavigator]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| 3D Mouse
| &lt;!--Model--&gt;SpacePilot Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| Mouse 
| &lt;!--Model--&gt;SpaceExplorer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| 3Dconnexion 
| Wireless Mouse 
| &lt;!--Model--&gt;SpaceMouse 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;3D Optical 
| &lt;!--Description--&gt;Wired 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;0000:3825
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Belkin
| Combo mouse
|
| 0x05FE
| 0x0011
| Low 0100
| {{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Cytec
| &lt;!--Description--&gt;Wired Mouse Gaming 
| &lt;!--Model--&gt;R.A.T 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Dell
| Mouse
| MO56UC
| 0x413C
| 0x3200
|
| {{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;equatech / clone logitech  
| &lt;!--Description--&gt;wireless mouse
| &lt;!--Model--&gt;49779 / M185 
| &lt;!--Vendor ID--&gt; 3151:2020 later 3151:3020 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{Yes|detected and works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Hama
| RF Optical Mouse
| AM-6000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;M3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;M5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Keycron 
| &lt;!--Description--&gt;Optical Wireless 
| &lt;!--Model--&gt;M6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1k polling and 16k dpi }}
|-
| &lt;!--Brand--&gt;Keychron 
| &lt;!--Description--&gt;Optical Wireless 
| &lt;!--Model--&gt;M7
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested barebones 1k polling and 16k dpi, great for small hands, loud clicks}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;LogiCAD 3D
| &lt;!--Description--&gt;3D Mouse
| &lt;!--Model--&gt;Magellan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Logitech
| Cordless Desktop Navigator 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|The Logitech Unifying Receiver pairing}}
|-
| Logitech Inc.
| First/Pilot Wheel Mouse
| N48/M-BB48 M-BE58 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested }}
|-
| Logitech
| Wireless mouse
| [http://www.logitech.com/en-roeu/mice_pointers/mice/devices/5484 M305]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{yes|works}}
|-
| Logitech
| Wireless RF Mouse
| MK710
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|The Logitech Unifying Receiver pairing}}
|-
| &lt;!--Brand--&gt;Logitech
| &lt;!--Description--&gt;Wireless Mouse 
| &lt;!--Model--&gt;MX Master Anywhere 2S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|untested}} micro USB charge port on front 
|-
| &lt;!--Brand--&gt;Logitech 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;M220 silent 
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|}}
|-
| &lt;!--Brand--&gt;Logitech Logi 
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;MX Master 3S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|2021 untested usb-c bluetooth, inbuilt battery but muted clicks}}
|-
| &lt;!--Brand--&gt;Logitach
| &lt;!--Description--&gt;Optical
| &lt;!--Model--&gt;G502 X Plus 
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 very clicky}}
|-
| &lt;!--Brand--&gt;Logitech
| &lt;!--Description--&gt;Optical 
| &lt;!--Model--&gt;MX Master 4 MXM
| &lt;!--Vendor ID--&gt;0x
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Bluetooth usb-c dongle, inbuilt lithium battery}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Brand
| Description
| Model
| Vendor ID
| Product ID
| Revision
| Opinion--&gt;
|-
| &lt;!--Brand--&gt;Maxxter 
| &lt;!--Description--&gt;Wireless
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8566
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Maxxter 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8518
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;OrzerHome Maxxter 
| &lt;!--Description--&gt;Wireless 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;248a:8514
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1 aa with no on/off switch }}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Microsoft
| Wheel Mouse optical
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| Sidewinder Mouse 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| IntelliMouse Explorer USB optical
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| Microsoft
| Wireless Optical Mouse 2000
|
| 0x045E
| 0x00F9 
|
| {{no|not working see keyboard Media Desktop 2000 above}}
|-
| &lt;!--Brand--&gt;Microsoft 
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;1461 1447 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{No|usb dongle matched to one mouse only no others}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Orochi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Mamba 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Naga
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 17 buttons 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB Optical
| &lt;!--Model--&gt;Naga Hex V2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} MOBA Gaming Mouse, Professional Grade 16,000 DPI Sensor - RGB lighting 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical 
| &lt;!--Model--&gt;DeathAdder 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Viper 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}} 
|-
| &lt;!--Brand--&gt;Razer
| &lt;!--Description--&gt;USB optical
| &lt;!--Model--&gt;Basilisk V3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested 1k polling, 35k dpi, }} 
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| Trust
| Slimline Lasermouse 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}}
|-
| SteelSeries 
| Tobii EyeX EyeMobile PCEye 
| Eye Tracking Control 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}} gaze interaction track technology for augment augmentative and alternative communication (AAC). 
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;The Eye Tribe Tracker 
| &lt;!--Description--&gt;Eye 
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;USB Optical Mouse 
| &lt;!--Model--&gt;MV3000
| &lt;!--Vendor ID--&gt;0x192f
| &lt;!--Product ID--&gt;0x0916
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|-
| &lt;!--Brand--&gt;
| &lt;!--Description--&gt;
| &lt;!--Model--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; {{N/A|untested}}
|}

=== Trackball ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;3Dconnexion SpaceBall 5000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{N/A|untested}} Labtec designed and rolled into new company 3dconnexion 2001 by owners Logitech 
|-
| &lt;!--Description--&gt;ACCO Kensington Orbit optical F1233A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kensington Turbo Mouse 64210
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Clearly Superior Technologies. Model:CST 1000-RC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Trackman Marble Mouse Wired USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Cordless Trackman Wheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Optical Trackman T-RB22 - Cordless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech M570 wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Microsoft Trackball Mouse Optical 1.0 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Microsoft X05-87473 Trackball USB Optical 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== KVM ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;NanoKVM 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== Gamepad ===

Controllers have mostly decided that the left analog joystick is keyboard equivalent of WASD and right joystick is your mouse. You also have 2 bumpers above the triggers. Shoot could be right trigger (so it doesn't involve taking your thumb off the right joystick). Face buttons for reloading or jump or other non-critical functions. Crank up the sensitivity and practice. 

Testing can be done with the TRIDENT Prefs, [https://devicetests.com/controller-tester html5], [https://greggman.github.io/html5-gamepad-test/ html5], or [https://gamepad-tester.com/ Tester]


==== Dinput Poseidon Default Plugin - Playstation(TM) style ====

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Betop Betong Bat D2E BTP-BD2E XD4D2E
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  
|- 
| &lt;!--Description--&gt;Gravis Eliminator Gamepad Pro USB  
| &lt;!--Vendor ID--&gt;047d
| &lt;!--Product ID--&gt;4005
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A}}
| &lt;!--Opinion--&gt;2002 2d only 
|-
| Hama Black Force USB Gamepad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2003 psx clone look 
|- 
| &lt;!--Description--&gt;Jess Tech Game Elements Philips GGE909 PC Recoil Pad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| [http://www.youtube.com/watch?v=TCbAmIhj6P4 Logitech Wingman Precision USB] G-UC3B 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A| }} 
| 2002 no 3D but good for 2D retro games like Turrican II
|-
| &lt;!--Description--&gt;Logitech Wingman Action Pad G-UB3A 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untested }} 
| &lt;!--Opinion--&gt;2002 1 blue lucid translucent - thin analog stick N64 type - 
|- 
| Logitech Wingman RumblePad UB05B
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc20a
| 1.12
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untesed }} 
| 2000 twin blue analogue sticks N64 type - poor 2d controls with single molded blue piece - vibration feedback - single shoulder buttons with throttle control below right one 
|-
| Logitech Wingman Cordless RumblePad G-RA4A 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc211
| 1.12
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|untested }} 
| 2001 twin blue analogue sticks N64 type - poor 2d controls with single molded black piece - vibration feedback - dual shoulder buttons L1 L2 R1 R2 with blue throttle control below right one - 4 aa mn1500 batteries; life not great - C-UD10A usb dongle - overall big and bulky 
|-
| &lt;!--Description--&gt;Logitech Precision Wired G-UG15
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 psx styling blue outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| &lt;!--Description--&gt;Logitech Cordless Precision G-X2E14A
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 ps2 styling blue outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| &lt;!--Description--&gt;Logitech G-X5C11A Cordless Precision Wireless Controllers
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A}} 
| &lt;!--Opinion--&gt;2002 psx styling black outer shell - no 3D analog and no shoulder buttons - no rumble 
|-
| [http://www.testfreaks.co.uk/game-console-accessories-controls/logitech-dual-actiontm-gamepad/ Logitech Dual Action] 
* G-UD8 has no mode (2D only?) button and no rumble 
* G-UF13A later 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc2
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|[http://www.morphzone.org/modules/newbb_plus/viewtopic.php?topic_id=7018&amp;forum=12 G-UF13A tested only]}} 
| 2003 New body shape psx style - dual analog 3D sticks - 4 small travel shoulder triggers no 5,6,7,8 
|-
| Logitech RumblePad 2 G-UF13
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc218
| 1.00
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes| }} 
| 2006 light blue top/black base - twin analogues 3D along with dual short travel shoulder buttons - rumble present - 
|-
| &lt;!--Description--&gt;[Logitech RumblePad 2 Cordless] 
* G-RC?? OLD version that take FOUR batteries and RED Logitech logo 
* G-RC14 uses TWO batteries has an ORANGE logo - dongle C-UE10 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;0xc219
| &lt;!--Revision--&gt;0x0200
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|mostly}}
| &lt;!--Opinion--&gt;2008 may have to remove 1 battery - G-RC?? 5 + 7 buttons - G-RC14 use buttons 6 + 8 to reset sticks - replace battery and push large button on receiver - 
|- 
| &lt;!--Description--&gt;Logitech F310 Wired Dual Action G-U0001 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0xc21
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|D mode switch}} 
| &lt;!--Opinion--&gt;2010 dual analog 3D with pc-xbox/psx switch on back (only D works) - both rear shoulder RT LT buttons have excess travel - no rumble vibration - 
|-
| &lt;!--Description--&gt;Logitech F510 Wired G-UG0002 
| &lt;!--Vendor ID--&gt;0x046d 
| &lt;!--Product ID--&gt;0xc21
| &lt;!--Revision--&gt;0x
| &lt;!--Merge with USB on Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }} 
| &lt;!--Opinion--&gt;2010 dual analog with dual xbox pc/psx X/D switched compatibility modes - 
|-
| Logitech F710 Wireless / Cordless RumblePad 2 G-R0001 
| &lt;!--Vendor ID--&gt;0x046d 
| 0xc219
| 3.05
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe| }} 
| When switch on top set to D and nano receiver for each controller to pair - 2 aa mn1500 batteries required - rumble support sometimes - rear back shoulder buttons excessive travel needed 
|- 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Megaworld 'TIME' USB pad
| &lt;!--Vendor ID--&gt;0x0735
| &lt;!--Product ID--&gt;0x9902
| &lt;!--Revision--&gt;Low 0100
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No |}}
| &lt;!--Opinion--&gt;2000 Poor quality
|-
| &lt;!--Description--&gt;Microsoft 
* SideWinder Precision Pro USB (1997)
* SideWinder Precision 2 (1998)
* Game Pad Pro (1999)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Microsoft Sidewinder Game Pad USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{yes| }}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{yes| }}
| &lt;!--Opinion--&gt;[https://www.arosworld.org/infusions/forum/viewthread.php?thread_id=1149&amp;rowstart=140&amp;pid=5934#post_5931 must setup first]
|- 
| &lt;!--Description--&gt;Microsoft Sidewinder Gamepad X04 Freestyle 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{N/A|N/A }} 
| &lt;!--Opinion--&gt;{{N/A|untested}} 1998 might need USB adapter 
|-
| &lt;!--Description--&gt;Microsoft Sidewinder X05 63895 92626 Flight stick
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;{{Yes|2000 [https://ae.amigalife.org/index.php?topic=929.msg11309#new tested]}}
|-
| &lt;!--Description--&gt;Microsoft Sidewinder Flight Stick X08-58736 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Microsoft 
    Plug &amp; Play Game Pad (2000)
    SideWinder Joystick (2000)
    Game Pad 2.0 (2001)
    SideWinder Force Feedback 2 (2002)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2002 long-standing static buildup problem and Force Feedback 2 was the removal of the power brick 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| Saitek [http://www.testfreaks.co.uk/game-console-accessories-controls/saitek-ps1000/ PS1000 Cyborg V.1], [http://www.testfreaks.co.uk/game-console-accessories-controls/saitek-ps2700-rumble-pad/ PS2700] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2000 no rumble function 
|- 
| Saitek [http://www.youtube.com/watch?v=xG0v-hf6ZPA P2600] [http://compactiongames.about.com/od/hardware/tp/gamepads.htm P3600], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2000 no rumble function
|- 
| Saitek P2900 wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{N/A|untested but runs on 1 AA battery}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Sony Batoh PS3 mini USB Wired hookup [http://ps3.jim.sh/sixaxis/usb/ SIXAXIS] 
*PCB  Ribbon      Notes
*Protos ALPS MSU Rev3 M3 and the later CBEH-1019
*?    SA1Q135A 	  for sixaxis
*PP4  
*V2   
*V25  
*VX   SA1Q146A    first dualshock 3 model
*VX   SA1Q147A    CECHZC2U (USA)
*VX35 SA1Q159A 	  
*VX3  SA1Q160A 	  
*VX?  SA1Q188A    
*VX4  SA1Q189A    shipped with a CECH-2504 datecode 0C 
*VX5  SA1Q194A    changed design ALPS, PS button changes
*VX6  SA1Q195A    red case, 
*VX7  SA1Q222A    superslims 2 ribbons
*VX8  SA1Q224A    superslims 2 ribbons 
| &lt;!--Vendor ID--&gt;0x054c
| &lt;!--Product ID--&gt;0x0268
| &lt;!--Revision--&gt;1.00 
| &lt;!--Merge with USB on Digital Pad--&gt;{{No|}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|}}
| &lt;!--Opinion--&gt;Sometimes detected but no support - no sixaxis features detected - mini usb lead will have varying results - 
|- 
| &lt;!--Description--&gt;Sony PS4 
*JDM JDS 001 010 011 
*JDM 030 040 055 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Sony PS5 Dual Sense 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Speed Link Strike 2 FX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Thrustmaster Firestorm Dual Power 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|[http://www.morphzone.org/modules/newbb_plus/viewtopic.php?topic_id=7018&amp;forum=12 only 1 axis joystick only]}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Trust Predator GM-1500 GM-1520
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 M series Aluminum Metal Joystick Hitbox Controller Arcade Fighting Stick
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 T series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Haute42 G series Gamefinger G12 G13 G16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; plastic - 
|- 
| &lt;!--Description--&gt;Haute42 S series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  thinner and lighter than G series 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mad Catz sf2 fightstick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Datel Paewang Arcade Pro Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mayflash F300 Fighting Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mayflash F500 Fighting Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Pico Flatbox GP2040-CE Hot Swappable Mini Hitbox Keyboard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  default it is configured for PS4 but before plugging usbc cable in, X for Dinput, B Xinput, RT HID - plastic build case - Rev4 based on RP2040 chip and firmware is based on GP2040-CE (Community Edition) - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Shenzhen Onebitdo Tech 8bitdo Fighting stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Venom 8 button 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
|}


==== Xinput Xbox Style Plugin ====

2018 extension added originally called AROSx but later redacted. Latest [https://github.com/medusalix/xone linux driver] might be useful. 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;8bitdo Ultimate C Wired 82CB (Shenzhen ONEBITDO TECH - GWOWO) 
| &lt;!--Vendor ID--&gt;0x2dc8 
| &lt;!--Product ID--&gt;0x3106 
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2022 - 4 t6 torx screws - non hall effect so drifting issues - triggers go faulty often - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 2C Wired Controller 82CD 
| &lt;!--Vendor ID--&gt;0x2dc8 
| &lt;!--Product ID--&gt;0x310A
| &lt;!--Revision--&gt;0114
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - HID keyboard assigned - 4 t6 torx screws - hall effect analogs and triggers  - 1000Hz polling - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 2C wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024  - 400mw battery - hall effect 3d nubs and triggers - micro switch shoulder buttons - d-pad poor for retro games - 
|- 
| &lt;!--Description--&gt;8bitdo ULtimate Mini Wired Controller for Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect 
|- 
| &lt;!--Description--&gt;8BitDo Pro 2 
*Wired Controller 
*Wireless
*Bluetooth
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect - playstation style layout for pc - slide button for S-A-D-X switch, android, dinput or xinput -  
|-
| &lt;!--Description--&gt;8BitDo Pro 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025  tmr hall effect analogs, hall effect triggers and some microswitches - button swap - ps2 style layout - 
|- 
| &lt;!--Description--&gt;8bitdo Ultimate 3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2026  - mw battery - hall effect 3d nubs and triggers - micro switch shoulder buttons - d-pad  for retro games - 
|- 
| &lt;!--Description--&gt;8BitDo Pro 3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2026  hall effect analogs, hall effect triggers and some microswitches - button swap - ps2 style layout - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Ace Aurora 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect joysticks with no deadzone mode, gyro, linear rumble, trigger stops, back paddles, button swap, macro, turbo, RGB LED effects -  tri-mode connection - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Betop Beitong Spartan BTP-2270U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;  no hall effect 
|- 
| &lt;!--Description--&gt;Betop Betong Asura 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;  no hall effect - noble linear trigger potentiometer and alps shoulder LB/RB micro switch 
|- 
| &lt;!--Description--&gt;BEITONG ASURA 2 Pro+ Game Controller Wireless Gamepad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Beitong Zeus 2  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BebonCool Dinofire Model Number: Q218 / TP28
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2021  - triggers aren't progressive but ON/OFF - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;EasySMX X05 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect analog and triggers - tri mode connection - 
|- 
| &lt;!--Description--&gt;EasySMX Wireless Controller PC PS3, 9013pro ESM-9013PRO
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 linear hall effect but device sometimes will not connect tried multiple attempts with the dongle
|- 
| &lt;!--Description--&gt;EasySMX X10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;EasySMX X20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 ABXY MICRO SWITCH - Bumpers Tactile switch Hall Effect analog 
|- 
| &lt;!--Description--&gt;EasySMX X15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect analog and triggers - membrane buttons - 
|- 
| &lt;!--Description--&gt;EasySMX S10 Wireless Gamepad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 TMR Hall effect and compatible with Switch 2/PC/Phone/TV/Steam, NFC, Gyro, HD Rumble - 
|- 
| &lt;!--Description--&gt;EasySMX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;202
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Fantech World EOS Pro WGP15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect trigger and sticks,2 back paddles, motion controlling 
|- 
| &lt;!--Description--&gt;Fantech EOS PRO II S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 controller with TMR hall effect analogues, mechanical face buttons and D-pad, 63 input macro, back paddles, turbo - analog triggers with trigger stops - tri mode bt wifi and wired - slide switch on back for switch, macos/android and xinput - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Flydigi Apex 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023  luxury model 
|- 
| &lt;!--Description--&gt;Flydigi Vader Pro 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023 the Pro(Hall Effects) and Non-Pro (No Hall) 
|- 
| &lt;!--Description--&gt;Flydigi Direwolf 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2023 hall effect sticks and triggers - poor wifi connection - 
|- 
| &lt;!--Description--&gt;Flydigi Apex 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024  luxury model 
|-
| &lt;!--Description--&gt;Flydigi Vader 4 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - hall effect, DInput mode (o+A hold) - 
|- 
| &lt;!--Description--&gt;Flydigi Direwolf 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 hall effect analog and triggers but membrane buttons with gold contacts - 800mhA battery - 
|- 
| &lt;!--Description--&gt;Flydigi Dunefox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 basic model hall effect analog and triggers but membrane buttons - 500mha battery - no gyros - 
|- 
| &lt;!--Description--&gt;Flydigi Vader 5 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2025 - hall effect stick with tension control, linear triggers, DInput mode (o+A hold) - 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Gamesir T4K Keleid, T4C Cyclone wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2023 poor to ok switch 
|- 
| &lt;!--Description--&gt;Gamesir Nova 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no|| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2024 - switch type layout 
|- 
| &lt;!--Description--&gt;Guangzhou Chicken Run Network Tech Nova Lite GameSir-T4n LITE - Zikway HID gamepad
*[https://www.reddit.com/r/Gamesir/comments/1c185ve/psa_keep_gamesir_nova_lite_t4n_lite_firmware_at/ fw 4200 seems to be xbox so B then Home for Xinput (green LED), A then Home for HID BT Android (green/yellow LED), Y then Home for Switch Pro (Red LED)] or X then Home for Wifi and start and select to alternatively swap modes 
* and if on [https://www.reddit.com/r/Gamesir/comments/1c185ve/psa_keep_gamesir_nova_lite_t4n_lite_firmware_at/ fw 5700 ds4 so Home + B (blue LED), ]
* firmware 6900 
| &lt;!--Vendor ID--&gt;0x3537
| &lt;!--Product ID--&gt;0x1040 0x1041
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2024 - hall effect 3d nubs - no usb-c cable - rubber membrane analog trigger travel and bumpers shoulder buttons - wifi 2.4G and bluetooth - xbox layout so ab and xy might need to be swapped via m and a buttons for switch type [https://www.youtube.com/watch?v=po-nNuC5fps fixes video] - 250Hz polling - 600mah battery - rigid carry case - poor d-pad esp diagonals - gamesir settings software only on android 6+ or ios based only - 
|- 
| &lt;!--Description--&gt;Gamesir Nova 2 Lite  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir G7 SE Wired Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect 
|- 
| &lt;!--Description--&gt;GameSir G8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Gamesir TEGENARIA T3 Lite Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 playstation aesthetic hall effect analog and membrane buttons - X+Home button connects as an Xbox controller
|- 
| &lt;!--Description--&gt;GameSir Cyclone 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 TMR Joysticks with anti-friction rings and metal anti-friction rings around the stems, gyro, rumble, macro, turbo, 2 back paddles, hall analog triggers with micro-switch trigger - tri mode bluetooth, 2.4GHz wifi and wired, 1000hz polling rate - gamesir connect software - 
|- 
| &lt;!--Description--&gt;GameSir G7 Pro for Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 TMR hall effect - hall effect triggers, tri mode connection - gamesir nexus software - 
|-
| &lt;!--Description--&gt;GameSir Super Nova Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2026 hall effect sticks and triggers, 1000Hz polling, tri mode connectivity, 
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GameSir 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;GuliKit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GuliKit KingKong 2 NS08 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;Electromagnetic Stick hall effect - hall linear triggers - Mechanical face buttons - wired and wireless - Built-in rechargeable lithium battery 
|-
| &lt;!--Description--&gt;GuliKit KingKong 2 PRO NS09
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;hall efect - wired and wireless - Mechanical face buttons - Built-in rechargeable lithium battery 
|-
| &lt;!--Description--&gt;GuliKit KingKong MAX 3 KK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;hall effect - wired and wireless - lithium battery - 
|-
| &lt;!--Description--&gt;Gulikit KK3 Max USB-c Bluetooth Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 Hall Joysticks and Triggers, Maglev/Rotor/HD Vibration, 1000Hz Polling Rate, 4 Back Buttons,  
|- 
| &lt;!--Description--&gt;GuliKit KK3 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 smaller version of KK3 MAX - hall effect analog and triggers, face buttons , maglev rumble, gyro, 4 back paddles - rigid case - 950mAh up to 8 hrs - 
|-
| &lt;!--Description--&gt;GuliKit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Hyperkin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Hori EX2 Turbo UHX3-45 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Machenike G1 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 Wireless Gaming Controller with 1K Polling Rate Hall Effect Trigger Joystick For Nintendo Switch PC iOS Android 
|- 
| &lt;!--Description--&gt;Machenike G5 Pro Wireless Gaming Controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 ABXY Switch Membrane, Bumpers Tactile switch and hall effect analog 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;microsoft sidewinder precision pro 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| [https://pineight.com/mw/index.php?title=USB_game_controllers Xbox 360 Wired Controller]
| 0x045e
| 0x028e
| 0x
| &lt;!--Merge with USB Digital Pad--&gt;{{No|needs specific driver and has poor 2D control pad}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|- 
| Microsoft (R) [https://blog.tkjelectronics.dk/2012/12/xbox-360-receiver-added-to-the-usb-host-library/ Xbox 360] (TM) Wireless Receiver for Windows(R) Model 1086 and Controller 
| 0x045e 
| 0x0719, 0x or 0x0291
| 0x0100
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;{{No|separate standalone usb dongle detected and shows as 8 vendor interfaces but no class associated and so not working - may need new class from code from xpad or xboxdrv to work the controllor}}
|-
| &lt;!--Description--&gt;Xbox 360 Kinect [http://hackaday.com/2010/11/10/kinect-open-source-driver-demo-and-hacking/ Video] 
[http://git.marcansoft.com/?p=libfreenect.git;a=commit;h=7655fcf7239ba4907654089dba535a196685dbe5 GIT]
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007  proprietary 2.4GHz RF protocol, 
|- 
| &lt;!--Description--&gt;Xbox One Wired Controller 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Xbox One wireless controller newer model with the 3.5mm headphone jack 1537 1697 and microsoft adapter 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02d1 or 0x02dd
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2014 
|- 
| &lt;!--Description--&gt;Microsoft Elite Series 1
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02e3
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2016 ok - 
|-
| &lt;!--Description--&gt;Xbox later models 1708+ Xbox One and Series use 5GHz and use Bluetooth, 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02e0
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2017 
|- 
| &lt;!--Description--&gt;Xbox One S
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02ea 0x02fd
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2019
|- 
| &lt;!--Description--&gt;Microsoft Elite Series 2 Core 
| &lt;!--Vendor ID--&gt;0x045E
| &lt;!--Product ID--&gt;0x02ff
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{no| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{no| }}
| &lt;!--Opinion--&gt;2022 ok - no hall - 125Hz polling - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Minisform MGP01 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;MOBAPAD N1HD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 has liquid silicone face buttons, hall effect analog, D-Pad swap, two back paddles, USB-A dongle, HD Rumble - 
|- 
| &lt;!--Description--&gt;Mobapad Huben 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 
|- 
| &lt;!--Description--&gt;Mobapad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON Gale 墨将 mòjiāng 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON Blitz PRO 2 TMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BIGBIG WON now MOJHON AETHER 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2025 hall effect joysticks, hall effect triggers, mechanical bumpers, 1000hz polling rate, mechanical D-pad, membrane face buttons, mechanical back paddles, rumble, deadzone issues - tri mode 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;MSI FORCE GC20 GC30 V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2021 not hall effect 
|- 
| &lt;!--Description--&gt;MSI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mytrix Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;NACON GC-100XF Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 average 
|- 
| &lt;!--Description--&gt;PXN P5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 hall effect joysticks &amp; triggers, limited trigger stops, 1000hz polling rate on wired, 4 back paddles, 32 macro record, anti-deadzone mode, RAW mode, gyro, turbo, tri-mode connection - 
|- 
| &lt;!--Description--&gt;PXN P50L 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;PowerA 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD Stellar T5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD Junior E5 Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;QRD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Razer Wolverine V3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024  hall 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;RetroFlag 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Speedlink XEOX Pro Analog Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;enclosed lithium battery? - xbox layout - switchable on back of controller to directinput (dinput) or xinput - USB dongle switchable to pc and ps3 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;SCUF Instinct Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2022 good 
|- 
| &lt;!--Description--&gt;SCUF Envision Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2023 good 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Steel Series Stratus Duo XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;usb adapter needed 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;[https://inputlabs.io/Inputlabs InputLabs Alpakka Open Source and build yourself] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;DIY it with 3d printer, pcb and components  - pi pico needed - 2 gyros for better accuracy - 
|- 
| &lt;!--Description--&gt;[https://inputlabs.io/kapybara Inputlabs kapybara] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;DIY one handed version wip 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Vilcorn Z03 BT Wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt;2024 - other Bluetooth modes (green, red, blue, purple, etc.) Select + M1 (or M2) - 400mAh - not great latency wired - 800mhz polling -  
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;zd ultimate legend 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;zd 0+ elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;zd 0+excellent
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;2024 
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
|}

&lt;pre&gt;
#ifndef AROSX_LIBRARY_H
#define AROSX_LIBRARY_H

#include &lt;exec/types.h&gt;

#define AROSX_CONTROLLER_TYPE_UNKNOWN  0x00
#define AROSX_CONTROLLER_TYPE_GAMEPAD  0x01

#define AROSX_GAMEPAD_DPAD_UP          0x0001
#define AROSX_GAMEPAD_DPAD_DOWN        0x0002
#define AROSX_GAMEPAD_DPAD_LEFT        0x0004
#define AROSX_GAMEPAD_DPAD_RIGHT       0x0008
#define AROSX_GAMEPAD_START            0x0010
#define AROSX_GAMEPAD_BACK             0x0020
#define AROSX_GAMEPAD_LEFT_THUMB       0x0040
#define AROSX_GAMEPAD_RIGHT_THUMB      0x0080
#define AROSX_GAMEPAD_LEFT_SHOULDER    0x0100
#define AROSX_GAMEPAD_RIGHT_SHOULDER   0x0200
#define AROSX_GAMEPAD_A                0x1000
#define AROSX_GAMEPAD_B                0x2000
#define AROSX_GAMEPAD_X                0x4000
#define AROSX_GAMEPAD_Y                0x8000

struct AROSX_GAMEPAD {
    ULONG   Timestamp;
    UWORD   Buttons;
    UBYTE   LeftTrigger;
    UBYTE   RightTrigger;
    WORD    ThumbLX;
    WORD    ThumbLY;
    WORD    ThumbRX;
    WORD    ThumbRY;
};

#define AROSX_EHMB_CONNECT    0x00
#define AROSX_EHMB_DISCONNECT 0x01
#define AROSX_EHMF_CONNECT    (1L&lt;&lt;AROSX_EHMB_CONNECT)
#define AROSX_EHMF_DISCONNECT (1L&lt;&lt;AROSX_EHMB_DISCONNECT)

struct AROSX_EventHook {
    struct Node         eh_Node;
    struct MsgPort     *eh_MsgPort;
    ULONG               eh_MsgMask;
};

struct AROSX_EventNote {
    struct Message      en_Msg;
    ULONG               en_Event;
    APTR                en_Param1;
    APTR                en_Param2;
};

#endif /* AROSX_LIBRARY_H */
&lt;/pre&gt;


=== Joystick ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;CH Products CombatStick 568 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Cyborg X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Logitech Extreme 3D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| [Logitech Attack 3 Joystick] 
| 0x0464
| 0xC214
| 0205
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;saitek X-52 x52 pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;saitek aviator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Speedlink Competition Pro USB 
| 
|
| 
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{maybe|works but games not working &quot;out of the box&quot;}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Trust Predator QZ 501
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust Predator TH 400
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust Predator GM-2500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Trust XK 100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

===[https://github.com/JacKeTUs/linux-steering-wheels Gaming Racing Steering Wheels]=== 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;40%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  [https://www.usb.org/sites/default/files/documents/pid1_01.pdf USB PID standard not supported], 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cammus C5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fanatec CSL Elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS4 and Xbox - belt driven wheel - 30cm wheel swapping 
|-
| &lt;!--Description--&gt;Fanatec Club Sport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; top belt $600 £500 system 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;FFBeast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Genius TRIO RACER F1 Racing Wheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Cheap and cheerful but not great - may need calibrating 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hama PC Racing Wheel Thunder V18 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Average 
|-
| &lt;!--Description--&gt;Hori Racing Wheel 3 with pedals 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS3 PC 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Logic3 PXU450 TopDrive GT450 Steering Wheel for PS3, PS4, XBox One and PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Logitech MOMO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Very good 
|-
| &lt;!--Description--&gt;Logitech Driving Force GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Logitech Drive Force Pro DFP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; wheel 900 degree - weighs in at 15&amp;nbsp;lbs
|-
| &lt;!--Description--&gt;Logitech Formula Force EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;200 degrees turn for the EX model is arcade-like driving - adds PS3 compatibility via the PSx/2 adaptor - weighs in at 9&amp;nbsp;lbs
|-
| &lt;!--Description--&gt;Logitech G25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;   - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G27 PC/PS3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; comes with gear shifter - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G29 PC PS3/PS4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  may need additional shifter - gear 900deg wheel / rumble - 3 peddle - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G920 PC XboxOne 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  may need additional shifter - gear 900deg wheel / rumble - 3 peddle - needs external psu - 
|-
| &lt;!--Description--&gt;Logitech G923 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft(R) SideWinder Precision Racing Wheel (1999)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R3
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R5
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R9
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Moza R12
| &lt;!--Vendor ID--&gt;0x346E
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://github.com/Ultrawipf/OpenFFBoard OpenFFBoard], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V12 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;PXN V12 Lite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simagic M10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; base direct drive $900 £800 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simplicity Simwheel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; direct 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simucube 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Simxperience Accuforce V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SPEEDLINK Drift O.Z. Racing Wheel with Pedals and Gear Stick 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SteelSeries Simraceway SRW-S1 Steering Wheel (PC) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Thrustmaster Nascar Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Thrustmaster Ferrari Challenge Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; Poor  
|-
| &lt;!--Description--&gt;Thrustmaster Ferrari FGT Rumble GT Experience 3-in-1 (PC/PS3)
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;b658
| &lt;!--Revision--&gt;0102
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Wheel and all buttons detected}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|}}
| &lt;!--Opinion--&gt;Not great - gear driven 240deg wheel rotation - no psu needed - 2 peddle - flappy gear change - rumble untested - red switch for PC PS3 selection 
|-
| &lt;!--Description--&gt;Thrustmaster F430 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Thrustmaster T500 RS Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; belt driven wheel/rumble for GT5 
|-
| &lt;!--Description--&gt;Thrustmaster T60 Challenge 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Thrustmaster T150 Wheel 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;  gear / belt combo wheel / rumble - 2 peddle 
|-
| &lt;!--Description--&gt;Thrustmaster TMX Pro PC/XboxOne
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{No| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| &lt;!--Opinion--&gt; direct drive rumble - no manual gear shift included 
|-
| &lt;!--Description--&gt;Thrustmaster T80 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;Base level and OK - PS4 - 270deg rumble - 2 peddle 
|- 
| &lt;!--Description--&gt;Thrustmaster T300 RS GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS3 PS4 - belt driven - 900deg rotation and modular 28cm wheel out - 2 peddles but 3 available 
|-
| &lt;!--Description--&gt;Thrustmaster TX Leather 
| &lt;!--Vendor ID--&gt;0x044f
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;TX Xbox version - 900deg rotation 
|-
| &lt;!--Description--&gt;Thrustermaster TS PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PC only belt wheel 
|-
| &lt;!--Description--&gt; TS XW Racer PC Xbox1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; top belt system 
|-
| &lt;!--Description--&gt;Thrustmaster T-GT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;PS4 $700 £600 with T-DFB 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion
|-
| &lt;!--Description--&gt;Tracer Zonda Racing Steering Wheel PC PS3 Vibration Feedback Pedals Gearbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


===Gamepad Joypad Adapters===

* Most adapters will work in most OS's without installing a driver. Special functions needing drivers will be noted. 
* Some adapters do not work with some [http://www.stepmania.com/wiki/Dance_Pads dance pads] because of voltage issues. Other adapters map the dancemat arrows as axes and not as buttons, causing problems.
* If using an adapters should be compatible with '''original''' PlayStation PS/Xbox Xbox/GameCube GC /Dreamcast DC/Sega Saturn SS gamepads. 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;35%&quot; |Description 
! width=&quot;5%&quot;  |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision
! width=&quot;10%&quot; |Merge with USB on Digital Pad
! width=&quot;10%&quot; |Analogue Hack with Analog Stick
! width=&quot;30%&quot; |Opinion
|- 
| &lt;!--Description--&gt;[http://www.maplin.co.uk/psx-usb-bridge-34887?tabid=3&amp;worldid=&amp;doy=21m9&amp;faqitem=playstation%20controller%20to%20pc%20adaptor Maplin] [http://www.rockfire.com.tw/ Padix Co. Ltd. Rockfire] PX-205 PSX/USB Bridge 
| &lt;!--Vendor ID--&gt;0x0583 
| &lt;!--Product ID--&gt;0x2050
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes}} but buttons mapped different from others 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Maybe|poor}}
| &lt;!--Opinion--&gt;Ok with dpads, but very poor support with analogue hack 
|-
| Boom PS Joy Converter adaptor 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| discontinued (2004/5). Hold Up, Start, and Select for three seconds. Very good [http://www.stepmania.com stepmania] recommendation. 
|-
| [http://www.hkems.com/m_main.htm EMS] [http://www.hkems.com/product/ps2/ps2-usb2.htm USB2] grey plastic box with 2 PSX ports, one on either side - UP and Select pressed for 3 seconds at the same time or the dance code (start+select+up) 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Tests/joystick shows the PS port works in digital mode on d-pad}}
| &lt;!--Analogue Hack with Analog Stick--&gt;
| Set in PC switch mode. Does not work when using 2 pads at the same time, likely higher power requirements. FPSE emu DualShock untested, Mat and Guitar untested but known lag involved 
|-
| Joytech (play.com) (EMS USB2 bad clone) Black box twin PSX
| 0x0b43
| 0x0003
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|buggy hardware}} 
| but poor on dance ddr mat and guitar hero as the left and right keys do not like being pressed together, Dual shock untested 
|-
| [ EMS Trio Linker ] 1 PSone connection at bottom
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX discontinued 2005 
|-
| [http://psxemulator.proboards.com/index.cgi?board=support&amp;action=display&amp;thread=421 EMS Trio Linker Plus] (blue box) 1 PSx at bottom
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX discontinued 
|-
| Gamtec [http://www.gamestone.co.uk/gradius/guides_usb_smartjoy_guide.php SmartJoy Plus] Lik Sang PS-&gt;USB converter Red 2005 
| 0x0925
| 0x0005
| Low 0110
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe|detected and digital dpad works with [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4138&amp;forum=2&amp;post_id=35952#forumpost35952 joystick and testjoystick tests] but  the second analog control is not mapping correctly in digital mode}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|Analogue Hack - hardware buggy not useable}} 
| Dual shock untested, Mat and Guitar untested. Nothing picked up upon plugging it in. Quite common, these items have grounding issues or feed voltage back into the USB host and freeze the host controller, preventing any plugins or removals being detected. 
|-
| Gamtec SmartJoy Plus Dual PS-&gt;USB converter Red 
| 0x0925
| 0x00
| Low 
| &lt;!--Merge with USB Digital Pad--&gt;{{Maybe| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|buggy hardware}}
| 
|-
| [http://uk.gear.ign.com/articles/700/700334p1.html Lik-Sang Super SmartJoy PSX] 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1PSX 
|-
| Soyo Kiki Kiky 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| eXcel PSX adaptor shaped a little like a stealth bomber with USB pass through 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| Venom 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|-
| Dragon Plus (Radio Shack) Pantherlord GreenAsia USB to PS2/PS3 converter single black cable
| 0x0e8f
| 0x03
| 1.07
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes| }}
| 
|-
| Deal Extreme 2 PSX black cables from 1 USB port
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| {{N/A|untested }}
|- 
| &lt;!--Description--&gt;HDE 2014 Personal Communication Systems Inc 
| &lt;!--Vendor ID--&gt;0x0810
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;0106
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Same as single cable above but with black block midway along cable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
|- 
| &lt;!--Description--&gt;TigerGame Ltd Mayflash PC001 Super Joy Box 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| TigerGame Ltd Mayflash PC016 Super Joy Box arrowhead triangle twin PSX] Original was lack with RED Leds. Clones Dilong pu203, Blue HDE Neewer ShineData SD-APS2USB, Red Octane and Black PC Power Box (NS3454) '''embossed circle''' on top 
| 0x0810
| 0x0001
| 1.06
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes|Tests/joystick shows one PS port does not work with analog control at all but the other port does and maps correctly in digital mode}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|Analogue hack works }}
| Still available 2013, poor construction though, falls to pieces easily. Dual Shock untested, Mat and Guitar untested 
|-
| &lt;!--Description--&gt;TigerGame Ltd [http://www.mayflash.com/pc/pc038/pc038-1.htm Mayflash PC038 Super Joy Box Pro triangle twin PSX] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| TigerGame Limited Mayflash SuperJoy Box 5 PC006 long V-shaped 4 port PS/PS2 Game Controller Adapter  
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 
|- 
| &lt;!--Description--&gt;TigerGame Limited Mayflash SuperJoy Box 5 PRO PC039 PS/PS2 Game Controller Adapter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Merge with USB on Digital Pad
| Analogue Hack with Analog Stick
| Opinion 
|- 
| Boom PSX+N64 USB converter (purple or blue see through box) (2003/4) - red led for psx and green led for n64
| 0x6666
| 0x0667
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{No|not detected by Tests/joystick}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No|Analogue hack }}
| Rumble Pak untested
|-
| [http://www.hkems.com/product/ps2/TrioLinkerPlus2.htm EMS Trio Linker Plus II] 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }} [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4753&amp;forum=24&amp;post_id=43102#forumpost43102 ]
| &lt;!--Analogue Hack with Analog Stick--&gt;
| 1DC 1GC 1PSX but not for ddr mat games 
|-
| TigerGame Mayflash PC043 clone HuiJia Black twin N64 converter for PC USB 
| 0x0e8f
| 0x3013
| 0x0
| &lt;!--Merge with USB Digital Pad--&gt;{{No|detected by Tests/joystick though two digital pads have their settings wrong}} 
| &lt;!--Analogue Hack with Analog Stick--&gt;{{Yes|Analogue hack works well with middle handle/grip little joystick}}
| Rumble Pack untested 
|-
| TigerGame Mayflash PC MagicBox SuperBox 3 
| 
| 
| 
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| untested 1SS 1DC 1PSX }
|-
| &lt;!--Description--&gt;Lik Sang SmartJoy X 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x0285
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SmartJoy X2 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt;0x0289
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
| TigerGame Mayflash PC018 Super Joy Box 9 Xbox (NOT 360) 
| 0x05e3
| 0x060
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| does not work. Hub(s) 0x0288 detected but 0x0289 xbox1 joypads are not detected as hid let alone as [http://www.amiga.org/forums/archive/index.php/t-62940.html xpad] or [http://pingus.seul.org/~grumbel/xboxdrv/ linux xboxdrv driver] 
|-
| TigerGame Mayflash PC019 Super Joy Box 10 Xbox Twin ports (NOT 360) 
| 0x05e3
| 0x060
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| does not work with the big Fatty Duke or smaller S Akebono controller(s) 
|-
| TigerGame Ltd Mayflash PC020 Super Joy Box 11 Xbox Quad ports (NOT 360) 
| 0x05e3
| 0x0604
| 
| &lt;!--Merge with USB Digital Pad--&gt;{{No|shows up as a Genesys Logic Hub}}
| &lt;!--Analogue Hack with Analog Stick--&gt;{{No| }}
| 
|- 
| &lt;!--Description--&gt;TigerGame Ltd Mayflash PC035 3 in 1 Magic Joy box PS GC Xbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;USB to NES [http://wiki.nesdev.com/w/index.php/Standard_controller SPI like protocol] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Buffalo Classic USB Pad SNES like 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash PC044 USB to SNES 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;USB to MEGADRIVE GENESIS Joypad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;[http://www.retrousb.com/product_info.php?cPath=21&amp;products_id=70 USB to 9 pin ATARI RETROPORT style JOYSTICK PORT] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;{{Yes| }} 
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Atari RetroLink 9pin to SB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;SLS Sega Saturn USB pad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB on Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash PC050 Dual Saturn ports 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Guitar Hero for PC/Mac 
| &lt;!--Vendor ID--&gt;0x1430
| &lt;!--Product ID--&gt;0x474C
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;{{Yes| }}
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Cronus Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;BrookX One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Gamecube to USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;Mayflash Magic NS 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt; WiiU 
|- 
| &lt;!--Description--&gt;Brook Converter WiiU P3 P4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt;CooV Xbox One Converter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Merge with USB Digital Pad--&gt;
| &lt;!--Analogue Hack with Analog Stick--&gt;
| &lt;!--Opinion--&gt;
|-
|}


* [http://www.bemanistyle.com/forum/f6/best-metal-pad-19066/ Metal dance pads with LEDs] - My My Box Blue Shark (Nexen), Cobalt Flux (CF) (Let's Groove), Red Octane Afterburner, TX-2000, Logic3 (Dance Dance Dance), Gamerose (Stay Cool), 
* Hard foam mat - [http://www.mayflash.eu/3in1-deluxe-dansmat-ignition-foam-ps2xboxpc-p-5.html Mayflash] FutureMax Deluxe 3 in 1 Ignition, [http://www.gamerose.com/ Gamerose] (Stay Cool), TrinPad orange, 
* Soft foam mat - Logic3 (PS420N), [http://www.positivegaming.com/index.php?id=36 Positive Gaming Impact],  Gamerose Miss Daisys Naki (Stay Cool), Pelican, MadCatz

*PS1 PS2 PS3 PS4 flex ribbon big source of button/trigger issues with all controllers 
*PS2 Phat KSA1Q40A (Board), SA1Q33A (Membrane) SCHP-10010 H 
*PS2 SA1Q42A SCHP-10010 A 
*PS2 SA1Q43-A SCHP-10010 H


The primary axes are either the Control Pad or the left stick. Buttons come in a rough order: face buttons, then shoulder buttons, then Select and Start, then buttons under sticks, and finally Control Pad directions if not assigned to a hat. But the order and number of buttons within a category are unpredictable, as is which button the user expects to use for each action.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Joypad 
! width=&quot;5%&quot; | HATS 
! width=&quot;5%&quot; | Button 01
! width=&quot;5%&quot; | Button 02
! width=&quot;5%&quot; | Button 03
! width=&quot;5%&quot; | Button 04
! width=&quot;5%&quot; | Button 05
! width=&quot;5%&quot; | Button 06
! width=&quot;5%&quot; | Button 07
! width=&quot;5%&quot; | Button 08
! width=&quot;5%&quot; | Button 09
! width=&quot;5%&quot; | Button 10
! width=&quot;5%&quot; | Button 11
! width=&quot;5%&quot; | Button 12
! width=&quot;5%&quot; | Button 13
! width=&quot;5%&quot; | Button 14
! width=&quot;5%&quot; | Axes 1 
! width=&quot;5%&quot; | Axes 2 
! width=&quot;5%&quot; | Axes 3 
! width=&quot;5%&quot; | Axes 4 
! width=&quot;5%&quot; | Axes 5 
! width=&quot;5%&quot; | Axes 6 
! width=&quot;10%&quot; | Comment 
|-
| [https://pineight.com/mw/index.php?title=USB_game_controllers Xbox 360 Wired Controller]
| 
| A (down-green) 
| B (right-red) 
| X (left-blue) 
| Y (up-yellow) 
| LB (white) 
| RB (black) 
| Back
| Start
| Guide 
| L3
| R3
| 
| 
| 
| Left X 
| Left Y
| LT
| Right X
| Right Y 
| RT 
| Poor 2D, Good 3D 
|- 
| &lt;!--Description--&gt;Gravis GamePad / Original PlayStation Controller 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Red (Sqleft)
| Yellow X (X down)
| Green O (O right)
| Blue (Tri up)
| L1
| R1
| L2
| R2
| Select
| &lt;!--Button 10--&gt;Start
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;Stick X
| Stick Y
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; PlayStation 2 Older Adapters 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Blue X (down) 
| Red O (right) 
| Pink Sq (left) 
| Green Tri (up) 
| L1
| R1
| L2
| R2
| Select
| &lt;!--Button 10--&gt;Start 
| Stick 1
| Stick 2
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; PlayStation 2 Newer Adapters 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;Up
| Right
| Down
| Left
| L2
| R2
| L1
| R1
| Select
| &lt;!--Button 10--&gt;Start
| Stick 1 (analogue Hack) 
| Stick 2 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; Wish Technologies N64 Adaptoid 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt; A
| C Down
| C Right
| B
| C Left
| C Up
| L
| R
| Start
| &lt;!--Button 10--&gt;Z
| Pad Up
| Pad Down 
| Pad Left
| Pad Right 
| &lt;!--Axes 1--&gt;Stick X
| Stick Y 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;
| 
| 
| 
| 
| 
| 
| 
| 
| &lt;!--Button 10--&gt;
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
| &lt;!--Description--&gt; 
| &lt;!--HATS DPAD--&gt; 
| &lt;!--Button 01--&gt;
| 
| 
| 
| 
| 
| 
| 
| 
| &lt;!--Button 10--&gt;
| 
| 
| 
| 
| &lt;!--Axes 1--&gt;
| 
| 
| 
|  
|  
| &lt;!--Opinion--&gt;
|- 
|}

Just plug in your digital/analogue joystick or gamepad into USB port. The device will be handled by Poseidon USB stack. Poseidon is the USB stack with Trident adding a GUI (graphical user interface) prefs. 


the context sensitive page would come up right on pressing the help key inside the relevant window. The manual is in this archive, just in case it isn't in SYS:Locale/Help  


*How to change joystick mode to analogue?

By default a connected USB joystick emulates Amiga digital joystick. To change this behaviour so that the joystick is presented as analogue you need to use Trident preferences application (System:Prefs/Trident).

Open Trident and go to Devices on the left hand side (mouse click once on it). Select your controller from the list to the right and then click on Settings button below. This will open a new window. On the &quot;General&quot; tab find the &quot;Lowlevel Library Joypad Emulation&quot; section near the bottom. Find ports which are set to &quot;Merge with USB&quot; or &quot;Override with USB&quot; and change them to &quot;Analogue Hack&quot;. 

Please note that analogue joystick support is an extension of original Amiga functionality, thus an Amiga application must be explicitly written to use it. AROS SDL library uses this functionality, thus all SDL applications that use joystick, can use the analogue joystick feature.

The HID class has several options how to handle the input data: 

* Don't touch: The movement and button data for is not modified by the hid class. This is the default for the ports 0, 2, and 3. 

* Overwrite with USB: This will kill the  original  data  that  might  had  come  from  the internal  ports  and  overwrites it with the joypad data for this USB interface. Note well: If you have multiple  joypads  connected,  take care  which setting you have selected for each port, because only the last interface with this option will actually send the joypad data to the game. 

* Merge with USB: This option merges the input data of the  lowlevel.library  with  the USB  stream. This only works, if the connected device on the original Amiga  ports  is  NOT  a  mouse  (because  then   the   streams   are incompatible).  Merging  should  be  the preferred method, because it leaves the original joysticks working. 

* Disable: Turns off the port for the application.

* Analogue Hack: Tells Poseidon to force reporting  of  analogue  data  at  the  port. Please  note  that  this only works with programs that understand the analogue  data,  because  it's   an   extension   to   the   original lowlevel.library   standard   made  by  Commodore.  If  you  want  to incorporate this feature in your software, just contact me and I will send you the necessary information. 

* Rumble Port: As addition to the analogue data, the HID class  supports  applications and  games  that want to utilize a rumble pack or force feedback motors in the gamepads. This field selects to  which  lowlevel  port  the  hid device responds, when attempting to use the rumble pack. Normally, this corresponds to the port that has  been  set  in  the  actions  for  the joypad.


*How to change joystick port assignment?

The low  level  library  supports up to four ports. Port 0 is usually used by the mouse, port 1 is the standard port for joysticks/joypads. By default a connected USB joystick is present in Port 1. To change its location to Port 0 you need to use Trident preferences. 

Open Trident and go to Devices window. Select your controller from the list and then click on Settings button. This will open a new window. On the &quot;General&quot; tab find the &quot;Lowlevel Library Joypad Emulation&quot; section. Port 1 should be set as either &quot;Merge with USB&quot; or &quot;Override with USB&quot;. Change this setting to &quot;Don't touch&quot;. Change Port 0 setting to &quot;Merge with USB&quot;.

Go to &quot;Actions&quot; tab. In the &quot;Reports and collection&quot; select first entry named &quot;Joystick&quot;. in the &quot;Usage items&quot; select &quot;X axis&quot;. Go to &quot;Performed actions&quot; area. On the left there will be a list of triggers. Each of them should have (port1) in their params. Click on the first trigger and using buttons to the right of the list change port1 into port 0. Repeat this for all triggers and for all items on &quot;Usage items&quot; list.


*How to make joystick simulate keyboard keys?

With Poseidon it is possible to make the joystick simulate the keyboard pressings. This might enable using joystick for playing games which only have keyboard support. This feature is configured in Trident preferences.

Open Trident and go to Devices window. Select your controller from the list and then click on Settings button. This will open a new window. Go to &quot;Actions&quot; tab. On the right top window select X axis. On the left bottom list select an entry &quot;Digital Joystick, Push left(port 1)&quot;. On the panel to the right change &quot;Digital joystick&quot; into &quot;Raw Key&quot;. A list of keys will be displayed. Select key you wish to send. Repeat the same procedure for &quot;Digital Joystick, Release left (port 1)&quot; option but this time check &quot;Send key up even instead of key down&quot;. Open shell and move your joystick to the left - your selected letter should appear in the shell. 


*Analogue in Trident Prefs
* Open the Trident USB Prefs -&gt; Devices -&gt; Select your joypad -&gt; Settings button -&gt; Action TAB 
* See some &quot;axis&quot; listed under &quot;Usage items&quot; in the top right of the window. They are your analog stick(s) 
* Check [x] Track Incoming Events which is half way down the window on the left 
And you should see some axis activity in &quot;Usage items&quot; when you move the analog stick 


*Actions

HID class item -&gt; Settings -&gt; HID Class Window -&gt; Action Tab -&gt; Action handling area 

Reports and collections -&gt; Usage Items -&gt; Performed actions 


Qualifier keys are *special*. You don't only need to create the actual keypress but also modify the qualifiers.
Go to the keyboard panel and find the windows menu key by enabling key tracking and pressing the windows menu key. Then assign the right amiga key to it.

Go to the actions panel and find the right amiga key (it's called &quot;Keyboard right GUI&quot;). Remember the actions stored there, best write them down in exact order. Then delete them.
Find the windows menu item and add the missing qualifier action. Be sure the parameters are exactly the same and the order is right.

Set them to Raw, then assign an up and down button for each character, etc.
when you change the settings to RAW so you can assign keyboard strokes. it will always say, KEYDOWN or what ever on the left, it never provides and option for key release.

The problem still remains though that if I try to assign the Directional Pad (Hat) to Arrow Keys, that things will get screwed up and you either can not move with the directional PAD (HAT), or movements are assigned to the Left Analog, and do not work as they should, it's as if the right and down arrow keys are ALWAYS On, regardless of the fact that I did indeed assign a Key release command to each input.

check that by pressing analog directions and see the current values, and the thresholds configured in poseidon to bind them to left/right/up/down.

misconfigured too much stuff in the HID settings, you can always go in poseidon-&gt;config list entry and delete the config item related to your device (or the HID class setting itself), back to basics.


*Rumble in Trident Prefs
Open Trident Prefs and click on the Devices option in the left hand window. Click with the mouse once on your gamepad choice on the right hand side and again on the Settings button below. In the new window, select the '''General''' TAB and half way down on the right there is an &quot;Open Now&quot; button in the section &quot;HID output control window&quot;. Clicking on that button opens another window (HID Control) with sliders for the two rumble engines inside the controllers and you can test if they work. '''Sometimes clicking that button does nothing, other times it will open the window and say nothing is detected.''' The leftmost two sliders do nothing, the third one has a large rumble effect, and the fourth one has a small rumble effect.

===Graphic Drawing Tablet===

There is a standard in HID for tablets possibly mouse type. If the tablet is HID conforming in that sense, it should work. Aiptek does a fairly good job at this. The other competitor, Wacom, didn't pay too much attention to this and simply adapted their legacy serial protocol into HID in a very awkward way. Older Wacom tablets have worked with the special support in the HID class, but not the more recent ones. 

 to use graphic tablets fully, applications need to be written that make use of the AmigaOS NewTablet events (which AROS has) 


* Entry level - A6 (6x4) work area 
* Medium A5 (6x8) A4 (10x7) size   (recommended but only a few ie years 2000 to 2003 models supported) 
* Semi Pro A3 (12x9) 
* Pro  Cintiq


* 2005/6 Some support added for Wacom tablets  
* 2008 Wacom's patent on battery free pens expires


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Micrograf Tabby (late 1980s and early 1990s) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;podscat pt 3030 graphics tablet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Summagraphics 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Wacom IV compatible (Graphire, ArtPad, A3, A4, A5 and PenPartner CT-0405-P - Wacom intuos GD-0405-R) Waycom Digitiser II UD-0608-R
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Wacom Artpad II (KT-0405-R) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AceCad boards 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AipTek HyperPen 6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Calcomp 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;AipTek HyperPen 8000 - Aldi/Medion MD 9310 and Aldi/Tevion LT 9310 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|-
| &lt;!--Description--&gt;Tablet PC penabled 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based like x61t X60t NC4200 NC4400 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|Serial RS232 based }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
* Wacom PenPartner
* PenPartner 2
* PenStation 2
| &lt;!--Vendor ID--&gt;0x056a
| &lt;!--Product ID--&gt;0x0000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Graphire - Wacom Tablet ET-0405-U UV1.1-1 (Slate Blue)  ET-0405UL (lime)  (orange)  (red)  (purple) 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0X0010
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{Yes|late 90s with A6 size - [Wacom Support] of X-axis 00000-10205  Y-AXIS 0000-7421 Tip Pressure 000-511 under Trident prefs. Air pen mouse type movements }}
|-
| &lt;!--Description--&gt;
* Grapphire 2 4x5  ET-0405A-U UV2.0-3 (Steel Blue) 
* Graphire 2 5x7 ET-0507A 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0011 and 0x0012
| &lt;!--Revision--&gt;0110
| &lt;!--Opinion--&gt;{{Yes|A6 and A5 versions - [Wacom Support] of X-axis 00000-10205  Y-AXIS 0000-7421 Tip Pressure 000-511. Air pen mouse type movements - mouse EC-120-0K tested}}
|-
| &lt;!--Description--&gt;Wacom Graphire 3
* cte-430/w 4x5 pearl   sapphire 
* cte 630 6x8 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0013 and 0x0014 
| &lt;!--Revision--&gt;0314
| &lt;!--Opinion--&gt;{{Yes|A6 and A5 size - [Wacom Support] Xaxis 0-10207 yaxis 0-7423 tip pressure 0-511 and the erase end appears to respond but avoid bluetooth BT versions }}
|-
| Wacom Graphire 4 
* cte-440/B Blue cte 440/s Silver 4x5
* cte-640 6x8 cte 640 u 0403 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0015 and 0x0016 
| &lt;!--Revision--&gt;403
| {{Yes|A6 and A5 work area detected [Wacom Support] x-axis 0000-10207 Y axis 0000-7423 Tip Pressure 000-511 and delete rub out end of the pencil seems detected but avoid bluetooth BT versions }}
|-
| &lt;!--Description--&gt;
* Wacom Intuos 4x5 GD-0405 
* Intuos 6x8    GD-0608
* Intuos 9x12    GD-0912
* Intuos 12x12  GD-1212-U 
* Intuos 12x18 GD-1218
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0020 0x0021 0x0022 0x0023 0x0024 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|detected and responses delivered back - x axis up to 30479 and y axis 31679, tip pressure up to 1023 and x and y tilt up to 127 - Wacom intuos GD-0912-A for Apple Macs NOT SUPPORTED}}
|-
| &lt;!--Description--&gt;
* Intuos 2 4x5 A6 - XD-0405-U 
* Intuos 2 6x8 A5 - xd 0608u uoc
* Intuos 2 9x12 XD-0912-U
* Intuos 2 12x12 XD-1212-U
* Intuos 2 12x18 XD-1218-U
| &lt;!--Vendor ID--&gt;0x056a
| &lt;!--Product ID--&gt;0x0041 0x0042 0x0043 0x0044 0x0045 
| &lt;!--Revision--&gt;0126
| &lt;!--Opinion--&gt;{{No|various sizes and recognised as [Wacom Support] but not working. x-axis 00000-20319 y-axis 00000-16239 tip presure 0000-1023 x-tilt y-tilt 000-127.  HID mouse xc-100-03 works but never could use it as a real tablet with pressure with TVPaint 3.6 }}
|-
| &lt;!--Description--&gt;
* Intuos 3 4x5 (PTZ-430) 
* Intuos 3 4x6   (PTZ-431W ) 
* Intuos 3 6x8   (PTZ-630 PTZ630) 
* Intuos 3 6x11 (PTZ-631W A3 wide)  
* Intuos 3 9x12 (A4 PTZ-930 PTZ930)  
* Intuos 3 
| &lt;!--Vendor ID--&gt;056a
| &lt;!--Product ID--&gt;0x00b0 0x00b1 0x00b2 0x00b3 0x00b4 0x00b5
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No}} Actions in HID setup window definitively locks the Pointer (mouse) reports settings and even after a clear and save, nothing changes, the configuration returns to default values.  &quot;[Wacom]&quot; reports don't see any events from the tablet, even with &quot;Pointer&quot; reports cleared and save, so is locked a in &quot;mouse&quot; state - but can send a special command to the tablet in order to put it into a special vendor mode. This mode enables Wacom specificities like pressure, tilt, absolute position, buttons, etc... you should send an HID report feature with ReportID=2 and data=2, the current HID class driver doesn't give a way to change that, even using the &quot;initial startup actions&quot; item in the extra collection. No listed features work 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Wacom Volito - Promethean FT-0405-U06 UV1.4-1 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0060
| &lt;!--Revision--&gt;0141
| &lt;!--Opinion--&gt;{{Yes|A6 work area with [Wacom Support] of x-axis 0000-5103 Y axis 0000-3711 Tip Pressure 000-511. Air and touch mouse movement - appears to be the budget option with some but limited features}}
|-
| &lt;!--Description--&gt;Wacom Volito 2 
* CTF-??? 2x3 
* CTF-420G CTF-420 V2.0-0 4x5
* Serif Penabled 6742 rebadge of CTF 420/020-B CTF-420/02
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0062
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{Yes|A6 work area with [Wacom Support] of x-axis 0000-5103 Y axis 0000-3711 Tip Pressure 000-511. Air and touch mouse movement - no erase function on the end of the pen - nylon nibs value option}}
|-
| &lt;!--Description--&gt;
* Wacom PL-400 LCD 
* PL-500
* PL-510
* PL-550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0030 0x0031 0x0032 0x0034 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
* PL-600
* PL-600 SX
* PL-700
* PL-710
* PL-800
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0033 0x0035 0x0036 0x0037 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Cintiq 21 UX and Cintiq Partner DTF-720
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Wacom PenTablet Bamboo (MTE), Bamboo Craft (CTH), Bamboo Fun (CTE), Bamboo Pen (CTL) and Bamboo Pen &amp; Touch (CTH) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Wacom Bamboo Fun Medium CTE-650 
| 
| 0x0018 
| 
| {{Maybe|[http://www.a1k.org/forum/showthread.php?t=11432 works on a1k forum]}}
|-
| &lt;!--Description--&gt;Bamboo Fun Small CTE-450 white 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0017 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Bamboo One CTF-430 V2.0-0 CTF 430/S
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0069
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{Maybe|A5 wired air pen and acts like a mouse only}}
|-
| &lt;!--Description--&gt;Wacom Intuos 4 
* Small PTK-440 PTK-540
* Medium - PTK-640 - PTK 540WL Wireless - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested  Intuos4 surface sheet was revised in October 2010 to reduce nib wear}}
|-
| &lt;!--Description--&gt;Wacom Intuos 5 Touch 
*
* Medium - PTH-650 - USB Wired and Wireless Kit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;0x0027 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested work, however wireless may glitch or drag }}
|-
| &lt;!--Description--&gt;Wacom Intuos Pro Medium - PTH-651 - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Bamboo Small Pen Tablet - MTE 450 MTE-450A (MTE-450/k) - 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x0065
| &lt;!--Revision--&gt;0116
| &lt;!--Opinion--&gt;{{Maybe|A6 work area - mouse movement but no pen detection except x-axis 2 to -2 and y-axis 2 to -2 - mini usb lead - 4 blue led lit buttons not detected as well as circular touch button??  }}
|-
| &lt;!--Description--&gt;Bamboo Pen CTL 460
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested all Bamboo versions were criticized for the drawing surface's roughness (which got smoother over time), which caused the small pressure-sensitive 'nib' to wear down, and become slanted or scratchy in the same way as pencil lead, albeit more slowly}}
|-
| &lt;!--Description--&gt;Wacom Bamboo Fun CTH-461/S wired 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x00D2
| &lt;!--Revision--&gt;0106
| &lt;!--Opinion--&gt;{{Maybe|A6 size - Pen tracking not working but finger touch works }}
|-
| &lt;!--Description--&gt;Wacom Bamboo Connect Pen Tablet CTL-470 CTL-470K 470-DE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;CTH 470K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom CTH 480/S wireless 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} lithium battery for pad - 
|-
| &lt;!--Description--&gt;Wacom Intuos Pen Small CTL-480/S CTL 480 K wired 
| &lt;!--Vendor ID--&gt;0x056A
| &lt;!--Product ID--&gt;0x030E
| &lt;!--Revision--&gt;0200
| &lt;!--Opinion--&gt;{{No|A5 detected as Intuos PS  but not working although the RHS blue led responds to pen on tablet }}
|-
| &lt;!--Description--&gt;CTH 490 PK S Photo - CTH-490CK-S Comic - CTH-490AK-S Art 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested lower hovering height pen nibs wear fast and input lag/responsiveness}}
|-
| &lt;!--Description--&gt;Intuos Pen &amp; Touch Medium - CTH-680 - USB Wired and Wireless Kit work 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wacom Intuos Pro (PTH-660 and PTH-860) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Waltop Media Tablet 10.6&quot;
    Genius G-Pen M609
    Genius G-Pen M609X
    iVista Media Tablet 10.6
    Aiptek MediaTablet 10000u

| &lt;!--Vendor ID--&gt;172f:0501
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Slim Tablet 12.1&quot;
| &lt;!--Vendor ID--&gt;0x172F
| &lt;!--Product ID--&gt;0x0034
| &lt;!--Revision--&gt;0x1105
| &lt;!--Opinion--&gt;{{yes|works}}
|-
| &lt;!--Description--&gt;Waltop Media Tablet 12 by 9&quot; 
    Aiptek HyperPen 12000u T-12000U Tablet Series 
    Nisis T-12000u USB Tablet Series Version 1.05 (aiptek rebadged)

    Trust item #1535
    ADESSO Cyber Tablet 12000 Graphic design tablet
    iVista Media Tablet 12
    PENTAGRAM O'pen Wide P 2003
    Genius G-Pen M712
| &lt;!--Vendor ID--&gt;172f:0500, 0x08ca
| &lt;!--Product ID--&gt;0x0010
| &lt;!--Revision--&gt;0105
| &lt;!--Opinion--&gt;{{Yes|detected with Nisis/Aiptek functioning as a tablet, untested with others  - Puck (mouse) x axis 0000 to 6000 y axis 0000 to 6000 - stylus (pen) x axis 00000 to 12000 y axis 00000 to 12000 tip pressure 0000 to 1023 - 16 function keys - AAA battery needed for pen and another for the mouse}}
|-
| &lt;!--Description--&gt;Waltop Media Tablet 14.1&quot; v5.1e
    Genius G-Pen M714X
    Aiptek MediaTablet 14000u WMK-H141 
    Trust item #15358
    Adesso CyberTablet 14000 M14
    iVista Media Tablet 14.1
    PENTAGRAM O'pen Wide P 2004

| &lt;!--Vendor ID--&gt;0X172f
| &lt;!--Product ID--&gt;0X0500
| &lt;!--Revision--&gt;0114
| &lt;!--Opinion--&gt;{{Yes|detected with Nisis/Aiptek functioning as a tablet - Stylus (Pen) X 16838 Y 16838 Tip Pressure 1023 }}
|-
| &lt;!--Description--&gt;Waltop PID 0038
    Genius G-Pen F509
    Manhattan 177405

| &lt;!--Vendor ID--&gt;172f:0038
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop PID 0052
    Yiynova MSP19

| &lt;!--Vendor ID--&gt;172f:0052
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Q Pad
    Aiptek HyperPen Mini
    NGS Flexi Style
    VisTablet PenPad
    iVistaTablet Q Flex Pad
    Bravod Q-PD65-S
    Trust Flex Design Tablet (#16937)

| &lt;!--Vendor ID--&gt;172f:0037
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Sirius Battery Free Tablet
    VisTablet Muse
    PENTAGRAM Designer P 2700
    Princeton PTB-S1BK

| &lt;!--Vendor ID--&gt;172f:0502
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Slim Tablet 12.1&quot;
    Genius G-Pen F610
    Trust Slimline Widescreen Tablet (#16529)
    VisTablet Original 12&quot;
    Adesso CyberTablet Z12
    Adesso CT-Z12A
    PenPower Tooya Pro
    Aiptek Slim 12.1 Inch
    Aiptek SlimTablet 600u Premium II
    NGS Slim Proguess
    iVistaTablet Slim 12.1
    PENTAGRAM ThinType P 2006

| &lt;!--Vendor ID--&gt;172f:0034
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Slim Tablet 5.8&quot;
    Genius G-Pen F350
    Trust item #16485
    VisTablet Mini
    iVistaTablet Slim 5.8
| &lt;!--Vendor ID--&gt;172f:0032
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Waltop Venus S Tablet
    Trust eBrush Widescreen Tablet (#17939)

| &lt;!--Vendor ID--&gt;172f:0503
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Aiptek GmBH MediaTablet Ultimate II - 16:10 Professional Graphic Tablet Model 1400U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Hanvon Beijing HanWang HW Micro Drawing Tablet ET0504U 
| &lt;!--Vendor ID--&gt;0x0b57
| &lt;!--Product ID--&gt;0x8030
| &lt;!--Revision--&gt;01111
| &lt;!--Opinion--&gt;{{No|does not work - recognised as an HID mouse - no tablet extensions detected}}
|-
| &lt;!--Description--&gt;KYE EasyPen 340, Genius EasyPen 340 
| &lt;!--Vendor ID--&gt;0458:5014
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| Aiptek Hyper Pen 6000u PC Tablet APT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{No|detected but does not work - win98 era cordless 6in by 4.5in - }}
|-
| &lt;!--Description--&gt;nisis T-8000U APT-2 Aiptek rebadge 
| &lt;!--Vendor ID--&gt;0x08CA
| &lt;!--Product ID--&gt;0x0021
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|A5 detected but no responses }}
|-
| &lt;!--Description--&gt;Acecad Flair II GT-504 Init Fkt  Fkt 0x5ab450c0
AIPTEK HyperPen 10000 U
Aiptek HyperPen 10000U, 
AIPTEK Slim Tablet U600 Premium II
| &lt;!--Vendor ID--&gt;0x0460
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Ace Cad Enterprise Co., Ltd Tablet - 5x3.75 drawing area 
| &lt;!--Vendor ID--&gt;0x0460
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Bosto's 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} UCLogic Digitizer 
|-
| &lt;!--Description--&gt;Adesso CyberTablet Z7, Adesso CyberTablet 12000, Adesso CT-12000A  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;UC-Logic / Lapazz WP8060, UC-Logic / Lapazz PF1209, UC-Logic / Lapazz Artistic Tablet 5540,   Manhattan 8&quot;x6&quot;, Manhattan 3&quot;x4&quot;, Manhattan
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested but suspect not working}}
|-
| &lt;!--Description--&gt;DigiPro 5.5×4” Graphics Tablet
Digital Ink Pad (A4 format) 
DigiPro WP8060, DigiPro WP5540,  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius G-pen
G-Pen 4500
Genius Wizardpen
Genius Mousepen
Genius Easypen i405 M610 
Genius PenSketch 9x12, Genius MousePen i608, Genius MousePen 8x6, Genius MousePen / WizardPen 5x4, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius G-Pen F610
Genius G-Pen M610 
Genius G-Pen 340 (UC-LOGIC Tablet WP4030U)
Genius G-Pen 450 (UC-LOGIC Tablet WP5540U)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Genius
UC-LOGIC
iBall Tablet PF8060
iBall
Iball Pen Tablet 8060U, Iball Pen Tablet 5540U, Iball Pen Tablet 4030U, Iball Design Tablet PF1209,
NGS CADBOY (UC-LOGIC Tablet WP5540U)
Pentagram
QWare
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Trust TB-3100
Trust TB-5300 Trust 15356 
Trust TB-6300 Trust 15357  WP8060U  Slimline but bulky with metal backing A5 size 
Trust 16486, Trust 16447,  Sketch Design Tablet,
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|clashes with usb and crashes AROS }}
|-
| &lt;!--Description--&gt;UC-Logic Tablet WP1062
    Aiptek HyperPen 10000U
    Monoprice 10X6.25 Inches Graphic Drawing Tablet
    Pickle 10x6.25 Inch Graphic Drawing tabletguess

| &lt;!--Vendor ID--&gt;5543:0064
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| [ VTech KidiPhoto Art Studio] 
| 
| 
|  
| {{yes|works}}
|-
|}

Tablet has a squared lines of wires which induce a current into the pen which is then detected by the metal grid in the tablet pad. Tablets report pressure (and tilt on expensive models) and are absolute pointing devices (put the pen at the top left and the mouse pointer will go to the top left of the screen). Graphic drawing area, what keys, report rate, resolution lpi lpmm, accuracy, pressure levels (may come from the app), origin position,

Wacom tablets use electromagnetic resonance technology.  Since the tablet provides power to the pen through resonant inductive coupling, no power is required for the pointing device. As a result, no batteries are inside the pen (or the accompanying puck), making them lighter and slimmer.

Under the tablet's surface (or LCD in the case of the Cintiq) is a printed circuit board with a grid of multiple send/receive coils and a magnetic reflector attached behind the grid. In send mode, the tablet generates a close-coupled electromagnetic field (also known as a B-field) at a frequency of 531&amp;nbsp;kHz. This close-coupled field stimulates oscillation in the pen's coil/capacitor (LC) circuit when brought into range of the B-field. Any excess resonant electromagnetic energy is reflected back to the tablet. In receive mode, the energy of the resonant circuit’s oscillations in the pen is detected by the tablet's grid. This information is analyzed by the computer to determine the pen's position, by interpolation and Fourier analysis of the signal intensity.

In addition, the pen communicates information such as pen tip pressure, side-switch status, tip vs. eraser orientation and ID number (to differentiate between different pens, mice, etc.). For example, applying more or less pressure to the tip of the pen changes the value of the pen's timing circuit capacitor. This signal change can be communicated in an analog or digital method. An analog implementation modulates the phase angle of the resonant frequency, while a digital method is communicated to a modulator that distributes the information digitally. The tablet forwards this and other relevant tool information in packets, up to 200 times per second, to the computer.


If you disable (delete all of them except for one that needs to be set to &quot;no action&quot;, so that it will not be regenerated as default) the Extra Startup actions, the tablet should remain in relative mouse mode—you will not get pressure information in that mode though. [http://tech.groups.yahoo.com/group/highway_usb/message/2394]}}


=== Handheld Barcode Scanner Readers ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Farsun 9100 barcode scanner 0-12&quot; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola Symbol LS2203 CMOS 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Tysso 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Simple}} Code 11, Code 39, Code 93, Code 128, Coda Bar, UPC-A, UPC-E, EAN-8, EAN-13, MSI/Plessey, Telepen, Interleaved 2 of 5, Industrial 2 of 5, Matrix 2 of 5 
|-
| &lt;!--Description--&gt;Unitech MS320 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wasp WCS3905 CCD 1&quot; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Code 93, Matrix 2 of 5, Industrial 2 of 5, Code 39, UCC/EAN-128, ISBN, Code 32, EAN/JAN-8 , EAN/JAN-13 , UPC-A, UPC-E, Codabar, Code 128, Code 11, Interleaved 2 of 5, MSI-Plessey, China Post, IATA 2 of 5, ISSN, UK-Plessey 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Datalogic Touch 90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Intermec  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell Metrologic MK9540-32A38 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola LS2208 Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Wasp WWS800 Laser 1D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Datalogic GD4130-BK-C066 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell 1202G-1USB-5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Motorola / Symbol DS6707-DC20007ZZR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;DataMan 8000 2D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Honeywell Voyager 9520/40 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Metrologic MS1690 USB 2D Barcode Scanner  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} QR Code GS1 Databar PDF417
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Syscan GM800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

[http://www.scandit.com/2011/11/04/types-of-barcodes-choosing-the-right-barcode-type-ean-upc-code128-itf-14-or-code39/ Types of Barcode]

&lt;pre&gt;
UPC-A       Grocery most common 
Code 128    
EAN-13      Library Books ISBN &amp; ISSN, 
Code 39     
Codabar     blood bank,

2D barcodes such as 
Data Matrix 
PDF417e     
Maxicode    
Aztec       
QR Code     old Nokia handsets, 
MicroPDF417 
&lt;/pre&gt;


===TouchScreens===

Projected capacitive (PCAP) touch screen product, amongst many options the widely used are I2C and USB 

*USB host–device structure which dominates consumer and industrial electronics devices where higher bandwidth needed and user-friendly (multiswipes)
*I2C Inter-Integrated Circuit simple serial standard for LCD display in embedded systems because of cost and low power 
*SPI arduino and rpi single boards 

We cover the USB here 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| eGalax Touch 4a
| 0eef 
| 0001 
| 0001
| {{yes|2009 works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lilliput HDMI Monitors
669GL-70NP/C/T (7 inch)
869GL-80NP/C/T (8 inch)
FA1011-NP/C/T (10 inch)
FA1046-NP/C/T (10 inch)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Iilyama Prolite Monitors
PROLITE T1513SR-1 (15 inch)
PROLITE T1730 (17 inch)
PROLITE T1713SR-1 (17 inch)
PROLITE T1913SR-1 (19 inch)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Smart Display Company (SDC) Touchscreens TFT Monitors
TOUCH-TFT-TS07 (7 inch)
TOUCH-TFT-TS08 (8 inch)
TOUCH-TFT-TS10 (10 inch)
TOUCH-TFT-TS12 (12 inch)
TOUCH-TFT-TS15 (15 inch)
TOUCH-TFT-TS17 (17 inch)
TOUCH-TFT-TS19W (19 inch wide)
TOUCH-TFT-TS22W (22 inch wide)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;XENARC Monitors 7 inch models
700TSH
700TSU
700TSV
702TSV
705TSV
706TSA
700IDT
MDT-X7000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;XENARC 
8 inch models:
800TSV
805TSV

10 inch models:
1020TSV
1026TSA
1040TS

12 inch models:
1200TS
1200TR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Asus VT229H 21.5&quot;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;CUQI 7&quot; Monitor Touchscreen 1024x600 IPS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Espresso 15&quot; Portable Touchscreen Display Monitor
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hannspree HT225HPB 21.5 inch
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;WaveShare 13.3inch HDMI LCD (H) (with case)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


===GPS tracking, running, cycling, biking, walking, hiking, ORIENTEERING, boaters and mapping===

Support for OpenStreetMap but not for Ordnance Survey, Map Pilot or National Geographic's Topo maps data gdb,

Data output supported nmea 0183 V1.5 APA, V1.5 XTE and V2.1 GSA formats, gpx, kml/kmz, tracks from tcx files, geo: URIs,  
NMEA0183(which is RS232, voltages range from -15 volts to 15 volts, 4800 baud), or need NMEA sentences connected to your computer

other method that some units support is a special serial cable that actually emits raw RS232 NMEA. These usually take 10-&gt;30 volts input, can run the unit, and have full voltage I/O for RS232 (not like spanner mode, which effectively turns the unit into a USB-&gt;Serial adapter inside the case).

Equivalent apps - merkator, mapsource,

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Garmin gpsmap 180 GPS/chart plotter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;1992 GARMIN GPS 55 AVD Portable System 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin GPS V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - waas pinpoint within 3 metres - nmea - 4AA battery}}
|- 
| &lt;!--Description--&gt;Garmin GPS 12 12XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Legend C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin eMap 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|possibly through usbmodem rs232 connection nmea 0183 protocol}}
|-
| &lt;!--Description--&gt;Garmin eTrex 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} rs232 these older units supported it and would provide the stream in either the standard NMEA 0183 format or a proprietary Garmin format.
|-
| &lt;!--Description--&gt;Garmin GPS 75 AVD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS Map 7000 model 45006 (1994) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS Tracker
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan Pioneer Satellite Navigator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Magellan GPS 300 315 320 Mentor Receiver (2003) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Not for dedicated sat nav units like the Nuvi, TomTom, etc 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;NaviLock NL-402U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested u-blox 5 SuperSense® chipset with receivers for GPS, GLONASS, Galileo, BeiDou and QZSS}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;GM1-86UB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| U-BLOX UB-6010 GGA,GSA,GSV, RMC and support VTG, GLL, TXT ublox binary and NMEA Command Dynamic Condition }}
|-
| &lt;!--Description--&gt;NAVILOCK GPS NL-602U USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|works via usbmodem.device - ublox ag 6 chipset - 50 channel}}
|-
| &lt;!--Description--&gt;TOPGNSS ton Receiver &amp; Antenna GM702  u-blox 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|UBLOX7020 chip design bloc u-blox}}
|-
| &lt;!--Description--&gt;VK-162 G-MOUSE u blox 7 
| &lt;!--Vendor ID--&gt;0x1546
| &lt;!--Product ID--&gt;0x01a7
| &lt;!--Revision--&gt;0100
| &lt;!--Opinion--&gt;{{N/A|UBX G70xx with RMC VTG GSV TXT GLL GGA GSA}}
|-
| &lt;!--Description--&gt;VK-172 u-blox 7 G7020-KT gps gnss white pen stick receiver - over 1 inch long 
| &lt;!--Vendor ID--&gt;0x1546 
| &lt;!--Product ID--&gt;0x01a7
| &lt;!--Revision--&gt;0100 
| &lt;!--Opinion--&gt;{{N/A| detected as cdc controlled plug in device - 18x18x2mm patch antenna but can be slow to update - nmea 0183 and ublox binary protocol}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;GlobalSat BU-353 WaterProof USB GPS Receiver 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested SiRF Star III}}
|-
| &lt;!--Description--&gt;Haicom HI-206 USB GPS receiver with RS-232 interfaces, RJ11 and PS/II connector EB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|usb-serial prolific pl2303 detected but GSP3F SiRF Star IV technology not detected or bound}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;BT760Y, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 5 GPS chipset}}
|-
| &lt;!--Description--&gt;GM-65 USB GPS Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 6 GPS chipset - 65 channel}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 7 GPS chipset}}
|-
| &lt;!--Description--&gt;GM-65 USB GPS Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested Skytraq Venus 8 GPS chipset - 167 channels}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Garmin Colorado 300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} USB 
|-
| &lt;!--Description--&gt;Garmin Geko 101 201 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} limited waas enabled only - waypoints - aaa battery 
|-
| &lt;!--Description--&gt;Garmin Edge 200 bike mount 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin ForeRunner 10 15 watch 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Montana 600
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Dakota 10 20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Map76s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin Oregon 450T  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} USB nmea 0183 
|-
| &lt;!--Description--&gt;Garmin eTrex 10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - no nmea0183 sentences data stream output - configuration an option to set it to &quot;Garmin&quot; mode, or &quot;Mass Storage&quot; mode. Since the mass storage mode seems to be required for waypoint/track/etc data exchange, the 'Garmin' mode would be for this data stream. Yet putting it in that mode doesnt seem to produce anything.}}
|-
| &lt;!--Description--&gt;Garmin Oregon 650T 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Garmin GPSMAP 64S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|untested}}
|-
| &lt;!--Description--&gt;GPSMap 78S or GPSMap 76CSX which has a NMEA port for talking to Nav equipment
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|untested}}
|-
| &lt;!--Description--&gt;Garmin eTrex Vista Cx GPS Receiver 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested - 2AA battery}}
|-
| &lt;!--Description--&gt;Garmin GPSmap 276c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 2000 XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan 3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Magellan Triton 300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} SiRFstarIII™, Antenna Type Multidirectional Patch with WAAS, EGNOS, MSAS support 
|-
| &lt;!--Description--&gt;Magellan Triton 400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


==massstorage.class (MSC/UMS - most cameras and mp3 players)==

=== USB Card Readers ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;15%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Installing
! width=&quot;15%&quot; |Booting
! width=&quot;30%&quot; |Opinion
|-
| A-Tec Model CR-362 
| 
| 
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{N/A|untested}}
|-
| [http://www.belkin.com/IWCatProductPage.process?Merchant_Id=&amp;Section_Id=200406&amp;pcount=&amp;Product_Id=179164 Belkin 15 in 1 Card Reader]
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Conrad CP440 60 in 1 
| 
| 
| 
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works on a1k forum}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Genesys Gtech Logic 19 in 1
| 0x05E3
| 0x0710
| High 0200
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Hama 19 in 1 Card Reader 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| Hama 35 in 1 Card Reader 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Integral Single Slot SD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kingston USB 3.0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lexar microsd adapter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} but wider than Sandisk version - could block other slot if below 
|-
| Pretec CardDriver 
|
|
| 
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{no|no driver}}
|-
| Sandisk MicroMate 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;Sandisk MobileMate SD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Sandisk MobileMate Micro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} has satisfying 'click' when microsd inserted 
|-
| &lt;!--Description--&gt;Sandisk MobileMate Duo MicroSD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} no 'click' insertion uses pressure so future wear and tear issues 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Serena metal cased microsd only 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|Maybe}} hit or miss on quality 
|-
| &lt;!--Description--&gt;Serena &quot;Sandisk MobileMate&quot; look-alike 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|Maybe}} hit or miss on quality 
|-
| SilverCrest 16in1 
|
|
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{yes|works}}
|-
| &lt;!--Description--&gt;Transcend 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Transcend P5 8 in 1 TSRDP5K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Transcend P8 15 in 1 TSRDP8K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Zyxel integralmemory 8 in 1 
| 0x0aec
| 0x3260
|  
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| {{no|not detected}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Installing--&gt;
| &lt;!--Booting--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

=== USB Hard Drives ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Datel MaxDrive 
| 
| 
|  
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Inateck 2.5 Inch USB 3.0 Hard Drive Disk Enclosure/ Case (FE2001) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Full USB 3.0 port but plastic teeth keeping drive in place can snap 
|-
| &lt;!--Description--&gt;Inateck case (FE2002) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} full USB 3.0 port - updated design 
|-
| &lt;!--Description--&gt;Inateck case (FE3001) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} wider USB 3.0 port and no on/off switch  Jmicron JMS578 chipset
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Iomega Desktop Hard Drive 500GB, 3,5“, USB2.0 
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Samsung T3 SSD 
|
|
|
| {{N/A|untested}} USB 3.1 Gen 1 space grey / black metal/ plastic 
|-
| Samsung T5 SSD 
|
|
|
| {{N/A|untested}} USB 3.1 Gen 2 256GB 512GB alluring blue 1Tb 2Tb black unibody metal 
|-
| Samsung
|
|
|
| {{N/A|untested}}
|-
| Seagate
|
|
|
| {{N/A|untested}}
|-
| Seagate 
|
|
|
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Toshiba Canvio 1TB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Yes|partition fat32 or sfs to 100GB max - ntfs partitions not detected out of the box - select usb drive in trident prefs and press disable to shutdown}}
|-
| Verbatim 160GB Smartdisk 
| 
| 
|  
| {{yes|works }}
|-
| Western Digital USB 
|
|
|
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;WD Essential 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;WD Passport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== USB DVD CD ROM Drives ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;12.5mm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;12.5mm enclosure mini-sata dvd-rw 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested needs sole usb3 port to power it}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;9.5mm enclosure ECD829 mini-sata dvd-rw with Initio Corporation INIC-1618L SATA 
| &lt;!--Vendor ID--&gt;0x13fd
| &lt;!--Product ID--&gt;0x0840
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested but probably needs sole usb3 port to power it}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|}


=== USB to NGFF NVMe SDD HDD DVD CD ROM Drives ===

The older Jmicron JMS539B seems to result in massive filesystem corruption given the amount of corrupted content. Prehaps always avoided Jmicron and opted for Asmedia even if it costed a bit more. Realtek seems to be working okay for me generally speaking and newer Jmicron chipsets are less buggy – but evidently not perfect. 

From [https://goughlui.com/2025/08/17/psa-validate-your-storage-jmicron-jms583-kioxia-bg4-series-ssd-issue/ thread] 

Here is a [https://forums.anandtech.com/threads/stable-nvme-usb-adapter.2572973/ very long thread] that discusses data corruption and stability issues with these bridges. The majority of the posts are complaining of dropouts, hangs and the like, which usually down to either a poor USB 3.x implementation (SuperSpeed connections are very picky as to cables, ports and trace routing) or problematic compatibility. Regardless, the [https://www.legitreviews.com/jmicron-jms583-controller-version-matters-for-portable-usb-drives_219422 JMS583 is known to have several versions] noting that the last revision (C) in that article is a 2021 release which should fix earlier stability and cable quality compatibility issues. 
JMS583-STD-Release-v00.02.01.04-Bus Power.bin is the latest JMS583 firmware as of August 2025. 

Early firmware RTL9210 seems to have issues as well 


* RTL9210B
* JMS583 rev1 with firmware A2 or A3  

* RTL9210A
* JMS583 firmware 2.0.9 
* Asmedia ASM2362

* RTL9201A


The reference Hardware ID for the JMS583 chipset from JMicron is:
VID_152D&amp;PID_0583&amp;REV_0209
where &quot;VID_152D&quot; identifies a JMicron product;
&quot;PID_0583&quot; is the generation chipset;
&quot;REV_0209&quot; is the firmware version installed.

In the same way, the reference Hardware ID for the RTL9210 from Realtek is:
VID_0BDA&amp;PID_9210&amp;REV_3100
&quot;VID_0BDA&quot; is for a Realtek product, &quot;PID_9210&quot; is referred to the chipset and &quot;REV_3100&quot; to the firmware.


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;ASM1153E / ASM1153 with firmware 140509_A1_82_40 or 141126_A1_EE_82. Both supports UASP and TRIM on USB 3.1 Gen.1 adapter
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|works with sabrent ec-uasp}}
|-
| &lt;!--Description--&gt;ASM235CM Ugreen aluminum bridging the USB3.2 Gen2x1 to Serial ATA host interface 
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;TI 9261 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;ASM225
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;JMicron JMS578 issues USB 3.1 Gen.1 adapter 
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0578
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;JMicron JMS576 issues USB 3 to usb-c adapter 
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0576
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|orico}}
|-
| &lt;!--Description--&gt;JMS562 JMicron Technology Corp
| &lt;!--Vendor ID--&gt;152d
| &lt;!--Product ID--&gt;0562
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;JMS561U
| &lt;!--Vendor ID--&gt;0x152d
| &lt;!--Product ID--&gt;0x1561
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|works with sabrent ec-uasp}}
|-
| &lt;!--Description--&gt;VL716Q4 Orico black meshed aluminum usb c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Asmedia ASM1053E 
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;ASmedia ASM1051E
| &lt;!--Vendor ID--&gt;0x174c
| &lt;!--Product ID--&gt;0x55aa
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Asmedia ASM1053
| &lt;!--Vendor ID--&gt;0x174C
| &lt;!--Product ID--&gt;0x1536
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Asmedia ASM104x
| &lt;!--Vendor ID--&gt;0x1B21 
| &lt;!--Product ID--&gt;0x1042 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} 
|-
| &lt;!--Description--&gt;Unknown Chinese version 
| &lt;!--Vendor ID--&gt;0x0bc2
| &lt;!--Product ID--&gt;0x2312 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|sometimes works}}
|-
| &lt;!--Description--&gt;JMicron N5321 gr
| &lt;!--Vendor ID--&gt;0x152d
| &lt;!--Product ID--&gt;0xa583
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Initio Corp INIC-1618L mini slimline sata 6 + 7 pins to usb2 adapter 
| &lt;!--Vendor ID--&gt;0x13FD
| &lt;!--Product ID--&gt;0x0840
| &lt;!--Revision--&gt;0114
| &lt;!--Opinion--&gt;{{maybe|sometimes works mini sata to usb2 detects 201x laptop DVD as MassStorage(CD/DVD) but may need powered USB hub}}
|-
| &lt;!--Description--&gt;Unknown mini sata to usb3 adaptor 
| &lt;!--Vendor ID--&gt;0x01F75
| &lt;!--Product ID--&gt;0x0621
| &lt;!--Revision--&gt;0036 
| &lt;!--Opinion--&gt;{{maybe|sometimes works mini sata to usb3 detects 201x notebook DVD drive as MassStorage(SCSI) but 5V 1.5Amp needs powered hub to burn }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|}


=== External Floppy ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;[http://techtravels.org/amiga/amigablog/ Amiga Floppy Project]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;[http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=842 Catweasel Mk4]
| 0xE159
| 0x0001
| 0x00
| {{yes|[http://archives.aros-exec.org/index.php?function=browse&amp;cat=driver/storage works]}}
|-
| &lt;!--Description--&gt;[http://hxc2001.free.fr/floppy_drive_emulator/ HxC Floppy Emulator]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;[http://www.softpres.org/glossary:kryoflux KyroFlux]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}}
|-
| &lt;!--Description--&gt;Samsung SFD-321U/EP USB Floppy
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver}} 
|-
| &lt;!--Description--&gt;[http://www.cbmstuff.com/proddetail.php?prod=SCP SuperCard Pro] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://www.facebook.com/groups/greaseweazle Greaseweazle STM hardware], [https://cowlark.com/fluxengine/index.html Greaseweasel support], [https://github.com/keirf/Greaseweazle/wiki software], [https://amigakit.amiga.store/greaseweazle-p-91279.html buy], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FL-2501 USB Portable Diskette Drive  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2009 usb - [https://amiga.robsmithdev.co.uk/ Drawbridge] [https://github.com/RobSmithDev/ArduinoFloppyDiskReader software] ribbon cable compat with p/n 19308801-19 and s/n U356244 - model ASM P/N 27l4226 and FRU P/N 05k9283 - 
|-
| &lt;!--Description--&gt;Dell Floppy Drive Module USB External 3.5&quot; - Teac FD-05PUB 1.44mb 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2004 usb 1.1 
|-
| &lt;!--Description--&gt;USB FLOPPY DISK DRIVE (USB External Floppy Disk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://github.com/SukkoPera/OpenFlops OpenFlops] with [https://github.com/keirf/flashfloppy FlashFloppy] Gotech clone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;[https://github.com/hmerrett/HenryFlops HenryFlops reworked OpenFlops] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


==ptp.class (PTP and MTP - other cameras and mp3 players)==

=== Cameras ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Canon EOS 20D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004  }}
|-
| &lt;!--Description--&gt;Canon 350D (also known as the Digital Rebel XT/Kiss Digital N) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 DIGIC II processor 8-megapixel }}
|-
| &lt;!--Description--&gt;Canon PowerShot A430 A560 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 }}
|-
| &lt;!--Description--&gt;Canon EOS 400D (XTi) digital SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;Canon EOS 1000D also known as Rebel XS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10.2mp 720p  }}
|-
| &lt;!--Description--&gt;Canon 450D aka Rebel Xsi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 12.2mp }}
|-
| &lt;!--Description--&gt;Canon PowerShot S90 S95 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 2010 720p video - 10Mpixel }}
|-
| &lt;!--Description--&gt;Canon Powershot SD960 IS Digtal ELPH 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 Still Image: Exif 2.2 (JPEG), Movie: MOV (Image: H.264; Audio: Linear PCM) Lithium-ion Battery Pack NB-4L }}
|-
| &lt;!--Description--&gt;Canon EOS 500D aka Rebel  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 1080p 15.1MP Lithium  }}
|-
| &lt;!--Description--&gt;Canon EOS 550D 600D aka Rebel T2i T3i DSLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010-2011 1080p 18MP Lithium LP-E8 }}
|-
| &lt;!--Description--&gt;Canon Powershot S100 S110 S120  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011-2013 720p-1080p video 12.1MP and above versions - }}
|-
| &lt;!--Description--&gt;Canon EOS 1100D DSLR Camera aka Rebel T3 SLR, EOS Kiss X50 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p 10Mpixels Lithium  }}
|-
| &lt;!--Description--&gt;Canon EOS 650D 700D aka Rebel T4i T5i T6i SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2013 1080p 18Mpixels Lithium LP-E8 articulating flip out twistable screen }}
|-
| &lt;!--Description--&gt;Canon ELPH 300 HS (IXUS 220 HS) 230 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 blogging camera }}
|-
| &lt;!--Description--&gt;Canon PowerShot N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013  12.1 MP CMOS, DIGIC 5 Wifi Lithium Battery Pack NB-9L }}
|-
| &lt;!--Description--&gt;Canon Powershot G7 X, G7X-II 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014-2016 1080p video 12.1MP and above versions - }}
|-
| &lt;!--Description--&gt;Canon EOS 1300D DSLR Camera aka Rebel T6 SLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 1080p 16Mpixels Lithium  }}
|-
| &lt;!--Description--&gt;Canon Powershot G7x G5X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| G7X flip up and G5X flip out - same batteries - no external microphone input - }}
|-
| &lt;!--Description--&gt;Canon EOS M3 M5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| flip out - same batteries - }}
|-
| &lt;!--Description--&gt;Canon EOS 60D 70D 80D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 6D 7D 8D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;Canon 5D Mark II III IV DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Canon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji FinePix A850
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;FujiFilm Finepix F100fd
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji FinePix F810
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xf1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| pocketable exr cmos 12mp }}
|-
| &lt;!--Description--&gt;Fuji xt1  x-t1  x10 x-t10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 1080p }}
|-
| &lt;!--Description--&gt;Fujifilm x100 x100s x100t 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xPro1 xPro2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji xt2 / x-t2 x-t20 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4K video }}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;Fuji 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested}}
|-
| &lt;!--Description--&gt;GoPro HERO 3 HERO4 HERO 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon D100, D60
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 Compact flash storage - non interchangeable lenses up to 12.3MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D50, D50x 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005  storage - 6.1MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D70, D80, D90 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 Compact flash storage - 10MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D40, D40x 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007  storage -  10MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D300, D700
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008  storage -  12.3MP sensor }}
|-
| &lt;!--Description--&gt;Nikon D2Xs, D2Hs, D3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006-2008  storage - sensor }}
|-
| &lt;!--Description--&gt;Nikon D3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 720p video }}
|-
| &lt;!--Description--&gt;Nikon D5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 720p video unlike D3000 }}
|-
| &lt;!--Description--&gt;Nikon D6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 16mpixel}}
|-
| &lt;!--Description--&gt;Nikon D7000  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 16.2mp 720p video }}
|-
| &lt;!--Description--&gt;Nikon L26 L27 L28 L29 L31 Coolpix compact cameras 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p video - 2 AA - pocket sized }}
|-
| &lt;!--Description--&gt;Nikon D3100   
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 720p video 14.2mp}}
|-
| &lt;!--Description--&gt;Nikon D5100 DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 16.2mp  720p}}
|-
| &lt;!--Description--&gt;Nikon L810 L820 L830 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2014 720p video }}
|-
| &lt;!--Description--&gt;Nikon D4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012  storage - sensor }}
|-
| &lt;!--Description--&gt;Nikon D7100 D7200  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012-2014 up to 24.2mp 1080p video }}
|-
| &lt;!--Description--&gt;Nikon D3200  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 1080p 24MPixel}}
|-
| &lt;!--Description--&gt;Nikon D5200 D5300  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 24.1MP 1080p }}
|-
| &lt;!--Description--&gt;Nikon D800 D600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 1080p video sd card storage - dust/oil issue at start}}
|-
| &lt;!--Description--&gt;Nikon D3300 DSLR
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24.2MP 1080p  }}
|-
| &lt;!--Description--&gt;Nikon D500, a high-performance DX-format (APS-C) DSLR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 }}
|-
| &lt;!--Description--&gt;Nikon D5500 D5600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016-2018 24.1MP 1080p }}
|-
| &lt;!--Description--&gt;Nikon D810 D610 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 1080p video sd card storage }}
|-
| &lt;!--Description--&gt;Nikon D7300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4K UHD video }}
|-
| &lt;!--Description--&gt;Nikon D900 D850 D820 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 4k 46MP }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nikon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Olympus C-370 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 3.2mp }}
|- 
| &lt;!--Description--&gt;Olympus Camedia C-725 Ultrazoom
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 3mp aa batteries, }}
|-
| &lt;!--Description--&gt;Olympus Evolt E-500
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 8mp  }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Olympus Evolt E-410 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007  }}
|- 
| &lt;!--Description--&gt;Olympus Evolt E-510
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 10MP Live MOS sensor with TruePic III processor,  }}
|-
| &lt;!--Description--&gt;Olympus E-420
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10mp, compactflash and xD cards,  }}
|-
| &lt;!--Description--&gt;Olympus E-520
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10mp, compactflash and xD cards,  }}
|- 
| &lt;!--Description--&gt;Olympus E-620
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 12.3mp, compactflash, xD and microdrive cards,  }}
|- 
| &lt;!--Description--&gt;Olympus E-30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  }}
|- 
| &lt;!--Description--&gt;Olympus E-450 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 10mp,  }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Pentax * ist DS DSLR camera
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 6.1mp  }}
|- 
| &lt;!--Description--&gt;Pentax K10D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 10.2mp APS-C CCD no video and older manual Pentax K-mount lenses}}
|-
| &lt;!--Description--&gt;Pentax K20D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2008 14.6MP APS-C but no video recording mode }}
|-
| &lt;!--Description--&gt;Pentax K30 K-5 II 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2012 16MP full HD (1080p) recording at 24/25/30 fps}}
|-
| &lt;!--Description--&gt;Pentax K-3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24MP 1080p  }}
|-
| &lt;!--Description--&gt;Pentax K-3 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 24MP  }}
|-
| &lt;!--Description--&gt;Pentax K-3 III
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 25.7MP BSI CMOS sensor  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix LZ10 LZ20 DMC-LZ30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 720p video }}
|-
| &lt;!--Description--&gt;Panasonic TZ1 TZ5  TZ9 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix GH1 GH2 like the DMC-GH2HEB-K - GH3 DMC-GH3HEB-K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| Four Thirds (GH2)  MFT Micro Four Thirds (GH3) limited to 29mins recording }}
|-
| &lt;!--Description--&gt;Panasonic AF series AF100 AF101 AF102 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic Lumix DMC-G2 DMC-G3 G5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic TZ60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic DMC LX7 10 LX15 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic GF7 GX8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic G80 G85 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| micro 4/3 }}
|-
| &lt;!--Description--&gt;Panasonic GH4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| micro 4/3 - shooting in MOV or MP4 formats recording limited to sd card size but split files because the FAT32 file system only supports files up 4GB in size, which amounts to around 5 minutes of 4K (100mbps) footage - GH4 appears to create 4GB files as a rule, regardless of whether the memory card’s file system supports larger files or not - }}
|-
| &lt;!--Description--&gt;Panasonic GH5 gx80 gx85 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| Effective: 20.3 Megapixel 5184 x 3888 - 2 sd card slots compatible with high-speed, high capacity UHS-II - sd card v rating like the v90 should record at 60MB/s to be compatible with the GH5 in the All-I format - possible file corruption with .mdt files - new firmware 2.0 update, the Panasonic GH5 becomes the first 5K - }}
|-
| &lt;!--Description--&gt;Panasonic FZ2000 FZ2500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Panasonic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung WB100 WB1100 WB150 WB2200 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 16MP }}
|-
| &lt;!--Description--&gt;Samsung NX11 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung  NX200, NX20, NX1000 and NX210
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 20.3Mp APS-C sized CMOS image sensor }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sanyo Xacti CG65
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sanyo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 6.1MP }}
|-
| &lt;!--Description--&gt;Sony Cyber-shot DSC camera models W110 W220 H300 H400 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 10.2MP }}
|-
| &lt;!--Description--&gt;Sony Alpha DSLR-A230
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 10.2MP }}
|-
| &lt;!--Description--&gt;Sony Cybershot HX20V HX30V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 18mp 720p  - steady shot unit / optical block can cause buzzing noise and/or jumping image in lcd / viewfinder - dots are dirt and this voids the warranty }} 
|-
| &lt;!--Description--&gt;Sony Cybershot HX50V HX60V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 20.2MP 1080p  - steady shot unit / optical block can cause buzzing noise and/or jumping image in lcd / viewfinder - dots are dirt and this voids the warranty }} 
|-
| &lt;!--Description--&gt;Sony A77 A99 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 }}
|-
| &lt;!--Description--&gt;Sony WX100 WX150 wx220 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 2014 }}
|-
| &lt;!--Description--&gt;Sony NEX-6 Sony NEX-7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 16 to 24MP }}
|-
| &lt;!--Description--&gt;Sony NEX-3N Sony NEX-5N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 16MP }}
|-
| &lt;!--Description--&gt;Sony α58 Sony α68 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 20.1 MP  2014 24mp }}
|-
| &lt;!--Description--&gt;Sony rx100 mk III 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 20.1MP 1.0-type back-illuminated Exmor R CMOS sensor, often after boot-up, the motor starts running for no reason for first versions' -  }}
|-
| &lt;!--Description--&gt;Sony α5000 a5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 20.1 Megapixel APS-C Exmor APS HD CMOS 1080p Sony E-mount [https://github.com/ma1co/Sony-PMCA-RE hack] using [https://www.youtube.com/watch?v=8M4hR9HiOzM this] }}
|-
| &lt;!--Description--&gt;Sony α6000 a6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 24MP APS-C sensor }}
|-
| &lt;!--Description--&gt;Sony α7 A7S a7r a7c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 mirror less - more compact }}
|-
| &lt;!--Description--&gt;Sony α77 II, α99 II, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 24.3 MP,  2016 42.4mp   }}
|-
| &lt;!--Description--&gt;Sony rx100 mk IV V 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 2016 }}
|-
| &lt;!--Description--&gt;Sony RX0 RX zero, RX0 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 2017 }}
|-
| &lt;!--Description--&gt;Sony α6500 a6500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 24.2MP APS-C sensor 4K }}
|-
| &lt;!--Description--&gt;Sony α7 Alpha 7 II E-mount interchangeable lens mirrorless camera 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 24.2mp,  }}
|-
| &lt;!--Description--&gt;Sony α7 A7Sii a7r a7c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 mirror less - more compact }}
|-
| &lt;!--Description--&gt;Sony a7 III α77 ILCE7M3/B Full-Frame Mirrorless Interchangeable-Lens Camera
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 24.2mp,  }}
|-
| &lt;!--Description--&gt;Sony ZV-1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 24mm optical zoom, }}
|-
| &lt;!--Description--&gt;Sony ZV-1F
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 entry-level vlogging, 1-inch 20.1MP, ultra-wide 20mm f/2 prime lens}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}

&lt;pre &gt;
Lens Mounts

Canon EF EF-S
Nikon F 
Panasonic 
Olympus OM 
Pentax DA, FA, F, A, M, and K series
Fujifilm X mount 
&lt;/pre &gt;

&lt;pre &gt;
Sensors

APS-C 
S35 
Full Frame 
43 Four Thirds 
M43 MFT Micro four thirds 
&lt;/pre &gt;


=== Digital Voice Recorder Dictaphone Dictation Machine Handheld ===
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-7000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2011 }}
|-
| &lt;!--Description--&gt;Olympus VN-7200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested 2012 no usb }}
|-
| &lt;!--Description--&gt;Olympus VN-7500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2012 }}
|-
| &lt;!--Description--&gt;Olympus VN-7600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2013 }}
|-
| &lt;!--Description--&gt;Olympus WS-100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested usb}}
|-
| &lt;!--Description--&gt;Olympus VN-7700 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-8600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-711PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-712PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus VN-731PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Olympus WS-811
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested slide out usb-a - aaa battery - ok recordings }}
|-
| &lt;!--Description--&gt;Olympus VN-540PC Olympus VN-541PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Philips DVT1250
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX470
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX560
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony ICD-UX570 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


=== USB eBooks Readers drm free EPUB version 2.0.1 (2007), 3.0 (2011), 3.1 (2015) or [https://www.w3.org/TR/epub-33/ 3.3 (2024)] [https://github.com/thansen0/sample-epub-minimal epub examples] formats access ===

EPUB file format is an open standard based on XHTML for content and XML for metadata, contained in a zip file archive 

PDF v2.0 in 2017, 2009 takeover by ISO Org, 1.7 in 2006 , 1.6 in 2005, 1.4 in 2001, 1.3 in 1999, 1.0 in 1993 


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Access
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Barnes and Noble Nook Simple Touch NST BNRV300 
| &lt;!--Vendor ID--&gt;0x2080
| &lt;!--Product ID--&gt;0x0003
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;when finding the right micro usb cable that works, internal nook memory not accessible but sd card fat32 readable and writable outside 
| &lt;!--Opinion--&gt;{{N/A|2011 6in 600x800 e-ink 16 grayscale .jpg}} battery remove sd card and Torx T5 back top for Cameron Sino CS-BNR003SL - USA 1.2.2 md5sum 351e26527e80156183e74be2da2ce89f *nook_1_2_update.zip - 1.2.1 UK fdba3981f7f221cc5143db6329645bc2 *nook_1_2_update.zip - skip registration, Turn on the device, but do NOT start setting it up. Hold down the top right button on the front of the device and slide your finger from left to right across the top of the E Ink screen. A ‘Factory’ button should appear in the top left corner of the screen. Press it. Once in the Factory menu, hold down the top right button on the front of the device and tap the bottom right corner of the screen should now see a ‘Skip Oobe’ button. Tap that and the Nook should finally load the home screen. Poor battery management - 
|-
| &lt;!--Description--&gt;Barnes and Noble Nook Simple Touch with Glowlight 
*2012 Nook Simple Touch with GlowLight BNRV350 
*2013 Nook GlowLight BNRV500
| &lt;!--Vendor ID--&gt;0x2080
| &lt;!--Product ID--&gt;0x0004 0x0007 
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2012 untested }} perform a hard reset: Turn off the nook completely, turn it on, as soon as you see the screen flash begin holding the bottom page turn buttons until the screen flashes with a message asking reset, press the 'n' key twice to start the reset - Poor battery management - 
|-
| &lt;!--Description--&gt;Nook Glowlight 4 Plus 7.8-inch screen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} Poor battery management - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
*NOOK 1st Edition (2009-2018) BNRZ100
*NOOK Color (2010-2024) BNRV200
*NOOK Tablet (8GB/16GB) (2011-2024) BNTV250A / BNTV250
*NOOK HD (2012-2024) BNTV400 
*NOOK HD+ (2012-2024) BNTV600 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Elonex 511EB 
| &lt;!--Vendor ID--&gt;045e:ffff
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2009 untested Preferences-&gt;advanced-&gt;debug device detection}}
|-
| &lt;!--Description--&gt;[https://jaforeck.wordpress.com/2012/08/05/ready-to-meet-viktor-navorski-gained-access-to-elonex-621ebs-terminal-52/ Elonex 621EB] eBook 
| &lt;!--Vendor ID--&gt;0x1f85
| &lt;!--Product ID--&gt;0x1688
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;unlocked ootb 
| &lt;!--Opinion--&gt;{{N/A|2010 untested usb mini charging 6&quot; diagonal eInk Screen - 800 x 600 pixels, 8 Level 166dpi Paperlike screen, Embedded 1GB Flash NAND, full SD Card Slot up to 16GB - WAV, MP3, JPG, PNG, BMP, GIF support and ePub and PDF(with reflow) (TXT, HTML) support}}
|-
| &lt;!--Description--&gt;Elonex 700eb 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2011 untested adjust screen blanking by menu then settings then device standby, you can then turn it off}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;iRiver Story HD eBook 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }} freescale imx.508 arm mcimx508cvkbb cpu with 2gb samsung nand, m13892aj charging chip, eb07_main_mp1_110321 mobo, mini usb, atheros ar61026 wifi - 
|-
| &lt;!--Description--&gt;iRiver Story 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Rakuten Touch A/B	kobo3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Touch C, Kobo Mini, Kobo Glo N613, Kobo Aura HD N514 N204	kobo4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Aura, Kobo Aura H2O, kobo5
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2013 6in untested }}
|-
| &lt;!--Description--&gt;Kobo Aura H2O Edition 2 v1, Kobo Glo HD, Kobo Touch 2.0, Kobo Aura ONE N709, Kobo Aura ONE Limited Edition, Kobo Aura Edition 2 v1 N236,	kobo6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Aura H2O Edition 2 v2, Kobo Aura Edition 2 v2, Kobo Nia, Kobo Clara HD, Kobo Forma, Kobo Libra H2O	kobo7
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kobo Elipsa, Kobo Sage	kobo8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
*Kobo Libra 2  kobo9, Kobo Clara 2E	kobo10, Kobo Elipsa 2E	kobo11
*Kobo Libra Colour	kobo13, Kobo Clara BW, Kobo Clara Colour	kobo12
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pandigital Personal eReader aka? Papyre 6.2 very similar to BQ Avant Firmware
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2011  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PRS 300 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PRS 350 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2009 epub bbeb cbz untested }}
|-
| &lt;!--Description--&gt;Sony PRS-650
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle K1 D00111 - Main Menu=: Settings: Menu=: Device Info shows S/N 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0002
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;256mb 
| &lt;!--Opinion--&gt;{{N/A|2007 untested Marvell Xscale PXA255}}
|-
| &lt;!--Description--&gt;Kindle K2, D00511 170-1012-00, D00701 D00801 S11S01B  
* k2 means K2 US
* k2i means K2 GW
* dx means KDX US
* dxi means KDX GW
* dxg means KDX Graphite 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0003
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb unless jb 
| &lt;!--Opinion--&gt;{{N/A|2010 untested Freescale i.MX31 }} the Kindle is a small computer running Linux 2.6 on an ARM processor
|-
| &lt;!--Description--&gt;AMAZON Kindle D00901 3rd Gen with keyboard - Menu, Settings for S/N and then Menu again to choose Update 
* S/N starts B006 means k3g aka K3 3G US 
* S/N starts B008 means k3w aka K3 WiFi 
* S/N starts B00A means k3gb aka K3 3G UK EU 
 - debug mode with ;debugON and ~help
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;{{yes|4Gb internal no access until jailbroken JB}} 
| &lt;!--Opinion--&gt;2010 with mobi and azw3 formats only - micro usb 5v 0.85a - freescale i.mx35 ARM soc with 12bit parallel interface with epson e-ink cpu, 256MB synchronous dynamic RAM, 4GB eMMC internal memory only but no sd slot, MC13892 PMIC - atheros wifi 54mbit pci-e a e keyed wifi - ?? later models wm96103 audio codec - display has 2Mbit serial memory ic on ribbon cable with 4bpp inverse grayscale display not touchscreen - 3g module - screen replacement really annoying - 4 test points near T07 = TX RX GND ? - as of 2025, JB v0.13.N, MKK2014, MKK2025, KUAL, KoReader Legacy2025, and maybe later SS v0.47.N, Python 0.14.N, Fonts v5.16.N, USBNet v0.57.N - USB-downloader mode when Vol+ is pressed during startup - Shift + Alt + M for Minesweeper - 
|-
| &lt;!--Description--&gt;Amazon Kindle 4th Generation k4 D01100 two buttons, square movement and two buttons at bottom 
*B00E 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0005
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb unless jb with USB MS, USBMS aka also known as USB MSC or UMS
| &lt;!--Opinion--&gt;{{N/A|2012 untested }} plastic back clipped in but taped down to battery cover, use Torx T5 to remove battery cover screws - battery glued down S2011-001-A 515-1058-01 DR-A015 MC-265360 - Freescale i.MX508 SOC, 2Gb eMMC storage, 256MiB of LPDDR1, MC13892 PMIC - vendor modified u-boot imximage based on u-boot v2009.08 - USB-downloader mode press the fiveway down button during startup resetmykindle - as of 2025 upgrade firmware from 4.1.x and to 4.1.4, sign into account and copy jb.1.8 bits, mkk-2014, mkk-2025, kual and then uninstall kual, koreader2025 - 
|-
| &lt;!--Description--&gt;Kindle Touch WiFi (Kindle 5th Gen) D01200 K5, KT
*Once signed into an Amazon Account get S/N under Settings -&gt; Device Options
*B00F 	Kindle Touch 3G + WiFi (Kindle 5) (U.S. and Canada) [Mostly]
*B011 	Kindle Touch WiFi (Kindle 5)
*B010 	Kindle Touch 3G + WiFi (Kindle 5) (Europe) 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0006
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;4gb unless jb 
| &lt;!--Opinion--&gt;{{N/A|untested }}  touchscreen i.MX508 SOC, 256MiB of LPDDR1 and USB-downloader mode by the SOC microcode when a specific key is pressed during startup: the home button on model D01200 - update firmware 5.3.2 to 5.3.7.3, access account, 
|-
| &lt;!--Description--&gt;Kindle PaperWhite 3G + WiFi (U.S.) [Mostly] PW 
&lt;pre&gt;
B024 	Kindle PaperWhite WiFi 
B01B 	Kindle PaperWhite 3G + WiFi (U.S.) [Mostly]
B020 	Kindle PaperWhite 3G + WiFi (Brazil) 
B01C 	Kindle PaperWhite 3G + WiFi (Canada)
B01D 	Kindle PaperWhite 3G + WiFi (Europe)
B01F 	Kindle PaperWhite 3G + WiFi (Japan)
&lt;/pre&gt;
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0007
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb 
| &lt;!--Opinion--&gt;{{N/A|untested Freescale i.MX508 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0008
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle PaperWhite 2 (2013) PW2 
*B0D4, 90D4 WiFi (U.S., Intl.) 
*B05A, 905A WiFi (Japan)
*B0D5, 90D5 3G + WiFi (U.S.) [Mostly]
*B0D6, 90D6 3G + WiFi (Canada] 
*B0D7, 90D7 3G + WiFi (Europe)
*B0D8, 90D8 3G + WiFi (Russia)
*B0F2, 90F2 3G + WiFi (Japan)
*B017, 9017 WiFi (4GB) (U.S., Intl.)
*B060, 9060 3G + WiFi (4GB) (Europe)
*B062, 9062 3G + WiFi (4GB) (U.S.) [Mostly]
*B05F, 905F 3G + WiFi (4GB) (Canada)
*B061, 9061 3G + WiFi (4GB) (Brazil) 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0009
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;2gb or 4gb 
| &lt;!--Opinion--&gt;{{N/A|untested }} PW2 uses Freescale/NXP i.MX6 SoloLite 
|-
| &lt;!--Description--&gt;Kindle Paperwhite 3 PW3 i.e. Kindle 7th gen 
*G090G1 (2015) WiFi 
*G090G2 (2015) 3G + WiFi (U.S.) [Mostly] 
*G090G4 (2015) 3G + WiFi (Mexico)
*G090G5 (2015) 3G + WiFi (Europe, Australia) 
*G090G6 (2015) 3G + WiFi (Canada)
*G090G7 (2015) 3G + WiFi (Japan) 
*G090KB (2015) WiFi 
*G090KC (2015) 3G + WiFi (Japan) 
*G090KE (2016) 3G + WiFi (International) White 
*G090KF (2016) 3G + WiFi (International) White 
*G090LK (2016) WiFi, 32GB (Japan) 
*G090LL (2016) WiFi, 32GB (Japan) White 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x000A
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;4gb 
| &lt;!--Opinion--&gt;{{N/A|untested }} ease up glued down front bezel rim panel gently, remove 11 screws underneath and lift screen up from bottom end - battery underneath - 
|-
| &lt;!--Description--&gt;Kindle PaperWhite 4 (2018) PW4
*G000PP, G8S0PP WiFi, 8GB
*G000T6, G8S0T6 WiFi, 32GB
*G000T1  WiFi+4G, 32GB
*G000T2  WiFi+4G, 32GB (Europe)
*G00102  WiFi, 8GB (India)
*G000T3  WiFi+4G, 32GB (Japan)
*G0016T, G8S16T WiFi, 8GB Twilight Blue
*G0016Q, G8S16Q WiFi, 32GB Twilight Blue
*G0016U  WiFi, 8GB Plum
*G0016V, G8S16V WiFi, 8GB Sage 
*G00103  WiFi, 32GB (India) 
*G0016R  WiFi, 32GB Plum
*G0016S  WiFi, 32GB Sage 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x000B
| &lt;!--Revision--&gt;100
| &lt;!--Access--&gt;8gb or 32gb
| &lt;!--Opinion--&gt;{{N/A|untested Freescale/NXP i.MX6 SoloLite }}
|-
| &lt;!--Description--&gt;Kindle Oasis 2 and 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 32gb
| &lt;!--Opinion--&gt;{{N/A|untested NXP i.MX7D  }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 16gb
| &lt;!--Opinion--&gt;{{N/A|untested MediaTek MT8110  }}
|-
| &lt;!--Description--&gt;Kindle 11 Scribe 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;8gb or 16gb
| &lt;!--Opinion--&gt;{{N/A|untested MediaTek MT8113 }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;16gb or 32gb
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kindle Paperwhite Gen 11 and 12 - Signature 
| &lt;!--Vendor ID--&gt;0x1949
| &lt;!--Product ID--&gt;0x0
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;16Gb or 32Gb 
| &lt;!--Opinion--&gt;{{unk|2024 account not blocked,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://github.com/Modos-Labs Modos Labs] open source e-ink 60Hz 75Hz caster controller and glider monitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xteink X3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.xteink.com Xteink X4] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;2025 4.3in 220ppi no touchscreen so [https://www.youtube.com/watch?v=R7RuokaVauo buttons navigation] - 650mAh battery - micro-sd slot up to 512Gb covering epub, txt, and jpg in directories with [https://github.com/crosspoint-reader crosspoint reader] esp32 cpu custom rom firmware using [https://xteink.dve.al/ Flash website] on usb-c but no ecosystem store 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;15%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |Access
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Amazon D01400 Kindle Fire (1st Generation) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{No|2010 too old }} android 2.3 and touchscreen digitizer fails often, battery SWE P/N 1002000004742 Model KC1 (EU) QP01 (US) 16.28whr, ti 257epl9l omap 4430 with elpida 88164b3pf-10-f88164b3pf or hynix,  mobo ??,, DAOKC1MB8F0 Rev F, ti aic3110 audio codec, 
|-
| &lt;!--Description--&gt;Amazon Fire 7in X43260 X43Z60 2nd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 untested FireOS Android 4 omap 4460 and PowerVR SGX540}}
|-
| &lt;!--Description--&gt;Amazon Kindle Fire HD (3rd Gen) P48WVB4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 untested }}
|-
| &lt;!--Description--&gt;Amazon 
*Amazon Fire HD10 (2015) 
*Amazon Fire HD8 (2015)	
*Amazon Fire HD7 (2015)	(5th Generation) 7 inch 8GB SV98LN 
*Amazon Fire HD7 (2014)	
*Amazon Fire HD6 (2014) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|untested android 5.1 max}}
|-
| &lt;!--Description--&gt;
*Amazon Fire 10 (2017) 
*Amazon Fire 8 (2017) 7th Gen 8 inch SX034OT 
*Amazon Fire 7 (2017) (7th Generation) 7 inch 16GB (SR043KL) 
*Amazon Kindle Fire 7 (7th Generation) 7 inch 8GB WIFI Tablet (SR043KL) 
*Amazon Fire HD8 (2016)	
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| Android 5.1 max 7in screen resolution of 1024 x 600, }}
|-
| &lt;!--Description--&gt;
*Amazon Fire 10/10+ (2021) 
*Amazon Fire 8/8+ (2020) 
*Amazon Fire 10 (2019) 
*Amazon Fire 7 (2019) 
*Amazon Kindle Fire 7 9th Gen 16GB M8S26G 
*Amazon Fire 8 (2018) 8th Gen 8 inch 32GB L5S83A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| android 9 max}}
|-
| &lt;!--Description--&gt;Amazon 
*Amazon Fire HD 10 (2023)	
*Amazon Fire Max 11 (2023)	
*Amazon Fire 8 (2022)	
*Amazon Fire 7 (2022)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| android 11 max}}
|-
| &lt;!--Description--&gt;Amazon Kindle Scribe 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;Amazon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Minimal Phone, Mudita Kompakt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| eink }}
|-
| &lt;!--Description--&gt;Bigme B751C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2022 android untested }}
|-
| &lt;!--Description--&gt;Bigme B7 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;Bigme B6
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android based color eink small - 300dpi b/w 150ppi color -}}
|-
| &lt;!--Description--&gt;Bigme 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| e-ink }}
|-
| &lt;!--Description--&gt;Bigme Hibreak Pro, Hisense A9
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| e-ink}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;iFlyTech AINote 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;iFlyTech AINote 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Meebook 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Page Palma 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 android untested }}
|-
| &lt;!--Description--&gt;Onyx Boox Leaf3C
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Go Color 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 untested 7in e-ink e-reader android tablet }}
|-
| &lt;!--Description--&gt;Onyx BooxTab Ultra X C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Note Max Air4 C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Leaf5C
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Poke6S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox Go 10.3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Onyx Boox MC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| color e-ink 13.3in }}
|-
| &lt;!--Description--&gt;Onyx Boox Go 10.3 (Gen 2) Lumi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 b/w eink with front light, no EMR annd capacitance pen,  }}
|-
| &lt;!--Description--&gt;Onyx Moaan Pantone 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;reMarkable 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2021 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable Paper Pro Move 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{N/A|2024 untested but subscriptions needed for some features }}
|-
| &lt;!--Description--&gt;reMarkable 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 untested but subscriptions needed for some features}}
|-
| &lt;!--Description--&gt;reMarkable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Supernote A5 X2 Manta
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;Supernote A6 X2 Nomad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk|2023  }}
|-
| &lt;!--Description--&gt;Supernote 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tolino Vision 2 3 4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Tolino Epos2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viwoods AI Paper and AI Paper Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Access--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


==printer.class - PostScript 3 and internal ghostscript drivers==


As the only printer driver that AROS supports natively is Postscript, our focus is on applications that generally output postscript formatted data for printing purposes and since the general Joe Public finds postscript capable printer very expensive, postscript interpreters (eg ghostscript) have been developed aas a cheaper option which sit in between postscript data streams and non postscript (HP PCL?) printers.

Set up Printer Prefs for Postscript and set the print to file option.


Ghostscript has internal printer drivers

 gs -h

and with something like

 gs -sDEVICE=stcolor -r300 -sOutputFile=RAM:tempfile gs813:examples/tiger.ps
 copytopar ram:tempfile

It checks if in RAM: exists a outputfile (Cinnamon can export to PS postscript) then it sends this via copytopar to the printer. There was only support for parport (parallel) but Terminillis added support for USB and ethernet. A big issue with using ghostscript for drivers is that data has to originate as postscript (.PS) file.

 gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=ljet4 -sOutputFile=RAM:tempfile RAM:file.pdf

the ljet4 output device generates PCL

also the pxlmono driver, which generates more generic PXL (PCL 6)

 gs -q -sstdout=%stderr -sDEVICE=pswrite -sOutputFile=- -dBATCH -dNOPAUSE -dPARANOIDSAFER testpage-a4.ps &gt; test.pdf

 gs -q -sstdout=%stderr -sDEVICE=pxlmono -sOutputFile=- -dBATCH -dNOPAUSE -dPARANOIDSAFER test.pdf &gt; test.pxl


Printers supported by ghostscript...Explanation [http://freebooks.by.ru/view/RedHatLinux6Unleashed/rhl6u151.htm here] or [http://www.gnu.org/software/ghostscript/devices.html here] and [http://pages.cs.wisc.edu/~ghost/doc/printer.htm here]

&lt;pre&gt;
bit            cljet5          ljet4d          pjxl300         pxlcolor
bitcmyk        cljet5c         ljetplus        pkm             pxlmono
bitrgb         deskjet         nullpage        pkmraw          stp
bj10e          djet500         pbm             pksm            tiff12nc
bj200          epswrite        pbmraw          pksmraw         tiff24nc
bjc600         faxg3           pcx16           png16           tiffcrle
bjc800         faxg32d         pcx24b          png16m          tiffg3
bmp16          faxg4           pcx256          png256          tiffg32d
bmp16m         ijs             pcxcmyk         pnggray         tiffg4
bmp256         jpeg            pcxgray         pngmono         tifflzw
bmp32b         jpeggray        pcxmono         pnm             tiffpack
bmpgray        laserjet        pdfwrite        pnmraw          uniprint
bmpmono        lj5gray         pgm             ppm             x11
bmpsep1        lj5mono         pgmraw          ppmraw          x11alpha
bmpsep8        ljet2p          pgnm            psgray          x11cmyk
cdeskjet       ljet3           pgnmraw         psmono          x11gray2
cdj550         ljet3d          pj              psrgb           x11gray4
cdjcolor       ljet4           pjxl            pswrite         x11mono
cdjmono
&lt;/pre&gt;

=== Internal Ghostscript support ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| Canon BJ10e
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested with Ghostscript drivers }}
|-
| Canon BJ200
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested with Ghostscript drivers }}
|-
| Epson Stylus Color 600 parport inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - internal ghostscript support}}
|-
| &lt;!--Description--&gt;HP Deskjet 500 Parallel Port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| HP1220C/PS USB Inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - PS3 emulation only}}
|-
| HP 1700PS USB Inkjet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{yes|works - PS3 emulation only}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| &lt;!--Description--&gt;LJ-III
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested HP PostScript Cartridge Plus (C2089A) a.. Press &lt;ON LINE&gt; (and take machine off line)
b.. Press &lt;Plus &amp; Minus&gt;, and while holding, press &lt;ALT&gt; and &lt;RESET&gt; together and watch the LCD and let go when the desired mode is displayed.}} 
|-
| &lt;!--Description--&gt;HP Laserjet 4 4M 4MP (1992)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested PS2 emulation HP 4 with optional ps cartridge - HP 4M and 4M+ built in}} 
|-
| &lt;!--Description--&gt;HP Laserjet 4L Parport 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{no|PCL5 HP 4L only - no postscript}} 
|-
| &lt;!--Description--&gt;HP Laserjet 5M (1995) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS2 emulation
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested you can try the ljet4 for the various lj5 drivers which produce various flavours of PCL. The 4, 4+ and 5 only really had one issue that plagued them, and it's hardly an issue at all. You would get accordian jams at the exit. A lot of people worked through this by pulling the sheet out before it got caught. Easily fixed by opening back door and scrubbing grime off of rubber rollers. }}
|-
| HP Laserjet 5L Parport (1997) (C3906A bk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;{{N/A}}
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{no|PCL5 support only.}}
|-
| HP Laserjet 5P 6P (1995) (C3906A bk) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested HP 5p, 6p - Less tiny, slightly less slow. They are pretty bullet proof for low volume best to get postscript module though }}
|-
| HP Laserjet 2100 2100N 2100TN (1999) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested PS2 emulation }}
|-
| HP Laserjet 4000 Series Parport (1998) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|PS3 emulation only (4200 and 4600 have issues)}}
|-
| HP Laserjet 4050 Parport (1999) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|works }}
|-
| HP Laserjet 5000 Parallel Port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|}}
|-
| HP LaserJet 6M, 1200, 1300, 2100, 2200, P2050 (and P2055) P3005, M3025, M3027, 3050, 3300, 4000, 4050, 4100, 4200, 4300, M4345, P3005, P3015, P4010, P4410, M5025, M5035, 5100, 5200, 8000, 8100, or 9000 series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;PS3 emulation optional only
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{untested }}
|-
| &lt;!--Description--&gt;HP Color LaserJet 2550, 3700, 4650, 8500 and 8550 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Lexmark Optra C, T, and W series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Xerox Phaser 850, 860 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

=== USB Monochrome ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Postscript Support
| GutenPrint Support
| Hardware Issues 
| Running Costs 
| Opinion 
|-
| &lt;!--Description--&gt;Brother HL-1270N
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRScript
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL-3070CW Printer USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|BR-Script3 (PS3) untested}}
|-				
| &lt;!--Description--&gt;Brother HL5240 HL5240L 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRScript (PostScript Level 2) 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL-7050N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR3
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother MFC-7860DW Monochrome B/W BW 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR-Script BRScript (PostScript Level 3) 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother HL4570CDWT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Epson EPL-6200 Laser Printer USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|cheap to buy but untested - running cost unknown}}
|-		
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kyocera FS-1370DN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| HP LaserJet CP1515n USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|cheap to buy but untested - running cost unknown}}
|-
| &lt;!--Description--&gt;Lexmark Optra E312 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;built in? 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}


=== USB Color ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;10%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;10%&quot; |Postscript Support
! width=&quot;10%&quot; |GutenPrint Support
! width=&quot;20%&quot; |Hardware Issues 
! width=&quot;10%&quot; |Running Costs 
! width=&quot;20%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother hl-3075cw
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BR-Script 3 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Brother MFC-9120CN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;BRS3 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;HP Color LaserJet 2500L (2003) USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| HP Color LaserJet 2550L 2550Ln (2004) USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| HP Color LaserJet CP1218, 2605, 3700, 4500, 4600, or 4650 series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{maybe|slow printing}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Konica Minolta Magicolour 4650EN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| Kyocera FS-1010 FS-1010N 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| Kyocera FS-C5200DN
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Kyocera Mita FS-1030D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;Kyocera FS-C5150DN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Lexmark C540n 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| Lexmark [http://www1.lexmark.com/products/view/Printers/Lexmark%20C780n/catId=cat10006-category&amp;prodId=3907-product C780n]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;{{yes|works PS3 emulation only}}
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| OKI C3600 Color Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Samsung CLP-315
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;untested 
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| Xerox 618x Color Laser 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Postscript Support--&gt;
| &lt;!--GutenPrint Support--&gt;
| &lt;!--Hardware Issues --&gt;
| &lt;!--Running Costs --&gt;
| &lt;!--Opinion--&gt;{{N/A|untested }}
|-
|}

See [http://www.irseesoft.de/tp_drive7.htm here] for compatibility with TP7 (TurboPrint 7) Last update 2004. Not tested under emulation. Janus-UAE, Emumiga, 

OS3.x support via [http://aminet.net/package/comm/tcp/NetPrinter NetPrinter] and [http://www.os4depot.net/index.php?function=browse&amp;cat=driver/printer OS4 drivers] and [http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=33955&amp;forum=27#622365 experiences].

usbparallel.device

untested with USB-&gt;Centronics - The printer.class is rather 'clever'. It remembers to which unit the printers were connected (until you reboot). So if you first plug in Printer1, it gets unit 0, and Printer2 gets unit 1. If you now remove both printers and replug Printer2, it still will get unit 1 and not 0. This is used not to confuse the programs using the different units (moreover, if some program uses the usbparallel.device unit of an USB printer, and the printer is unplugged, the device unit cannot be freed immediately as the application still keeps it open). Sticking to the same units is generally a good idea I think (and therefore this mechanism is also used with all other classes creating exec.devices).

You may not send a short packet (packet less than maxpktsize == 64) nor zero byte packets until the very last byte of your printout. Otherwise the printer will silently ignore the data you sent. Some printer drivers print very short sequences that never fill the endpoint buffer, so printer ignore them. Bufferize all printer driver writes in the ieee1284.device and send them by epsize packets. So my hppsc2210 works fine with a classic HP560C driver, on a classic A2000 subwayized :)


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Beige cream D shape centronics end (Prolific chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Belkin F5U002v1 centronics end (chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Belkin F5U002VEA v2 centronics end (Prolific PL2305L chipset) 
| 
| 
| 
| {{N/A|untested}}
|-
| DYNAMODE USB-C-PP-1284 USB to 36pin (Prolific 2305 chipset) 
| 0x067b
| 0x2305
| 0x02
| {{N/A|untested but similar to BAFO below}}
|-
| IOGear GUC1284B 
| 
| 
| 
| {{N/A|untested}}
|-
| My-Link (raised ellipse on centronics plastic end) (unknown chipset) 
| 
| 
| 
| {{N/A|untested but more expensive }}
|-
| NEWLink (Prolific chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| Targus PA096E centronics end (chipset?) 
| 
| 
| 
| {{N/A|untested}}
|-
| TRENDnet ware TU-P1284
| 
| 
| 
| {{N/A|untested}}
|-
| True PnP (Prolific chipset 2305) cheap 36pin Centronics (series of ridges along both short sides) 
| 0x067b
| 0x2305
| 2.00
| {{N/A|untested on BAFO BF-1284 but reports of poor quality and lack of support on other OSs }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| Transparent See Through Blue 
| 
| 
| 
| {{N/A|untested but possible poor quality build }}
|-
| Dynamode USB-PARALLEL 25pin female (prolific) 
| 0x067b
| 0x2305 
| 0x02 
| {{N/A|untested}}
|-
| FDL USB to 25pin 
| 
| 
| 
| {{N/A|untested}}
|-
| PlusKom USB to 25pin female connector for printer (IEEE 1284) 
| 
| 
| 
| {{N/A|untested}}
|-
| QinHeng Electronics (CH340S chipset) 
| 0x1a86
| 0x7584
| 
| {{N/A|untested curvy sides - flat top }}
|-
| StarTech 
| 
| 
| 
| {{N/A|untested}}
|-
| Syba SD-USB-DB25 
| 
| 
| 
| {{N/A|untested}}
|-
|}


==rawwrap.class - some old flatbed scanners supported==

Scandal is the MUI frontend to [http://www.ppa.pl/bugtracker/ Betascan Bugtracker] and [http://aminet.net/search?query=betascan Search for Betascan scanner drivers] derived from [http://www.sane-project.org/sane-backends.html sane backends] 


[http://www.sane-project.org/sane-backends.html#S-EPSON2 Epson2] 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Expression 1600 1640XL 1680 10000XL
| 0x04b8
| 0x0107 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Prefection 1200U, 1200 Photo, 
| 0x04b8
| 0x0104
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 1240U
| 0x04b8
| 0x010b
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{[https://amigaworld.net/modules/newbb/viewtopic.php?topic_id=45760&amp;forum=25 works]|Needs 24V 0.8A psu but in Trident, click on &quot;Classes&quot;, then on &quot;rawwrap.class&quot;, then on &quot;Configure&quot;. There, under &quot;Global&quot;, activate the Option &quot;Bind to Vendor/Unknown Interfaces&quot;. Now go to the second tab &quot;Default Interface&quot; and select/enter these values: 
Default usbraw.device Unit: 0
Exclusive access: Yes
Out NAK Timeout: 20000ms
In NAK Timeout: 20000ms
In Buffer Mode: No buffering
Buffer Size: 36 KB
Short Reads Terminate: Yes
Now click on &quot;Use as Default&quot; and select &quot;Devices&quot; on the left. There, click on your scanner and click on &quot;Class Scan&quot;. Now close Trident by clicking on &quot;Save&quot;. }}
|-
| Perfection 1640SU Photo
| 0x04b8
| 0x010a
| 0x0104
| {{yes|works, even the transparency unit}}
|-
| Perfection 1650 Photo, 1660 Photo, 3200 Photo
| 0x04b8
| 0x011c
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 2400 Photo, 2450 Photo 
| 0x04b8
| 0x011b 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection 4870 Photo, 4990 Photo, 
| 0x04b8
| 0x0128
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Perfection V700 V750 Photo
| 0x04b8
| 0x012c
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Stylus CX2800 2900 3200 3500 3600 3650 3700 3800 3900

Stylus CX4100 4200 3500 4600 4700 4800 4900 500 5100 5200 5300 5400 5900
| 0x04b8 
| 0x0802 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Stylus Office BX300F USB 
| 0x04b8
| 0x0848
| 
| {{yes| works with good scan quality}}
|-
|}


[http://www.meier-geinitz.de/sane/gt68xx-backend/ gt68xx] scanners based on the Grandtech GT-6801 and GT-6816 &quot;System-On-Chip&quot; scanner chipsets 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Artec Ultima 2000 and e+, Trust Flat Scan USB 19200 (ePlus2k.usb / Gt680xfw.usb) 
| 0x05d8
| 0x4002
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Genius Colorpage Vivid3x 4x 1200x
| 0x0458
| 0x2011 to 0x201f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (ccd548.fw)}}
|-
| &lt;!--Description--&gt;Lexmark	X70	also X73 [http://subfusion.net/drivers/oslo3071b2.usb OSLO3071b2.usb]
| &lt;!--Vendor ID--&gt;0x043d
| &lt;!--Product ID--&gt;0x002d
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Medion/Lifetec/Tevion/Cytron MD/LT 9375 and Artec Ultima 2000, MD LT 9385 Gt680xfw.usb 
| &lt;!--Vendor ID--&gt;0x05d8
| &lt;!--Product ID--&gt;0x4002
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| BearPaw 2448 CS and TA Plus [http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/A2Nfw.usb A2Nfw.usb]
| 0x055f
| 0x021a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  }}
|-
| Mustek BearPaw 1200 CS 
| 0x055f
| 0x021e
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/A1fw.usb A1fw.usb])}}
|-
| &lt;!--Description--&gt;Mustek 1200 CU Plus Scanner [http://www.meier-geinitz.de/sane/gt68xx-backend PS1Dfw.usb / SBSfw.usb]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2000 }}
|-
| Mustek ScanExpress 1200 UB plus, Trust Compact Scan USB 19200, ScanMagic 1200 UB Plus
| 0x05d8
| 0x4002 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/sbfw.usb sbfw.usb])}}
|-
| Mustek ScanExpress 1248 UB aka PC-World PC Line PCL-3000 
| 0x055f
| 0x021f
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| ([http://www.meier-geinitz.de/sane/gt68xx-backend/firmware/SBSfw.usb SBSfw.usb])}}
|-
| Mustek BearPaw 2400CS TA aka Goodmans GSC 12/24
| 0x055f
| 0x0218
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| (Transparency adapter untested) }}
|-
| BearPaw 2400 CS aka TA Plus
| 0x055f
| 0x0219
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (Transparency adapter) }}
|-
| Packard Bell Diamond 1200 Plus
| 0x055f
| 0x021c or 0x021b 
| 0x0
| {{yes|works - [http://www.meier-geinitz.de/sane/gt68xx-backend/ firmware required] but slow usb 1.1 speed with poor quality output (scanner fault not scandal)}}
|-
| Packard Bell Diamond 2400 Plus aka BearPaw 2400 CU Plus [http://www.meier-geinitz.de/sane/gt68xx-backend/ PS2Dfw2.usb firmware rename to PS2Dfw.usb]
| 0x055f
| 0x021d 
| 1.00
| {{yes|works slow usb 1.1 speed with ok quality output (scanner fault not scandal)}}
|-
| Plustek OpticPro 1248U
| 0x07B3
| 0x0400 0x0401
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| (ccd548.fw)}}
|-
| Plustek OpticSlim 2400
| 0x07b3
| 0x0422
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (cis3R5B1.fw)}}
|-
| Visioneer OneTouch 7300
| 0x04a7
| 0x0444
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  (Cis3r5b1.fw)}}
|-
| &lt;!--Description--&gt;Mustek ScanEpress 1200 UB (Plus) clone [http://www.meier-geinitz.de/sane/ use mustek_usb backend]
| &lt;!--Vendor ID--&gt;0x055f
| &lt;!--Product ID--&gt;0x0006
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Lexmark - needs testing
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Lexmark X1110 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1140
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1150 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1170 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1180 
| 
| 
| 
| {{N/A|untested}}
|-
| Lexmark X1185
| 0x043d
| 0x007c
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Lexmark X12xx 
| 
| 
| 
| {{N/A|untested in USB1.1, not fully tested in USB2.0}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Dell A920 
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


HP - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| HP ScanJet 4100C
| 0x03f0 
| 0x0101
| 
| {{no|no driver}}
|-
| HP ScanJet 5200C
| 0x03f0 
| 0x0401
| 
| {{no|no driver}}
|-
| HP ScanJet 62X0C
| 0x03f0 
| 0x0201
| 
| {{no|no driver}}
|-
| HP ScanJet 63X0C
| 0x03f0 
| 0x0601
| 
| {{no|no driver}}
|-
| HP  
| 0x03f0
| 0x0102, 0x0105, 0x0205, 0x0305, 0x0405
| 
| {{no|no driver}}
|-
| HP
| 0x03f0
| 0x0705, 0x0805, 0x0901, 0x0a01
| 
| {{no|no driver}}
|-
| HP
| 0x03f0
| 0x1205, 0x1305, 0x2005, 0x2205
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Plustek [http://www.sane-project.org/sane-backends.html#S-PLUSTEK LM983x] - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Plustek OticPro U12 UT12 UT16 U24 UT24
| 0x07B3
| 0x0010 to 0x0017
| 
| {{no|no driver}}
|-
| KYE/Genius Colorpage HR6-V2 HR6A HR7 HR7LE HR6X
| 0x0458
| 0x2008 to 0x2016 
| 
| {{no|no driver}}
|-
| Hewlett-Packard ScanJet 2100C and 2200C
| 0x03F0
| 0x0505 and 0x0605
| 
| {{no|no driver}}
|-
| Mustek BearPaw 1200 and 2400 
| 0x0400 	
| 0x1000 and 0x1001
| 
| {{no|no driver}}
|-
| UMAX 3400/3450 and 5400 	
| 0x1606
| 0x0050, 0x0060 and 0x0160 
| 
| {{no|no driver}}
|-
| Epson Perfection 1250 and 1260
| 0x04B8
| 0x010f and 0x011d
| 
| {{no|no driver}}
|-
| CANON CanoScan N650/656U N1220U D660U N670/676U N1240U LIDE20 LIDE25 LIDE30
| 0x04A9
| 0x2206 to 0x2220
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


[http://snapscan.sourceforge.net/ SnapScan] - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Acer Benq 310U, 320U, 340U
| 0x4a5
| 0x0
| 
| {{no|no driver}}
|-
| Acer Benq 620U, 620UT, 640U, 640UT
| 0x4a5
| 0x20
| 
| {{no|no driver}}
|-
| Acer Benq 1240 3300 4300
| 0x4a5
| 0x020
| 
| {{no|no driver}}
|-
| Agfa SnapScan e10 e20 e25 e26 e40 e42 e50 e52
| 0x06bd
| 0x20
| 
| {{no|no driver}}
|-
| Epson Perfection 660
| 0x04b8
| 0x0114
| 
| {{no|no driver}}
|-
| Epson Perfection 1270 1670
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Epson Perfection 2480 2580
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Epson Perfection 3490 3590
| 0x04b8
| 0x0
| 
| {{no|no driver}}
|-
| Mitsubishi
| 0x0
| 0x0
| 
| {{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}

==hub.class (self-powered and external ac powered hubs)==

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Dynamode USB-H41 4 ports 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Belkin 4 Port 
| 
| 
| 
| {{yes|works}}
|-
| Conrad
| 
| 
| 
| {{yes|[http://www.a1k.org/forum/showthread.php?t=11432 works on a1k forum] }}
|-
| DLink DUB-H4 AC Adapter 
| 0x05e3
| 0x0608
| High 0200
| {{maybe|WARNING Genesys Logic Hub Broken - Will cause failures with USB}}
|-
| [http://service.targa.co.uk/faq.php?lang_id=2&amp;baseid=178&amp;artdesc=SilverCrest+USB+Hub+2040&amp;artid=760&amp;artpic=silvercrestHUB2040.jpg SilverCrest 4-port slim USB 2.0 HUB - HUB2040 (40775) - Targa GmbH]
| 0x05e3
| 0x0608
| 0901
| {{yes|works  Genesys Logic, Inc., [http://service.targa.co.uk/dokumente/USB_HUB_2040_0109_manual_EN.pdf Manual]}}
|-
| Skymaster
| 0x05e3
| 0x0605
| 060B
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| No Name active 4-port
| 0x1a40
| 0x0101
| 0111
| {{yes|works}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Thinkpad USB 3.0 Dock DU9019D1 
| &lt;!--Vendor ID--&gt;0x17e9
| &lt;!--Product ID--&gt;0x4302
| &lt;!--Revision--&gt;0014
| &lt;!--Opinion--&gt;{{Maybe|works a bit}} classed as dfu.class with two further USB 2.0 hubs - USB 3.0 ports detected and work (2.0 backwards compatibility) - DisplayLink DL-3900 with VIA VL811 chipset - usb ethernet not working - two dvi not working - 20V psu 2a (40w) with a 5.5 - 2.5mm tip (no bus power) - data through a-b printer/scanner usb lead - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


==Internet==

===rndis.class USB Tethering ===

The rndis class provides support for Ethernet access over Remote NDIS. Most USB based devices should be supported including smartfones.

Before opening Network Prefs, activate USB Tethering on the Smartfon, on Network prefs, type in usbrndis.device and tick &quot;Start Network during system boot&quot; and saved the configuration, the Connection is immediate no reboot is needed.

When restart AROS my Smartphone deactivates the connection and to access the network again, have to reactivate it before starting the browser.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Alcatel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| Huawei U8800
| 0x12d1
| 0x1039
| 
| {{yes|works}}
|- 
| &lt;!--Description--&gt;Huawei
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| HTC (Android phone)
| 0x0bb4
| 0x0ffe
| 
| {{Yes|any android phone with usb tethering option}}
|- 
| &lt;!--Description--&gt;Nokia 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;Oppo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;Samsung Galaxy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|untested}}
|- 
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
|- 
| &lt;!--Description--&gt;iPhone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- 
| &lt;!--Description--&gt;Microsoft winPhone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


===USB &amp;rarr; ethernet lan adaptor===

*2002 playstation 2 usb1.1 era - a little support but very old and slow 
*2006 wii asix era - a little support but very much miss than hit 
*2026 usb0: or eth0: of CDC Ethernet protocol (cdcether) with Ethernet Control Model (ECM) and [https://www.usb.org/document-library/class-definitions-communication-devices-12 others like Wireless Mobile Communication Devices WMC] and later CDC EEM (Ethernet Emulation Model) and NCM (Network Control Model) are USB Communication Device Class (CDC) protocols packing more Ethernet traffic over every USB bundle. For CDC Ethernet - NCM is better than EEM is better than ECM 


* USB1.1 Up to 010 meg broadband (1.25MBytes/s) - ADM8511, DM9601 poor speeds 
* USB2.0 Up to 400 meg broadband (60MBytes/s) - MCS7830, AX88772 a little especially the 2010 apple version but buy many as very very poor odds of working one 
* USB3.0 Over 400 meg broadband (60+MBytes/s) - not supported at the moment 


SANA (Standard Amiga Network Architecture) to usb 

ADMtek Infineon ADM8511 Pegasus II (USB 1.1 and 10Mbit/s - Sony PlayStation 2 network adapter) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| 3Com 3c460b 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| Abocom UFE1000 / Abocom DSB650TX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Accton USB320-EC / Accton SpeedStream Ethernet
| 0x083a
| 0x0320
| &lt;!--Revision--&gt;
| {{unk|2002 }}
|-
| AEI USB Fast Ethernet / Allied Telesyn AT-USB100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2002 }}
|-
| ATEN UC-110T
| 0x0557
| 0x4000
|
| {{unk|2001 }}
|-
| BAFO USB To Ethernet Adapter BF-310
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| Belkin F5D5050 v1 1101 
| 0x050D
| 
| &lt;!--Revision--&gt;
| {{maybe|2002 sometimes works from old amiga.org post which is now removed}}
|-
| Belkin F5D5050 v2 2101
| 0x050D
| 0x0121
| &lt;!--Revision--&gt;
| {{no|2006 does not works}} 
|-
| Belkin F5U122-PC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Billionton USB-100 / Billionton USBLP-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Billionton USBEL-100 / Billionton USBE-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Compex LinkPort/UE202A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DSB-H3ETX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DSB-650 / D-Link DSB-650TX / D-Link DSB-650TX-PNA
| 0x2001
| 0x4000
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| D-Link DU-E10 / D-Link DU-E100
| 0x2001
| 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Edimax USB Ethernet Adapter EU-4201 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Elsa AG MicroLink USB2 Lan Ethernet adapter
| 0x05cc
| 0x3000
| &lt;!--Revision--&gt;1.01
| &lt;!--Opinion--&gt;{{unk| }}
|-
| GetNet
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| GIGABYTE GN-BR402W Wireless Router
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Goodway Fellowes USB UE-120 REV:V1 UE120 ADMTek 1011594 HO2419741 
| &lt;!--Vendor ID--&gt;0x07a6
| &lt;!--Product ID--&gt;0x0986
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{maybe|2001 USB Specification 1.1 compliant}} 
|-
| GWC Tech USB Ethernet Adapter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Hawking UF100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| HP HN210E / I/O DATA USB ETTX / Kingston KNU101TX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Jinco USB Ethernet Adapter 10/100 Base-T UE-110
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Kouwell USB to Ethernet 588A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Linksys USB10T / TA / TX
| 0x066b
| 0x2202
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|untested - possible peg1/peg2}}
|-
| Linksys (Cisco) USB100TX / H1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitec LAN-TX/U1 H2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| [http://www.mayflash.com/psps2/ps2024/ps2024.htm Mayflash PS2024] Playstation2 compatible clone of Proxim/Farallon NetLine?
| 0x07a6
| 0x8511
| &lt;!--Revision--&gt;1.01
| &lt;!--Opinion--&gt;{{maybe|works with DHCP router option on old 32bit distros but not on newer 64bit, best to go asixeth apple 2010 but buy many of them as poor success rate i.e. a lottery}}
|-
| Netgear FA101
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Philips CPWUE01/00 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Planet UE-9500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| PlayStation 2 SCPH-10000 50000 models 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Proxim (formerly Farallon) NetLine USB PN796-650
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Siemens SpeedStream USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| SOHOware NUB100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| SMC EZNET-USB 2202USB/ETH / SMC 2206USB/ETH
| 0x0707
| 0x0100 0x0200 0x0201
| &lt;!--Revision--&gt;
| {{unk|untested but should work very well }}
|-
| Surecom EP-1427X 100/10M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Target USB to 10/100M Fast Ethernet Converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Trendnet TU-ET100C
| 0x07a6
| 0x8511 
| &lt;!--Revision--&gt;0x0
| {{yes| sometimes works well, very stable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Digitus USB NIC DN-3016-A 
| 0x07a6
| 0x8513
| 1.01
| {{unk|untested new chipset }}
|-
| Digitus lanusb ADM8515
| 0x07a6
| 0x8515
| 1.01
| {{unk|untested because new chipset }}
|-
| VE285 usblan ADMtek 8515 
| 0x07a6
| 0x8515
| 1.01
| {{no|not working as new chipset }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


Davicom DM9601 eth (USB 1.1 and up to 10Mbit/s) 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Davicom USB-100 see clone below 
| 0x0a46
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2001 }}
|-
| [http://wiki.maemo.org/USB_to_ethernet_networking chinese translucent transparent crystal blue] but variants are also found in clear, white and black. Just over 6&amp;nbsp;cm long. 
| 0x0a46
| 0x9601
| 0x0
| {{yes|2002 success can be sporadic so technically okay, but lacking in reliability. Out of 4 tested by me, only 2 worked. One case cracked open. }}
|-
| Corega FEther USB-TXC
| 0x07aa
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Dynamode USB-NIC-1427-100
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Hirose USB-100
| 0x0a47
| 0x9601
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| KY-RS9600
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585358&amp;postcount=12 works] }}
|-
| ShanTou ST268 USB NIC
| 0x0a46
| 0x0268
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| ZT6688 USB NIC 
| 0x0a46
| 0x6688
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ICS Advent DM9601 USB 2.0 10/100M Ethenet Adaptor JP1081B 
| &lt;!--Vendor ID--&gt;0x0FE6
| &lt;!--Product ID--&gt;0x9700
| &lt;!--Revision--&gt;0101
| &lt;!--Opinion--&gt;{{No|only USB 1.1 10M ethernet support but will plug into an usb 2.0 port}} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


MosChip MCS7830 (USB 2)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Digitus DN-10050
| 0x9710
| 0x7830
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2004 }}
|-
| Edimax [http://www.edimax.co.uk/images/Image/datasheet/USB/EU-4206/EU-4206.pdf EU-4206]
|
| 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2005 }}
|-
| Speed Dragon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| STLabs 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| StarTech Compact USB2105S [http://www.kustompcs.co.uk/acatalog/info_6790.html USB2106S]
| 0x9710
| 0x7830
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| Sunrich Technologies [http://www.st-lab.com/admin/upfile/UploadFile/manual/manual(u-250).zip U-250]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 }}
|-
| Syba 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;MCS 7832 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2008 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|}


* USB2 [https://www.asix.com.tw/en/product/USBEthernet Asix Ethernet] AX88178A, AX88772C, AX88772B, AX88772A (wii), AX88172A 
* USB3 AX88179A, AX88179  

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| AirLink101 AGIGAUSB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009  AX88172}}
|-
| ATEN UC210T 
| 0x0557
| 0x2009
| 0x
| &lt;!--Opinion--&gt;{{unk| AX88172}}
|-
| &lt;!--Description--&gt;Billionton Systems USB2AR
| &lt;!--Vendor ID--&gt;0x08dd
| &lt;!--Product ID--&gt;0x90ff
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;Buffalo LUA-U2-KTX
| &lt;!--Vendor ID--&gt;0x0411
| &lt;!--Product ID--&gt;0x003d
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;corega FEther USB2-TX
| &lt;!--Vendor ID--&gt;0x07aa
| &lt;!--Product ID--&gt;0x0017
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| }}
|-
| D-Link DUB-E100 up to rev A4
| 0x2001
| 0x1a00
| 
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;D-Link DUB-E100 rev B1 onwards 
| 0x07d1 or 0x2001 
| 0x3c05
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|AX88172 works on Deneb with [http://amigax.com/2010/02/21/usb-ethernet-speed-test-amigaos-4-0-classic/ Amiga OS4 Classic] and [http://www.a1k.org/forum/showthread.php?t=11432 on a1k] }}
|-
| &lt;!--Description--&gt;goodway corp USB gwusb2e
| &lt;!--Vendor ID--&gt;0x1631
| &lt;!--Product ID--&gt;0x6200
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hawking UF200 
| 0x07b8
| 0x420a 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[Linksys USB200M] 
| 0x077b
| 0x2226
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585601&amp;postcount=20 works] }}
|-
| &lt;!--Description--&gt;Netgear FA120 
| 0x0846 
| 0x1040
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested 2002 10/100 Rev.B1&quot; is silkscreened on the board of the device populating this entry (S/N: FA12254CB100409, date code 0508). This device may be manuf. by [http://www.cameo.com.tw/ Cameo] &quot;AX88172 L&quot;, &quot;F05040157&quot;, and &quot;ED3&quot; Chip1 ASIX AX88172  Chip2 Realtek RTL8201BL}}
|-
| &lt;!--Description--&gt;Intellinet
| 0x0b95 
| 0x1720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;JVC MP-PRX1 Port Replicator
| &lt;!--Vendor ID--&gt;0x04f1
| &lt;!--Product ID--&gt;0x3008
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ST Lab USB Ethernet
| &lt;!--Vendor ID--&gt;0x0b95 
| &lt;!--Product ID--&gt;0x1720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Sitecom LN-029 &quot;USB 2.0 10/100 Ethernet adapter&quot;
| &lt;!--Vendor ID--&gt;0x6189
| &lt;!--Product ID--&gt;0x182d
| &lt;!--Revision--&gt;0
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;Surecom EP-1427X-2
| &lt;!--Vendor ID--&gt;0x1189
| &lt;!--Product ID--&gt;0x0893
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v2
| 0x07b8
| 0x420a 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|version 2}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;A-LINK NA1GU 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 88772}}
|-
| &lt;!--Description--&gt;AirLink101 ASOHOUSB Wii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AirLive EtherWe-1000U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;APPLE AX88772 Model No. A1277 MC704LL/A P/N 825-7098-A 
| &lt;!--Vendor ID--&gt;0x05ac 
| &lt;!--Product ID--&gt;0x1402
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2008  usb2, }}
|-
| &lt;!--Description--&gt;APPLE Model No. A1277 (MB442Z/A 0885909217434) MC704ZM/A PN 825-7579-A 
| &lt;!--Vendor ID--&gt;0x05ac 
| &lt;!--Product ID--&gt;0x1402
| &lt;!--Revision--&gt; 
| &lt;!--Opinion--&gt;{{Maybe|2010 model, usb2 and controller AX88772 where prehaps 1in3 units working with owb - really poor odds i.e. a lottery, could be situation where various ethernet phy chipsets are used - press Use in network prefs after Save initial setup typing in usbasixeth.device, }}
|-
| &lt;!--Description--&gt;ASIX AX88772 bulbous casing 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{maybe|2008 works on 32bit and 64bit though setup can take a few attempts but may have issues with phy ethernet chip changing,  }}
|-
| &lt;!--Description--&gt;Datel Wii Lan Adapter DUS0204 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 }}
|-
| &lt;!--Description--&gt;EdiMax EU-4207 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;Goodway HE2230 Maplin ASIX 88772 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;Intec LAN G5626 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;LevelOne USB-0202
| 0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{unk|2008 }}
|-
| &lt;!--Description--&gt;LevelOne USB-0301
| 0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{unk|2009 }}
|-
| &lt;!--Description--&gt;Linksys USB200M Rev 2
| &lt;!--Vendor ID--&gt;0x13b1
| &lt;!--Product ID--&gt;0x0018
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|2008 sparsely randomly working AX88772 or with &quot;Sana-II Meter Tool 37.11&quot; network monitoring program, showing continuous &quot;Bad Packet&quot; errors which could means &quot;CRC&quot; errors}}
|-
| &lt;!--Description--&gt;Linksys USB300M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{maybe|2009 AX88772  }}
|-
| &lt;!--Description--&gt;Mayflash W001 or clones Lupo/PEGA S-Wii-0680 light gray rectangular with third of one top 45 degree angled slope
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{unk| may have randomly changed phy ethernet chips, }}
|-
| &lt;!--Description--&gt;Max Value MVF00446 ASIN B006EG568A 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{Maybe|Trident prefs recognises as AX88772 sometimes works on 32bit and 64bit}} 
|-
| &lt;!--Description--&gt;NEWLink N14050 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;NEWLink Wii-ETH USB2.0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nintendo Wii LAN Adaptor 2110566 and clones 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x07720
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{Maybe|Poseidon recognises as AX88772 with usbasixeth.device sometimes works seems different ethernet phy chips can be matched affecting compatibility}} 
|-
| &lt;!--Description--&gt;Nyko Wii Net Connect 87024
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes|[http://www.amiga.org/forums/showpost.php?p=585624&amp;postcount=22 works] }}
|-
| &lt;!--Description--&gt;0Q0 cable ethernet
| &lt;!--Vendor ID--&gt;0x1557
| &lt;!--Product ID--&gt;0x7720
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB2-E100 (2009/2010) Bulbous housing 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x7720 
| &lt;!--Revision--&gt;0x0
| &lt;!--Opinion--&gt;{{Maybe|Trident prefs recognises it as ax88772A and typing in usbasixeth.device sometimes works}}
|-
| &lt;!--Description--&gt;Sabrent KINAMAX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SpeedLink SL-3401-SGY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;UGreen 20254 USB2 to 10/100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| AX88772}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Afunta Apple-style White USB2.0 I/O Crest SY-ADA24005 ASIX Electronics Corp. AX88772A Fast Ethernet Adapter 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{no|usbasixeth.device accepted by network prefs but does not work}}
|-
| &lt;!--Description--&gt;Amazon Basics USB 2.0 AX88772A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Digitus DN-10050-1
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;0x0 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Edimax EU-4230  
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x772a
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sabrent KINAMAX NT-USB20 AX88772A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt; AX88772B USB 2.0 to 10/100M 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EdiMax EU-4208 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt;0x772b
| &lt;!--Revision--&gt;0x
| &lt;!--Opinion--&gt;{{No|Detected but not working}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB2100 ASIX AX88772C 
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.asix.com.tw/en/product/USBEthernet/High-Speed_USB_Ethernet/AX88772D AX88772D]
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.asix.com.tw/en/product/USBEthernet/High-Speed_USB_Ethernet/AX88772E AX88772E]
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0B95
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;AX88178 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2004 }} 
|-
| &lt;!--Description--&gt;Plugable USB2-E1000 i.e. USB 2.0 to Gigabit Ethernet 10/100/1000 LAN 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 ASIX AX88178 Controller and Realtek RTL8211CL PHY}}
|-
| &lt;!--Description--&gt;AX88178A USB 2.0 to 10/100/1000M Gigabit Ethernet controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2005 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AmazonBasics USB3.0 adapter [https://github.com/nothingstopsme/AX88179_178A_Linux_Driver AX88179] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Cable Matters SuperSpeed USB 3.0 RJ45 adapter 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Hori Nintendo Switch 1 USB3 ethernet AX88179 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 AX88179 not binding to asixeth.class }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB3-E1000  
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2020 ASIX AX88179 not binding to class, USB 3.2 Gen1 to Gigabit Ethernet controller with integrated 10/100/1000Mbps Gigabit Ethernet PHY}}  
|-
| &lt;!--Description--&gt;Plugable AX88179 = [https://plugable.com/products/usb3-e1000-deal USB3-E1000] before mid-2023 or USB3-E1000; AX88179A = USBC-E1000 after mid-2023
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022  controller is AX88179 phy is ??, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000SPTW ax88179 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| AX88179 not binding to asixeth.class, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000NDS AX88179 USB-A
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech US1GC301AU AX88179 USB-c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech US1GC30B2 AX88179A USB-c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB32000SPT AX88179A USB-c Rev 1 (AX88179) Rev 2 (AX88179A) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;USB32000SPT the Lot code sticker will have a bar code accompanied by a 10 digit number. The 5th and 6th digits of this lot code number would signify the revision. (Ex. xxxx02xxxx which would indicate rev. 2)
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;SYBA SY-ADA24029 Gigabit AX88179 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} may depend on the PHY chip connected to the controller chipset
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TP-Link UE306 AX88179 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TeckNet® Orico UL677G 10/100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TeckNet® UL688G USB 3.0 10/100/1000 Base-T Ethernet port 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;AX88179 178A 
|-
| &lt;!--Description--&gt;Tecknet UL699G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;TrendNet TU2-ET100 v6 
| &lt;!--Vendor ID--&gt;0x07b8
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|no support }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;uGreen 50922 USB3-A to 100/1000 dark grey rounded barrels 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| ax88179 not binding to asixeth.class, }}
|-
| &lt;!--Description--&gt;UGreen USB3-C to 100/1000 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;uGreen CR111 20256 usb3 a black plastic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| AX88179}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;  AX88179A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Plugable USB3-E1000 USBC-E1000 after mid-2023 i.e. AX88179A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;StarTech USB31000SPTB 
| &lt;!--Vendor ID--&gt;0x0b95
| &lt;!--Product ID--&gt;0x1790
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  AX88179A USB-A, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;  AX88179B
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


==USB  &amp;rarr; SerialPort Converter==

*2002 some support for early revisions of PL2303 
*2005 Prolific PL2303H PL-2303X and Pl-2303HX (same usb ids as pl2303) no support 
*2025 FTDI 232R [https://www.arosworld.org/infusions/forum/viewthread.php?thread_id=1135&amp;highlight=232r&amp;rowstart=20 work in progress] 
*2026 CDC-ACM i.e. Serial port over USB standard 

serialpl2303.class make sure you specify serialpl2303.device or Echo &quot;Test&quot; &gt;SER1: 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| ATEN UC-232A 
| 0x0557 
| 0x2008 
| Full 0x0300
| {{N/A|untested}}
|- 
| IOGear GUC232A 
| 0x0557  
| 0x2008 
| Full 0x0110
| {{N/A|untested}}
|- 
| Alcatel 
| 0x11f7 
| 0x02df 
|
| {{N/A|untested}}
|- 
| BAFO BF-810 
| 0x067B  
| 0x2303 
| 0x0
| {{N/A|untested}}
|- 
| Belkin F5U103 
| 0x
| 0x
| 0x0
| {{N/A|untested}}
|- 
| Davibe SP611 
| 0x067B 
| 0x2303 
| 0x0 
| {{N/A|untested}}
|- 
| Dcu10 
| 0x0731
| 0x0528
| 
| {{N/A|untested}}
|- 
| Elcom 
| 0x056e
| 0x5003
| 
| {{N/A|untested}}
|- 
| IOData 
| 0x04bb 
| 0x0a03 
| 0x0
| {{N/A|untested}}
|- 
| Itegno 
| 0x0eba
| 0x1080
| 
| {{N/A|untested}}
|- 
| Nokia CA42 
| 
| 
| 
| {{N/A|untested}}
|- 
| Radioshack 
| 0x1453
| 0x4026
| 
| {{N/A|untested}}
|- 
| Ratoc 
| 0x0584
| 0xb000
| 
| {{N/A|untested}}
|- 
| Samsung 
| 0x04e8
| 0x8001
|
| {{N/A|untested}}
|- 
| Siemens DCA-510 
| 0x067B 
| 0x2303 
| 0x0 
| {{N/A|untested}}
|- 
| Sitecom CN104
| 0x6189
| 0x2068
|
| {{N/A|untested}}
|- 
| Sitecom CN116 
| 0x6189
| 0x2068
|
| {{N/A|untested}}
|- 
| Some Cut Ma620 
| 0x0df7
| 0x0620
| 
| {{N/A|untested}}
|- 
| Speed Dragon Multimedia MS3303H 
| 
| 
| 
| {{N/A|untested}}
|- 
| Syntech 
| 
| 
| 
| {{N/A|untested}}
|- 
| &lt;!--Description--&gt;Tripp 
| 0x2478
| 0x2008
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Airlink101 AC-USBS
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Belkin F5U103v
| 0x067B  
| 0x2303 
| 0x0
| {{no|no driver }}
|- 
| Dynamode U232-P9
| 0x067B
| 0x2303
| 300
| {{no| no driver [http://koti.mbnet.fi/lonnberg/pl2303x.html linux patch] and using lsusb -v -d 067b:2303 gave bMaxPacketSize as 64 - pl2303x }}
|- 
| Konig CABLE-146/2 USB to RS232 
| 0x067b
| 0x2303
| 400
| {{no|no driver }}
|-
| MANHATTAN 205146 USB to Serial Converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|- 
| Sabrent SBT-USC1M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Trendnet TU-59
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver }}
|-
| &lt;!--Description--&gt;Unbranded black case and lead USB 232 Converter
| &lt;!--Vendor ID--&gt;0x067B
| &lt;!--Product ID--&gt;0x2303
| &lt;!--Revision--&gt;0300
| &lt;!--Opinion--&gt;{{No| }}
|-
|}


[http://www.ftdichip.com/index.html Future Technology Devices International Ltd FTDI]-FT232R.class [https://ftdichip.com/software-examples/code-examples/c-builder/ FTProg src], [http://rtr.ca/ft232r/ ft232r src], [https://ftdichip.com/wp-content/uploads/2020/08/DS_FT232R.pdf FT232R datasheet], [], 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt;0x6001 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} [https://www.youtube.com/watch?v=1GE-gKgHxZI beware of cheap clones fake with s/n A50285BI SN]
|-
| &lt;!--Description--&gt;Lynx Astro FTDI 
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232R 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Sabrent CB-FTDI
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| {{no|no driver TTL-232R cables use FTDI's [http://n1mm.hamdocs.com/tiki-index.php?page=USB+Interface+Devices FT232RQ ic device] }}
|-
| &lt;!--Description--&gt;Startech.com 1 Port FTDI USB to Serial RS232 DB9M Adapter Cable with COM Retention ICUSB2321F 
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232RL Chipset
|-
| &lt;!--Description--&gt;StarTech.com 2 Port FTDI USB to Serial RS232 Adapter Cable ICUSB2322F
| &lt;!--Vendor ID--&gt;0x0403
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FTDI FT2232D Chipset
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} FT232RL is the SSOP-28 and the FT232RQ is the QFN-32 package option 
|}


[https://www.onetransistor.eu/2017/08/ch341a-mini-programmer-schematic.html ch341a.class] 

*I2C EEPROMS (3.3V and 5V) compatible and also SPI FLASH memories (3.3V devices) making sure 1.8V is covered  
*each having their own [https://winraid.level1techs.com/t/guide-how-to-use-a-ch341a-spi-programmer-flasher-with-pictures/33041 4x2 connection blocks] using [https://github.com/flashrom/flashrom flashrom] 

 sudo flashrom --programmer ch341a_spi -r backup.bin
 sudo flashrom --programmer ch341a_spi -w &lt;new bios name&gt;

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Jiangsu QinHeng Ltd CH341A emulate UART communication, standard parallel port, memory parallel port and synchronous serial (I2C, SPI) 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x5512
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;QinHeng USB2.0-Serial HL-340 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x7523
| &lt;!--Revision--&gt;0252
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|}


==simplemidi.class and CAMD==

Currently support includes 

* simplemidi.class SimpleMidi maps some keyboard keys to corresponding computer keys as used by music trackers to emulate a musical keyboard 
* camdusbmidi.class follows the rules of the m68k implementation of Commodore's CAMD midi specification and usb class compliant 

for 

* usb host like a computer 
* usb device controllers - keyboards, drum machines, djay turntables, grooveboxes, etc 
* interfaces - cables or boxes which convert usb to 5pin DIN plug midi 


What is needed is a fully class-compliant '''brand name''' USB MIDI keyboard, especially manufactured in the last 10 years are best 

*Arturia
*Novation
*M-Audio
*Akai

Plugging this in one of your USB ports, the camd.library will make the keyboard's MIDI IN/OUT ports available in the system. 

Then select the keyboard's MIDI IN port (known as a &quot;cluster&quot; in CAMD) for input, and the software instrument's cluster as output 


ShowCluster (shows midi ports available in and out)

MidiWatch (usually port usbmidi.in.0 less often usbmidi.out.0) (Ctrl-C to end output stream) 
 usbmidi.in.0 Message on channel 01, NoteOn  90  39  08  00
 usbmidi.in.0 Message on channel 01, NoteOff 80  39  00  00

MidiThru (forwards messages from one port to another)
 run &gt;nil: c:midithru usbmidi.out.0 usbmidi.out.2 

MidiSendC (sends a middle C to a specific port)


Midi Controller + Sound Module (together aka as a synth) -&gt; Audio Output 


The difference between midi and midi over USB is that in old school Midi the transmitter transmits whenever it wants and the receiver always has to be prepared to receive data. Easy to do at the rate of a 1990's modem speed these days.

USB over midi.. turns midi into a polled protocol.. So the USB host (typically the computer) has to ask &quot;do you have anything for me&quot; before the remote will send. If the USB host gets busy doing other things or there is a lot of things on the USB bus to get polled, you can get delays.

For its age midi is still a great protocol for music

* [https://www.usb.org/sites/default/files/midi10.pdf USBIF's &quot;USB Device Class Definition for MIDI Devices&quot; document, version 1.0 from Nov 1, 1999]
* [https://www.usb.org/sites/default/files/USB%20MIDI%20v2_0.pdf MIDI v2.0 from 2020 which AROS still needs, adds support for MIDI 2.0, MIDI-CI, and Universal MIDI Packet] 

Nearly all synthesizers now use the 16 MIDI channels available on a MIDI bus in one instrument alone, requiring multiple MIDI busses in a typical setup with more than
one MIDI instrument. In addition, by handling multiple &quot;virtual&quot; cables, USB offers a solution to go beyond MIDI's 16-channel limit. 

MIDI data is transferred over USB using 32-bit USB-MIDI Event Packets. These packets provide an efficient method to transfer multiple MIDI streams with fixed length messages. The 32-bit USB-MIDI Event Packet allows multiple &quot;virtual MIDI cables&quot; routed over the same USB endpoint. This approach minimizes the number of required endpoints. It also makes parsing MIDI events easier by packetizing the separate bytes of a MIDI event into one parsed USB-MIDI event. 


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Computer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{Yes|which acts as USB midi host to get all usb devices talking together}} 
|-
| &lt;!--Description--&gt;Hobbytronics usb host standalone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;bomebox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;raspberry pi with several midi interface(s) and linux scripting 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Kenton MIDI USB Host mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;25%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;5%&quot; |Product ID
! width=&quot;5%&quot; |Revision 
! width=&quot;15%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acorn Instruments Masterkey 49 device 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 untested usb powered 5V regulated - similar keybed to keystation 49es but unplug then re-plug the USB cable while it is powered the device might reconnect 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Akai SynthStation 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 - sticky rubber keys - usb 
|-
| &lt;!--Description--&gt;Akai MPK Mini Laptop Production Keyboard 
| &lt;!--Vendor ID--&gt;0x09e8
| &lt;!--Product ID--&gt;0x007c
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected and camd usb to use, not tested with apps}}
| &lt;!--Opinion--&gt;2010 25 mini key self powered by mini USB lead - sustain port - no top left corner joystick - tested icaros 2.3 -  
|-
| &lt;!--Description--&gt;Akai LPK25 LPK37 LPK49 Laptop Production Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }}
| &lt;!--Opinion--&gt;2012 untested velocity sensitive mini keys with synth action - weak mini USB port - latency issues -  
|-
| &lt;!--Description--&gt;Akai Professional APC Key 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;Akai MPK49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2012 untested 49 key 49-key full-sized, semi-weighted keyboard with aftertouch - 
|-
| &lt;!--Description--&gt;AKAI Max25 MAX49 control keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }} 
| &lt;!--Opinion--&gt;2014 usb compliant 
|-
| &lt;!--Description--&gt;Akai Professional MPK249 MPK261 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}} 
| &lt;!--Opinion--&gt;2015 USB2 USB-b - full keys semi-weighted aftertouch - midi in out - sustain and peddle port 
|-
| &lt;!--Description--&gt;Akai Professional Advance 49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 
|-
| &lt;!--Description--&gt;Akai MPK Mini MKII MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2017 untested USB2 USB-b midi connection only - 4 way thumb joystick top left - 25 tiny keys - velocity drum pads - plastic build quality - 
|-
| &lt;!--Description--&gt;AKAI Professional APC Key 25 MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| driver}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;Akai MPK Mini Play
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 untested USB2 USB-b midi connection only - synth basic samples - class compliant? - small led display top centre - 25 mini keys - press and hold the &quot;Prog Select&quot; button then use the &quot;Program&quot; knob to assign a MIDI channel - 
|-
| &lt;!--Description--&gt;Akai MPK Mini 3 MKIII MK3 
| &lt;!--Vendor ID--&gt;0x09E8
| &lt;!--Product ID--&gt;0x1049 
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class -  - midi in out untested - }}
| &lt;!--Opinion--&gt;2021 USB2 USB-b midi controller connection no 5pin legacy - small led display top centre - 25 mini keys goofy uneven feel of the akai keyboards - press and hold the &quot;Prog Select&quot; button and press pad 1 to 8 to assign a MIDI channel - tested on AROS One 2.4 usb
|-
| &lt;!--Description--&gt;Akai Force / MPC One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Akai Pro MPK Mini Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2023 untested 37 mini keys - class compliant device - usb-b bus powered only with 5pin midi in and out - Shift and Global for Midi Ch - 
|-
| &lt;!--Description--&gt;Akai Pro Ableton Push Mk 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Akai Professional MPC Key 37 49 61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2023 untested USB2 usb-b
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Alesis Photon PH-25 X25 Midi &amp; USB keyboard/synth
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2005 midi keyboard controller  
|-
| &lt;!--Description--&gt;Alesis Q25 Q49 Q61 Q88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2014 untested 
|-
| &lt;!--Description--&gt;Alesis Coda Pro Portable 88-Key Digital Piano USB MIDI Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 
|-
| &lt;!--Description--&gt;Alesis V25 V49 V61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;Alesis V Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Alesis VI49 VI61 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Alesis VX49 VX61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 1 5-pin MIDI input, 1 5-pin MIDI output, 1 USB port,
|-
| &lt;!--Description--&gt;Alesis Q25 Q49 Q61 Mk2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Alesis Recital 88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;Alesis V25 V49 V61 MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022
|-
| &lt;!--Description--&gt;Alesis Qmini portable 32-key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;audiothingies MicroMonsta 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested synth - 
|-
| &lt;!--Description--&gt;audiothingies MicroMonsta 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019  synth - 
|-
| &lt;!--Description--&gt;Arturia Analog Experience “The Player” USB MIDI Master Keyboard Model APE25
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 usb-b bus powered - 
|-
| &lt;!--Description--&gt;Arturia MiniLab Mk1
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2013 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia MiniLab MkII Mk2
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2016 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia Keystep 32 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2016 untested 32 mini keys  usb compliant 
|-
| &lt;!--Description--&gt;Arturia KeyLab 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Maybe| }}
| &lt;!--Opinion--&gt;2017 untested hammer-action Fatar keybed - reset Press and hold Oct + and Oct – buttons then insert the USB cable - 
|-
| &lt;!--Description--&gt;Arturia MiniLab mkII
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt;0x2209 
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class -  - midi in out untested - }}
| &lt;!--Opinion--&gt;2017 USB2 usb-b bus power - metal base heavier than most - Shift and press a key to select the MIDI Channel - To reset to original factory, unplug the USB cable, hold down the Oct- and Oct + buttons, plug the USB cable back in and continue to hold the buttons until the pads turn white - need software to change parameters like velocity sensitive assistance - 
|-
| &lt;!--Description--&gt;Arturia KeyLab MK2 MKII 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested }}
| &lt;!--Opinion--&gt;2017 untested hammer-action Fatar keybed 
|-
| &lt;!--Description--&gt;Arturia MicroFreak
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019 hybrid digital/analog synthesis, 
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=PeYIAfn3UMs Arturia Minilab 3] [https://www.youtube.com/shorts/chj1WgMupGw ] [https://www.youtube.com/shorts/FMVdfhzg1Dw ]
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2020 untested usb-c bus powered - 25 mini keys semi - 
|-
| &lt;!--Description--&gt;Arturia Keystep Pro 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;Arturia MiniLab 3 Mk3
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2022 maybe class complaint 
|-
| &lt;!--Description--&gt;Arturia MiniFreak
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2022 
|-
| &lt;!--Description--&gt;Arturia KeyLab Essential 49 61 88 mk3 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested usb-c and 1 midi out - lack of aftertouch - 
|-
| &lt;!--Description--&gt;Arturia AstroLab 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;Arturia KeyLab MK3 MKIII 61 88 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2025 untested hammer-action Fatar keybed 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer UMX61
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe|untested}}
| &lt;!--Opinion--&gt;2007 
|-
| &lt;!--Description--&gt;Behringer U-Control UMX490 UMX610 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Behringer U-Control 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer Swing 32-Key
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer MOTOR 49 - 49-Key USB/MIDI Master Controller Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Creative EMU Xboard 25 E-MU X-Board 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|untested}}
| &lt;!--Opinion--&gt;2008 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;CME M-Key Mkey 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2008 stops sending MIDI on a regular basis. The simplest &quot;fix&quot; is to flip it off and on via the power switch at the back
|-
| &lt;!--Description--&gt;CME Ukey U-Key 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2009 
|-
| &lt;!--Description--&gt;CME Xkey 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 low-profile aluminium  full size pressure sensitive with polyphonic aftertouch but keys make too much noise and that they can be too sensitive to velocity - low power draw 25ma 
|-
| &lt;!--Description--&gt;CME M-Key 49 V2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 simplified version of the U-key Mobiltone 
|-
| &lt;!--Description--&gt;CME XKEY AIR 37
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019
|-
| &lt;!--Description--&gt;cme xkey 37 le
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Donner Spaceline DMK-25 Donnerdeal Rantion 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Donner DMK25 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;  25 mini velocity keys with limited aftertouch - usb-c powered - 8 drum pads - 3.5mm &quot;midi out&quot; socket - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Digitakt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 expensive later midi usb class compliant with since 1.5 Update
|-
| &lt;!--Description--&gt;Elecktron Digitone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Digitone Keys 37-key Digital FM Synthesizer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2018 expensive 
|-
| &lt;!--Description--&gt;Elektron Analog Four MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Elektron Octatrak MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{ | }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 49+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI keycontrol 25xt
| &lt;!--Vendor ID--&gt;0x2702 
| &lt;!--Product ID--&gt;0x2702
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected and usb driver working}}
| &lt;!--Opinion--&gt;2011 bus powered or 12v 0.5a dc in - metal base so heavy - midi out 5pin - sustain pedal port - modulation slider - rubber coated knobs becomes sticky - 
|-
| &lt;!--Description--&gt;ESI keycontrol 49xt 61xt 88xt 
| &lt;!--Vendor ID--&gt;0x2702
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Yes|detected}}
| &lt;!--Opinion--&gt;2011 12v 0.5a center pin +ve external psu required - USB i/o and 1 legacy 5pin out - full sized keys - heavy aluminium case keyboard metal base - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Evolution MK-125 MK-149
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2000 9v 
|-
| &lt;!--Description--&gt;Evolution MK-225C MK-249C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 9v 
|-
| &lt;!--Description--&gt;Evolution USB/Midi Controller MK-425C MK-449C MK-461C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|25, 49, 61 keys -  }}
| &lt;!--Opinion--&gt;2006  9V or 12V - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 37 full keys 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys Pro Mobile
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2014 25 or 37 mini keys 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 mini velocity keys no aftertouch - 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 2 PRO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2020 full velocity keys no aftertouch - 
|-
| &lt;!--Description--&gt;IK Multimedia iRig Keys 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Kawai VPC 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; weighted keys - heavy build - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Keith McMillen Instruments K-Board
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; omni class compliant to all channels? each keypad makes them velocity, pressure, and location sensitive but  not really suited for piano playing 
|-
| &lt;!--Description--&gt;Keith McMillen  BopPad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; omni class compliant to all channels? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg NanoKontrol 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;mini usb
|-
| &lt;!--Description--&gt;Korg Prophecy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;KORG microKONTROL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010
|-
| &lt;!--Description--&gt;Korg microKEY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2011 velocity-sensitive Natural Touch keys but  joystick is an alternative to the common pitch/modulation wheel design - power draw - 
|-
| &lt;!--Description--&gt;Korg nanoKey nanoPad 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 
|-
| &lt;!--Description--&gt;Korg Taktile 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg microKEY2 25 37 49 61 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|2015 untested}}
| &lt;!--Opinion--&gt;2015 USB powered - semi weighted - 
|-
| &lt;!--Description--&gt;Korg MiniList 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg MinKey nanoPad nanoPad 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Nautilus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Kurzweil PC3 7 series - Artis 7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}} 
| &lt;!--Opinion--&gt;fatar TP-8 semi-weighted action  
|-
| &lt;!--Description--&gt;Kurzweil PC1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Kurzweil PC3 A8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Line 6 Mobile keys 25
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Line 6 POD Studio KB37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Line 6 Tone Port KB37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 
|-
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Midiman (later M-Audio) Oxygen8 Ozone Ozonic 25 32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|not class compliant - untested 5pin legacy }}
| &lt;!--Opinion--&gt;2002 2004 untested - 25 full keys - slider/fader to left of lcd display - 
|-
| &lt;!--Description--&gt;m-audio oxygen keystation (61 key) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;M-Audio eKeys 37 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;M-Audio Axiom 25, 49, 61
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 bus powered and 12v psu - if sliders/faders are on right - legacy midi 5pin - chunky unit -
|-
| &lt;!--Description--&gt;M-Audio Oxygen 8v2, 49, 61 (silver) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 full size velocity sensitive 12v psu - sending random pitchbend info - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 37e 49e, 61e MK1 MKI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 - ok key action - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 37es 49se 61es, 88es MK1 MKI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 - 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25/49/61/88 (blue) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 [https://m-audio.com/products/view/oxygen-25-legacy advised Class-compliant and GM/GM2/XG SysEx messages] with full size velocity sensitive 12v psu - sending random pitchbend info - 
|-
| &lt;!--Description--&gt;M-Audio Axiom 25, 49, 61 (2nd Gen) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 semi-weighted mini keys - bus powered and 9v psu for 25/49 and 12v for 61 - if sliders/faders are on left - legacy midi 5pin - chunky unit - 
|-
| &lt;!--Description--&gt;M-Audio Axiom Pro 25, 49, 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 poor construction 
|-
| &lt;!--Description--&gt;MAudio Axiom AIR 25 M-Audio Axiom Air Mini 32
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25 III (3rd Gen) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 untested - usb only - rubber keys sticky - 
|-
| &lt;!--Description--&gt;MAudio Keyrig 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Keystation Mini 32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 - mini usb - plays a few notes and then stops responding randomly - try plugging it into port 1 or 2 on your pc - 
|-
| &lt;!--Description--&gt;M-Audio Keystation 49 MK2 II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2012 USB port and class compliant
|-
| &lt;!--Description--&gt;M-Audio Keystation 61 MK3 MKIII MIDI keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 usb compliant untested 
|-
| &lt;!--Description--&gt;M-Audio Oxygen 25 IV
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| untested}}
| &lt;!--Opinion--&gt;2016  choice 
|-
| &lt;!--Description--&gt;M-Audio CTRL-49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2017 
|-
| &lt;!--Description--&gt;M-Audio ProKeys 88, 88sx 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Keystation Mini 32 MK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2019 mini usb - some power or incompatibility issue with the native USB ports of the laptop, plugged in a passive USB 2.0 HUB (not USB 3.0, not powered)
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=3328SvuJsLw M-Audio Oxygen25 MKV]
| &lt;!--Vendor ID--&gt;0x0763
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;0023
| &lt;!--CAMD--&gt;{{Yes|detected audio class and bindings with camdusbmidi.class  - midi in out untested}}
| &lt;!--Opinion--&gt;2020 25 full size semi keys - USB2 usb-b but no 5pin classic plugs - channel select SHIFT button and CHANNEL on keybed - plastic build - holding down both the Octave + and - for factory reset -  more limited in what you can do with it than IV 4th one - tested on AROS One 2.4 usb
|-
| &lt;!--Description--&gt;M-Audio Oxygen Pro 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 untested semi full keys 
|-
| &lt;!--Description--&gt;M-Audio Oxygen Pro Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested - 32 smaller keys - not endless encoders - usb only - 
|-
| &lt;!--Description--&gt;M-Audio Hammer 88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Moog 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Moog Minitaur 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-VAVE SMK-25mini 25key MIDI Control Keyboard Y6I0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Native Instruments NI Primus A25 JamMate 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2008 not compliant, 
|-
| &lt;!--Description--&gt;Native Instruments Maschine MK1 MKI
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2009 not compliant uses snd-usb-caiaq module, 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol S88 S61 S49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 - weighted keys - 
|-
| &lt;!--Description--&gt;Native Instruments Maschine MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe compliant, 
|-
| &lt;!--Description--&gt;Native Instruments Maschine Micro Mikro MK2 MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe? 
|-
| &lt;!--Description--&gt;NI Komplete Kontrol S49 S61 S88 MkII MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 all MK2 MK3 power up the keyboard using USB, it will set the keyboards MIDI port to computer MIDI only without any option to set it to use the MIDI DIN, meaning you cannot connect the keyboard to hardware and power from USB, you MUST power with the power adapter and physically unplug from any USB connection - 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol A25 A49 A61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe compliant,  
|-
| &lt;!--Description--&gt;[https://github.com/sikorak666/maschine-mikro-mk3-driver Native Instruments Maschine Micro Mikro Plus MK3 MKIII]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Kontrol M32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 untested 32 smaller keys - no drum pads - USB only - 
|-
| &lt;!--Description--&gt;NI Komplete Kontrol S49 S61 S88 MkIII MK3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;NI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2025 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Neusonik iBoard 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nektar Impact LX25+ LX49+ LX61+ LX88+ SE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 budget full-size velocity-sensitive synth-action keyboard - 
|-
| &lt;!--Description--&gt;Nektar Impact GX49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; USB port - 
|-
| &lt;!--Description--&gt;Nektar Panorama P4 P6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  USB &amp; USB Micro B, 5-pin MIDI out, 2 x TRS inputs with 49 semi-weighted, velocity sensitive with aftertouch
|-
| &lt;!--Description--&gt;Nektar SE25 SE49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; mini keys - micro usb bus powered - velocity and sustain button 
|-
| &lt;!--Description--&gt;Nektar Panorama P6 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nektar Panorama T6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nord Stage 3 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; sysex 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Novation ReMote 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 lhs XY touchpad and the joystick -
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 49 61 88 Mk1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 not USB class compliant 
|-
| &lt;!--Description--&gt;Novation 49 61 SL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 semi-weighted Fatar TP-8 or TP-9 keybed
|-
| &lt;!--Description--&gt;Novation ReMote 25SL 49SL 61SL soft label 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 - two long top liquid-crystal display LCD strips - XY touchpad and the joystick - 
|-
| &lt;!--Description--&gt;Novation ReMOTE 25LE 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x0004
| &lt;!--Revision--&gt;0001
| &lt;!--CAMD--&gt;{{Yes|detected, usb driver in devs/midi for camd to use}}
| &lt;!--Opinion--&gt;2007 USB-b powered, 9v center pin positive or 6 MN1500 AA batteries - X/Y touchpad and the combined pitch and modulation joystick - no aftertouch but can use both the legacy MIDI OUT and USB port simultaneously 
|-
| &lt;!--Description--&gt;Novation Nocturn 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Unk| }} 
| &lt;!--Opinion--&gt;2008 untested sending random pitchbend info
|-
| &lt;!--Description--&gt;Novation 49 61 SL MkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 semi-weighted Fatar TP-8 or TP-9 keybed 
|-
| &lt;!--Description--&gt;Novation MiniNova 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2013 
|-
| &lt;!--Description--&gt;Novation Impulse 25 49 61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 velocity aftertouch‑sensitive semi-weighted keyboards and eight backlit pads -  USB, 5-pin MIDI out - 
|-
| &lt;!--Description--&gt;Novation Circuit Tracks / Rhythm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 untested 
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 49 61 88 MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 USB class compliant - full keys - 
|-
| &lt;!--Description--&gt;Novation Launchpad Mini MK2 MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested 8x8 buttons with 16 backlit
|-
| &lt;!--Description--&gt;Novation LaunchKey Mini MK2 MKII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 untested - 25 soft mini keys - 2 rotary wheels lhs - 
|-
| &lt;!--Description--&gt;Novation LaunchKey 25 37 49 61 88 MK3 MKIII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 USB class compliant choice - full keys - 
|-
| &lt;!--Description--&gt;Novation LaunchKey Mini MK3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 untested - 25 soft mini keys - 2 sliders lhs -  
|-
| &lt;!--Description--&gt;Novation 61SL Mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Nymphes Dreadbox 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt; 6 voice analog synth
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Oberheim MC 2000 EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 88 keys fully weighted - very heavy - 
|-
| &lt;!--Description--&gt;PreSonus ATOM SQ Hybrid MIDI Keyboard/Pad
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://polyend.com/tracker/ Polyend Tracker]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland ED PC-300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2002 USB MIDI keyboard controller 49-key
|-
| &lt;!--Description--&gt;Roland EDIROL PCR-M30 PCR-M50 PCR-M80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;Roland Edirol PCR-30 PCR-50 PCR-80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 untested 32 key - 
|-
| &lt;!--Description--&gt;Roland PC-50 PC-80
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2007 
|-
| &lt;!--Description--&gt;Roland PCR-500 PCR-800
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 61 velocity-sensitive keys with aftertouch 
|-
| &lt;!--Description--&gt;Roland A-88 a-49
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 USB port - weighted keys velocity no aftertouch - class compliant with press FUNCTION so it is lit. Press the key labelled &quot;ADV.&quot;, Press the &quot;+&quot; button so it is lit - 
|-
| &lt;!--Description--&gt;Roland PC-200 mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 some had fatar keys 
|-
| &lt;!--Description--&gt;Roland MC-707 Groovebox
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 
|-
| &lt;!--Description--&gt;Roland MC-101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 untested 
|-
| &lt;!--Description--&gt;Roland A-500 A500Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Roland A-300 A300Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 
|-
| &lt;!--Description--&gt;Roland JUNO DS, FA, Fantom, JUPITER X / Xm 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 (be sure that USB driver is set to &quot;Generic&quot; - requires device rebooting) 
|-
| &lt;!--Description--&gt;Roland A-88 a-49 MKii MK2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 expensive with USB-c port - hammer-action keyboard weighted keys - Class-compliant if  USB-C enables bus power - MIDI 2.0 later - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ROLI Seaboard RISE 25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|-
| &lt;!--Description--&gt;Samson Graphite 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Samson Carbon 49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Sequential TAKE 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic VMK-161 and VMK-161 Plus Organ version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;TP-8O action is the unweighted, organ-style waterfall keybed - usb midi in out - 9v psu - 
|-
| &lt;!--Description--&gt;Studiologic SL990XP midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic VMK176 Plus
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }} 
| &lt;!--Opinion--&gt;USB and midi connectivity
|-
| &lt;!--Description--&gt;Studiologic SL880 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Studiologic SL73 SL88 Studio midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; hammer-action Fatar TP semi-weighted keys 
|-
| &lt;!--Description--&gt;Studiologic Numa Organ 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 73 key TP-8O action is the unweighted, organ-style waterfall keybed used in nearly all clonewheels 
|-
| &lt;!--Description--&gt;Studiologic Numacompact 2/2x, Numa X Piano
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero CommandKey49 CommandKey25 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero SZ-MiniCommand Mini-Command USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SubZero SPC61 MIDI Controller
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; bus powered - 5 octave 
|-
| &lt;!--Description--&gt;SubZero ControlKey49S 49 Key Slim MIDI Controller Keyboard
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Synido TempoKey K25
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 25 mini keys - usb-c powered 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{maybe| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Worlde Panda 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha KX8 KX49 KX61 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2008 not compliant 
|-
| &lt;!--Description--&gt;Yamaha CMC-PD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Yamaha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 not class compliant 
|-
| &lt;!--Description--&gt;Yamaha P45B P-45 Digital Piano 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2011 not compliant 
|-
| &lt;!--Description--&gt;Yamaha P-115 midi controller  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 untested weighted keys - USB midi port 
|-
| &lt;!--Description--&gt;Yamaha MX49 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 should compliant untested 
|-
| &lt;!--Description--&gt;Yamaha Montage, CP73/88, YC, MODX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi keyboard controller 
|-
| &lt;!--Description--&gt;Yamaha PSR-E353, PSR-E443
PSR-S670, PSR-S770, PSR-S970, PSR-A3000, TYROS-5
NP-12, NP-32
DGX-650, DGX-660
P-105, P-115, P-255
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha MX49 II V2 Black Blue 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi keyboard controller 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;DJM V10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; dj 
|-
| &lt;!--Description--&gt;Native Instruments Kontrol DJ Pro midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; detected but untested 
|-
| &lt;!--Description--&gt;Numark Mixtrack Pro II USB DJ Controller Djay 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;older generation pioneer DDJ-SX2 dj 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Alyseum AL-22 AL22c  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alyseum AL-88 Schneidersladen AL88c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alyseum U3-88c Midi Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; no CopperLan support Midi network using a UTP Ethernet patch cable) 
|-
| &lt;!--Description--&gt;Behringer BCF2000 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[http://www.behringer.com/EN/home.aspx Behringer] BCR2000 1in 2out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer B-CONTROL DEEJAY BCD3000 DJ Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer UMD404 UMD202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Creative EMU 0404/USB midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;DigiDesign / Focusrite Command 8 Control Surface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005 supports MIDI continuous controller (CC) and note data. SysEx dumping and loading is also supported  
|-
| &lt;!--Description--&gt;Digidesign Digi 002
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006   firewire only 
|-
| &lt;!--Description--&gt;Digidesign Digi 003
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2009   firewire only 
|-
| &lt;!--Description--&gt;emagic m4 2x4 AMT8 Unitor 8 Mk2  8x8 
| &lt;!--Vendor ID--&gt;0x00d0
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;0x010 0x0103
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2000 offers MTS (Midi Time Stamping) - 12v 2a psu centre pos - usb mini with rs232 and rs422 serial ports - 16 channels (8-in / 8-out), this rack-mountable unit - 
|-
| &lt;!--Description--&gt;Evolution U-Control UC-16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| detected}}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Focusrite Saffire 6 USB 1.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Guillemot Maxi Studio ISIS Vintage Sound Card MIDI Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;1998 
|-
| &lt;!--Description--&gt;[http://www.ucapps.de/mbhp_usb.html MidiBox] Hardware Platform USB Module
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Mackie Control Universal Pro XT with One Two Extenders 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2008 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Audiophile USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Midisport UNO old version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio MidiMan 1x1 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004  [http://sourceforge.net/projects/linux-hotplug/ firmware update]
|-
| &lt;!--Description--&gt;M-Audio Midisport 2x2 yellowy green blue, green or silver chassis plastic box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|MIDISPORT 2x2 or 4x4 interfaces from previous production series (blue, green or silver chassis) are not class-compliant}}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;MAudio Audiosport Quattro USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant as [http://usb-midi-fw.sourceforge.net/ firmware required and that is buggy], 
|-
| &lt;!--Description--&gt;M-Audio UC-33
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 not compliant, 
|-
| &lt;!--Description--&gt;M-Audio Midisport 1x1 2x2 4x4 Anniversary Edition, black box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe class compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;[http://www.amiga.org/forums/showthread.php?t=52920 Mark of the Unicorn Motu Fastlane] 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|[http://www.amiga.org/forums/showpost.php?p=560852&amp;postcount=8 not working on OS4]}} 
| &lt;!--Opinion--&gt; not class compliant, 
|-
| &lt;!--Description--&gt;Motu Micro Lite 1x1 and MOTU microlite 5x5 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt; good unit but poor just plug in support and not class compliant - USB2 usb-b - 
|-
| &lt;!--Description--&gt;Motu MIDI Express 128 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;poor support serial port only - offers MTS (Midi Time Stamping) A serial port based MIDI interface or a USB interface without MTS will have a MIDI slop of up to 2ms on record and playback. MTS provides accuracy for record and playback to around .3ms - five times more accurate than serial or non-MTS.&quot; 
|-
| &lt;!--Description--&gt;MOTU.com MIDI Express XT 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt;2008 for many USB should have octocoupled connection to reduce groundloop humm, usually the timing is off 
|-
| &lt;!--Description--&gt;MOTU MIDI Timepiece AV 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|dedicated driver}}
| &lt;!--Opinion--&gt; not class compliant is one of the best multi-port MIDI interfaces ever made as USB model connects to the computer as an 8x16 interface
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Native Instruments GmbH Audio 8 DJ, 4 DJ, 2 DJ
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt;0x
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|needs dedicated driver}}
| &lt;!--Opinion--&gt;2006 not class compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Qcon 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Roland Edirol UA-100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|did not match to camdusbmidi.class USB audio midi with onboard DSP}}
| &lt;!--Opinion--&gt;1998 
|-
| &lt;!--Description--&gt;Roland Corp Edirol UM-2 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0005
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{no|is not bound via camdusbmidi.class }}
| &lt;!--Opinion--&gt;1999 not bound to any midi class - 2x2 - tested Aros One USb 2.4 
|-
| &lt;!--Description--&gt;Roland Edirol UA-100G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;1999 USB audio midi with onboard DSP 
|-
| &lt;!--Description--&gt;Roland Edirol UM-880 8x8 midi interface 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2000 under poseidon but could work with run &gt;nil: c:midithru out.0 &quot;EDIROL UM-880.out.2&quot;
|-
| &lt;!--Description--&gt;Roland Edirol UM-1 blue plastic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{Unk| bound??? via camdusbmidi.class - untested midi in out}}
| &lt;!--Opinion--&gt;2000 UM-1 -  1-in/1-out (16 channels) 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1S
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2000 1-in/1-out (16 channels)
|-
| &lt;!--Description--&gt;Roland Edirol UM-2E
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2000 
|-
| &lt;!--Description--&gt;Roland Edirol UM550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1X midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|do not have the Advanced Driver Switch on them}}
| &lt;!--Opinion--&gt;2001 
|-
| &lt;!--Description--&gt;Roland Edirol UM-1SX
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0052
| &lt;!--Revision--&gt;0200
| &lt;!--CAMD--&gt;{{No|do not have the Advanced Driver Switch on them}}
| &lt;!--Opinion--&gt;2003 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-2C - 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2003 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-1G 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;Roland Edirol Cakewalk UM-2G 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;[https://github.com/spotify/linux/blob/master/sound/usb/usbquirks.h Roland Edirol UA20 UA-20] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|not working}} 
| &lt;!--Opinion--&gt;2004 
|-
| &lt;!--Description--&gt;Roland UM-1EX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2005
|-
| &lt;!--Description--&gt;Roland Edirol UM-2EX 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005  adds a second MIDI OUT
|-
| &lt;!--Description--&gt;Roland Cakewalk UM-3G - 3x3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2006 
|-
| &lt;!--Description--&gt;Roland Cakewalk ua-25excw 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2009 not class compliant mode 
|-
| &lt;!--Description--&gt;[https://alsa.opensrc.org/Edirol_UA-25EX Roland Edirol UA55 UA-55 Cakewalk UA25 EX] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|detected but not working}} 
| &lt;!--Opinion--&gt;2011 not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Sonuus B2M Bass MIDI Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Sonuus G2M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Steinberg CMC Series 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Subzero SZ-MB44 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Swisssonic MIDI1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt;2012 AmigaOS there is no output at midichannel one and two but if play a midi file there is only output on some channels and if pressed stop the prog freezes or the whole system crashes
|-
| &lt;!--Description--&gt;Teac Tascam US-428 US-422 midi interface 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 2000 not compatible 
|-
| &lt;!--Description--&gt;Teac Tascam [http://web.archive.org/web/*/http://www.tascam.com/Products/US-224.html US-224]
| &lt;!--Vendor ID--&gt;0x1604
| &lt;!--Product ID--&gt;0x8004
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 2002 does not bind to any class
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-1x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }} 
| &lt;!--Opinion--&gt;2002 
|-
| &lt;!--Description--&gt;Teac Tascam US-122 MKII midi interface 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt;0x8021
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{No|not detected / binding to camdusbmidi.class on AROS 2.4 usb }} 
| &lt;!--Opinion--&gt;2004 detected but not working 2-in/2-out USB two XLR microphone preamps with phantom power for condenser microphones 
|-
| &lt;!--Description--&gt;Teac Tascam US-200 US-400 US-600 US-800 US-1200 US-1800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|no driver}}
| &lt;!--Opinion--&gt;2010 may not be totally usb compliant 
|-
| &lt;!--Description--&gt;Yamaha UX-16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|no driver}}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| CAMD
| Opinion 
|-
| &lt;!--Description--&gt;Akai EIE and Pro version midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 dc 6v power - 3 USB hubs, midi in out , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Alesis I/O2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 powered USB hub required, not compliant 
|-
| &lt;!--Description--&gt;Alesis IO2 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 usb compliant?
|-
| &lt;!--Description--&gt;Alesis IO4 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;Behringer XTouch 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; psu needed 
|-
| &lt;!--Description--&gt;Behringer X-Touch Compact
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant?
|-
| &lt;!--Description--&gt;Behringer X-Touch Mini
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant?,  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Behringer U-Phoria UMD404HD UMD202HD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe class compliant - volume low, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;CME U2 MIDI Pro 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; current model 
|-
| Creative EMU XMIDI 1X1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 early versions with sysex checksum errors 
|-
| &lt;!--Description--&gt;Creative E-MU Xmidi 1x1 Tab (V3) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 tab version class compliant but report that when transferring 'System Exclusive' messages (SysEx) the unit could not handle the highest data rate leading to data corruption 
|-
| Creative EMU XMIDI 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 sysex errors 
|-
| &lt;!--Description--&gt;Digidesign Mbox 2 Mini now Avid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 USB powered but not compliant 
|-
| &lt;!--Description--&gt;Digidesign Mbox II Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 USB powered but not compliant 
|-
| &lt;!--Description--&gt;Engl Z7 MIDI Interface (E660/E610/E360/E930)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; guitar?
|-
| &lt;!--Description--&gt;Elektron TurboMidi TM-1 1in 1out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI MidiTerminal M4U 4x4 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;supposedly class compliant - USB bus powered - 
|-
| &lt;!--Description--&gt;ESI MidiTerminal M8U 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI MidiTerminal M4U XL 4x4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; ploytec chipset 
|-
| &lt;!--Description--&gt;ESI MidiTerminal M8U XL 8x8
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; no hardware routing e.g. x on input 5 to synth y on output 7 - ploytec chipset 
|-
| &lt;!--Description--&gt;ESI MidiMate 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; supposedly class compliant - USB bus powered 
|-
| &lt;!--Description--&gt;ESI MidiMate II 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ESI ROM I/O
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2005 romio version 
|-
| &lt;!--Description--&gt;ESI M4U XT
| &lt;!--Vendor ID--&gt;0x2573
| &lt;!--Product ID--&gt;0x0002
| &lt;!--Revision--&gt;0100
| &lt;!--CAMD--&gt;{{Maybe|is bound via camdusbmidi.class AROS One 2.4  - untested midi in out}}
| &lt;!--Opinion--&gt;2010  - 
|-
| &lt;!--Description--&gt;ESI M8U XT 8in 8out
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 discontinued 2018 
|-
| &lt;!--Description--&gt;ESI M8UEX USB3.0
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 current model 
|-
| &lt;!--Description--&gt;ESI M4U eX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 current model 
|-
| &lt;!--Description--&gt;ESI MidiMate eX midi interface 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 curent model, well liked and might class compliant?? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;icon midiport 2x2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;iCON CubeMi 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant? 
|-
| &lt;!--Description--&gt;iConnectivity 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;iConnectivity mio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 class compliant but reported issues with sending System Exclusive (SysEx) MIDI messages and MIDI signals getting cut off 
|-
| &lt;!--Description--&gt; iConnectMidi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 
|-
| &lt;!--Description--&gt;iCM2 iCM4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 
|-
| &lt;!--Description--&gt;iConnectivity iConnectMIDI4+ L
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 class compliant?? 
|-
| &lt;!--Description--&gt;iConnectivity MioXL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;IK Multimedia iRig MIDI 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant 
|-
| &lt;!--Description--&gt;iRig Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton Electronics pro solo mk2 midi to cv converter
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Kenton Midi Thru-25 5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Keytech MT18E 8 Way Midi Thru box 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 9 to 12v psu required 
|-
| &lt;!--Description--&gt;MidiPlus Midi 2x2 midi interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;MidiPlus Midi 4x4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; supposedly class compliant - USB bus powered 
|-
| &lt;!--Description--&gt;MidiTech MIT-00151 Midiface 4x4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;MidiTech Midiface 4x4 8x8 16x16 thru merge 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Miditech Midilink mini 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;M-Audio Midisport UNO only if box is labeled Class Compliant and latest MIDISPORT 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Fast Track Ultra (6 in 6 out) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 not usb compliant, - 
|-
| &lt;!--Description--&gt;M-Audio Midiman Midisport 2x2 Anniversary Edition [https://gearspace.com/board/electronic-music-instruments-and-electronic-music-production/1133862-why-there-hardly-any-midi-interfaces.html not stable enough] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 USB2 usb-b - does not need firmware and supposedly plug and play - 
|-
| &lt;!--Description--&gt;M-Audio Midisport 4x4 Anniversary Edition
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; rumored does not need firmware - supposedly plug and play -  issues with its firmware for some and lacks configurable routing
|-
| &lt;!--Description--&gt;Maudio Fast Track Ultra 8R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Native Instruments Komplete Audio 6 Mk1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2011 maybe usb compliant but bus powered, 
|-
| &lt;!--Description--&gt;Nektar Midiflex 4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|untested}}
| &lt;!--Opinion--&gt;2015 class compliant and usb-b powered - used as a 1 in / 3 out, 2 in / 2 out or 4 out 5pin sockets - 
|-
| &lt;!--Description--&gt;Neusonik IM-One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Peavey Xport
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; guitars only 
|-
| &lt;!--Description--&gt;Roland UM-ONE UM-1 mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 USB class compliant if switch to TAB for class compliant mode rather than the COMPUTER mode 
|-
| &lt;!--Description--&gt;Squarp Hermid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Steinberg Midex 8x8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; class compliant?  supporting MIDI Time Stamping protocol
|-
| &lt;!--Description--&gt;Swissonic MidiConnect 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Tapco LiNK.midi USB 4x4 (Loud technologies) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no|dedicated driver}}
| &lt;!--Opinion--&gt;2005 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-2x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{no| }}
| &lt;!--Opinion--&gt; 2014 5v dc power, midi out in, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-4x4
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;Teac Tascam US-16x08 US-20x20
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;Zoom U-24
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi to 5pin interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi to 5pin interface 
|-
| &lt;!--Description--&gt;Unbranded cable 
| 0x552d
| 0x4348
| F110 
| &lt;!--CAMD--&gt;{{Maybe|detected but no usb driver in devs/midi for camd to use}}
| &lt;!--Opinion--&gt;detected but not working the USB-MIDI conversion functionality of the cheapo USB MIDI &quot;cable&quot; interface is simply lacking, possibly being incapable of handling MIDI strings longer than 3 bytes long SysEx strings (e.g. SysEx dumps) - tested in Icaros 2.3 - 
|-
| &lt;!--Description--&gt;USB2.0-MIDI Unbranded cable with clear braided underneath leads 
| &lt;!--Vendor ID--&gt;0x1A86
| &lt;!--Product ID--&gt;0x752D 
| &lt;!--Revision--&gt;0254 
| &lt;!--CAMD--&gt;{{Maybe|detected binding to camdusbmidi.class but untested midi in / out}}
| &lt;!--Opinion--&gt;untested but better to get a branded version - tested AROS One 2.4 usb
|-
| &lt;!--Description--&gt;LogiLink USB to Midi In-Out 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk|}}
| &lt;!--Opinion--&gt;untested cheap cable version but issues with latency on other systems 
|-
| &lt;!--Description--&gt; gm5 USB midi chip  DIY option only
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Doremidi LEKATO MIDI USB C Interface 1x1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;Thomann Midi USB 1x1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;   Prodipe made 
|-
| &lt;!--Description--&gt;Prodipe MIDI 1i/1o 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  usb to 5pin midi interface 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|}


Classic 5pin DIN controllers for above interfaces 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; | Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |CAMD
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;Akai s5000 s6000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  midi digital samplers 
|-
| &lt;!--Description--&gt;Akai AX80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Casio CZ-5000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Casio CZ-3000 CZ-1000 CZ-101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Cheetah MS6 midi controller 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{No|untested}}
| &lt;!--Opinion--&gt;2000 multi-timbral, six-voice (twelve-oscillator), analogue synthesiser module is loaded with CEM 3396s 
|-
| &lt;!--Description--&gt;Ensoniq ESQ1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Integra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Wavestation Ex A/D SR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1986 ex has piano and drum sounds 
|-
| &lt;!--Description--&gt;Korg DW-8000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg DW-6000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Korg Poly 800 MK1 Poly-800ii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  all plastic and can run on batteries - 49 keys non-velocity dco synt analogue filter 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland D-50
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|1987 untested greater concern would be moisture and wear}}
|-
| &lt;!--Description--&gt;Roland A50 (76) A80 (88) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|1989 untested}}
|-
| &lt;!--Description--&gt;ROLAND JUNO-D
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Roland Juno 106 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;80s kx73 or kx88 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Roland ED PC-160A PC-180A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}} legacy DIN5 MIDI port only - 6 AA batteries or 9v psu - One regular source of failure for me were emty batteries (even with red control light still active). Another source was a bad MIDI cable - unplug then re-plug the USB cable while it is powered the device might reconnect 
|-
| &lt;!--Description--&gt;Roland M1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland S-550 S-760 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt; digital samplers kontakt replaced these? 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha DX7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1983 12bit 
|-
| &lt;!--Description--&gt;Yamaha DX7S DX72IID DX7IIFD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1987 16bit versions 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--CAMD--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
|}


The MIDI standard was published in August 1983. The inventors, Kakehashi and Smith finally received a Technical Grammy Award in 2013 for their work. 

The MIDI files that contained just the note data, velocity and timing meant you could transfer an entire studio session from one place to another on one floppy disk and it could control all the synths and drum samplers. Pass-thru meant that one computer could run an entire bands worth of instruments. 

It's bulletproof too. MIDI never goes wrong, it's always a bug in software that causes any issue - you can absolutely rely on it to go gigging with, take your synths, controllers and computers and not crash an entire gig at your 100,000 person venue. 

The MIDI hardware specification is very simple (voltage, polarity, screening, protection and a fast enough opto-isolator), it assumes that the data it sends and receives between MIDI devices is to the MIDI data standard and just passes it on. The microprocessor in the hardware does all the work.

The minimum for a computer/MIDI interface is that it meets the MIDI hardware specification. It is attached to the computer bus and handles the electrical conversions required. To meet the MIDI hardware specification, to be class compliant as a USB device all it has to do is report itself properly when plugged in.

The other half of the equation is the MIDI data standard, and for a computer MIDI interface the main issue is the speed of data transmission. The bus speed of the computer is faster than the speed of the MIDI standard so it can generate and send MIDI data faster than a MIDI device can receive it. The MIDI standards have nothing to say on that bottleneck at all. MIDI was designed to be very simple and very open, it just defines a standard for the messages and leaves it up to manufacturers to implement them in the way they want. That's what makes it so powerful a tool, and also what makes it so confusing and frustrating at times.

For midi, the hardware/software combination at various connection points handles the translation to/from midi (or other protocols). Drivers would be needed for midi, including clock and SysEx signal (actually claiming to handle ALL midi quirks transparently

All the important MIDI data types can be sent (CC, NRPN, RPN, MMC, Note On/Off, program change)

There is no official way to solve the data bottleneck. Early software sequencers and librarians tried to solve it by having an option to buffer SYSEX data in software and transmit it at the MIDI data rate. The downside is that hogs the bus and can hit computer performance. Interface manufacturers would add a hardware buffer which would take all the MIDI data from the PC bus and feed it into the MIDI at the slower data rate, but that added cost and created timing issues.

Things have moved on since then, but the principles remain the same. You can buffer in the hardware or in software, whether that is in the application or the interface driver. SYSEX will work perfectly well with that budget cable if your software handles the buffering. And while the cables with hardware buffers make SYSEX easier, they still have potential problems because of the limitations of the MIDI data rate. Your MIDI clock doesn't like being interrupted with a big program dump 

The serial / parallel ports were a direct connection, so faster. Now, everything in the computer is virtual and the only thing connected to the hardware is the kernel, hence everything is by default bottlenecked and jittery, regardless of which connection. So by the time the interface gets the information it's already too late. 

Ethernet network cable to transport MIDI over large distances, connect 2 MIDI In and 2 MIDI Out ports to patch, remap, filter and merge MIDI flows on a fine channel basis for tight MIDI throughput, latency and jitter 

Possibilities for DAWs of the future including a kind of sync reference for timing reference which an interface could sync to, hence all the timings then would be locked between the grid on the DAW screen and the MIDI info. 

Preemptible, low latency and accuracy are essential for good communication.  

One of the first things you need to do, is make sure your MIDI software sets the interface to the same MIDI channel as your keyboard (usually 1) 


Do you want to send just your master keyboard to other synths or to be able to use any keyboard with any synth?

1st option is relatively simple. Just need to send midi from your master keyboard into a midi splitter that redistributes the signal onto your synths. Each synth will be set up to receive midi on a specific channel so the only challenge is to find a way to select to which channel you are sending midi. Some master keyboards can do that although not many that have a dedicated knob or switch on the panel and most require a bit of menu diving. Could use a midi box that offers channel selection but usually this is not very workflow friendly. The software route would require using the mouse. 

2nd option is a bit more complex but superior workflow by sending midi messages into a merge box, from there into a hardware sequencer that allows to select midi channel, then on to a midi interface that distributes the signal to the synths. 

Master keyboard MIDI-in to computer. External hardware sampler MIDI-out from computer. Audio-out from sampler to audio-in on computer/device. 


Blue Ribbon Soundworks Bars &amp; Pipes Professional (1993/4) 

GM (1984), GS (1987), XG level 1-3 (1994-1997), GM level 2 (1999) 	

GM GM1 imposes several requirements beyond the MIDI 1.0 specification. While MIDI 1.0 by itself provides a communication protocol which ensures that different instruments can interoperate at a fundamental level e.g sound modules. GM goes further in two ways. First, GM requires that all compliant MIDI instruments meet a certain minimal set of features, such as being able to play at least 24 notes simultaneously (polyphony). Second, GM attaches specific interpretations to many parameters and control messages which were left unspecified in the MIDI 1.0 specification. A minimum of 128 MIDI Program Numbers (conforming to the GM 1 Instrument Patch Map) and 47 percussion sounds (conforming to the GM 1 Percussion Key Map). Support for controller number 1, 7, 10, 11, 64, 100, 101, 121 and 123; support for channel pressure and pitch bend controllers. 

General MIDI Level 2 or GM2 is a specification for synthesizers which defines several requirements beyond the MIDI standard and is based on General MIDI (GM) and Roland GS extensions. It was adopted in 1999 by the MIDI Manufacturers Association (MMA).

* Number of Notes: 32 simultaneous notes
* MIDI Channels: 16
* Simultaneous Melodic Instruments – up to 16 (all Channels)
* Simultaneous Percussion Kits – up to 2 (Channel 10/11)

Program and bank change events
General MIDI 2 compatible synthesizers access all of the 256 instruments by setting cc#0 (Bank Select MSB) to 121 and using cc#32 (Bank Select LSB) to select the variation bank before a Program Change. Variation bank 0 contains the full GM (General MIDI 1) sound set. Variations using other bank numbers are new to General MIDI 2, and correspond to variation sounds introduced in Roland GS. 


[https://www.youtube.com/watch?v=CluuHrr7HG4 Major WWHWWWH, Minor WHWWHWW scale], [https://www.youtube.com/watch?v=Jjm7Ti-iwz0 Chords], 


==usb audio==

 AROS currently does not support natively any USB audio interface for recording audio 

USB audio is only available for limited Amiga like OSs, independent of the USB protocol version USB1.x USB2, USB3.x, which are not backwards compatible. 

*Introduced 2000 and from 2014 USB Audio 1 UAC1 16bit 44.1kHz
*Introduced 2006 and from 2014 USB Audio 2 [https://www.usb.org/document-library/usb-device-class-definition-audio-devices-release-20-errata-and-ecn-through-april UAC2] 24bit 192kHz
*Introduced 2016 and from 2024 USB Audio 3 [https://www.usb.org/documents UAC3] 32bit 384kHz 

USB group decided to rewrite the audio standard, so [https://os4depot.net/?function=showfile&amp;file=audio/record/usbaudio2.lha UAC2] and [https://archive.fosdem.org/2019/schedule/event/linux_and_usb_audio_class_3/attachments/slides/3345/export/events/attachments/linux_and_usb_audio_class_3/slides/3345/Linux_and_USB_Audio_Class_3___FOSDEM_2019.pdf UAC3]. They added clock selection and control, timing domains and others. Part of the changes included changing many of the descriptors that an audio device uses to describe itself to the machine. 

PsdErrorlog/PsdDevlister? The AHI driver generated only supports mono/stereo at any bit rates between 8 and 32 bit per sample, but not multichannel modes and only rates up to 65KHz (because AHI uses a 16-bit word for frequencies). If the soundcard does not offer such a PCM 8-32 bit mode at frequencies lower than 65 KHz, there's nothing much that can be done about it on the computer side other than revising and expanding the AHI standard. Most cheap USB soundcards do though. 

AHI does not support six channel playback. It only supports mono, stereo and multichannel (8 channels). Due to the multichannel mode not being used by any application so far, the usbaudio.class does not support multichannel playback, especially not &quot;upchannelling&quot; stereo to six or more channels. If this USB device does not support a two channel mode, you can't use it under AHI.

Untested but most likely to work, at least 2 mic inputs (low impedance) &amp; instruments (high impedance) and made in the last 10 years 
*[https://www.youtube.com/watch?v=gMuA-2FbJxE Entry level &lt;100Euro]   BOMGE U202, Behringer UMC, Presonus Studio, 
*[ Next tier &lt;200Euro]   Audient iD, Solid SSL2 and SSL2+, Lewitt, Focusrite Scarlett, Arturia MiniFuse, 
*[ Prosumer &lt;300Euro]   Focusrite Clarett+, 
*[ Professional &lt;500Euro]   RME Babyface, 
*[ Studio &gt;500Euros]    

Bands may need 4 or more mic inputs 

[http://forum.xda-developers.com/showthread.php?p=38364030 XDA Forum thread],

&lt;pre&gt;
                                            &lt;- Computer 
                                            &lt;- Mobile Phone / Tablet (OTG)
                                            &lt;- Digital Cameras 
                            &lt;- Video        &lt;- Webcams 

Base Computer &lt;-&gt; OBS like  &lt;- Audio Mixer  &lt;- Microphone(s) 

                            -&gt; Internet     -&gt; Youtube &amp; Chat 

&lt;/pre&gt;

USB AUDIO CARDS - UAC Compliant 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;20%&quot; |Description 
! width=&quot;10%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;10%&quot; |Playback
! width=&quot;10%&quot; |Records 
! width=&quot;30%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Arturia Mini Fuse 1
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant, okay pre amp 1 combi input, cirrus logic cs4272 ad converter, 
|-
| &lt;!--Description--&gt;Arturia MiniFuse 2
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant usb-c with usb2.0, okay pre amps with good dynamic range 110dB, cirrus logic cs4272 ad converter, two combi inputs for mic, line or guitar, 
|-
| &lt;!--Description--&gt;Arturia MiniFuse 4 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, okay 110dB dynamic range, -129dB EIN, 
|-
| &lt;!--Description--&gt;Arturia AudioFuse 16Rig 
| &lt;!--Vendor ID--&gt;0x1C75
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audient iD44 mk1 mki 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2018 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Audient evo4 EVO8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Audient iD4 mk2 mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Audient id14 mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Audient iD24 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 maybe usb compliant and usb-c bus powered, good, , 0-in/14-out audio interface with ADAT expandability, balanced inserts
|-
| &lt;!--Description--&gt;Audient iD44 Mk2 Mkii 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC22 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC202HD 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps ein -129 dBu, 24bit ADC, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC404HD 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, okay, midas pre-amps, 24bit adc, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UMC204HD 192 Empower Tribe 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt;0x0508
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 maybe usb compliant, okay, midas pre-amps
|-
| &lt;!--Description--&gt;Behringer UMC1820 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2016, bus complaint?, okay midas pre amps, adc, 
|-
| &lt;!--Description--&gt;Behringer U-PHORIA UM2 
| &lt;!--Vendor ID--&gt;0x1397
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, poor zenyx pre-amps with high noise floor, plastic build no rf shielding, latency issues, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Focusrite Saffire 6 USB 1.1
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, , , midi, strictly NEC USB 2.0, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 8i6 Gen 1 MOSC0001 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, but 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 1 MOSC0003 
*TP1 - 3.3V, tested ok
*TP2 - U4 control signal, 3.3V present at all time.
*TP4 - Ground
*TP6 - 48V, tested ok
*TP7 - Ground
*TP8 - Ground
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 usually avoid early Gen 1, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2021/08/75-focusrite-scarlett-2i4-1st-gen.html Focusrite Scarlet 2i4 Gen 1 (slide toggles) MOSC0004] 
*TP1 - 3.3V, tested 3.22v
*TP2 - U4 control signal, 3.3V present 
*TP4 - Ground
*TP6 - measure 47.72v 
* AKM 4384ET (VDD 5v)
* Cirrus Logic CS4272-CZZ (VA 4.94v/ VD 3.2v/ VL 3.2v)
* all four HC4066 (VCC 4.96v)
* XMOS XS1-L01A-TQ128-C5 (all VDD 1.08v/ all VVDIO 3.23v/ PPLAVDD 0.99v/ PCU-VDDIO 3.23v)
2i4S
*TP1 seems to be 0V
*TP2 should be 5V
*TP3 should be 
*TP6 should be 48V
*TP8 should be 3.3V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, pre amps JRC NJM2122 and NJM4565, [https://statics.cirrus.com/pubs/proDatasheet/CS4272_F1.pdf CS4272 adc], [https://pdf.datasheet.live/e5e5fd1c/akm.com/AK4384.pdf AK4384 output pair], Xmos XS1-L8A-64-TQ128 processor and firmware in Winbond 25X40CL 4Mbit, an SMSC Microchip USB3343 interface and a Microchip PL611 clock generator - two Intersil / Renesas ISL97519A for the phantom power rail, two OnSemi NCP1521B for the 3.3V (digital) and 1V (Xmos core) rails - 
|-
| &lt;!--Description--&gt;Focusrite iTrack Solo USB Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2012 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 1st Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, , Cirrus CS4272, 
|-
| &lt;!--Description--&gt;[http://wiki.linuxaudio.org/wiki/current_audio_gear Focusrite ] Scarlett 4i4 Gen  MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, , Cirrus CS4272, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 6i6 Gen1 MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, , , 12v psu, the headphone outs mirror the outs on the back panel, so that's six independent outs. 4 independent analog output paths, plus two over spdif, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2019/03/38-focusrite-scarlett-18i8-gen1-teardown.html Focusrite Scarlett 18i8 1st Gen MOSC0008]
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, JRC NJM4565 provide most of the opamps, pair of JRC NJM2122's for inputs 1 and 2, [http://www.mouser.com/ds/2/76/cs4272_f1-43250.pdf Cirrus CS4272], 12v 1a +central psu to a pair of National Semiconductor LM2672 for 3.3V rail and the +6.9V rail, Xmos XS1–L16A–128 dual-row QFN package, firmware a Winbond 25X40C 4Mbit SPI Flash and an SMSC USB3343 interface chip, the two headphone outs are completely independent so 6 independent analog output paths, plus two over spdif, 
|-
| &lt;!--Description--&gt;Focusrite Clarett+ 8Pre 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 great, expensive, maybe usb compliant?  
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 2 (slide toggles) MOSC0006 
*TP6 should be 48V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8202
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, USB-b bus powered, good preamps ein equivalent input noise -128 dBu, 24-bit 192kHz CS4272 as well as an additional AKM AK4384ET for the second stereo output pair, 4 screws under bottom rubber,  
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2021/07/focusrite-scarlett-2i4-2nd-gen-teardown.html Focusrite Scarlett 2i4 Gen 2 (slide toggles) MOSC0014]
*TP6 should be 48V
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, USB-b bus powered, good preamps NJM2122's, NJM4565's and CMOS switches (HEF4053 and HEF4066), CS4272 and a AKM AK4384ET, Xmos XU208-256-TQ64-C10 with firmware stored in a Macronix MX25L8006E 8Mbit flash memory, clocking by a Cirrus Logic CS2100, an MP1542 boost converter creates +6V and -6V rails, powering the opamps and the rest of the analog circuitry, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 6i6 Gen2 MOSC0016
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 2nd Gen MOSC0019
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 
|-
| &lt;!--Description--&gt;[https://khronscave.blogspot.com/2024/03/focusrite-scarlett-18i8-gen2-teardown.html Focusrite Scarlett 18i8 2nd Gen MOSC00]
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 3rd Gen MOSC0024
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant usb-c but usb2, preamps, ad/dc 24bit 192kHz, most Focusrite gen3 interfaces have encrypted processors, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i6 Gen3 MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, USB2 class compliant device, but with custom mixer interface
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 Gen 3 (push in switches) MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8210
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, USB-c bus powered, good preamps ein equivalent input noise -128 dBu, 24-bit 192kHz Cirrus Logic xfr002c and cs4272 chips, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 3rd gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i8 3rd Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;0x8214
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, , , no screws under the rubber pads on the bottom, 12v psu, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo Studio Mk3 USB Audio Interface MOSC0030 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2020
|-
| &lt;!--Description--&gt;Focusrite Scarlett 2i2 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 4i4 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Studio 4th Gen USB 
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett Solo 4th Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Focusrite Scarlett 18i20 4th Gen MOSC00
| &lt;!--Vendor ID--&gt;0x1235
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Lewitt Connect 6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Lewitt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Motu UltraLite AVB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt; usb not compliant? 
|-
| &lt;!--Description--&gt;MOTU M2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant?, usb-c, good pre amps, ad/dc, 
|-
| &lt;!--Description--&gt;MOTU M4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;MOTU U2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  maybe not usb compliant, good but latest had hardware revision 
|-
| &lt;!--Description--&gt;MOTU UltraLite-mk3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 not usb compliant, great 
|-
| &lt;!--Description--&gt;MOTU UltraLite-mk5
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 not usb compliant, great 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Nuemann MT48 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, okay 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Presonus AudioBox USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe not usb compliant, usb1.1 usb-b bus powered, okay pre-amps, 24bit ADC 48Khz max, 
|-
| &lt;!--Description--&gt;Presonus Audiobox 1818VSL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Presonus AudioBox 44VSL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 may not be usb compliant, 12v psu, 
|-
| &lt;!--Description--&gt;PreSonus AudioBox 22VSL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 2|4 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, usb-b, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 2|6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;|PreSonus Studio 6|8 USB Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe compliant, needs ext psu, 
|-
| &lt;!--Description--&gt;PreSonus Studio 24c 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, good, adc, 
|-
| &lt;!--Description--&gt;PreSonus Studio 26c 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, 
|-
| &lt;!--Description--&gt;PreSonus® Studio 68c
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, usb-c, 
|-
| &lt;!--Description--&gt;PreSonus AudioBox USB 96 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, high preamp noise, 
|-
| &lt;!--Description--&gt;Presonus Quantum ES2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, okay, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Prism 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Prism Lyra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe not usb compliant, great 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Platane UP1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant usb- UAC2 asynchronous protocol, 64dB Low-noise Mic amplifier, 32Bit High End ADC and DAC, 16dBu High-power ti headphone amplifier
|-
| &lt;!--Description--&gt;Platane UP2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Platane 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;RME Babyface/UC/UFX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant, good 
|-
| &lt;!--Description--&gt;RME Fireface UCX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 might be able to put into class compliant cc although a firewire device, pre amps, adc,  
|-
| &lt;!--Description--&gt;RME Babyface Pro FS  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe not usb compliant, good 
|-
| &lt;!--Description--&gt;RME Fireface UCX II
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 might be class compliant usb-b, pre amps, adc,  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Solid State Logic SSL2 SSL2+ Mk1 1st Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe usb compliant, good, adc, 
|-
| &lt;!--Description--&gt;Solid State Logic SSL12 SSL18 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, bus powered, good pre-amps, up to 32-bit 192kHz AD/DA converters, 12-in 8-out, 
|-
| &lt;!--Description--&gt;Solid State Logic SSL2 SSL2+ MkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant, good pre amps ein -130 dBu, ad/dc, okay latency, 
|-
| &lt;!--Description--&gt;Solid State Logic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Topping E1x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;Topping Pro E2x2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant, good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;UAD UA Apollo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;UA apollo 2nd Gen twin X (Duo/Quad), X4, X6, X8, X8P, and X16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 bus compliant?, usb-
|-
| &lt;!--Description--&gt;UA apollo twin x quad 3rd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 bus compliant?, usb-
|-
| &lt;!--Description--&gt;Universal Audio Volt 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;|Universal Audio Volt 276 2|76 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;Universal Audio Volt 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant, good, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;Akai EIE Pro AI01 Electromusic Interface Expander - 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 4-in/4-out USB 2.0 audio interface with a built-in USB hub and MIDI I/O, up to 24-bit/96kHz 
|-
| &lt;!--Description--&gt;Akai EIE Pro AI02 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;|Alesis io2 io|2, io14 io|14, io26 io|26 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 bus powered but not usb compliant, okay pre-amps, 2, 4 or 8 mics respectively, 
|-
| &lt;!--Description--&gt;Alesis iO2 Express 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010  not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Alesis Core 1 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe cc, mini usb, poor latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Apogee Duet 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 firewire only, not usb compliant micro-usb with most features, , ,  two‑channel two‑in, two‑out, 
|-
| &lt;!--Description--&gt;Apogee Ensemble 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 firewire, not usb compliant micro-usb with most features, , ,  two‑channel 
|-
| &lt;!--Description--&gt;Apogee One USB 1st Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant micro-usb for basic features, , , single‑channel up to 48kHz
|-
| &lt;!--Description--&gt;Apogee One USB 2nd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant usb- and maybe aa batteries, 
|-
| &lt;!--Description--&gt;Apogee Duet 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c with most features, , , 
|-
| &lt;!--Description--&gt;Apogee One USB 3rd Gen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Apogee Ensemble Thunderbolt 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 maybe not usb compliant micro-usb with most features, , ,  two‑channel 
|-
| &lt;!--Description--&gt;Apogee Boom 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c, , , 
|-
| &lt;!--Description--&gt;Apogee Duet 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2022 maybe usb compliant usb-c with most features, , , 
|-
| &lt;!--Description--&gt;Apogee 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;ART PRO Audio Usb Mix 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 maybe usb compliant bus powered, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 1 USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt;01000
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2002 mbox original was usb1 and not a usb class compliant device, and had the much hated &quot;focusrite designed&quot; mic preamps, light blue front plate and the sticky out feet 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 midi not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Pro USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Mini USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 not usb compliant 
|-
| &lt;!--Description--&gt;Avid Digidesign Mbox 2 Micro USB Audio 
| &lt;!--Vendor ID--&gt;0x0dba
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not usb compliant 
|-
| &lt;!--Description--&gt;AVID MBox 3rd gen Mini or Standard but Pro is Firewire 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2010 maybe usb compliant, 
|-
| &lt;!--Description--&gt;behringer u-control uca202 
| &lt;!--Vendor ID--&gt;0x8bb
| &lt;!--Product ID--&gt;0x2902
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, draws a lot of power - dac ti burr-brown - no microphone pre-amp - 
|-
| &lt;!--Description--&gt;Behringer U-CONTROL UCA 222 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2009 maybe usb compliant,  - no microphone pre-amp - 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Black Lion Audio 2x2 evolution 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 maybe usb compliant but , okay with 109dB range - poor noise floor, 24-bit 192kHz Cirrus Logic CS4272, average latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Bomge 11s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 
|-
| &lt;!--Description--&gt;Bomge 22s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 
|-
| &lt;!--Description--&gt;Bomge BMG22 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2021 usb-c, 24bit 192kHz but only use much lower, may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge U202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-c, 32bit 192kHz but only use much lower, may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge U204 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-c, 32bit 192kHz but only use much lower , may have to spend time cleaning up some of the noise, high latency, 
|-
| &lt;!--Description--&gt;Bomge Mini 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2024 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;TI Burr-Brown PCM2702E PCM2704 PCM2704C Muse Audio Mini USB DAC board 
| &lt;!--Vendor ID--&gt;0x08bb 
| &lt;!--Product ID--&gt;0x2704
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, no mic input - goodish quality
|-
| &lt;!--Description--&gt;TI Burr-Brown PCM2900 PCM2902 PCM2906 USB DAC board 
| &lt;!--Vendor ID--&gt;0x08bb
| &lt;!--Product ID--&gt;0x2900
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, no mic input - goodish quality 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Depusheng MD22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2022 usb-b powered, 24bit 192kHz though is 96kHz, 
|-
| &lt;!--Description--&gt;Depusheng USB Audio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 usb-b powered, 24bit 192kHz though is 96kHz, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;|Emagic emi 2|6 em2|6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2002 not uac 
|-
| &lt;!--Description--&gt;|Emagic emi 6|2m 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 not uac 
|-
| &lt;!--Description--&gt;|Emagic emi 6|2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 not uac 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Ego Systems, Inc. in Korea (ESI) joining with RIDI GmbH 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2006 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;esi Mixvibes U46 Mk II USB audio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2007 not usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;ESI ESU22
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2008 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;esi U24XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, 24 bits, 2 analogue inputs and outputs with 6.3 mm jack connection, Output L can be used as a headphone output, S / PDIF digital input - 
|-
| &lt;!--Description--&gt;esi U46XL 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;ESI Originals, Inc ESIO MAYA22USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;ESI MAYA44USB+ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, usb-b powered,  xlr, 
|-
| &lt;!--Description--&gt;ESI Originals, Inc ESIO MARA22XTU 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;ESI U22XT
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb class compliant
|-
| &lt;!--Description--&gt;ESI Gigaport Ex
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2020 usb compliant?, usb-c usb3.1, , , 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;iConnectivity iConnectAUDIO2+ icaudio-02 USB audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;LexiconPro - Omega 8x4x2 (USB-1.1)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2003 not usb complaint 
|-
| &lt;!--Description--&gt;Lexicon Alpha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;Lexicon Lambda
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 may not be compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Line 6 Toneport UX1 and Tone Port UX2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2004  not usb compliant, 
|-
| &lt;!--Description--&gt;Line 6 TonePort UX8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2005 maybe not class compliant, 
|-
| &lt;!--Description--&gt;Line 6 POD Studio UX1 UX2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2006  not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Lokchonk UX22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=ljSiNmudMm0 Lokchonk UX44HD] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2023 usb-b , , , 2in 2out only, average latency, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Mackie Onyx Artist 1·2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2006 maybe not usb compliant, usb-b powered, 
|-
| &lt;!--Description--&gt;Mackie Onyx Producer 2X2 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b midi 
|-
| &lt;!--Description--&gt;Mackie Onyx Blackjack
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 USB powered but maybe not usb compliant, Two Onyx Preamps, 2-in, 2-out which are combo Neutrik-type connectors to handle XLR, instrument or line level 
|-
| &lt;!--Description--&gt;Mackie 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, , , 
|-
| &lt;!--Description--&gt;Media Assistance USB-One
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not uac cc comliant, 
|-
| &lt;!--Description--&gt;M-Audio Fast Track USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2004 maybe not usb compliant, - guitar 
|-
| &lt;!--Description--&gt;M-Audio Fast Track Ultra (6 in 6 out) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2008 maybe usb cc providing 24-bit/96kHz audio capabilities but requires manual configuration of the mixer settings 
|-
| &lt;!--Description--&gt;M-Audio M-Track 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 usb compliant?, okay - guitar and vocal mainly 
|-
| &lt;!--Description--&gt;[https://htyp.org/M-Audio/Fast_Track_Ultra/Linux M-Audio FastTrack Ultra] and Ultra 8R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2010 maybe usb compliant, low round-trip latency, okay octane pre amps, adc, 
|-
| &lt;!--Description--&gt;M-Audio M-Track 2x2M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb compliant? usb-c - okay pre-amps, , 
|-
| &lt;!--Description--&gt;M-Audio M-Track (MkII) 2x2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2016 usb compliant? usb-c - okay pre amps, , 
|-
| &lt;!--Description--&gt;M-Audio M-Track Solo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 usb compliant? - okay but issues, MJN4580C opamps (lower gain 55 dB at volume 9-10), ti PCM2900C ADC 16bit means there is a hard noise floor at -96 dB, plastic build no rf shielding, 
|-
| &lt;!--Description--&gt;M-Audio M-Track DUO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 usb compliant? - okay but issues, MJN4580C opamps (lower gain 55 dB at volume 9-10), ti PCM2900C ADC 16bit means there is a hard noise floor at -96 dB, plastic build no rf sheild, 
|-
| &lt;!--Description--&gt;M-Audio Air
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, okay 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;NI AK1 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, 
|-
| &lt;!--Description--&gt;[https://www.pogo.org.uk/~mark/linuxdj/ Native Instruments Traktor Audio 8 DJ], [ Traktor Audio 4 DJ], [ Traktor Audio 2 DJ], 
| &lt;!--Vendor ID--&gt;0x17cc
| &lt;!--Product ID--&gt;0x1978, 0x0839, 0x041C 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2009 not usb compliant uses snd-usb-caiaq module, [https://mixxx.discourse.group/t/problems-with-native-instruments-audio-8-dj-on-linux/14719/2 Audio 8 device has 4 subunits which are not recognized correctly], Cirrus Logic DACs spec'd at 24-bit/96KHz over a USB2, 
|-
| &lt;!--Description--&gt;NI Komplete Audio 6 Mk1 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2011 maybe usb compliant, pre amps, 24bit 96kHz adc, ocassional dropouts, plastic build top with metal around 3/4, 
|-
| &lt;!--Description--&gt;Native Instruments NI Komplete Audio 1 and 2 USB 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, good pre amp ein -129.5 dBu, ad/dc, 
|-
| &lt;!--Description--&gt;[https://support.native-instruments.com/hc/en-us/articles/360014683497-Apple-Silicon-Compatibility-News Native Instruments Komplete Audio 6 Mk2] 
| &lt;!--Vendor ID--&gt;0x17CC
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, pre amps, 24bit 192kHz adc, black aluminum glass build, 
|-
| &lt;!--Description--&gt;[ Native Instruments Traktor Pro] 
| &lt;!--Vendor ID--&gt;0x17cc
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2023 maybe usb compliant 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Novation AudioHub 2x4 NOVHUB01 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant, usb-b powered, no xlr, focusrite sounds inside, 
|-
| &lt;!--Description--&gt;Novation AudioHub 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant, 
|-
| &lt;!--Description--&gt;Prodipe Studio 22 Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Roland Edirol UA-3 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;1998 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-30 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;1999 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA1A UA-1D Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-5 Audio Capture (Roland)
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-1000 Audio Capture
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland Edirol UA-1EX, Cakewalk UA-1G  
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2005 not usb compliant driver also supports ASIO (Steinberg Audio Stream I/O Interface), noisy 
|-
| &lt;!--Description--&gt;Roland Duo Capture UA-11 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;Roland QUAD-CAPTURE Analog 2x2 Digital 2x2 USB 2.0 4in/4out
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2005 not usb compliant, usb-b powered 
|-
| &lt;!--Description--&gt;[https://wiki.debian.org/DebianEdu/Documentation/Manuals/Rosegarden/Setup Roland Edirol UA-101 and UA-1000 (Clemens Ladisch driver)]
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2006 not usb compliant, 
|-
| &lt;!--Description--&gt;[https://github.com/mmueller-kaffeeschluerfercom/UA-25-Firmware-Modification Roland Edirol ua-25]
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2007 maybe usb compliant 16bit 44.1kHz sampling without MIDI but not USB class complient when in Advanced mode for 24bit or midi 
|-
| &lt;!--Description--&gt;Edirol by Roland USB AudioCapture UA-25EX 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x00e6, 0x00e7
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2008 maybe usb compliant if ADVANCED DRIVER switched to OFF might play and record at 44.1kHz and 16-bit samples 
|-
| &lt;!--Description--&gt;Roland Audio Interface V-Studio 20 VS-20 Cakewalk
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2010 maybe not usb compliant, usb-b powered, 1 xlr, 
|-
| &lt;!--Description--&gt;Roland Edirol UA55 UA-55 Quad Cakewalk 
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x012f
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2011 not USB class compliant, 
|-
| &lt;!--Description--&gt;Roland DUO-CAPTURE EX UA-22 USB Audio
| &lt;!--Vendor ID--&gt;0x0582
| &lt;!--Product ID--&gt;0x0159
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant but not be used with a USB 3.0 port that is not compatible with USB 2.0 specification, vs pre amps, adc, three AA batteries in base, or an AC adapter psb-1u 9V 2A - 
|-
| &lt;!--Description--&gt;Roland Rubix series Roland Rubix22 USB 2.0 Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Roland Rubix series Roland Rubix24 USB 2.0 Audio Interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2017 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Roland 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant 
|-
| &lt;!--Description--&gt;Steinberg MI2, Steinberg MI4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2004 not usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg (2004 Yamaha buys) MIDI interface hardware including the CC like CC121 CC-121 and CI1 CI2 series.
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2008 not usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg UR12 UR22
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR44 usb audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 maybe not usb compliant, poor pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR242 audio interface
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2015 maybe usb compliant, usb powered or 5v psu, okay pre-amps, 
|-
| &lt;!--Description--&gt;Steinberg UR22mkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, okay pre-amps ein -123 dBu, ad/dc, 
|-
| &lt;!--Description--&gt;Steinberg UR-RT 2 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2018 maybe usb compliant, usb2.0 usb-b, pre-amps, ad/dc, 
|-
| &lt;!--Description--&gt;Steinberg UR44C (USB3) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2019 maybe usb compliant, 
|-
| &lt;!--Description--&gt;Steinberg URX22C UR22C  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2021 maybe usb compliant, preamps okay but little noisy, ad/dc. 
|-
| &lt;!--Description--&gt;Steinberg UR22 MkIII UR series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe usb compliant usb-c, okay pre-amps, adc, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Tapco LiNK.USB 2x2 (Loud technologies WA, USA) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2005 maybe not compliant, usb-b, poor pre-amps hum, latency issues, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[https://git.alsa-project.org/?p=alsa-tools.git;a=blob;f=usx2yloader/README;hb=3843634ef0310a952b256bcb6a4ddd0ad4ebe396 Teac Tascam US-422 US-428 US2XYloader] 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2000 not usb compliant, 
|-
| &lt;!--Description--&gt;Tascam US-122 US-224 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2003 not usb compliant, needing firmware usx2yloader/us122fw.ihx for audio sound card - Tascam US-122 and US-122L are not the same - 
|-
| &lt;!--Description--&gt;Tascam US-122L 
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt;0x800e
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2006 not usb compliant, obsolete needs tascam_loader.ihx and us122fw.ihx firmware loaded each time unless automated 
|-
| &lt;!--Description--&gt;Tascam US122 US-122 Mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 not usb compliant although USB2 downgrade so using USB1.1 UHCI, tascam units suffer from high round-trip latency as do most typical USB units
|-
| &lt;!--Description--&gt;Tascam US144 US-144 Mk2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2004 maybe usb compliant although USB2 downgrade so using USB1.1 UHCI, tascam units suffer from high round-trip latency as do most typical USB units
|-
| &lt;!--Description--&gt;Teac TASCAM US-200 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac US-366 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac TASCAM US-600 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac TASCAM US-800 USB 2.0 Audio / MIDI Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no|no driver}}
| &lt;!--Records--&gt;{{no|no driver}}
| &lt;!--Opinion--&gt;2011 may not be totally usb compliant 
|-
| &lt;!--Description--&gt;Teac Tascam iU2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{no| }}
| &lt;!--Records--&gt;{{no| }}
| &lt;!--Opinion--&gt;2012 maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-2x2
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2014 usb compliant?, 5v dc power, midi out in, 
|-
| &lt;!--Description--&gt;Teac Corp Tascam US-4x4
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; usb compliant?, 
|-
| &lt;!--Description--&gt;Teac Tascam US-16x08 US-20x20
| &lt;!--Vendor ID--&gt;0x0644
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;teyun q12 Q-12, q22 Q-22 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant - unknown pre amp, unknown ad/dc, 
|-
| &lt;!--Description--&gt;Teyun q26 Q-26, q24 Q-24 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe usb compliant - unknown pre amp, unknown ad/dc, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Yamaha UW500
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2000 not class compliant, 
|-
| &lt;!--Description--&gt;Yamaha Audiogram 3 USB Digital Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2012 maybe usb compliant, okay pre amp, 16bit 44kHz adc no advanced features without dedicated asio driver, 1 xlr, 1 instrument, 
|-
| &lt;!--Description--&gt;Yamaha Audiogram 6 USB Digital Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2013 maybe usb compliant, okay, 2 xlr, 2 instrument, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Zoom UAC-232 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;Zoom UAC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; maybe not usb compliant, okay, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;[http://www.arcam.co.uk/products,rseries,usb-dacs,rPAC.htm Arcam rPac] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audioquest Dragonfly 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Audioengine D1 Premium 24-bit DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Beresford TC-7520 (Burr Brown PCM 1716) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Beresford TC-7520 + Burson Buffer + MK3 JKSPDIF
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;[http://epiphany-acoustics.co.uk/products-page/dacs/e-dac-24bit-miniature-usb-dac/ Epiphany E-DAC 24bit] ES9023 DAC chip 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Firestone Audio FUBAR II Mk2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Firestone Audio iLoveTW 24Bit USB DAC
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO D5 ta2020 chip amp 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO E07K Andes 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;FiiO E17 Alpen 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Magnum 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Martini-U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;GoVibe Vulcan 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Halide Design DAC HD (Wolfson WM8716) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;HRT Steamer II USB DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;John Kenny JKDAC uses a 24-bit/192&amp;nbsp;kHz Sabre ES9022 DAC or better JKDAC32 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt; iBasso D12  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Leckerton UHA-6S MKII  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;MyST 1866 PortaDAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Objective DAC ODAC+O2  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Rega DAC (Wolfson WM8742) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;[http://www.henryaudio.com/open-source.php Henry Audio USB DAC 128 also known as QNKTC AB-1.2 open source DAC] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Henry Audio mkII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;AKM4430 DAC chip comes from Asahi Kasai 
|-
| &lt;!--Description--&gt;DevilSound USB DAC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Zoom U series
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;KingRex UD-01 SE (Burr-Brown PCM 2702E) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;SuperPro 24/192 USB DAC (24bit 192&amp;nbsp;kHz, CS-4398 D/A chip) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| CMedia CM108 7.1ch emulation I2S in and out
| 0x1926
| 0x0003
| 0x0100
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| [http://www.lindy.co.uk/usb-2-audio-adapter/42961.html Lindy USB 2.0] (Chipset CM108)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| Speed-Link SL-8850-SBK Vigo ([http://mightyohm.com/forum/viewtopic.php?p=1036#p1030 CMedia CM108])
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Dynamode USB SOUNDCARD 2.0 
| &lt;!--Vendor ID--&gt;0x0003
| &lt;!--Product ID--&gt;0x1130
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| Dynamode Virtual 7.1 USB-SOUND7 (C-Media )
| 0x0d8c
| 0x000c 0x000e
| 1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Generic White box with very little red led and white USB lead (CMedia )
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt; 0c000e
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| CM109 CiT SC-U119 5.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| CMedia CM1197.1ch I2C MCU port Penguin 
| 0x0D8C
| 0x0000
| 0x010
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;Sweex 7.1 Startech External USB, WMA Blue metal box SYBA SD-AUD20040, Sabrent USB-SND8, Sewell Vantec NBA-200U (C-Media CM6206 CM106 like) 
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x0102
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
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| &lt;!--Opinion--&gt;50/50 if the item is detected but does not work 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative Labs SoundBlaster X-fi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative X-Fi Go 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative X-Fi 5.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Creative Sound Blaster Play! USB sound adapter (SB1140) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; working with [http://www.amiga.org/forums/showpost.php?p=646431&amp;postcount=15 Deneb on OS3] 
|-
| &lt;!--Description--&gt;Asus Xonar U1 (ASUS UA100 USB Audio Chip) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Asus Xonar U3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Playback
| Records 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Griffin iMic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;M-Audio Transit
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Icemat Siberia (steel series) (Cmedia chipset) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;JMTek HY554, ZyXEL NSA-220, Logilink (Tenx Technology TP6911 and SSS-1623 headphone set) 
| 0x0C76 0x1130
| 0x1605 0x1607  0xf211
| 0x
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt; reports on other OS not good 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Plantronics &quot;DSP Adapter-01&quot; (or &quot;USB Adapter-02&quot;) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Rocksmith Real Tone Cable 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;RSA Intruder Predator 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;StarTech ICUSBAUDIO7
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x000c
| &lt;!--Revision--&gt;1.00
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Stoner Acoustics UD100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Teac UDH01-B  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Terratec Aureon 5.1 USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Terratec Aureon 5.1 USB MKII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;TerraTec Electronic GmbH Aureon Dual USB
| 0x0ccd
| 0x0077 
| &lt;!--Product ID--&gt; 
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Terratec Phase26
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Trust 510 EX 5.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Logitech A-5572A USB 2.0  to 3.5mm jacks Virtual 7.1 Surround Sound Adapter or accessory of Logitech Clearchat pro USB or Logitech USB Headset H530 
| &lt;!--Vendor ID--&gt;0x0003 
| &lt;!--Product ID--&gt;0x046D
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Trumix TM-10 USB Audio Interface 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;2024  maybe cc 
|-
| &lt;!--Description--&gt;Trumix TM-12 USB-C 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;2024 maybe cc usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Turtle Beach Audio Advantage Amigo Micro II USB Sound Card &amp; Headset Adapter 
| &lt;!--Vendor ID--&gt;0x10F5
| &lt;!--Product ID--&gt;0x0211
| &lt;!--Revision--&gt;0100
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;Vantec NBA-100U 7.1 Channel 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt;{{unk| }}
| &lt;!--Records--&gt;{{unk| }}
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Playback--&gt; 
| &lt;!--Records--&gt;
| &lt;!--Opinion--&gt;
|}

 Companies including Access, Alesis, Allen&amp;Heath, American Audio, CME, ESI, Infrasonic, Lexicon, Numark, Presonus, Reloop, SIMS, Sound Devices, Steinberg, Swissonic, Tascam, Terrasoniq, Terratec, Yamaha and Yellowtec decided to license and bundle this driver. So fully functional custom drivers are available for Access Virus TI, Access Virus TI snow, Alesis Multimix 8 USB2.0, Alesis Multimix 16 USB2.0, Allen&amp;Heath XONE:2D, Allen&amp;Heath XONE:3D, Allen&amp;Heath XONE:4D, Allen&amp;Heath XONE:DX, Allen&amp;Heath XONE:DB4, American Audio Versa Port, CME XCORPIO, ESI ESU1808, ESI Gigaport AG / DG, ESI Maya 44 USB, Infrasonic Amon, Lexicon I-ONIX U22, Lexicon I-ONIX U42S, Lexicon I-ONIX U82S, Mindprint DI-MOD USB, Numark DJ IO, Numark NS6, Numark NS7, Numark Omni Control, Numark V7, Presonus Audiobox USB, Reloop Digital Jockey, SIMS Primus, Sound Devices USB pre, Steinberg MI2, Steinberg MI4, Swissonic Easy USB, Tascam M-164UF, Tascam US-122L, Tascam US-144, Tascam US-Tascam US-144mkII 122mkII, Tascam US-200, Tascam US-600, Tascam US-1641, Tascam US-1800, Tascam US-2000, Terratec Area 61, Terrasoniq Phase X64, Terratec Phase 26 USB, Yamaha UW10, Yamaha UW500, Yellowtec PUC2 and many others.

Well, those companies are using the same driver framework because all of those interfaces use the same microprocessor/firmware architecture to communicate with the USB bus. Just like almost all FireWire audio interfaces use the same TC Dice or BridgeCo chipsets. Usually it does not make sense for companies to develop their own USB1.1/USB2/FW framework for a product they are going to sell for &lt;$500.

However, that isn't the end of the story. The companies who develop audio interfaces implement different features into their devices and must update the driver and firmware to accommodate those features. That is where things can go wrong. Sometimes there is miss-communication about how things are coded, sometimes the developer who started a project leaves without transferring his knowledge to his successor, etc. You have to keep in mind that there are no &quot;big&quot; computer audio companies. Even the companies that seem big in the scale of the market, probably have fewer employees than you'd think.

A very well made interface that is designed from scratch from the ground up would be a very expensive device, regardless of whether it's USB, FW, PCIe or whatever.

Round-trip latency is the sum of the following:
&lt;pre&gt;
    ASIO input buffer
    ASIO output buffer
    A/D D/A converter latency
    The driver's hidden safety buffer
&lt;/pre&gt;
At a 64-sample ASIO buffer size/44.1k, Tascam units yield ~18ms total round-trip latency.

Typical USB audio interfaces use a large hidden safety buffer.
This helps ensure glitch-free playback... even under less than ideal circumstances. But... this comes at the expense of much higher round-trip latency. Short of doubling the sample-rate, there's no means of mitigating the higher round-trip latency.
If you have no plans of ever monitoring in realtime thru software based EFX/processing (ie: playing/monitoring DI bass thru an AmpSim plugin as you're playing), then this may not matter to you.
If you want the ability this play/monitor in realtime thru software based EFX/processing, make sure to get an audio interface that yields low round-trip latency.

As a point of reference the best PCI/e audio interfaces yield about 5ms total round-trip latency at a 64-sample ASIO buffer size/44.1k
The best Firewire and USB units yield 5.5-5.6ms total round-trip latency at those same settings.
Typical USB and Firewire units (that use a large hidden safety buffer) yield 12-18ms total round-trip latency at those same settings.

Anything above ~6ms starts to feel sluggish.
Anything above ~10ms feels like playing thru molasses.


USB Microphones 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;C-Media Electronics, Inc. CM108 Audio Controller Mic
| &lt;!--Vendor ID--&gt;0x0d8c
| &lt;!--Product ID--&gt;0x013c 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato WaveMic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato Wave:1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 no driver }}
|-
| &lt;!--Description--&gt;Elgato Wave:3
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 no driver lightweight }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;hyperx solocast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver}}
|-
| &lt;!--Description--&gt;hyperx quadcast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sennheiser CC510 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Alesis USB-Mic microphone podcasting kit 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio-Technica AT2020 (AT202) AT4040
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio-Technica AT2035 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Behringer B1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Blue Microphones Snowball 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Blue Microphones Snowball iCE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| cardioid only }}
|-
| &lt;!--Description--&gt;Blue Microphones Yeti 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|can pick up a lot of background noise but not sure if right mode used }}
|-
| &lt;!--Description--&gt;Blue Microphones Yeti Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| can pick up a lot of background noise but not sure if right mode used }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MXL 2001A/600 Studio Microphone Pack / MXL 2003A Studio Condenser
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Microsoft LifeChat LX-3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Namtai SingStar(TM) PS2 SCEH-0001 USBMIC 
| &lt;!--Vendor ID--&gt;0x1415
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;0.01
| &lt;!--Opinion--&gt;{{unk| mono microphones }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Neumann 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Razer Seiren X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Razer Seiren Mini USB Condenser Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rockband USB Mic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rode NT1A VideoMic Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rode Podcaster 2 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| RODECaster Pro usb audio compatible}}
|-
| &lt;!--Description--&gt;Rode NT1A NT2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|  NT2 better }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Roland R-07
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samson Go Mic - Portable USB Microphone for Recording 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| mini usb r.h.s. and clip on the bottom left hand side}}
|-
| &lt;!--Description--&gt;Samson Go Mic Clip On USB Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| switch to choose between Cardiod, Omni and -10&amp;nbsp;dB modes, a 3.5mm headphone socket and a USB socket}}
|-
| &lt;!--Description--&gt;Samson C01U  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| cardoid only}}
|-
| &lt;!--Description--&gt;Samson C03U 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Shure MV7 USB Podcast Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;SONY PCM-D50 handy 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb 5V, }}
|-
| &lt;!--Description--&gt;Sony PCM-M10 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out 5V, }}
|-
| &lt;!--Description--&gt;SONY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out, }}
|-
| &lt;!--Description--&gt;SONY 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| one mini usb out, }}
|-
| &lt;!--Description--&gt;TASCAM DR-1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008, one mini usb out, lithium battery}}
|-
| &lt;!--Description--&gt;Tascam DR-07 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009, one mini usb out, aa battery}}
|-
| &lt;!--Description--&gt;Tascam DR05 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011, one mini usb port for file transfer and charging the AA batteries }}
|-
| &lt;!--Description--&gt;Tascam DR-40
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011  mini usb aa battery }}
|-
| &lt;!--Description--&gt;Tascam DR-07mkII
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 , one mini usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-05X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-07X 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb out, }}
|-
| &lt;!--Description--&gt;Tascam DR-40X
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 , one micro usb 3 aa battery }}
|-
| &lt;!--Description--&gt;Tascam DR-05XP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c , }}
|-
| &lt;!--Description--&gt;Tascam DR-07XP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c , }}
|-
| &lt;!--Description--&gt;Tascam DR-40XP
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , one usb-c, }}
|-
| &lt;!--Description--&gt;Tascam DR-100mkIII 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| , usb , }}
|-
| &lt;!--Description--&gt;Tascam 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| , usb , }}
|-
| &lt;!--Description--&gt;Zoom H4 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2006 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H2 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;0x0095
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2007 no driver, mini usb 5V audio i/f USB Card and USB Audio; press the Record button when USB Audio is displayed. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H4n 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2009 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H1 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;0x0120
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 no driver, mini usb 5V and display will alternate between USB Card and USB Audio; press the Record button when USB Audio is displayed. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H2n 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 no driver, mini usb 5V audio i/f press the Record. Press Record again to choose the default }}
|-
| &lt;!--Description--&gt;Zoom H4n PRO 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2011 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H6 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 untested, 2xlr, 5v mini usb, }}
|-
| &lt;!--Description--&gt;Zoom H5 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 no driver, 5v mini usb, 2 xlr, }}
|-
| &lt;!--Description--&gt;Zoom H1n-vp handy 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 no driver, mini usb 5V }}
|-
| &lt;!--Description--&gt;Zoom H6studio 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 untested}}
|-
| &lt;!--Description--&gt;Zoom 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|no driver}}
|-
| &lt;!--Description--&gt;Zoom Q3
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2008 untested usb a cord, no hdmi, 480p}}
|-
| &lt;!--Description--&gt;Zoom Q3HD Handy Video Recorder 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2010 untested, built in usb-a cord, mini hdmi, 1 hour on 2 AA batteries, H.264 movies 480p }}
|-
| &lt;!--Description--&gt;Zoom Q2HD Handy 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2012 untested, up 720p but no stablisation, mini usb cord, 1 hour on 2 AA batteries}}
|-
| &lt;!--Description--&gt;Zoom Q4
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 untested, li-ion battery}}
|-
| &lt;!--Description--&gt;Zoom Q4N 
| &lt;!--Vendor ID--&gt;0x1686
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 untested, li-ion battery}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Audio Technica ATR4697-USB Boundary Microphone
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;CAD Audio CAD USB Condenser Boundary Microphone 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;MXL AC-44 Boundary Conferencing Mic 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samson Audio SAUB1 Boundary Microphone (USB)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|}


USB Speakers 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Focal XS 2.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


USB Headset Wired/Wireless 
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Logitech Vantage Wired (came free with PS2 Socom3)
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech G330 
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech Premium USB Stereo Headset 350
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Plantronics DSP-300 
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Plantronics GameCom 777
| 
| 
| 
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Logitech G-930 Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| [http://www.makeuseof.com/tag/set-usb-wireless-earphones/ Plantronics Audio 995 Wireless RF] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| Sennheiser  Wireless
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


[https://www.youtube.com/watch?v=Be1e0QPIPK0 Mixers]

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;ALESIS MULTIMIX 4 CHANNEL USB MIXER
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Alesis - MultiMix 8 USB FX (USB 1.0)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2010 usb compliant?, up to 16-bit/48kHz, 18v 500mA - 
|-
| &lt;!--Description--&gt;Alesis - MultiMix 8 USB 2.0 FX (USB 2.0)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2012 usb compliant?, up to 16-bit/48kHz, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Allen&amp;Heath MixWiz16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;Allen and Heath ZED Power 1000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 8 xlr, usb-b out, }}
|-
| &lt;!--Description--&gt;Allen &amp; Heath ZEDi-10
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; maybe not usb compliant, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Behringer XENYX 302USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 5-Input Mixer/Audio Interface - 1 xlr - }}
|-
| &lt;!--Description--&gt;Behringer Xenyx Q502USB Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|no driver}} Behringer 2*18.5V 250ma psu - 1 xlr - phanton power - 
|-
| &lt;!--Description--&gt;Behringer Xenyx Q802USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} Behringer 2*18.5V 250ma psu - 2 xlr - phanton power - 
|-
| &lt;!--Description--&gt;BEHRINGER XENYX 1204USB 8-Channel 2-Bus Mixer USB/Audio Interface Studio/Live
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} iec kettle psu lead - can develop constant background hiss over time 
|-
| &lt;!--Description--&gt;Behringer XENYX X1222USB
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver - 12-Channel Analog Mixer with USB Interface and Effects}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Depusheng HT-7 HT7USB 7 Channel Audio Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2023 cheap no driver, USB MP3 player to work, format your USB stick Fat32 as a Logical drive - not primary}}
|-
| &lt;!--Description--&gt;Depusheng XT7 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2025 cheap no driver}}
|-
| &lt;!--Description--&gt;Depusheng DT8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2025 cheap no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Spirit soundcraft Folio FX8 with Lexicon Effects Processor
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} unusual power connector - [https://github.com/lack/soundcraft-utils usb routing] -  
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Weymic Professional F7 7-Channel 2-Bus Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2022 no driver, cheap mixer with 3pin ac input (introduces noise) and 1 usb-a port}}
|-
| &lt;!--Description--&gt;Weymic Professional F7-Pro 7-Channel 2-Bus Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2022 no driver}}
|-
| &lt;!--Description--&gt;Weymic A80 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2024 no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Yamaha 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


Mixer no hardware usb 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;ALTO Lynx MIX82FX Audio Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Alto L16 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer MXUL5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer MX602A 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB502
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 17.5V 3pin psu needed}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB802 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 2 xlr,}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1002 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 2 xlr,}}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1202 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb 4 xlr, }}
|-
| &lt;!--Description--&gt;Behringer Eurorack UB1602 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer RX1602 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer 802 XENYX 8-Input 2-Bus Mixer Small Format Mixer
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} Behringer 18.5V ???ma psu - 2 xlr - phanton power - 
|-
| &lt;!--Description--&gt;Behringer Xenyx 502 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer Xenyx 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;Behringer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;IMG stage Line MMX-122 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, 4 xlr, iec cable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Mackie 802VLZ4 Mackie 802-VLZ4
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb , psu}}
|-
| &lt;!--Description--&gt;Mackie 1202-VLZ Pro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, mains iec}}
|-
| &lt;!--Description--&gt;Mackie Mix5 Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}} 18v 300mA psu - 5 Channel - 
|-
| &lt;!--Description--&gt;Mackie Mix8 Mixer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}} 9v x2 600mA psu - 
|-
| &lt;!--Description--&gt;Mackie MIX12FX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb, 4 xlr, 9v 500mA x2 psu, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no usb}}
|-
| &lt;!--Description--&gt;[https://www.soundcraft.com/en/product_documents/en/owners_manual Soundcraft] Spirit Folio F1 Fader 100 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} 16 Channel Mixer - 
|-
| &lt;!--Description--&gt;Soundcraft EPM6 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Soundcraft EPM8 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Harman Soundcraft EPM 12 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}} iec kettle power lead - 
|-
| &lt;!--Description--&gt;Soundcraft EPM 16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;Soundcraft Notepad 8FX
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;Soundcraft Notepad UI12
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; connect via wifi 
|-
| &lt;!--Description--&gt;Soundcraft Notepad UI16
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt; connect via wifi 
|-
| &lt;!--Description--&gt;Soundcraft Notepad 124FX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection, 14.8V x2 3 pin psu}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;t.mix xmix 1402fx mp usb
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection, mains iec, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no hardware usb connection}}
|-
|}


==Webcameras==

A USB camera has two dedicated chips: a controller or bridge and an image sensor.

There was no Commodore support for video interfaces. The only commercial, now discontinued application that defined some sort of standard was VHI Studio by iospirit.

===OLD standards===

See [http://www.e3b.de/usb/main_supported_e.html support pages] and [http://www.e3b.de/usb/main_faq_e.html here] and some [http://webcam-osx.sourceforge.net/cameras/index.php?orderBy=status further compatibility]


Pencam STV680
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| AIPTEK stv680 
| 0x0553 
| 0x0202 
| 
| {{N/A|untested}}
|-
| Konica e-mini 
| 0x04c8 
| 0x0722 
|
| {{N/A|untested }}
|-
| DigitalDream l'espion XS 
| 0x1183 
| 0x0001 
|
| {{N/A|untested}}
|-
| [http://reviews.cnet.com/webcams/creative-webcam-go/1707-6502_7-1446174.html Creative WebCam Go mini] 
| 0x041e 
| 0x4007 
|
| {{N/A|untested}}
|-
|}


SonixcamTool (Sonix webcams and derivates)

'''Note [http://amigadev.free.fr/sonix/ some] Sonix Webcams with a Sonix SN9C1xx controller ''and'' a pas106b or tas5110c1b sensor support bulk mode which works even with pciusb.device!'''
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Macally IceCam II
| 0x0c45
| 0x05d8
| 
| {{N/A|untested}}
|-
| Sweex MiniCam 100K 
| 0x0c45 
| 0x6005 
| 
| {{N/A|untested - sensor tas5110c1b}}
|-
| Macally IceCam Portable 
| 0x0c45
| 0x6007
| 
| {{N/A|untested - sensor tas5110d}}
|-
| Sweex 100K 
| 0x0c45 
| 0x6009 
| 0x0101
| {{yes|bulk works - sensor pas106b}}
|-
| [http://www.epinions.com/pr-Chicony_TwinkleCam_Webcam/display_~full_specs Chicony Twinkle DC-2110A] 
| 0x0c45
| 0x600d
| 
| {{no|no}}
|-
| Unknown
| 0x0c45
| 0x601e
| 
| {{no|no}}
|-
| USB PC Camera (SN9C102)
| 0x0c45 
| 0x6028
| 
| {{no|no - sn9c10x + pas202b}}
|-
| Trust SpaceC@m 120 and 150
| 0x0c45 
| 0x6029
| 
| {{N/A|untested - sensor pas106a}}
|-
| HiRes Webcam Live
| 0x0c45 
| 0x602c
| 
| {{no|no - sensor ov7630}}
|-
| [http://www.sweex.com/en/assortiment/sound-vision/webcams/JA000020 Sweex USB Webcam 300K]
| 0x0c45
| 0x608f
| 
| {{no|no - sensor ov7630}}
|-
| Speedlink Sphere Webcam SL-6820, 350K
| 0x0c45
| 0x613c
| 0x0101
| {{N/A|untested - sensor HV7131R}}
|-
| WB-3250P
| 0x0c45
| 0x613e
| 
| {{no|no - sensor ov7630}}
|-
| Unknown
| 0x0c45 
| 0x6207
| 
| {{no|no}}
|}

&lt;pre&gt;
micromaxx USB Camera 	STM 	1363 	514 	works 	---
USB Tower 	Lego 	1684 	1 	works 	need NCQ
Trust Spycam 100plus 	STM 	1363 	514 	works
&lt;/pre&gt;


ov51x.class - no driver
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| D-Link VGA Webcam (640x480) 
| 0x05a9
| 0x8519
| 
| {{no|no driver}}
|-
| Sony PS2 EyeToy Logitech/Logicool Black (ov519) SCEH-0004 
| 0x054c
| 0x0154
| 
| {{no|no driver}}
|-
| Sony PS2 EyeToy Namtai Silver (ov519) SLEH-00031 SLEH-00030
| 0x054c
| 0x0155
| 
| {{no|no driver}}
|-
|}


===UVC.class - [https://www.usb.org/document-library/video-class-v15-document-set USB Device Class Definition for Video Devices or USB Video Class]===

 AROS needs realtime isochronous transfers in EHCI and XHCI, then a usb uvc.class which might create a virtual UVC.VHI type device driver for use by AROS apps 

since 2019 the market is filled with UVC Compliant USB HDMI Capture

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acasis 4K30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Acasis 4K60 HD VS009
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|4k 60hz ok for chat streams}}
|-
| &lt;!--Description--&gt;Acasis 4K60 HDMI HDR Game Live Video Capture
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| for chat streams }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AJA U-tap HDMI 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;ASUS TUF CU4K30 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ATEN CAMLIVE HDMI to USB-C UVC Video Capture adapter UC3020 HDMI (F) TO USB-C M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 possibly UVC and UAC standard support allows up to 1080P @ 60}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Avermedia Live Streamer Cap 4K - BU113 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 uvc usb3}}  
|-
| &lt;!--Description--&gt;AVerMedia GC515 video capturing device 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.2 Gen 1 (3.1 Gen 1)}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra GC553
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 usb3 powered by Type C USB cable and 4K HDMI cable}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra S GC553PROW 302AGC553DL2 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1553
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 powered by good quality type C USB3 cable and 4K HDMI 2.0 cable}}
|-
| &lt;!--Description--&gt;AVermedia Live Gamer Mini GC311 302AGC311DG9 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1311
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 uvc compliant up to 1080p 60fps capture and supports internal hardware H.264 encoding }}
|-
| &lt;!--Description--&gt;AVerMedia Ez Recorder 330 (ER330) 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 designed to work independently and is generally not compatible as a plug-and-play UVC capture card }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer extreme3 GC551G2 (LGX3) 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x3551
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc compliant for intensive gaming streams, some vrr but no hdr with maximum recording resolution of 4K30/1080p60 from fully wired usb3 compatible cable - passing through 4K60/1080p120 Game Capture video capturing device HDMI}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra Pro GC553Pro 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 usb3 }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Ultra 2.1 GC553G2 61GC553G20BV video capturing device 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 USB 3.2 Gen 1 (3.1 Gen 1)}}
|-
| &lt;!--Description--&gt;AVerMedia GC575
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 usb3 powered by Type C USB cable and 4K HDMI cable}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;AVMatrix 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ClonerAlliance Flint 4KP Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;DIGITNOW U600 video capture card 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc uac  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Epiphan AV.io HD
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Epiphan AV.io 4K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Elgato Cam Link 4K 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 uvc }}
|-
| &lt;!--Description--&gt;[https://github.com/elgatosf/capture-device-support Elgato HD60 S+]
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt;0x006C, 0x006E
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 4K 30FPS capture, 1080p 60FPS uvc}} 
|-
| &lt;!--Description--&gt;Elgato HD60 X 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc }}
|-
| &lt;!--Description--&gt;Elgato Cam Link 4K HDMI video capture card 
| &lt;!--Vendor ID--&gt;0x0FD9
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 uvc compliant but can have usb disconnects}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EVGA XR1 USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.0 device with 1080/60 capture and 4K/60 passthrough}}
|-
| &lt;!--Description--&gt;EVGA XR1 lite USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 USB 3.0 device }}
|-
| &lt;!--Description--&gt;EVGA XR1 Pro USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 USB 3.0 device with 1080/60 capture and 4K/60 passthrough}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;EZcap Game Link Raw - ezcap321 usb3.1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 2160p30, 1080p120 and 1440p60 HDMI input and pass-through. - 1080p120, 2160p30 and 1440p60 recording. - Latency less than 50ms uvc}} 
|-
| &lt;!--Description--&gt;EZCap GameDock Ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 record at 4K30, 1440p60, and 1080p120}}
|-
| &lt;!--Description--&gt;EZcap 360 Game Capture Extreme 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 USB 3.0, 4K 60FPS passthru and 1080p 240FPS}}
|-
| &lt;!--Description--&gt;EZCAP 364 GameDock Extreme 2.1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Genki ShadowCast 1 &amp; 2, the Pro version 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HAUPPAUGE HD PVR Pro 60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021  4K in/Out 1080P 60fps Capture and Streaming PC Connected and Stand Alone }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Kondor Blue 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Nanjing Magewell Electronics Co ltd USB 3.0 XI100DUSB-HDMI Pro Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 }}
|-
| &lt;!--Description--&gt;Magewell USB3.0 Silver HDMI Full HD Video Capture Device 1080p 32011 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 usb audio extract HDMI embedded audio output via headphones}}
|-
| &lt;!--Description--&gt;Magewell USB capture HDMI PLUS 2K 32040 320400000
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2014 captures video up to 1920×1200, 1920×1080 or 2048×1080 at 60 fps over an HDMI capture from devices such as game consoles in up to DCI 4Kp60 4:2:0 input resolution, and it automatically upscales/downscales the signal to 2K for recording or streaming}} 
|-
| &lt;!--Description--&gt;Magewell USB capture HDMI Gen2 32060 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2015 1080p gets hot, 165M HDMI receiver, max input 2048x1080 60fps 4:4:4, RGB/YUV 4:4:4 8/10/12-bit, YUY 4:2:2 12-bit, up to 8-channel 24-bit HDMI-embedded audio at 192kHz, HDMI 1.4a, output from 480p to 1080p, YUY2/UYVY/RGB24/RGB32 support video cropping, up/down scaling, de-interlacing, aspect ratio conversion, color format conversion, frame rate conversion, flip and mirror, up to 2-channel IEC60958 audio streams, 5V 0.5A 2.5W, }}
|-
| &lt;!--Description--&gt;Magewell USB Capture 4K Plus 32090 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 limited by the bandwidth of USB 3.0, the maximum frame rate can only reach 30 fps when capturing}}
|-
| &lt;!--Description--&gt;Magewell USB Capture 4K PRO
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 }}
|-
| &lt;!--Description--&gt;Magewell Pro Convert IP to USB 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Captures one network eth NDI® High Bandwidth, NDI® HX2, NDI® HX3 sources or H.264/H.265 video source into software at resolutions up to 1080p60}}
|-
| &lt;!--Description--&gt;Magewell USB Fusion 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|versatile USB video capture device that allows users to switch between two HDMI inputs and one USB webcam input for live presentations}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;ROLAND UVC-01 USB Video Capture
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sunplus Innovation Technology Inc. MiraBox HSV321 ARX321 Video Capture device 
| &lt;!--Vendor ID--&gt;ox1bcf
| &lt;!--Product ID--&gt;0x2c99
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 uvc uac  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;UGREEN CM716 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| uvc uac but disable HDCP on your source device (PS4/PS5, Xbox) }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;VisionTek UVC HD60 Capture Card
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Acer Aspire Crystal Eye AOA110 AOA150 0.3M 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2008 webcam }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;AVerMedia Live Streamer CAM 313 (PW313) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2019 uvc 1080p/30 webcam}}
|-
| &lt;!--Description--&gt;AVerMedia Live Streamer DUO 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2021 uvc 1080p/60 webcam}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;[http://reviews.cnet.co.uk/webcams/creative-live-cam-optia-af-review-49294183/ Creative Live Cam Optia AF] 2.0M
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| {{no|2008 }}
|-
| &lt;!--Description--&gt;DSLR macro extensions + a cheap 50mm E-Series lens + some PVC tubing and a negative holder 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes| if uvc camera chosen}}
|-
| &lt;!--Description--&gt;DSLR scanning using a macro lens, for the adapter, for a 3d printed negative holder) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{yes| if uvc camera used }}
|-
| &lt;!--Description--&gt;Logitech C270 
| &lt;!--Vendor ID--&gt;0x046d
| &lt;!--Product ID--&gt;0x0825
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|720p }}
|-
| &lt;!--Description--&gt;Logitech C910 C920 HD Pro 5Megapixels 720p 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Output mjpg 1080p}} 
|-
| &lt;!--Description--&gt;Logitech C920s c922 HD Pro 5Megapixels 1080p 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|Output mjpg 1080p}} 
|-
| &lt;!--Description--&gt;Logitech 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Logitech Brio 100 300 500 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}} 1080p 
|-
| &lt;!--Description--&gt;Logitech MX Brio 4k 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|4k}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|}}
|-
| &lt;!--Description--&gt;Microsoft's LifeCam HD-3000 HD-5000 
| &lt;!--Vendor ID--&gt;0x045e
| &lt;!--Product ID--&gt; 0x0779
| &lt;!--Revision--&gt;1.06
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Microsoft LifeCam Cinema 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Microsoft LifeCam Studio 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} sony imx179 1080p 
|-
| &lt;!--Description--&gt;Pi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} 1/2.8” Sony IMX291 image sensor, it's a 2MP, UVC-compliant, ultra-wide-angle, low light, high-speed USB 2.0 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} OV5648 
|-
| &lt;!--Description--&gt;razer kiyo 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} 4 megapixel sensor 1080p 30fps 720p 60fps - 12 led ring light adjustable 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;TeckNet C068 1.3mpixel HTD USB2.0 Camera Vimicro Z-Star Corp 
| &lt;!--Vendor ID--&gt;0x0AC8
| &lt;!--Product ID--&gt; 0x3420 
| &lt;!--Revision--&gt;0x01FA
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;YEALINK(XIAMEN) NETWORK UVC50 is compatible with the UVC 1.1 protocol CP960-UVC50 and CP960-UVC80 kits PTZ, CP960-UVC30 Kit is UVC 1.5 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID 
| Product ID
| Revision 
| Opinion 
|-
| &lt;!--Description--&gt;Amcrest ProHD 1080P WiFi Wireless IP Security Camera - 1080P (1920TVL), [https://www.ispyconnect.com/man.aspx%3Fn%3DAmcrest IP2M-841] nvr 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} h264/rtsp, motion detection, features Sony image sensor and Ambarella processor - rtsp://[username]:[password]@[IPaddress]:[port]/cam/realmonitor?channel=[channel]&amp;subtype=[stream] - [username] - username to login to the DVR or NVR, [password] - password, [IPaddress] - IP address of the device. If you are not on the same local network, this should be the external IP address of the device's network, [port] - port number, [channel] - channel number of the stream, [stream] - view the Main or Sub stream. (main stream is 0, sub stream is 1) , eg. rtsp://admin:admin@192.108.1.108:80/cam/realmonitor?channel=1&amp;subtype=1 - utilizing RTSP ( rtsp://user:pass@ipcam1 )  
|-
| &lt;!--Description--&gt;Axis all modern ones 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} RTSP/RTP + H264/mjpeg or MJPEG over HTTP
|-
| &lt;!--Description--&gt;PTZ 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;DLink DCS-5222 5222L network camera 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} camera streams H.264 over RTP controlled by RTSP 
|-
| &lt;!--Description--&gt;Dlink DCS900 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Sony 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;Wansview 1080p [http://marc.merlins.org/perso/linuxha/post_2013-11-10_Reviewing-IP-Webcams-for-Linux-and-Zoneminder_Dlink-DCS900_-Ubnt-Aircam_-Foscam-FI8904W-FI8910W_-FFI9820W_-FI9821W_-Wansview-NCB541W_-and-Zavio-F3210.html#NCM625GA NCM625GA] IP Camera WiFi Wireless IP Security Camera , Full HD Plug n Play Home Surveillance / Baby Monitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}} RTSP/RTP + H264/mjpeg - play its HD stream without problem with vlc rtsp://ip/live/ch0 and getting  jpegs http://ipaddr/mjpeg/snap.cgi?chn=0 - methods involve transcoding h.264 video from the camera into jpeg's, which is cpu intensive - able to pull images manually, using http://username:password@ip/mjpeg/snap.cgi - 
|-
| &lt;!--Description--&gt;Wansview NCB541W
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|}}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;Avermedia Game Capture HD C281 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2011 standalone h.264 recording of up to component cable not hdmi but not uvc}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Avermedia GL310 Live Gamer Portable (LGP Lite)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 not working usb2 and USB Lite no uvc}} 
|-
| &lt;!--Description--&gt;Avermedia AVerMedia Live Gamer Portable ([https://github.com/Trouffman/octv_gears_lgp Model C875])  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 usb2 no uvc}}   
|-
| &lt;!--Description--&gt;AVerMedia LGX Live Gamer extreme GC550
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2015 but [https://github.com/ChrisAJS/lgx2userspace driver]}}
|-
| &lt;!--Description--&gt;AVerMedia LGX2 Live Gamer extreme2 gc550 plus gc551 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 but [https://github.com/ChrisAJS/lgx2userspace driver]}}
|-
| &lt;!--Description--&gt;Avermedia ExtremeCap UVC - BU110 
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 maybe not uvc and uac}}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer Portable 2 Plus GC513 Micro-USB Capture Box LGP2 Plus
| &lt;!--Vendor ID--&gt;0x07ca
| &lt;!--Product ID--&gt;0x1513
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2017 powered by a standard Micro-USB cable, video capture output up to 1080p60 capture to hdmi in, standalone sd card recording on exFAT or FAT32 of .MOV, 2160p pass-through hdmi out to tv - no vrr - [https://www.avermedia.com/uk/support/download#ans_part firmware latest 2.1.7.13, 2.1.7.14], SN74AVC8T245 8bit, DRV604 stereo, iTE IT6663FN hdmi 2.0 splitter, TLV320DAC3101 DAC, CS42L73 audio codec, CDCE913 PLL clock, W29N01HVSINA nand bios, I-Catch V35MA SOC CPU 32bit MIPS24K, ADV7480 hdmi mhl, }}
|-
| &lt;!--Description--&gt;AVerMedia Live Gamer 4K LG4K GC573 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2018 not uvc but [https://github.com/derrod/lg4k-linux drivers here], }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Blackmagic intensity Extreme Capture Card
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2011 not uvc }}
|-
| &lt;!--Description--&gt;BlackMagic Intensity Pro 4k 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2015 }}
|-
| &lt;!--Description--&gt;Elgato Video Capture (1VC108601000)
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Elgato Game Capture HD60 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc, }}
|-
| &lt;!--Description--&gt;Elgato Game Capture HD GCHD 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc https://github.com/tolga9009/elgato-gchd needs firmware mb86h57_h58_idle.bin and mb86h57_h58_enc_h.bin}}
|-
| &lt;!--Description--&gt;Elgato HD60S Elgato Game Capture 4K60 S+ Video Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|non uvc, }}
|-
| &lt;!--Description--&gt;August EZCap.tv model 116 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} poor audio recording 
|-
| &lt;!--Description--&gt;E-SDS Diamond Maplin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Hauppauge 1212 HD PVR 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} analog and component only - PlayStation (.m2ts), AVCHD (ts), or XBox(.mp4) recording formats - switched the component output from the default YPbPr to RGB. 
|-
| &lt;!--Description--&gt;Hauppauge 1431 1445 HD PVR Gaming Edition HDMI Capture 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 not working, can get warm}}  
|-
| &lt;!--Description--&gt;Hauppauge HD Rocket 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;Hauppauge HD-PVR2 (model 145210 Rev E4) 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xE502
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Hauppauge 1480 1482 HD PVR 2 GE Gaming Edition HDMI Capture green LED - 1498 1503 1504 Plus version with Mac support 
| &lt;!--Vendor ID--&gt;0x2040 
| &lt;!--Product ID--&gt;0xe514 0xe524
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| can get warm - [https://ez.analog.com/video/w/documents/581/adv7482-design-support-files ADV7482] [https://patchwork.kernel.org/patch/9201075/ video chip] with Magnum DXT H.264 encoder blob, IDR keyframe generation poor - best for model 157210 and not 157221 and Game Edition Plus (model 157320) 2040:E505 E505-00-00AF1234 [http://www.hauppauge.com/site/support/linux.html#tabs-3 ]}} 
* HDMI: 1920x1080p50/60, 1920x1080i50/60, 1280x720p50/60, 720x480i, 720x576i, 640x480p60.
* Component: 1920x1080p50/60, 1920x1080i50/60*, 1280x720p50/60, 720x480p60, 720x480i, 720x576i.
* Composite: 720x480i and 720x576i 
* Audio Inputs : HDMI PCM and RCA support with Adjustable Bitrate Quality 2 Channel AAC/AC3 audio codec 
|-
| &lt;!--Description--&gt;Hauppauge 1512 HD PVR 2 PC blue LED with optical in input on the back 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xe525
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }} can get quite warm - IR Blaster added - 
|-
| &lt;!--Description--&gt;Hauppauge Colossus2 E585-00-00AF4321 
| &lt;!--Vendor ID--&gt;0x2040
| &lt;!--Product ID--&gt;0xe585
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Ion SLIDES2PC 35mm Portable Slide &amp; Film Scanner 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Ion Pics 2 PC 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;ION PowerScan USB film and slide scanner
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2011 not uvc }}
|-
| &lt;!--Description--&gt;Koolertron Sunny 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;FilmScan35 35mm Film Negative Scanner 1304 marks spencer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;U3 HD Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Razer Ripsaw HD - Game Capture 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc}} put in usb2 slot and use video BGR3 (Emulated) and OpenRazer drivers 
|-
| &lt;!--Description--&gt;Razer Ripsaw HD USB HDMI Capture Card 
| &lt;!--Vendor ID--&gt;0x1532
| &lt;!--Product ID--&gt;0x0d01
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no| not uvc compliant}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Silvercrest 35mm Photo Slide Scanner 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc but not great quality}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;Z-Star Microelectronics Corp. Traveler TV 6500 SF Dia-scanner
| &lt;!--Vendor ID--&gt;0x0ac8
| &lt;!--Product ID--&gt;0x3370
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2010 not uvc and poor scans}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| not uvc }}
|-
|}


=== AR VR XR Headset ===

 AROS needs realtime isochronous transfers in EHCI and XHCI, then an usb based uvc.class to vhi type driver for virtual display and maybe more 

The primary engineering challenge of VR is motion sickness caused by a mismatch of visual and inner ear information, which is extremely well established as causing people to throw up in a wide range of contexts outside of VR. The experiences that make some people sick are low framerate. Foveated rendering doesn't solve vergence accommodation. Your eye will still be focused at infinity regardless of where you are looking, you'll just have the illusion that the foreground or background are out of focus. Eye tracking plus dynamic lenses (perhaps liquid lenses) or real light fields are necessary. 

First start with apps that have simple static features at first, then advance to dioramasa and teleportation options for 10, 20 minutes and then gradually upgrade over a timespan of four weeks to train your brain. Avoid smooth motion stuff like rollercoaster or mountain heights until much later. Even with this preparation, VR makes 40% of people seasick nausea. If so, you may be able to use VR glasses just to watch videos and some slow moving apps [https://www.emuvr.net/ emuVR] instead.

*2014-2019 1st Gen, low resolution, 
*2020-2025 2nd Gen, higher resolution, 
*2026-

Most hardware typically has a 1-3 year retail lifespan with 1-3 years of updates after. Really need &quot;right&quot; tethered PCVR rather than wireless. 
The advantage to being tethered to a PC is processing power. Any standalone headset is going to be running purely off of batteries.

VR and AR are known as XR

Technology will get immersed enough so not making people sick. Higher resolution, faster frame rates, and [https://github.com/opentrack/opentrack better tracking]. 
Eventually, hyper reality brings VR, AR and MR digital layers together as a less chaotic, optic tracking with no delay, agents understanding, experiences with objects 

3Dgs 4Dgs gassian splats bullet time slice photo snaps .ply for WebXR 

[https://lvra.gitlab.io/docs/hardware/ ], 

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Big Screen Beyond 1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 pcvr 2560 x 2560, fixed IPD,  }}
|-
| &lt;!--Description--&gt;bigscreen Beyond 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pcvr oled 5120 x 2560 @75Hz 2688x2688 @90Hz over pancake lenses, 116 FOV, virtual screens, custom facial plate from iphone app, streamvr 2.0 basestations and controllers not included, no passthrough, 107g-196g, }}
|-
| &lt;!--Description--&gt;bigscreen Beyond 2e 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 pcvr oled 5120 x 2560 total up to 90Hz pancake lens 116 FOV adjustable IPD app needed for adjustment, eye tracking, custom face mask cushion, streamvr 2.0 basestations and controllers not included, seperate head strap and speaker modules extra costs, 110g-300g }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Dpvr P1 Pro 4k Ultra Vr Headset 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 wireless snapdragon, }}
|-
| &lt;!--Description--&gt;DPVR P2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Play for Dream MR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android modular 3840x3552 uoled per eye 90Hz or qled mura issues, Arm snapdragon XR2+ Gen 2, eye tracking and 11 cameras 7 sensors 22 ir leds 14ms latency and foveated rendering, 1.5hrs battery, }}
|-
| &lt;!--Description--&gt;Play for Dream GravityXR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 ultralight head gear gx100 3w }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }} 
|-
| &lt;!--Description--&gt;[https://lvra.gitlab.io/docs/community/ Valve Index HMD] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 tethered PC VR headset 1440 x 1600 120Hz, 108° and 104° FOV, fresnel lenses, SteamVR2 compatible tracking ir basestations, controllers aka Knuckles, dp 1.2 and usb3 cable proprietary cable end, no battery, }}
|-
| &lt;!--Description--&gt;Valve Steam Frame (Valve Deckard / Valve’s Index 2) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 - 2160 x 2160 up to 144Hz pancake lens, 108° and 96° FOV, wifi 6 fovelated streaming, Qualcomm Snapdragon 8 Gen 3 with [https://github.com/FEX-Emu/FEX fex] arm-to-x86 x64 translation layer, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sony PSVR2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|2023 PCVR with adapter, two, one for each eye, 2000 x 2040 resolution OLED panels from 90Hz 120Hz refresh rates,  fresnel lenses, 116° and 102° FOV, sony proprietary headset cable end, needs additional comfort options, }}
|-
| &lt;!--Description--&gt;VisionPro
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Goertek glasses 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive ?
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| 2016 2x 1080x1200 needs external power supply, }} 
|-
| &lt;!--Description--&gt;HTC Vive Original 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 108° and 96° FOV}}
|-
| &lt;!--Description--&gt;HTC Vive Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2016 , uvc, at least 2 powered steamvr basestations so 3 to 5 wall warts in total, proprietary cable end, }}
|-
| &lt;!--Description--&gt;HTC Vive Pro 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 dual 1440x1600 oled displays, 116° and 100° FOV - steamvr 2.0 basestation 2 for 5m2 area 4 for 10m2 - steamvr 2.0 joypads - low latency wireless later - type USB-c headphone adapter required, [https://github.com/CertainLach/VivePro2-Linux-Driver Rust on Linux] with [https://github.com/santeri3700/vive-pro-2-on-linux Shell], proprietary cable end, }} 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lynx R1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 android Qualcomm Snapdragon XR2 Gen 1, }}
|-
| &lt;!--Description--&gt;Lynx R2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2026 company liquidated, 2 x 2312x2160 110 FOV pancake lenses, LynxOS android Qualcomm Snapdragon XR2 Gen, openxr 1.1, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Oculus Rift prototype development kit [https://www.virtual-boy.com/forums/t/the-oculus-rift-dk1-thread/ DK1] with [https://www.youtube.com/watch?v=X_T4DJyy2Bo wired razer hydra controllers]
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2013 pcvr LCD 1280 × 800 resolution 640 × 800 per eye up to 110° FOV, and 3DoF rotational tracking via a 1000Hz 9-axis IMU (Accelerometer, gyroscope, and magnetometer), no positional optical tracking either inside-out or outside-in, 380g, nausea issues, , }}
|-
| &lt;!--Description--&gt;Oculus Rift prototype development kit [https://github.com/facebookarchive/RiftDK2/tree/master DK2], [https://www.ifixit.com/Teardown/Oculus+Rift+Development+Kit+2+Teardown/27613 ifixit teardown] 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2014 pcvr, 5.7&quot; Super AMOLED display with a resolution of 960 x 1080 per eye 100° field of view, 1 usb Positional Tracker DK2 camera, lots of wires}}
|-
| &lt;!--Description--&gt;Facebook [https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter Oculus Rift CV1] [https://noraisin.net/diary/?m=202201 some Linux support] [] [https://github.com/OpenHMD/OpenHMD/issues/330 AMD usb issues] [https://github.com/OpenHMD/OpenHMD/wiki/Xorg ] [https://github.com/Doc-Ok/OculusRiftCV1Camera Live Video] [https://www.youtube.com/@thaytan Youtube] [https://github.com/Fredrum/riftOnLinux Pi] [https://github.com/OhioIon/riftDriverPi ], but not quite there with the [https://www.youtube.com/watch?v=DSsCN6HFkWc consumer CV1], [https://forum.dcs.world/topic/142259-cv1-not-working-in-dcs/#comment-2878168 orange led could be HDMI Signal is not within HDMI Spec and might be Overclocked or usb3 not getting enough power frustrating],  
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x3031, 0x2031, 0x0031 and 0x0211 for 3p-a basestations lighthouses, 0x045e 0x02e6 for xbox wireless adapter 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2016 powered run from your PC maybe uvc via wired dual PenTile OLED 2160x1200 (1080x1200 per eye) @ exactly 90Hz but screen door effect (space between pixels), 87 FOV, IPD from 58mm to 72mm, good 3D audio and okay mic, constellation headset 6DOF (3-axis rotational tracking + 3-axis positional tracking) with up to 3 usb infrared basestation (1 in front and 2 behind pointing upwards) on usb3 and usb2 to your PC but the tracking can be fragile so set it up on a weekly basis, wired only HDMI 1.3, USB 3.0 bus powered with proprietary plug in headset, 470g 1lb front heavy, 2 robust 1st Gen touch controllers with external sensors i.e. outside-in - 1 aa alkaline over rechargable battery each , press occulus and B buttons for 2 secs to connect, headset traps air so gets very warm inside and random disconnects due to twisting action on the top of the headset and/or cables, t4 torx screws }} 
|-
| &lt;!--Description--&gt;Facebook Occulus Go 32Gb 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2018 discontinued 2020 android based, 1280x1440 per eye 60Hz LCD, not gaming, no inside-out and limited self tracking, }} 
|-
| &lt;!--Description--&gt;Facebook Oculus Rift S [https://noraisin.net/diary/?m=202201 some Linux support] 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x0051 headset (cdc, audio, tracking data), 0x2052 usb hub, 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 PCVR wired dual LCD 1080 by 1200, 88 horizontal FOV, display port (fibre optic strands) and annoying USB3 copper cables (power, audio and other data) but proprietary port in the headset, cameras on the headset (&quot;inside-out&quot;) tracking so no base stations, non removeable head band and cushions and ipd hard to set, requires specific fragile Rift S/Quest1 2nd Gen Touch controllers which has a ring of translucent plastic with leds inside - t5 torx to disassemble for sticks drifting}} 
|-
| &lt;!--Description--&gt;Facebook Occulus Quest 1 
*032Gb
*064Gb
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x0183 (single adb boot), 0x0
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 android standalone wireless, 1440 x 1600 72Hz oled, front heavy though, play area 2m x 2m or bigger, low clocked Qualcomm Snapdragon 835 (MSM8998) (4x Kryo 280 Gold cores ARM Cortex-A73) + (4x Kryo 280 Silver A53), 2 to 3 hrs play time, 575g, 2nd Gen touch controllers, }}
|-
| &lt;!--Description--&gt;Meta Oculus Quest 2 KW49CM aka Codename Del Mar [https://www.meta.com/en-gb/help/quest/967070027432609/ fragile 3rd Gen Touch controllers] [https://www.youtube.com/watch?v=Cgejky8ZeoM internal battery] and selling over 20 million, more than all other quest headsets combined 
*064Gb 
*128Gb (110Gb free) 
*256Gb 
Setup continuous wifi, create Meta Oculus account, [https://developers.meta.com/horizon/ verify dev account, click on My apps], [ create Organization -&gt; My Organization Groupings], [https://www.youtube.com/watch?v=QPInS5xxF-0 finally, meta quest mobile app to switch on adb], 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;0x5010 (), 0x0083 (massstorage), 0x0086 (), 0x0186 (adb and xrsp [https://github.com/shinyquagsire23/xrsp_tests tests]), 0x0090 (composite adb), 0x0081 (), 
| &lt;!--Revision--&gt;0419
| &lt;!--Opinion--&gt;{{unk|2021 android stand alone, lcd 1832x1920 per-eye 90Hz refresh rate, 97 FOV, fresnel lenses, 6DOF (degrees of freedom), 58-63-68 IPD settings, low clocked Arm snapdragon xr2 gen 1 apps with Meta Link cable USB-C usb3.2 pcvr maybe, b/w but no color passthrough, 6 t2 torx and 5 ph00 screws in headset (long bit), discontinued December 31, 2024, feature updates until December 2026, critical bug fixes and security updates until December 2027, 470g, Oculus + B button on right controller (move) and Menu + Y button on left controller (click) for about 3 seconds, 10W 5v 2a, RTL8153 chipset usb support, 
*V60 unable to 
*V77 pcvr issues 
*V79 unable to }}
|-
| &lt;!--Description--&gt;Facebook Occulus Quest Pro aka Codename Seacliffe 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 android standalone wireless 1440 x 1600 72Hz oled, 106° and 96° FOV mini lcd local dimming, pancake lenses, limited eye tracking, play area 2m x 2m or bigger, higher clocked snapdragon xr2 gen 1 arm cpu Arm apps, 1 to 2 hrs play time, new pro controllers with 3 cameras each, battery at rear, wireless charging, color passthrough, 9V 3A or 5V 3A, 
*v77 capped wifi }}
|-
| &lt;!--Description--&gt;Meta Oculus Quest 3 aka Codename Eureka [ Air Light ALVR] or [ WiVRn] with fragile touch plus q3 controllers 
*128Gb
*512Gb
streaming from PC with [https://github.com/alvr-org/Monado-ALVR ALVR], runtime of [https://monado.freedesktop.org/ Monado steamvr alternative openxr openVR], with Envision GUI, 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 standalone, pancake lenses on lcd 2064 x 2208 res panel per eye 1200ppi - 104° and 96° FOV - up to 120Hz, Arm snapdragon xr2 gen 2 apps,  foveated rendering, Meta Link cable USB-C 3.2, headstrap clamshell or halo style, speaker arms fragile, color passthrough, 510g, 18W 9v 2A or 15W 5V 3A, 
*v74 ok }}
*v76 pcvr issues }}
|-
| &lt;!--Description--&gt;Meta Quest 3S aka Codename Ventura 
*128Gb
*256Gb
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 Arm snapdragon xr2 gen 2 cpu, lcd 1832 x 1920 fresnel lenses, 97 FOV, headphone arms fragile, better air flow, no promixity sensor inside, Meta Link cable USB-C 3.2, passthrough, }}
|-
| &lt;!--Description--&gt;Meta Boba 3 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027 ultra-wide 180° x 120° FOV, snapdragon XR2 G2,  }}
|-
| &lt;!--Description--&gt;Meta Tiramisu 
| &lt;!--Vendor ID--&gt;0x2833
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2027  µOLED displays with 90 pixels per degree,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pimax 5K Super Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 }}
|-
| &lt;!--Description--&gt;Pimax 8K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020  }}
|-
| &lt;!--Description--&gt;Pimax 8K-X 8KX 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021  }}
|-
| &lt;!--Description--&gt;Pimax Crystal Light 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tethered to PC with 2160 x 2160 4k 120Hz, 115° and 96° FOV, inside-out tracking, no battery, display port cable, variable qc and customer service, }}
|-
| &lt;!--Description--&gt;Pimax Crystal Super 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tethered to PC with 3640 x 3640 4k 90hz, 116°+ and 100° FOV,  eye tracking, inside-out tracking, no battery, display port cable, }}
|-
| &lt;!--Description--&gt;Pimax Dream Air with Lighthouse(s)  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 tethered 3840 by 3552 @90Hz micro oled with pancake lens, 100 HFOV 96 VFOV but FOV IPD changes in app, link box for headset 2 split y cables, removable face gasket, 290g, steamVR2 bases and controllers, eye tracking, }}
|-
| &lt;!--Description--&gt;Pimax Dream Air SLAM 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026  Simultaneous Localization and Mapping (SLAM) tracking inside-out so no base stations,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://somniumspace.com/ Somnium VR One VR1] [https://portal.vrgineers.com/user-guide/software/ open source] VR headset
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 pcvr 2880 x 2880 per eye @90 @120Hz, 125° horizontal 100° vertical FOV, 2 x SteamVR 2.0 bases, passthrough, 900g }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero VR-1 Headset 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 psu needed, 2 x Mini LED binocular of 150 nits, 2880x2720 per, 90Hz, FOV 102° horizontal, 73° vertical, 720g with headstrap, 2 x SteamVR 2.0 basestations, no speakers/mic, hdmi and usb3.0}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero XR-3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Varjo Aero XR-4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Camelo La Melaza Music Shield 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2026 no usb only bluetooth ,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;InAir 2 elite suite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar  nits 46FOV , , 4h battery life, 80g, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Oakley Vanguard 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;RayNeo Air 3s 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 100in 46FOV 650nits, usb-c 79g  }}
|-
| &lt;!--Description--&gt;RayNeo Air 3S Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 135in virtual display 46FOV 1200nits, usb-c 80g }}
|-
| &lt;!--Description--&gt;RayNeo Air 4 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 AR oled vision 4000 processing, HDR10, 47 FOV }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Rokid Max 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 147in 50 FOV 650nits, usb-c back left, 76g, }}
|-
| &lt;!--Description--&gt;Rokid AI Spatial with Station 2 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 AR 600nits 147in 50FOV  75g, }}
|-
| &lt;!--Description--&gt;Rokid 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| ar ai smart glass}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viture Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 135in 46 FOV 1000nits, magnetic connector, 77g, }}
|-
| &lt;!--Description--&gt;VITURE XR Luma 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 147in 1200p 50 FOV, }}
|-
| &lt;!--Description--&gt;Viture Luma Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 152in 52 FOV 1000nits 1200p, 3dof, , 79g, }}
|-
| &lt;!--Description--&gt;Viture Luma Ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 in  FOV, 2 cameras, 3dof 6dof,  }}
|-
| &lt;!--Description--&gt;[https://github.com/wheaney/XRLinuxDriver Viture Luma Pro] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Viture Beast 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 1250nits 58FOV 174in, magnetic,  88g,  }}
|-
| &lt;!--Description--&gt;VITURE Beast X Glasses models (Immersive 3D Moonlight) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 based 2D to 3D conversion with support DP Alt Mode (DisplayPort over USB-C), 1200p, 3df tracking, practic lenses 58deg POV, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xreal One 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 600nits, 50FOV, 3dof, usb-c 84g,  }}
|-
| &lt;!--Description--&gt;XReal One Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 ar 700nits 57FOV 171in, usb-c, x1 3dof, }}
|-
| &lt;!--Description--&gt;Nreal now Xreal Air 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 , micro-oled 1080p, audio, virtual uvc ar displays, }}
|-
| &lt;!--Description--&gt;Nreal now Xreal Real3D 1S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 AI based 2D to 3D conversion 57 FOV, , virtual uvc ar displays not vr, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xiami XR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Xtal 8k
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Apple Vision Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 tethered AR mixed reality glasses,   3300ppi, 800g, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Google XR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive Focus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 standalone }}
|-
| &lt;!--Description--&gt;HTC Vive Focus Plus 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 android with 2 1440 x 1600 75Hz amoled, inside-out, durable motion controllers, Vive port,  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HTC Vive Pro EYE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 dual-OLED displays 2880 x 1600 combined resolution), SteamVR 2.0 tracking, foveated rendering, Tobii, it enables gaze-based menu navigation with avatar eye contact, proprietary cables, }}
|-
| &lt;!--Description--&gt;HTC Vibe Cosmos 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2018  poor tracking and lifespan on controllers,  }}
|-
| &lt;!--Description--&gt;HTC Vibe Cosmos Elite 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2020 1440x1700 per eye resolution, 90 Hz refresh rate, 6 DoF tracking, 2880 x 1700 combined pixel resolution, 97° FoV, two controllers and two base stations. Lighthouse tracking, }}
|-
| &lt;!--Description--&gt;HTC Vive Focus Vision Wired 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No| }}
|-
| &lt;!--Description--&gt;HTC Vive Focus 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2021 per-eye resolution of 2448×2448 at 90 Hz, a 120-degree field of view, Qualcomm Snapdragon XR2 Gen 1,  }}
|-
| &lt;!--Description--&gt;HTC Vive XR Elite VR Headset Deluxe Pack 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2022 snapdragon xr2 gen 1, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Pico Goblin 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 android based, 2.5K 1280x1440 per eye @70Hz, 92° FoV, and 3DoF (three degrees of freedom) tracking (Orientation tracking only—yaw, pitch, roll), single controller, snapdragon 820, ipd adjustment 54-71 mm, 600g,  }}
|-
| &lt;!--Description--&gt;ByteDance Pico G2 4K
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 android standalone VR headset, 3840 x 2160 (4K) LCD screen, Snapdragon 835 processor, 3DoF so rotational movement (looking around, pointing) rather than positional movement (walking, leaning), does not support hand or eye tracking, 800g }}
|-
| &lt;!--Description--&gt;ByteDance Pico NEO 2 EYE
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 6DoF 360g snapdragon 845 display 4k 75Hz tracking inside-out - magnetic field for controllers - pico software on android 8 - eye tracking }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 Snapdragon XR2 Gen, 4K 3664 x 1920 90Hz lcd, battery at rear, displayport, Pico apparently emulates Oculus controllers, }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 Pro 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;ByteDance Pico Neo 3 Link 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2022 }}
|-
| &lt;!--Description--&gt;ByteDance Pico 4 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 2160x2160 panel per eye 75Hz 90Hz 105 FOV, Arm snapdragon xr gen 1, }}
|-
| &lt;!--Description--&gt;ByteDance Pico 4 ultra 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2023 2160 x 2160 @90 105 FOV, snapdragon XR2 G2, streaming from PC with alvr, wireless streaming from PC with WiVRn, Pico apparently emulates Oculus controllers, not plug and play, }}
|-
| &lt;!--Description--&gt;ByteDance Pico 5 aka Project Swan aka Vision Pro Competitor 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 micro-oled BOE 3840 x 3840 4000ppi per eye, MLA pancake lenses, custom pico arm cpu, pico os 6 android, eye and hand tracking, 300g,  }}
|-
| &lt;!--Description--&gt;ByteDance Pico  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung Galaxy XR VR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 3552 x 3840 @60-90 109 FOV , Arm snapdragon XR2+ Gen 2, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Shiftall MeganeX 8K 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2024 android  }}
|-
| &lt;!--Description--&gt;[https://en.shiftall.net/products/meganex8k MeganeX Superlight 8K] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 android (3552 x 3840 pixels) into pixel count yields 27.27MP 10-bit HDR-compatible 4K resolution micro OLED panels @90Hz, pancake lenses 94 FOV, SteamVR™ tracking, 180g, 5V 2A, }}
|-
| &lt;!--Description--&gt;[https://en.shiftall.net/products/meganex8kmk2 MeganeX 8K Mk2 MkII] [https://github.com/sboys3/CustomHeadsetOpenVR community] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 pcvr linux, 4K per eye (1.35inch micro OLED 3552x3840 10 bit HDR) 27MP @90Hz 75Hz 72Hz pancake, upto 108 hor 100 vert FOV, usb-c and dp cables to breakout box, 5V 2.1A, 200g}}
|-
| &lt;!--Description--&gt;Shiftall 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2026 }}
|-
| &lt;!--Description--&gt;Shiftall 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;Acer Windows(TM) MR AH101 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 Dual 2.89” LCD panels 2880 x 1440 combined (1440 x 1440 per eye) Up to 90Hz (HDMI 2.0), or 60Hz (HDMI 1.4), Field of View FOV 95, Tracking Inside-out, lots of light leak, }} 
|-
| &lt;!--Description--&gt;Acer H7001 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 wmr 1440 x 1440 per-eye resolution @90Hz refresh rate, and 100-degree field of view FOV, inside-out tracking with front-mounted cameras so no external sensors, flip-up visor design but has a &quot;screen door effect,&quot; subpar foam padding, win10 to win11 24H2,  }}
|-
| &lt;!--Description--&gt;Dell Visor Mixed Reality VRP100 VR118
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 2x 1440x1440 a bit of nose light leak }}
|-
| &lt;!--Description--&gt;Fujitsu 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2017 cheap and lots of light leak }}
|-
| &lt;!--Description--&gt;[https://github.com/HadesVR HadesVR] with [https://github.com/ManoloMancelli/Persephone-Classic-Controller Persephone Controller]
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;[https://www.youtube.com/watch?v=HFaVjB1uNOM Persephone 3 Pro DiY 6Dof SteamVR Headset], 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;HP Reverb G1 VR1000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 WMR 2160 x 2160 @90Hz, 115 FOV, , hp proprietary headset cable end, 2 camera tracking but poor and controllers can be unresponsive, 500g front heavy, flight sims rather than gaming,  }}
|-
| &lt;!--Description--&gt;HP 1440p Spatial Computing 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 dim display }}
|-
| &lt;!--Description--&gt;[https://forums.x-plane.org/forums/topic/294764-vr-in-linux-without-steam/ HP Reverb G2] WMR VR3000 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2020 2 2160 x 2160 90Hz, needs Windows10 or Win 11 24H2, 4 camera tracking, controllers can be unresponsive, hp proprietary headset cable end, , }} 
|-
| &lt;!--Description--&gt;HP 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Mirage Solo is a Standalone VR headset
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 Qualcomm Snapdragon 835, 1280x1440 per eye resolution, 75 Hz refresh rate, }}
|-
| &lt;!--Description--&gt;Lenovo Explorer VR2511N (G0A2) VR windows mixed reality (WMR) 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 LCD 2.89&quot; 1440 x 1440 per eye @90Hz, 6 DOF position tracking, 400g, }}
|-
| &lt;!--Description--&gt;[https://github.com/relativty/relativty open source relativty] 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Samsung MHD Odyssey XE800ZAA WMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2018 9V 500mA oled screens 2x 1440x1600 with usb3 and hdmi cables but bluetooth dongle required }}
|-
| &lt;!--Description--&gt;Samsung MHD Odyssey+ Plus WMR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2019 dual 3.5-inch AMOLED displays 2880 x 1600 total @90Hz, 6DOF inside-out tracking with usb3 and hdmi cables but bluetooth dongle required, use only win10 or win11 24H2,  }}
|-
| &lt;!--Description--&gt;Sony PSVR 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2016 2x 1080x960 up to 120Hz, lots of cables and computation brick, sony camera needed for tracking, ps4 or move controllers, }} 
|-
| &lt;!--Description--&gt;Virtuality 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|1992 , , Amiga 3000 with TI chips, }}
|-
| &lt;!--Description--&gt;Virtuix Omni 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2013 VR treadmill changed course to commercial VR and pivotted back again 2020, }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


=== HDMI CEC transmitter and receiver ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


=== TV Remote Control MCE IR transmitter and receiver ===

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Compro K100 K300
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|need extra software support}}
|-
| &lt;!--Description--&gt;Elitegroup Computer Systems
| &lt;!--Vendor ID--&gt;0x1019
| &lt;!--Product ID--&gt;0x0f38
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;GMYLE MCE 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{Maybe|acts as usb-hid with limited keyboard like controls }}
|-
| &lt;!--Description--&gt;Hauppauge WinTV-PVR kit
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested}}
|-
| &lt;!--Description--&gt;Logitech Harmony 300 i300 600 650 800 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|need extra software support}}
|-
| &lt;!--Description--&gt;Microsoft MCE Commander 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|2005 need extra software support}}
|-
| &lt;!--Description--&gt;Microsoft 1039 rev 1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2005 home top of square shape direction keys}}
|-
| &lt;!--Description--&gt;Microsoft 1039 rev 2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2006 home under circle spaced direction keys}}
|-
| &lt;!--Description--&gt;Microsoft 1069 SMK Manufacturing, Inc
| &lt;!--Vendor ID--&gt;0x0609
| &lt;!--Product ID--&gt;0x0334 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2007 untested}}
|-
| &lt;!--Description--&gt;Philips RC1974506/00 
| &lt;!--Vendor ID--&gt;0x0471
| &lt;!--Product ID--&gt;0x0815
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE10E PC REMOTE CONTROL VGN-AR21M VGX-XL100 VGN-AR21B/AR21S 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE20E PC REMOTE CONTROL
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE30E PC REMOTE CONTROL VGN-AW21XY VGX-TP3E VGX-TP3G 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Sony RM-MCE50E PC REMOTE CONTROL VGC-LA2R 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;TSDX-IR14 USB MCE Media Center External Infrared IR Receiver
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;chipsets support CIR (consumer IR) Winbond W83977F/AF, SMC IrCC 2.0 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|technical reasons it's not possible to use USB IrDA dongles}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| &lt;!--Description--&gt;Zotac RC2604323/01G Zbox Media Remote Control with IR USB Receiver OVU710
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;Anycubic Cobra 2 Max 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Bambu Labs A1 Mini 3D printer 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{No|2019 EMS proprietary slicer app and cloud use, eSUN}}
|-
| &lt;!--Description--&gt;Bambu Labs X2D 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality K1
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality K2
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Creality 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Lulzbot 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Prusa 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt; 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Qidi 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Snapmaker U1 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk|2025 tool changer  }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;Sovol SV08 Max
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| open source voron model, }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


==ethwrap.class - Host Data Link &quot;Cable Bridge&quot; for data transfer==

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Advance USBNET (eTEK design)
| 0x0525
| 0x9901
| 
| {{N/A|untested}}
|-
| ALi Uli M5632 (chip)
| 
| 
| 
| {{N/A|untested}}
|-
| Aten (Ali Corporation) UN201
| 0x0402
| 0x5632
| 
| {{maybe|force binding from rawwarp to ethwrap}}
|-
| Belkin (eTek design see below)
| 0x050d
| 0x0004
| 
| {{N/A|untested}}
|-
| Digitus DN-3004 - USB Host Link
| 
| 
| 
| {{yes|works}}
|-
| EPSON USB client
| 0x0525
| 0x2888
| 
| {{N/A|untested}}
|-
| eTEK
| 0x056c
| 0x8100
| 
| {{N/A|untested}}
|-
| KC-190
| 0x050f
| 0x0190
| 
| {{N/A|untested}}
|-
| GeneSys GL620USB
| 
| 
| 
| {{no|no driver the half-duplex GL620USB is NOT supported, products using it include the Inland Pro USB Quick Link}}
|-
| GeneSys GL620USB-A
| 
| 
| 
| {{N/A|untested}}
|-
| Laplink Gold (uses NetChip 1080)
| 
| 
| 
| {{N/A|untested}}
|-
| Prolific 2301/2302 (Jaton USB ConNET) (BAFO DirectLinq) 
| 0x067b
| 0x0000 and 0x0001
| 0x0004
| {{maybe|detected but untested}}
|-
| Xircom PGUNET (uses AnchorChips 2720)
| 0x0547
| 0x2727
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}

==cdcacm.class - USB modem==

The CDC ACM driver exposes the USB modem as a virtual serial modem or a virtual COM port to the operating system. The driver enables sending both data and AT commands, either through ACM (separating data and AT commands over different channels) or through Serial Emulation (passing the AT commands as is and as part of the data stream).

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Alcatel OT-I650 
| 0x1bbb
| 0x0003
| 
| {{N/A|untested}}
|-
| Acatel Dymamode/Dynamite
| 0x06b9
| 0xa5a5
| 
| {{N/A|untested Zyxel Prestige 630-13 - untested PROLiNK Hurricane 8000 external link }}
|-
| AnyData ADU-100A ADU-E100A ADU-E100D ADU-E100H D10
| 0x16d5
| 0x6501
| 
| {{N/A|untested}}
|-
| AnyData ADU-310
| 0x16d5
| 0x650
| 
| {{N/A|untested}}
|-
| AnyData ADU-500A ADU-510A ADU-510L ADU-520A
| 0x16d5
| 0x6502
| 
| {{N/A|untested}}
|-
| AnyData ADU-610 ADU-620
| 0x16d5
| 0x650
| 
| {{N/A|untested}}
|-
| BT On-Air USB MODEM 
| 0x079b
| 0x000f
| 
| {{N/A|untested}}
|-
| Conexant USB MODEM CX93010 
| 0x0572
| 0x1321
| 
| {{N/A|untested}}
|-
| Conexant USB MODEM RD02-D400 
| 0x0572
| 0x1324
| 
| {{N/A|untested}}
|-
| Conexant Chipset 
| 0x06ea
| 0x0002
| 
| {{N/A|untested AUS N367 Roadster II 56 USB (Model AM5050R3) - untested }}
|-
| [http://accessrunner.sourceforge.net/ Conexant AccessRunner]
| 0x0586
| 0x330a
| 
| {{N/A|untested }}
|-
| Creative Modem Blaster USB DE5670
| 0x1690
| 0x0101
| 
| {{N/A|untested}}
|-
| FIREFLY, MediaTek Inc
| 0x0e8d
| 0x0003
| 
| {{N/A|untested}}
|-
| Huawei E122
| 0x12d1
| 0x1446
| 
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=49126#forumpost49126]
|-
| Huawei E160, E160E, E160G
| 0x12d1
| 0x1003
| 
|{{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?post_id=51888#forumpost51888] (Chipset: Qualcomm MSM6246)
|-
| Huawei E169 also known as Vodafone K3715 and Huawei K3715 
| 0x12d1
| 0x1001
| 
|{{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4941&amp;forum=4&amp;post_id=44683#forumpost44683] (Chipset: Qualcomm MSM7200)
|-
| Huawei E220 &quot;Vodafone EasyBox II&quot; &quot;T-Mobile wnw Box Micro&quot; also known as Huawei K3565 
| 0x12d1
| 0x1003
|
| {{yes|works, see E169 above (Chipset: Qualcomm MSM6280)}}
|-
| Huawei E1750
| 0x12d1
| 0x1001
| 
| {{N/A|untested (Chipset: Qualcomm MSM6290)}}
|-
| Huawei E170, E172, E176 
| 0x12d1
| 0x1003
| 
| {{N/A|untested (Chipset: Qualcomm MSM7200)}}
|-
| Huawei E180
| 0x12d1  
| 0x1406
| 
| {{yes|Works (Chipset: Qualcomm MSM7200)}}
|-
| KYOCERA AH-K3001V 
| 0x0482
| 0x0203
| 
| {{N/A|untested}}
|-
| LG CU515
| 
| 
| 
| {{N/A|untested}}
|-
| MediaTek Inc GPS 
| 0x0e8d
| 0x3329
| 
| {{N/A|untested}}
|-
| Metricom GS Modem 
| 0x0870
| 0x0001
| 
| {{N/A|untested}}
|-
| Motorola MOTOMAGX phones 
| 0x22b8
| 0x6425
| 
| {{N/A|untested}}
|-
| Motorola Q Phone 
| 0x22b8
| 0x7000
| 
| {{N/A|untested}}
|-
| Hummingbird huc56s (Conexant) 
| 0x0572
| 0x1329
| 
| {{N/A|untested}}
|-
| Netcomm Roadster II 128 ISDN
| 
| 
| 
| {{N/A|untested}}
|-
| Nokia n70 N95 HSDPA
| 
| 
| 
| {{yes|works - see [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=4415&amp;viewmode=flat&amp;order=ASC here]}}
|-
| OGO
| 0x045E
| 0x0079
| 0090
| {{no|no driver}}
|-
| Olitec ADSL Modem V2 
| 0x08e3
| 0x0100 / 0x0102
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;Onda PT502HS 
| &lt;!--Vendor ID--&gt;0x19D2
| &lt;!--Product ID--&gt;0x0001
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
| Radicom V92HU-E2
| 
| 
| 
| {{N/A|untested}}
|-
| &lt;!--Description--&gt;Samsung i8510 Innov8 Symbian smartphone
| 0x04e8
| 0x6651
| &lt;!--Revision--&gt;
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=5552&amp;viewmode=flat&amp;order=ASC&amp;type=&amp;mode=0] 
|-
| Samsung Tocco Lite (aka GT-S5230)
| 0x04e8
| 0x6795
| &lt;!--Revision--&gt;
| {{yes|works}} [http://aros-exec.org/modules/newbb/viewtopic.php?start=0&amp;topic_id=5552&amp;viewmode=flat&amp;order=ASC&amp;type=&amp;mode=0] 
|-
| Shiro / Aztech USB MODEM UM-3100 
| 0x0572
| 0x1328
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM 
| 0x0ace
| 0x1602
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM 
| 0x0ace
| 0x1608
| 
| {{N/A|untested}}
|-
| ZyDAS 56K USB MODEM - new version 
| 0x0ace
| 0x1611
| 
| {{N/A|untested}}
|-
| Zoom Telephonics Model 3095F USB MODEM 
| 0x0803
| 0x3095
| 
| {{N/A|untested}}
|-
| Ugobe Pleo
| 0x6962
| 0x0100
| 0x0100
| {{Yes|Works}}
|}


==Misc==

palmpda.class - no [http://aminet.net/package/util/libs/PdaLinkPoseidon pdalink.library and tools] in AROS 

 Palm PDA (discontinued) synchronisation requires a port of pdalink.library and its tools through virtual usbpalm.device.

{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Palm IIIx (OS3.1) serial rs-232 only
| 
| 
| 
| {{no|no }}
|-
| Palm IIIc (OS3.5)
| 
| 
| 
| {{no|no }}
|-
| Palm V
| 
| 
| 
| {{no|no }}
|-
| Palm m100
| 
| 
| 
| {{no|no }}
|-
| Palm m125 first USB - last with aaa batteries
| 
| 
| 
| {{no|no }}
|-
| Palm m500 (OS4)
| 
| 
| 
| {{no|no }}
|-
| Tungsten T (OS5) first arm cpu 
| 0x
| 0x
| 0x
| {{no|no }}
|-
| Zire 31 (OS 5.28) color arm-based
| 
| 
| 
| {{no|no }}
|-
| [[:w:Handspring (company)|Handspring Visor]] – USB support out of box
|
|
|
| {{no|no }}
|-
| Handspring Treo 600 – last one for [[:w:Handspring (company)|Handspring]] 
| 
| 
| 
| {{no|no }}
|-
| Treo 700w
| 
| 
| 
| {{no|no }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


bluetooth.class - needs Bluetooth (Viking King Harald &quot;Bluetooth&quot; Gormsson (Old Norse: Haraldr Blátǫnn Gormsson; Danish: Harald Blåtand Gormsen) stack to work (not written due to licensing fees to use the symbol merging the Younger Futhark runes for H (ᚼ) and B (ᛒ), representing Harald's initials)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
|}


ccid.class - Chip/Smart Card Interface Devices (not implemented)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;cyberJack RFID basis
| &lt;!--Vendor ID--&gt;0x0C4B
| &lt;!--Product ID--&gt;0x9102
| &lt;!--Revision--&gt;0001
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{no|no driver}}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{N/A|untested}}
|-
|}


dfu.class - DFU firmware upgrade
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| &lt;!--Description--&gt;iPhone 3, 4, 5, 5c 
| &lt;!--Vendor ID--&gt;0x05ac
| &lt;!--Product ID--&gt;0x1290 0x1292 0x1294
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 32bit use with caution could cause damage}}
|-
| &lt;!--Description--&gt;iPhone 5s, 6, 7, 8, X 
| &lt;!--Vendor ID--&gt;0x05ac
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| 64bit use with caution could cause damage}}
|-
| &lt;!--Description--&gt;M-Audio/Midiman USB audio
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt;
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|- style=&quot;background:lightgrey; text-align:center; font-weight:bold;&quot;
| Description
| Vendor ID
| Product ID
| Revision
| Opinion 
|-
| &lt;!--Description--&gt;iPad 1, iPad 2 A1395 A1430, iPad 3, ipad mini A1432, iPad A1458 4th Gen (MD512LL/A),  
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2008-2013 32bit A4, A5 up to Apple A6X, iOS 1 to 10, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|-
| &lt;!--Description--&gt;iPad Air (1st generation) A1474, A1475, A1476, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2014-2015 [https://github.com/AsahiLinux 64bit], A7, iOS 11 up to 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2015 64bit A8, A8X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2016 64bit A9, A9X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2017 64bit A10, A10X, 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2018 64bit A11 
|-
| &lt;!--Description--&gt;iPad Air 3rd Gen A2153, A2123, A2154, iPad Mini 5th Gen, 
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;2019 64bit A12 
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;{{unk| }}
|-
|}


RocketTool (USB Rocket Launchers - Toy missile launchers)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;3px&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Original Launcher and StrikerII (includes laser)
| 0x1130
| 0x0202
| 
| {{yes|works }}
|-
| Dream Cheeky USB Missile Launcher or USB Cirus Cannon
| 0x1941
| 0x8021
| 
| {{no|no driver }}
|-
| Dream Cheeky USB Webcam Missile Launcher
| 0x1941
|
| 
| {{no|no driver }}
|-
| Rocket Baby
| 0x0a81
| 0x0701
| 
| {{no|no driver }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|}


DRadioTool (FM Radios - USB radio devices D-Link/Gemtek)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;5%&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| D-Link DSB-R100 USB 
| 0x04b4
| 0x1002
| 0x0410
| {{yes|works }}
|-
| [http://www.neoseeker.com/forums/383/t257009-link-usb-dru-r100-radio/ GemTek USB FM Radio 21]
| 0x04b4
| 0x1002
| 
| {{N/A|untested }}
|-
| &lt;!--Description--&gt;
| &lt;!--Vendor ID--&gt;
| &lt;!--Product ID--&gt; 
| &lt;!--Revision--&gt;
| &lt;!--Opinion--&gt;
|}


UproarTool (Valencia MPX mp3 player and others)
{| class=&quot;wikitable sortable&quot; width=&quot;90%&quot;
! width=&quot;30%&quot; | Description 
! width=&quot;3px&quot; |Vendor ID
! width=&quot;10%&quot; |Product ID
! width=&quot;10%&quot; |Revision 
! width=&quot;50%&quot; |Opinion
|-
| Korean D Square Valencia MPX-Player
| 0x04e8
| various
| 
| {{N/A|untested }}
|-
|}


[https://www.youtube.com/watch?v=vIuT7rJgc8w with unlocked android bootloader], 

&lt;pre&gt;

Kill and restart the server a few times

 sudo adb kill-server
 sudo adb start-server 

And finally type in

sudo adb devices

adb devices                 Lists connected devices              

adb shell                   Opens a terminal shell on the device hollywood:/ $
su 
id
df -h
top
ls -la
ls sdcard
ls sdcard/Android
ls sdcard/Oculus
wm size 

cd ..
cd data/system              look inside bad Corejava folder 
cd data/system/etc/init     look 
cd data/system/app
cd /data
cd /dev/block


 adb shell 
 pm disable-user --user 0 com.oculus.nux.ota


adb shell am start -a android.intent.action.VIEW -d com.oculus.tv -e uri com.android.settings/.DevelopmentSettings com.oculus.vrshell/.MainActivity

Don't change your Oculus account password after doing the FB account bypass. You'll break the log-in session, and have to factory-reset and start over 

adb shell 'setprop debug.oculus.cpuLevel 5 &amp;&amp; setprop debug.oculus.gpuLevel 5 &amp;&amp; setprop debug.oculus.adaclocks.force 0 &amp;&amp; setprop debug.oculus.phaseSync 1 &amp;&amp; settings put global always_finish_activities 1 &amp;&amp; settings put global wifi_scan_throttle_enabled 1 &amp;&amp; settings put global window_animation_scale 0.25 &amp;&amp; settings put global transition_animation_scale 0.25 &amp;&amp; settings put global animator_duration_scale 0.25 &amp;&amp; sync'


 settings list --user 0 secure or global or system 
   user_setup_complete=0

 adb shell 
 screenrecord

 adb shell reboot


 adb install &lt;path_to_apk&gt;   Installs an app like adb install -g -r alvr_client_android.apk or adb install -r app.apk 

 memtester 

 lsmod 

 
adb command to enable hand tracking, possible, but root access is required 
 adb root
 oculussetting --set hand_tracking_opt_in 1 hand_tracking_enabled 1 

adb push &lt;local&gt; &lt;remote&gt;   Copies files to the device
adb pull &lt;remote&gt; &lt;local&gt;   Copies files from the device 

pull them using CFB, extract original apk using LL 

adb forward tcp:9943 tcp:9943 (Used for advanced, such as ALVR streaming)

 adb shell pm disable-user --user 0 com.oculus.partnercustomization  Enterprise versions 

adb reboot                       Performs a standard system restart
adb reboot bootloader            Restarts the device into fastboot/bootloader mode
adb reboot recovery              Restarts the device into recovery mode
adb reboot download              Reboots Samsung devices into Download Mode
adb reboot fastboot              Directly enters fastboot mode

[https://gist.github.com/pantasio/3d0eb4bb03a1e696aae8696f60730859#file-enable-usb-debug-adb usb dev debug adb]

&lt;/pre&gt;


{{BookCat}}</text>
      <sha1>j56yumovxvn8h5goindfk3ewhetpqfx</sha1>
    </revision>
  </page>
  <page>
    <title>Introduction to Inorganic Chemistry</title>
    <ns>0</ns>
    <id>293741</id>
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      <contributor>
        <username>Tem5psu</username>
        <id>1013978</id>
      </contributor>
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      <text bytes="9013" sha1="6c6fvrust50pol50an67zj5pzsje3qm" xml:space="preserve">[[File:Periodic_table.svg|thumb|450px|Periodic Table of the Elements]] &lt;big&gt;'''Inorganic chemistry'''&lt;/big&gt; is the study of the synthesis, reactions, structures and properties of compounds of the elements.  This subject is usually taught after students are introduced to organic chemistry, which concerns the synthesis and reactions of compounds of carbon (typically containing C-H bonds).  Inorganic chemistry encompasses the compounds - both molecular and extended solids - of everything else in the [https://ptable.com/?lang=en# periodic table], and overlaps with organic chemistry in the area of organometallic chemistry, in which metals are bonded to carbon-containing ligands and molecules.  Inorganic chemistry is fundamental to many practical technologies including catalysis and materials (structural, electronic, magnetic,...), energy conversion and storage, and electronics.  Inorganic compounds are also found in biological systems where they are essential to life processes.


This textbook (in its initial form) is intended for use in a first semester course in inorganic chemistry, covering the basic concepts in structure, bonding, and properties that underlie the field.  The objective of this book is for students to understand how to use valence bond theory, crystal field theory, and molecular orbital theory to describe bonding in inorganic compounds, learn periodic trends in redox and acid-base equilibria, and learn the structures of solid elements and simple compounds. Building on this foundation we will develop a conceptual framework for understanding the stability and the electronic, magnetic, electrochemical, and mechanical properties of inorganic solids. We will also connect the chemistry of inorganic materials to some of their current and emerging applications, especially in the realm of nanoscale chemistry. By the end of the book the diligent student should know many of the elements in the periodic table as good friends, and the others at least as familiar acquaintances.  This course will also help students understand the connection between inorganic chemistry and technological problems of current relevance, including:

*Where in the periodic table should we look for new semiconductors to make cheap and efficient solar cells? 
*What's in a lithium battery, and how can we improve them for electric cars?
*How do inorganic compounds store and sequester hydrogen, methane, and CO&lt;sub&gt;2&lt;/sub&gt;?
*Some of the water supply in the developing world is contaminated with arsenic and other toxic substances. How can we clean up the water?
*How do nanoparticles provide better technology for flat screen displays, environmental cleanup, medical diagnostics and therapy?
*How do the devices (transistors, LEDs, piezoelectrics, alloys) in a cell phone and computer work?
&lt;br /&gt;

We hope to add second-semester topics, including group theory, spectroscopy, organometallic chemistry, and bioinorganic chemistry, in future editions of this book.&lt;br&gt;
[[file:chem310_2014.jpg|350px|right]]

&lt;big&gt;'''Authors'''&lt;/big&gt;&lt;br /&gt;
Born in 2014, this wikibook is a cooperative learning project of students in Chemistry 310 at [https://www.psu.edu Penn State University] and Chemistry 2610 at the [https://www.upenn.edu University of Pennsylvania].  It is a work in progress, and students and teachers of inorganic chemistry are encouraged to edit the book and add to it.
&lt;br /&gt;&lt;br /&gt;
===[[/Review of Chemical Bonding|Chapter 1: Review of Chemical Bonding]]===
*1.1  Valence bond theory: Lewis dot structures, the octet rule, formal charge, resonance, and the isoelectronic principle
*1.2  The shapes of molecules (VSEPR theory) and orbital hybridization
*1.3  Bond polarity and bond strength
*1.4  Discussion questions
*1.5  Problems
*1.6  References

===[[/ Molecular Orbital Theory|Chapter 2: Molecular Orbital Theory]]===
*2.1  Constructing molecular orbitals from atomic orbitals
*2.2  Orbital symmetry
*2.3  σ, π, and δ orbitals
*2.4  Diatomic molecules
*2.5  Orbital filling
*2.6  Periodic trends in π bonding
*2.7  Three-center bonding
*2.8  Building up the MOs of more complex molecules: NH&lt;sub&gt;3&lt;/sub&gt;, P&lt;sub&gt;4&lt;/sub&gt;&lt;br&gt;
*2.9  Homology of σ and π orbitals in MO diagrams
*2.10 Chains and rings of π-conjugated systems
*2.11 Discussion questions
*2.12 Problems
*2.13 References

===[[/ Acid-Base Chemistry|Chapter 3: Acid-Base Chemistry]]===
*3.1  Brønsted and Lewis acids and bases
*3.2  Hard and soft acids and bases
*3.3  The electrostatic-covalent (ECW) model for acid-base reactions
*3.4  Frustrated Lewis pairs
*3.5  Discussion questions
*3.6  Problems
*3.7  References

===[[/ Redox Stability and Redox Reactions|Chapter 4 : Redox Stability and Redox Reactions]]===
*4.1 Balancing redox reactions
*4.2  Electrochemical potentials
*4.3  Latimer and Frost diagrams
*4.4  Redox reactions with coupled equilibria
*4.5  Pourbaix diagrams
*4.6  Discussion questions
*4.7  Problems
*4.8  References

===[[/  Coordination Chemistry and Crystal Field Theory|Chapter 5 :  Coordination Chemistry and Crystal Field Theory]]===
*5.1  Counting electrons in transition metal complexes
*5.2  Crystal field theory
*5.3  Spectrochemical series
*5.4  π-bonding between metals and ligands
*5.5  Crystal field stabilization energy, pairing, and Hund's rule
*5.6  Non-octahedral complexes
*5.7  Jahn-Teller effect
*5.8  Tetrahedral complexes
*5.9  Stability of transition metal complexes
*5.10 Chelate and macrocyclic effects
*5.11  Ligand substitution reactions
*5.12  f-Block element salts and coordination compounds
*5.13  Discussion questions
*5.14  Problems
*5.15  References

===[[/  Metals and Alloys: Structure, Bonding, Electronic and Magnetic Properties|Chapter 6 : Metals and Alloys: Structure, Bonding, Electronic and Magnetic Properties]]===
*6.1  Unit cells and crystal structures
*6.2  Bravais lattices
*6.3  Crystal structures of metals
*6.4  Bonding in metals
*6.5  Conduction in metals
*6.6  Atomic orbitals and magnetism
*6.7  Ferro-, ferri- and antiferromagnetism
*6.8  Hard and soft magnets
*6.9  Discussion questions
*6.10  Problems
*6.11  References

===[[/  Metals and Alloys:  Mechanical Properties|Chapter 7 :  Metals and Alloys:  Mechanical Properties]]===
*7.1  Defects in metallic crystals
*7.2  Work hardening, alloying, and annealing
*7.3  Malleability of metals and alloys
*7.4  Iron and steel
*7.5 Amorphous alloys
*7.6 Discussion questions
*7.7 Problems
*7.8 References

===[[/  Ionic and Covalent Solids - Structures|Chapter 8 :  Ionic and Covalent Solids - Structures]]===
*8.1  Close-packing and interstitial sites
*8.2  Structures related to NaCl and NiAs
*8.3  Tetrahedral structures
*8.4  Layered structures and intercalation reactions
*8.5  Bonding in TiS&lt;sub&gt;2&lt;/sub&gt;, MoS&lt;sub&gt;2&lt;/sub&gt;, and pyrite structures
*8.6  Spinel, perovskite, and rutile structures
*8.7  Discussion questions
*8.8  Problems
*8.9  References

===[[/  Ionic and Covalent Solids - Energetics|Chapter 9 :  Ionic and Covalent Solids - Energetics]]===
*9.1  Ionic radii and radius ratios
*9.2  Structure maps
*9.3  Energetics of crystalline solids: the ionic model
*9.4  Born-Haber cycles for NaCl and silver halides
*9.5  Kapustinskii equation
*9.6 Discovery of noble gas compounds
*9.7 Stabilization of high and low oxidation states
*9.8 Alkalides and electrides
*9.9 Resonance energy of metals
*9.10 The strange case of the alkali oxides
*9.11 Lattice energies and solubility
*9.12 Discussion questions
*9.13 Problems
*9.14 References

===[[/  Electronic Properties of Materials: Superconductors and Semiconductors|Chapter 10 :  Electronic Properties of Materials: Superconductors and Semiconductors]]===
*10.1  Metal-insulator transitions
*10.2  Superconductors
*10.3  Periodic trends:  metals, semiconductors, and insulators
*10.4  Semiconductors:  band gaps, colors, conductivity and doping
*10.5  Semiconductor p-n junctions
*10.6  Diodes, LED's and solar cells
*10.7  Amorphous semiconductors
*10.8  Discussion questions
*10.9  Problems
*10.10 References

===[[/Basic Science of Nanomaterials|Chapter 11: Basic Science of Nanomaterials]]===
*11.1  Physics and length scales: cavity laser, Coulomb blockade, nanoscale magnets
*11.2  Semiconductor quantum dots
*11.3  Synthesis of semiconductor nanocrystals
*11.4  Surface energy
*11.5  Nanoscale metal particles
*11.6  Applications of nanomaterials
*11.7  Discussion questions
*11.8  Problems
*11.9  References

===[[/Resources for Students and Teachers|Chapter 12: Resources for Students and Teachers]]===
*12.1 VIPEr: Virtual Inorganic Pedagogical Electronic Resource: A community for teachers and students of inorganic chemistry
*12.2 Beloit College / University of Wisconsin Video Lab Manual
*12.3  Atomic and Molecular Orbitals (University of Liverpool)
*12.4  Interactive 3D Crystal Structures (University of Liverpool)
*12.5  Appendix 1:  Periodic Tables
*12.6  Appendix 2:  Selected Thermodynamic Values
*12.7  Appendix 3:  Bond Enthalpies

  
{{Shelves|Chemistry}}
{{alphabetical|I}}
__NOEDITSECTION__
{{status|100%}}</text>
      <sha1>6c6fvrust50pol50an67zj5pzsje3qm</sha1>
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  </page>
  <page>
    <title>Introduction to Inorganic Chemistry/Coordination Chemistry and Crystal Field Theory</title>
    <ns>0</ns>
    <id>294000</id>
    <revision>
      <id>4636869</id>
      <parentid>4629970</parentid>
      <timestamp>2026-05-21T13:25:08Z</timestamp>
      <contributor>
        <username>Tem5psu</username>
        <id>1013978</id>
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      <origin>4636869</origin>
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      <format>text/x-wiki</format>
      <text bytes="120942" sha1="a6ox22htps55o7623x7hjaso3d3pcl1" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
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The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
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The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

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[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
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We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
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In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
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==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==
&lt;br&gt;
[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are [[hsab theory|hard]] acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for [[redox]] chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the [[nuclearity]] of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
      <sha1>a6ox22htps55o7623x7hjaso3d3pcl1</sha1>
    </revision>
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      <parentid>4636869</parentid>
      <timestamp>2026-05-21T13:26:04Z</timestamp>
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        <username>Tem5psu</username>
        <id>1013978</id>
      </contributor>
      <minor />
      <comment>/* Coordination chemistry and catalysis */</comment>
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      <text bytes="120938" sha1="d8mqh7d0dg49mmwha6h8fjbhv4xi3j4" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
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==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
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==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
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The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
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:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
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The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
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&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
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Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
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'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
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'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
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If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
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The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
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[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
&lt;br /&gt;
&lt;br /&gt;
[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==
&lt;br&gt;
[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are [[hsab theory|hard]] acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for [[redox]] chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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      <text bytes="120949" sha1="nhajj994c58236voqztk90a8ehcqgh6" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
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==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
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The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
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The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
&lt;br /&gt;
&lt;br /&gt;
[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==
&lt;br&gt;
[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are [[hsab theory|hard]] acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for [[redox]] chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

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      </contributor>
      <minor />
      <comment>/* &amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds */</comment>
      <origin>4636872</origin>
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      <text bytes="120945" sha1="bbtofbg93w7xuycnm3ewayhqbofcjqd" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
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The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are [[hsab theory|hard]] acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for [[redox]] chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

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        <id>1013978</id>
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      <comment>/* Lanthanide coordination chemistry and catalysis */</comment>
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      <text bytes="120941" sha1="4dcbry68too66zlopr2zf7zy7bnb4gh" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
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The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are [[hsab theory|hard]] acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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        <username>Tem5psu</username>
        <id>1013978</id>
      </contributor>
      <minor />
      <comment>/* &amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds */</comment>
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      <text bytes="120940" sha1="hdem89pxx7css98beupjl7nio87e8qb" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
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==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
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&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are [[hsab theory|hard]] acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}
====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

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      <text bytes="120925" sha1="0aq7ed6ni1suu8udql3metikxqbog26" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
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:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
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The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
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&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
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Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
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'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
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If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
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&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

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[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
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&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
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==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
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There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
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'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.14 References==
{{reflist|colwidth=30em}}

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      <text bytes="120925" sha1="p88dmld6jd5a2xx9vcrlleluc2b6f4r" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
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==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
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==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
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The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
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For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
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For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
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:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
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The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
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&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
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Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
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'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
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'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
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If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
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The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
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[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
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The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
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The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
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Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
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The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

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[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
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We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
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In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
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==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
&lt;br /&gt;
&lt;br /&gt;
[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block Element Salts and Coordination Compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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      <text bytes="120925" sha1="re0ddvfz4tyhrl5dn695x4yqn5zupd2" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
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In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
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[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
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'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
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[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
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Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
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Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
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[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
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The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
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What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
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It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
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==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
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An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
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'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
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The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
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The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
&lt;br /&gt;
&lt;br /&gt;
[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).&lt;ref name = &quot;Greenwood&amp;Earnshaw&quot;/&gt;

====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

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      </contributor>
      <minor />
      <comment>/* &amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds */</comment>
      <origin>4636896</origin>
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      <text bytes="120890" sha1="5t7fkmoge330v5rci25a7oyu55anaxn" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
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The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}{{open access}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

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        <id>1013978</id>
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      <comment>/* Ln(II) and Ln(IV) compounds */</comment>
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      <text bytes="120875" sha1="121cp9nuy6qvo166axf7wck0u1i0g1c" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
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The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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        <username>Tem5psu</username>
        <id>1013978</id>
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      <minor />
      <comment>/* &amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds */</comment>
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      <text bytes="120892" sha1="kfihx7rkfkk29a1vy0a5xidv2omzen3" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
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==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
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&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|650px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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      <text bytes="120892" sha1="6pawvg4kjnr8fpz9nq8hx5ipr71hq76" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

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[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
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&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
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==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
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There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
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'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|700px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
      <sha1>6pawvg4kjnr8fpz9nq8hx5ipr71hq76</sha1>
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        <username>Tem5psu</username>
        <id>1013978</id>
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      <minor />
      <comment>/* Ln(III) compounds */</comment>
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      <text bytes="120892" sha1="8qz2pjrqnj7tdngap201urd5464r42r" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
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==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
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==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
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The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
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For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
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For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
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:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
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The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
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&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
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Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
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'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
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'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
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If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
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The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
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[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
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&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
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The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
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Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
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The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

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[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
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We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
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In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
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==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
&lt;br /&gt;
&lt;br /&gt;
[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|730px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
      <sha1>8qz2pjrqnj7tdngap201urd5464r42r</sha1>
    </revision>
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      <id>4636910</id>
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      <contributor>
        <username>Tem5psu</username>
        <id>1013978</id>
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      <minor />
      <comment>/* Ln(III) compounds */</comment>
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      <text bytes="120892" sha1="td2vuhf7763sobj2jtt2pkyn2hm36qr" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
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In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
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[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
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'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
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[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
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Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
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Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
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[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
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The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
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What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
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It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
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==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
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An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
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'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
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The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
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The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
&lt;br /&gt;
&lt;br /&gt;
[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|750px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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      <text bytes="120892" sha1="amqddasp9rmcr2zxr1j63suaf8t51bs" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
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The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|authors=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|750px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarize bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

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        <id>1013978</id>
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      <text bytes="120891" sha1="a0px049sg0g4e553fptlut0czefe6iu" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | authors = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
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The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|author=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|750px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarize bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

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        <id>1013978</id>
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      <comment>/* &amp;#160;&amp;#160;5.6 Non-octahedral complexes */</comment>
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      <text bytes="120890" sha1="4fpoewt7uwuvfgj31gyek12o70yipne" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
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==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
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&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | author = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
&lt;br /&gt;
'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

&lt;br /&gt;

[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
&lt;br /&gt;&lt;br /&gt;

[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
&lt;br /&gt;
&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
&lt;br /&gt;&lt;br /&gt;


==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
&lt;br /&gt;
&lt;br /&gt;

There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
&lt;br /&gt;

'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|author=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|750px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarize bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

{{BookCat}}</text>
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        <id>1013978</id>
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      <comment>/* Lanthanide coordination chemistry and catalysis */</comment>
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      <text bytes="120892" sha1="gf29dqmyhsk6k5akryllxvoebwluruj" xml:space="preserve">== &lt;big&gt;'''Chapter 5:  Coordination Chemistry and Crystal Field Theory'''&lt;/big&gt;==

[[File:MOF-5.png|350px|right|thumb|Zn&lt;sub&gt;4&lt;/sub&gt;O(BDC)&lt;sub&gt;3&lt;/sub&gt;, also called MOF-5, is a metal-organic framework in which 1,4-benzenedicarboxylate (BDC) anions bridge between cationic Zn&lt;sub&gt;4&lt;/sub&gt;O clusters.&lt;ref&gt;
{{cite journal
|first=Nathaniel L.
|last=Rosi
|first2=Juergen
|last2=Eckert
|first3=Mohamed
|last3=Eddaoudi
|first4=David T.
|last4=Vodak
|first5=Jaheon
|last5=Kim
|first6=Michael
|last6=O'Keefe
|first7=Omar M.
|last7=Yaghi
|title=Hydrogen storage in microporous metal-organic frameworks
|journal=Science
|volume=300
|issue=5622
|pages=1127–1129
|year=2003
|url=
|pmid=12750515
|doi=10.1126/science.1083440
|bibcode=2003Sci...300.1127R }}
&lt;/ref&gt;  The rigid framework contains large voids, represented by orange spheres.  MOFs can be made from many different transition metal ions and bridging ligands, and are being developed for practical applications in storing gases, especially H&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;.  MOF-5 has a volumetric storage density of 66 g H&lt;sub&gt;2&lt;/sub&gt;/L, close to that of liquid H&lt;sub&gt;2&lt;/sub&gt;.]]
'''Coordination compounds''' (or '''complexes''') are molecules and extended solids that contain bonds between a '''transition metal''' ion and one or more '''ligands'''.  In forming these '''coordinate covalent bonds''', the metal ions act as Lewis acids and the ligands act as Lewis bases.  Typically, the ligand has a lone pair of electrons, and the bond is formed by overlap of the molecular orbital containing this electron pair with the d-orbitals of the metal ion. Ligands that are commonly found in coordination complexes are neutral molecules (H&lt;sub&gt;2&lt;/sub&gt;O, NH&lt;sub&gt;3&lt;/sub&gt;, organic bases such as pyridine, CO, NO, H&lt;sub&gt;2&lt;/sub&gt;, ethylene, and phosphines PR&lt;sub&gt;3&lt;/sub&gt;) and anions (halides, CN&lt;sup&gt;-&lt;/sup&gt;, SCN&lt;sup&gt;-&lt;/sup&gt;, cyclopentadienide (C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;), H&lt;sup&gt;-&lt;/sup&gt;, etc.).  The resulting complexes can be cationic (e.g., [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;), neutral ([Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]) or anionic ([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;).  As we will see below, ligands that have weak or negligible strength as Brønsted bases (for example, CO, CN&lt;sup&gt;-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, and Cl&lt;sup&gt;-&lt;/sup&gt;) can still be potent Lewis bases in forming transition metal complexes.
&lt;br /&gt;&lt;br /&gt;
With ligands that are Lewis bases, coordinate covalent bonds (also called dative bonds) are typically drawn as lines, or sometimes as arrows to indicate that the electron pair &quot;belongs&quot; to the ligand X:  [[File:Classical dative bond.png|left|100px]]
&lt;br /&gt;&lt;br /&gt;
In counting electrons on the metal (described below), the convention is to assign both electrons in the dative bond to the ligand, although in reality the bonds are typically polar covalent and electrons are shared between the metal and the ligand.

When writing out the formulas of coordination compounds, we use square brackets [&lt;sup&gt;...&lt;/sup&gt;] around the metal ions and ligands that are directly bonded to each other.  Thus the compound [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]Cl&lt;sub&gt;2&lt;/sub&gt; contains octahedral [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;Cl]&lt;sup&gt;2+&lt;/sup&gt; ions, in which five ammonia molecules and one chloride ion are directly bonded to the metal, and two Cl&lt;sup&gt;-&lt;/sup&gt; anions that are not coordinated to the metal.
&lt;br /&gt;&lt;br /&gt;
[[Image:Cis-dichlorotetraamminecobalt(III).png|left|150px|thumb|''cis''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]][[File:Alfred Werner ETH-Bib Portr 09965.jpg|200px|right|thumb|Alfred Werner was a Swiss chemist who received the Nobel prize in 1913 for elucidating the bonding in coordination compounds.]][[Image:Trans-dichlorotetraamminecobalt(III).png|left|150px|thumb|''trans''-[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt; Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;]]

'''History.'''  Coordination compounds have been known for centuries, but their structures were initially not understood.  For example, Prussian Blue, which has an empirical formula Fe&lt;sub&gt;7&lt;/sub&gt;(CN)&lt;sub&gt;18&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O, is an insoluble, deep blue solid that has been used as a pigment since its accidental discovery by Diesbach in 1704.  Prussian Blue actually contains Fe&lt;sup&gt;3+&lt;/sup&gt; cations and [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; anions, and a more descriptive formulation is (Fe&lt;sup&gt;3+&lt;/sup&gt;)&lt;sub&gt;4&lt;/sub&gt;([Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;)&lt;sub&gt;3&lt;/sub&gt;•xH&lt;sub&gt;2&lt;/sub&gt;O.  Simpler compounds such as the ammonia complex of Co&lt;sup&gt;3+&lt;/sup&gt; were known to chemists but did not fit the expected behavior of ionic solids.  For example, cobalt(III)hexammine chloride, [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;3&lt;/sub&gt; was formulated as CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt;.  It had mysterious properties, in that it dissolved in water like an ionic solid, but it retained its six ammonia molecules when recrystallized.  Even more intriguing was the observation that chemically different forms (isomers) of transition metal complexes such as [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]Cl could be made.  The puzzle was solved by [[w:Alfred_Werner|Alfred Werner]], who proposed in 1893 that these Co complexes contained octahedrally coordinated metal ions that made primary (covalent) bonds to six ligands.  Werner showed through conductivity measurements that solutions of CoCl&lt;sub&gt;3&lt;/sub&gt;•6NH&lt;sub&gt;3&lt;/sub&gt; contained three free Cl&lt;sup&gt;-&lt;/sup&gt; anions and one [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; cation per formula unit.  Magnetic susceptibility measurements later confirmed the presence of diamagnetic Co&lt;sup&gt;3+&lt;/sup&gt; in both the salt and its solutions.  Werner's theory also explained the existence of two (and only two) structural isomers for [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;.  

  
Like organic compounds, transition metal complexes can vary widely in size, shape, charge and stability.  We will see that bonds formed from the d-orbitals of the metal largely control these properties.
&lt;br /&gt;
&lt;br /&gt;
'''Learning goals for Chapter 5:'''

*Determine oxidation states and assign d-electron counts for transition metals in complexes.
*Derive the d-orbital splitting patterns for octahedral, elongated octahedral, square pyramidal, square planar, and tetrahedral complexes.
*For octahedral and tetrahedral complexes, determine the number of unpaired electrons and calculate the crystal field stabilization energy.
*Know the spectrochemical series, rationalize why different classes of ligands impact the crystal field splitting energy as they do, and use it to predict high vs. low spin complexes, and the colors of transition metal complexes.
*Use the magnetic moment of transition metal complexes to determine their spin state.
*Understand the origin of the Jahn-Teller effect and its consequences for complex shape, color, and reactivity.
*Understand the extra stability of complexes formed by chelating and macrocyclic ligands.

==&amp;#160;&amp;#160;5.1 Counting electrons in transition metal complexes==
The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes.  Many of the important properties of complexes - their shape, color, magnetism, and reactivity - depend on the electron occupancy of the metal's d-orbitals.  To understand and rationalize these properties it is important to know how to count the d-electrons.

[[file:HexacyanidoferratIII_2.svg|left|200px|thumbnail|Structure of the octahedral ferricyanide anion.  Because the overall charge of the complex is 3-, Fe is in the +3 oxidation state and its electron count is 3d&lt;sup&gt;5&lt;/sup&gt;.]]Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign '''both electrons''' in the bond to the '''ligand'''.  For example, in the ferricyanide complex [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, if the cyanide ligand keeps both of its electrons it is formulated as CN&lt;sup&gt;-&lt;/sup&gt;. By difference, iron must be Fe&lt;sup&gt;3+&lt;/sup&gt; because the charges (3&lt;sup&gt;+&lt;/sup&gt; + 6(1&lt;sup&gt;-&lt;/sup&gt;)) must add up to the overall -3 charge on the complex.  

The next step is to determine how many d-electrons the Fe&lt;sup&gt;3+&lt;/sup&gt; ion has.  The rule is to count '''all''' of iron's valence electrons as '''d-electrons'''.  Iron is in group 8, so

::group 8 - 3+ charge = d&lt;sup&gt;5&lt;/sup&gt; (or 3d&lt;sup&gt;5&lt;/sup&gt;)
::  8     -      3    = 5

The same procedure can be applied to any transition metal complex. For example, consider the complex [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;.  Because ammonia is a neutral ligand, Cu is in the 2+ oxidation state.  Copper (II), in group 11 of the periodic table has 11 electrons in its valence shell, minus two, leaving it with 9 d-electrons (3d&lt;sup&gt;9&lt;/sup&gt;). In the neutral complex [Rh(OH)&lt;sub&gt;3&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;3&lt;/sub&gt;], Rh is in the +3 oxidation state and is in group 9, so the electron count is 4d&lt;sup&gt;6&lt;/sup&gt;.   Zinc(II) in group 12 would have 10 d-electrons in [Zn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, a full shell, and manganese (VII) has zero d-electrons in MnO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;.  Nickel carbonyl, Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, contains the neutral CO ligand and Ni in the zero oxidation state.  Since Ni is in group 10, we count the electrons on Ni as 3d&lt;sup&gt;10&lt;/sup&gt;.


A frequent source of confusion about electron counting is the fate of the s-electrons on the metal.  For example, our electron counting rules predict that Ti is 3d&lt;sup&gt;1&lt;/sup&gt; in the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  But the electronic configuration of a free Ti atom, according to the Aufbau principle, is 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;2&lt;/sup&gt;.  Why is the Ti&lt;sup&gt;3+&lt;/sup&gt; ion 3d&lt;sup&gt;1&lt;/sup&gt; and not 4s&lt;sup&gt;1&lt;/sup&gt;? Similarly, why do we assign Mn&lt;sup&gt;2+&lt;/sup&gt; as 3d&lt;sup&gt;5&lt;/sup&gt; rather than 4s&lt;sup&gt;2&lt;/sup&gt;3d&lt;sup&gt;3&lt;/sup&gt;? The short answer is that the metal s orbitals are higher in energy in a metal complex than they are in the free atom because they have antibonding character.  We will justify this statement with a MO diagram in Section 5.2.
&lt;br&gt;&lt;br&gt;
[[w:Covalent_bond_classification_method|'''Covalent Bond Classification (CBC) Method''']].  Although the electron counting rule we have developed above is useful and works reliably for all kinds of complexes, the assignment of all the shared electrons in the complex to the ligands does not always represent the true bonding picture. This picture would be most accurate in the case of ligands that are much more electronegative than the metal.  But in fact, there all all kinds of ligands, including those such as H, alkyl, cyclopentadienide, and others where the metal and ligand have comparable electronegativity.  In those cases, especially with late transition metals that are relatively electronegative, we should regard the metal-ligand bond as covalent.  The CBC method, also referred to as LXZ notation, was introduced in 1995 by [[w:Malcolm Green (chemist)|M. L. H. Green]]&lt;ref&gt;{{cite journal|url = http://www.sciencedirect.com/science/article/pii/0022328X9500508N | doi=10.1016/0022-328X(95)00508-N | volume=500 | title=A new approach to the formal classification of covalent compounds of the elements | year=1995 | journal=Journal of Organometallic Chemistry | pages=127–148 | last1 = Green | first1 = M.L.H.}}&lt;/ref&gt; in order to better describe the different kinds of metal-ligand bonds.  The molecular orbital pictures below summarize the difference between L, X, and Z ligands.&lt;ref&gt;[http://www.columbia.edu/cu/chemistry/groups/parkin/cbc.htm The CBC Method,] Parkin group, Columbia University.&lt;/ref&gt;   Of these, L and X are the most common types.

[[file:CBC_scheme.png|center]]


'''L-type ligands''' are Lewis bases that donate two electrons to the metal center regardless of the electron counting method being used.  These electrons can come from lone pairs, pi or sigma donors.  The bonds formed between these ligands and the metal are dative covalent bonds, which are also known as coordinate bonds.  Examples of this type of ligand include CO, PR&lt;sub&gt;3&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;O, carbenes (=CRR'), and alkenes.

[[File:Cyclopentadiene.png|thumb|Cp|75px]][[File:Ferroceen.png|right|thumb|Ferrocene|75px]]'''X-type ligands''' are those that donate one electron to the metal and accept one electron from the metal when using the neutral ligand method of electron counting, or donate two electrons to the metal when using the donor pair method of electron counting.&lt;ref&gt;Crabtree, Robert. The Organometallic Chemistry of the Transition Metals:4th edition.  Wiley-Interscience, 2005
&lt;/ref&gt;  Regardless of whether it is considered neutral or anionic, these ligands yield normal covalent bonds. A few examples of this type of ligand are H, CH&lt;sub&gt;3&lt;/sub&gt;, halogens, and NO (bent).

'''Z-type ligands''' are those that accept two electrons from the metal center as opposed to the donation occurring with the other two types of ligands.  However, these ligands also form dative covalent bonds like the L-type.  This type of ligand is not usually used, because in certain situations it can be written in terms of L and X.  For example, if a Z ligand is accompanied by an L type, it can be written as X&lt;sub&gt;2&lt;/sub&gt;.  Examples of these ligands are Lewis acids, such as BR&lt;sub&gt;3&lt;/sub&gt;.
&lt;br&gt;&lt;br&gt;
Some multidentate ligands can act as a combination of ligand types. A famous example is the cyclopentadienyl (or Cp) ligand, C&lt;sub&gt;5&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;.  We would classify this neutral ligand as [L&lt;sub&gt;2&lt;/sub&gt;X], with the two L functionalities corresponding to the two “olefinic” fragments while the X functionality corresponds to the CH “radical” carbon in the ring. The addition of one electron makes the Cp&lt;sup&gt;-&lt;/sup&gt; anion, which has six pi electrons and is thus planar and aromatic.  In the ferrocene complex, Cp&lt;sub&gt;2&lt;/sub&gt;Fe, using the &quot;standard&quot; donor pair counting method we can regard the two Cp&lt;sup&gt;-&lt;/sup&gt; ligands as each possessing six pi electrons, and by difference Fe is in the +2 oxidation state.  The Fe&lt;sup&gt;2+&lt;/sup&gt; ion is d&lt;sup&gt;6&lt;/sup&gt;.  Thus the iron atom in the complex (regardless of the counting method) has 6+6+6=18 electrons in its coordination environment, which is a particularly stable electron count for transition metal complexes.

==&amp;#160;&amp;#160;5.2 Crystal field theory==

[[w:crystal_field_theory|Crystal field theory]] is one of the simplest models for explaining the structures and properties of transition metal complexes.  The theory is based on the electrostatics of the metal-ligand interaction, and so its results are only approximate in cases where the metal-ligand bond is substantially covalent.  But because the model makes effective use of molecular symmetry, it can be surprisingly accurate in describing the magnetism, colors, structure, and relative stability of metal complexes.
&lt;br /&gt;

Consider a positvely charged metal ion such as Fe&lt;sup&gt;3+&lt;/sup&gt; in the &quot;field&quot; of six negatively charged ligands, such as CN&lt;sup&gt;-&lt;/sup&gt;.  There are two energetic terms we need to consider.  The first is the '''electrostatic attraction''' between the metal and ligands, which is inversely proportional to the distance between them:

::&lt;math&gt;
E_{elec} = {1\over4\pi\varepsilon_0}\sum_{ligands}{q_Mq_L\over r_{ML}}
&lt;/math&gt;

The second term is the '''repulsion''' that arises from the Pauli exclusion principle when a third electron is added to a filled orbital.  There is no place for this third electron to go except to a higher energy antibonding orbital.  This is the situation when a ligand lone pair approaches an occupied metal d-orbital:
::[[file:ligand-repulsion.png|130px|left]]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;

[[file:crystal-field.png|left|thumb|500px|A Fe&lt;sup&gt;3+&lt;/sup&gt; ion has five d-electrons, one in each of the five d-orbitals.  In a spherical ligand field, the energy of electrons in these orbitals rises because of the repulsive interaction with the ligand lone pairs.  The orbitals split into two energy levels when the ligands occupy the vertices of an octahedron, but the average energy remains the same.]]
Now let us consider the effect of these attractive and repulsive terms as the metal ion and ligands are brought together.  We do this in two steps, first forming a ligand &quot;sphere&quot; around the metal and then moving the six ligands to the vertices of an octahedron.  Initially all five d-orbitals are degenerate, i.e., they have the same energy by symmetry.  In the first step, the antibonding interaction drives up the energy of the orbitals, but they remain degenerate.  In the second step, the d-orbitals split into two symmetry classes, a lower energy, triply-degenerate set (the t&lt;sub&gt;2g&lt;/sub&gt; orbitals) and a higher energy, doubly degenerate set (the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;
&lt;br /&gt;

The '''energy difference''' between the e&lt;sub&gt;g&lt;/sub&gt; and t&lt;sub&gt;2g&lt;/sub&gt; orbitals is given the symbol '''Δ&lt;sub&gt;O&lt;/sub&gt;''', where the &quot;O&quot; stands for &quot;octahedral.&quot;  We will see that this splitting energy is sensitive to the degree of orbital overlap and thus depends on both the metal and the ligand.  Relative to the midpoint energy (the '''barycenter'''), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt; and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are destabilized by 3/5 Δ&lt;sub&gt;O&lt;/sub&gt; in an octahedral complex.
[[File:d-orbital-splitting.png|thumb|left|d-orbitals and their orientation with relation to ligands in an octahedral complex.]]
{{clr}}

What causes the d-orbitals to split into two sets? Recall that the d-orbitals have a specific orientation with respect to the Cartesian axes.  The lobes of the d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;xz&lt;/sub&gt;, and d&lt;sub&gt;yz&lt;/sub&gt; orbitals (the '''t&lt;sub&gt;2g&lt;/sub&gt; orbitals''') lie in the xy-, xz-, and yz-planes, respectively.  These three d-orbitals have '''nodes''' along the x-, y-, and z-directions.  The orbitals that contain the ligand lone pairs are oriented along these axes and therefore have '''zero overlap with the metal t&lt;sub&gt;2g&lt;/sub&gt; orbitals'''.  It is easy to see that these three d-orbitals must be degenerate by symmetry.  On the other hand, the lobes of the d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals (the '''e&lt;sub&gt;g&lt;/sub&gt; orbitals''') point directly along the bonding axes and have strong overlap with the ligand orbitals.  While it is less intuitively obvious, these orbitals  are also degenerate by symmetry and have antibonding character.  
&lt;br /&gt;
&lt;br /&gt;

It is informative to compare the results of '''crystal field theory''' and '''molecular orbital theory''' (also called [[w:ligand_field_theory|'''ligand field theory''']] in this context) for an octahedral transition metal complex.  The energy level diagrams below make this comparison for the d&lt;sup&gt;1&lt;/sup&gt; octahedral ion [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.  In the MO picture at the right, the frontier orbitals are derived from the metal d-orbitals.  The lower t&lt;sub&gt;2g&lt;/sub&gt; set, which contains one electron, is non-bonding by symmetry, and the e&lt;sub&gt;g&lt;/sub&gt; orbitals are antibonding.  The metal 4s orbital, which has a&lt;sub&gt;1g&lt;/sub&gt; symmetry, makes a low energy bonding combination that is ligand-centered, and an antibonding combination that is metal-centered and above the e&lt;sub&gt;g&lt;/sub&gt; levels.  This is the reason that our d-electron counting rules do not need to consider the metal 4s orbital.  The important take-home message is that crystal field theory and MO theory give '''very similar results''' for the frontier orbitals of transition metal complexes.  

[[Image:LFTi(III).png|thumb|400px|Ligand-field diagram for the octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;]. Note that this diagram considers only sigma bonding between the metal ion and the water ligands. For cases in which π-bonding can occur (see Section 5.4), the t&lt;sub&gt;2g&lt;/sub&gt; orbitals are no longer strictly non-bonding.]]&lt;br /&gt;

[[File:d1-octahedral-crystal-field.png|300px|left|thumb|Crystal field energy diagram for the d&lt;sup&gt;1&lt;/sup&gt; octahedral complex [Ti(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;.]]
{{clr}}

==&amp;#160;&amp;#160;5.3 Spectrochemical series==
[[File:Cobalt(II)-nitrate-photo.jpg|290px|right]]

'''Strong and weak field ligands.'''  The [[w:spectrochemical_series|spectrochemical series]] ranks ligands according the '''energy difference Δ&lt;sub&gt;O&lt;/sub&gt;''' between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals in their octahedral complexes.  This energy difference is measured in the spectral transition between these levels, which often lies in the visible part of the spectrum and is responsible for the colors of complexes with partially filled d-orbitals.  Ligands that produce a large splitting are called '''strong field''' ligands, and those that produce a small splitting are called '''weak field''' ligands.  
&lt;br /&gt;

An abbreviated [[w:spectrochemical_series|spectrochemical series]] is: 
&lt;br /&gt;&lt;br /&gt;

'''Weak field''' &amp;nbsp;&amp;nbsp;&amp;nbsp; I&lt;sup&gt;-&lt;/sup&gt; &lt; Br&lt;sup&gt;-&lt;/sup&gt; &lt; Cl&lt;sup&gt;-&lt;/sup&gt; &lt; NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; F&lt;sup&gt;-&lt;/sup&gt; &lt; OH&lt;sup&gt;-&lt;/sup&gt; &lt; H&lt;sub&gt;2&lt;/sub&gt;O &lt; Pyridine &lt; NH&lt;sub&gt;3&lt;/sub&gt; &lt; NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; &lt; CN&lt;sup&gt;-&lt;/sup&gt; &lt; CO &amp;nbsp;&amp;nbsp;&amp;nbsp; '''Strong field''' 


[[file:weak-strong-field.png|300px|left|thumb|Water is a weak field ligand.  The electronegative O atom is strongly electron-withdrawing, so there is poor orbital overlap between the electron pair on O and a metal d-orbital.  The more electropositive C atom in the strong field ligand CN&lt;sup&gt;-&lt;/sup&gt; allows better orbital overlap and sharing of the electron pair.  Note that CN&lt;sup&gt;-&lt;/sup&gt; typically coordinates metal ions through the C atom rather than the N atom.]][[File:Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png|280px|thumb|Cobalt (II) complexes have different colors depending on the nature of the ligand.  In crystals of the red compound cobalt(II) nitrate dihydrate, each cobalt ion is coordinated by six water molecules.  The [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; cations and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; anions crystallize to make a salt.  When the complex is dissolved in water, Co(II) retains its coordination shell of six water molecules and the solution has the same red color as the crystal.]]

'''Orbital overlap.'''  Referring to the molecular orbital diagram above, we see that the splitting between d-electron levels reflects the antibonding interaction between the e&lt;sub&gt;g&lt;/sub&gt; metal orbitals and the ligands.  Thus, we expect ligand field strength to correlate with metal-ligand orbital overlap.  Ligands that bind through very electronegative atoms such as '''O and halogens''' are thus expected to be '''weak field''', and ligands that bind through '''C or P''' are typically '''strong field'''.  Ligands that bind through '''N''' are '''intermediate''' in strength.   Another way to put this is that hard bases tend to be weak field ligands and soft bases are strong field ligands.  


::'''Energy units.'''  Energy can be calculated in a number of ways and it is useful to try to relate the splitting energy Δ&lt;sub&gt;O&lt;/sub&gt; to more familiar quantities like bond energies.

::When Δ&lt;sub&gt;O&lt;/sub&gt; is measured optically, a photon of wavelength λ is absorbed as an electron is promoted from a t&lt;sub&gt;2g&lt;/sub&gt; to an e&lt;sub&gt;g&lt;/sub&gt; orbital.  The photon energy is related to its wavelength and frequency by:

:::E = hν = hc/λ = hc&lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt;

::Here ν is the frequency of the electromagnetic radiation, h is Planck's constant (6.626x10&lt;sup&gt;-34&lt;/sup&gt; J*s), and c is the speed of light.  &lt;math&gt;\scriptstyle\tilde{\nu}&lt;/math&gt; is called the &quot;wavenumber&quot; and is the inverse of the wavelength, usually measured in cm&lt;sup&gt;-1&lt;/sup&gt;.  Energy gaps are often expressed by spectroscopists in terms of wavenumbers.

::For example, a red photon has a wavelength of about 620 nm and a wavenumber of about 16,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  In other energy units, the same red photon has an energy of 2.0 eV (1 eV = 1240 nm) or 193 kJ/mol (1 eV = 96.5 kJ/mol).  If we compare this to the dissociation energy of a carbon-carbon single bond (350 kJ/mol), we see that the C-C bond has about twice the energy of a red photon.  We would need an ultraviolet photon (E &gt; 350 kJ/mol = 3.6 eV = 345 nm = 29,000cm&lt;sup&gt;-1&lt;/sup&gt;) to break a C-C bond.  
&lt;br /&gt;

We will see that Δ&lt;sub&gt;O&lt;/sub&gt; varies widely for transition metal complexes, from near-infrared to ultraviolet wavelengths.  Thus the energy difference between the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals can range between the energy of a rather weak to a rather strong covalent bond. 

'''Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metal and the ligand.'''  We can learn something about trends in Δ&lt;sub&gt;O&lt;/sub&gt; by comparing a series of d&lt;sup&gt;6&lt;/sup&gt; metal complexes:   

:{| class=&quot;wikitable&quot;
|-
! Complex !! Δ&lt;sub&gt;O&lt;/sub&gt; (cm&lt;sup&gt;-1&lt;/sup&gt;)
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; || &lt;center&gt;9,300&lt;/center&gt;
|-
| [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;18,200&lt;/center&gt;
|-
| [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;33,500&lt;/center&gt;
|-
| [Rh(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; || &lt;center&gt;27,000&lt;/center&gt;
|-
| [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || &lt;center&gt;45,500&lt;/center&gt;
|}

'''Important trends in Δ&lt;sub&gt;O&lt;/sub&gt;''':

: '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;2+&lt;/sup&gt;''' complexes with the same ligand.  This reflects the '''electrostatic''' nature of the crystal field splitting.

:'''Rh&lt;sup&gt;3+&lt;/sup&gt;''' complexes have larger Δ&lt;sub&gt;O&lt;/sub&gt; than '''Co&lt;sup&gt;3+&lt;/sup&gt;''' complexes.  In general, elements in the 2nd and 3rd transition series (the '''4d and 5d elements)''' have '''larger splitting''' than those in the 3d series.  

:For a given metal in one oxidation state (e.g., Co&lt;sup&gt;3+&lt;/sup&gt;), the trend in Δ&lt;sub&gt;O&lt;/sub&gt; follows the '''spectrochemical series'''.  Thus Δ&lt;sub&gt;O&lt;/sub&gt; is larger for [Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;, which contains the strong field CN&lt;sup&gt;-&lt;/sup&gt; ligand, than it is for [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; with the weak field ligand H&lt;sub&gt;2&lt;/sub&gt;O.&lt;br /&gt;&lt;br /&gt;

[[File:1g Osmiumtetroxid.jpg|200px|thumb|Both Os and Ru form volatile, molecular tetroxides MO&lt;sub&gt;4&lt;/sub&gt;.  OsO&lt;sub&gt;4&lt;/sub&gt; is used in epoxidation reactions and as a stain in electron microscopy.  In contrast, the highest binary oxide of iron is Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;.]]
'''The 4d and 5d elements are similar in their size and their chemistry.'''  In comparing Δ&lt;sub&gt;O&lt;/sub&gt; values for complexes in the 3d, 4d, and 5d series (e.g., comparing elements in the triads Co,Rh,Ir or Fe,Ru,Os), we always find  3d &lt;&lt; 4d ≲ 5d.  This trend reflects the spatial extent of the d-orbitals and thus their overlap with ligand orbitals.  The 3d orbitals are smaller, and they are less effective in bonding than the 4d or 5d.  The 4d and 5d orbitals are similar to each other because of the [[w:lanthanide_contraction|lanthanide contraction]].  At the beginning of the 5d series (between &lt;sup&gt;56&lt;/sup&gt;Ba and &lt;sup&gt;72&lt;/sup&gt;Hf) are the fourteen lanthanide elements (&lt;sup&gt;57&lt;/sup&gt;La - &lt;sup&gt;71&lt;/sup&gt;Lu).  

Although the valence orbitals of the 5d elements are in a higher principal quantum shell than those of the 4d elements, the addition of 14 protons to the nucleus in crossing the lanthanide series contracts the sizes of the atomic orbitals.  The important result is that the '''valence orbitals of the 4d and 5d elements have similar sizes''' and thus the elements resemble each other in their chemistry much more than they resemble their cousins in the 3d series.  For example, the chemistry of Ru is very similar to that of Os, as illustrated at the right, but quite different from that of Fe.  
&lt;br /&gt;&lt;br /&gt;

'''Colors of transition metal complexes.'''  A simple, qualitative way to see the relative crystal field splitting energy, Δ&lt;sub&gt;O&lt;/sub&gt;, is to observe the color of a transition metal complex. The higher the energy of the absorbed photon, the larger the energy gap. However, the color a complex absorbs is '''complementary''' to the color it appears (i.e., the color of light it reflects), which is '''opposite''' the absorbed color on the color wheel. [[File:color_wheel_wavelengths.png|thumb|left|270px|alt=A color wheel.|Complementary colors are across the color wheel from each other.]] 

'''Examples:''' (all d&lt;sup&gt;7&lt;/sup&gt; Co&lt;sup&gt;2+&lt;/sup&gt; complexes) &lt;br /&gt; 
[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; looks purple in its salts and in concentrated solution because it absorbs in the green range.

[Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is straw-colored because it absorbs in the blue range. 

[Co(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, looks red, absorbs in the violet and ultra-violet part of the spectrum. This is consistent with the idea that CN&lt;sup&gt;-&lt;/sup&gt; is a stronger field ligand than NH&lt;sub&gt;3&lt;/sub&gt;, because the energy of a UV photon is higher than that of a red-orange photon.

This method is applicable to most transition metal complexes, as the majority of them absorb somewhere in the visible range (400-700 nm = 25,000 to 14,300 cm&lt;sup&gt;-1&lt;/sup&gt;), or have UV transitions that tail into the visible, making them appear yellow; however there are complexes such as [Rh(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; that appear colorless because their d-d transitions are in the ultraviolet.  Other complexes such as [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt; are weakly colored because their d-d transitions involve a change in the spin state of the complex.
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;

==&amp;#160;&amp;#160;5.4 π-bonding between metals and ligands==
[[file:d-pi-bonding.png|right|220px]]An important factor that contributes to the high ligand field strength of ligands such as CO, CN&lt;sup&gt;-&lt;/sup&gt;, and phosphines is '''π-bonding''' between the metal and the ligand.  There are three types of pi-bonding in metal complexes: 
[[file:CO-backbonding.png|left|250px]]
The most common situation is when a ligand such as carbon monoxide or cyanide donates its sigma (nonbonding) electrons to the metal, while accepting electron density from the metal through overlap of a metal t&lt;sub&gt;2g&lt;/sub&gt; orbital and a ligand π* orbital.  This situation is called &quot;'''[[w:pi_backbonding|back-bonding]]'''&quot; because the ligand donates σ-electron density to the metal and the metal donates π-electron density to the ligand.  The ligand is thus acting as a '''σ-donor and a π-acceptor.''' In π-backbonding, the metal donates π electrons to the ligand π* orbital, adding electron density to an ''antibonding'' molecular orbital. This results in weakening of the C-O bond, which is experimentally observed as lengthening of the bond (relative to free CO in the gas phase) and lowering of the C-O infrared stretching frequency. 

'''d-d π bonding''' occurs when an element such phosphorus, which has a σ-symmetry lone pair and an empty 3d orbital, binds to a metal that has electrons in a t&lt;sub&gt;2g&lt;/sub&gt; orbital.  This is a common situation for phosphine complexes (e.g., triphenylphosphine) bound to low-valent, late transition metals.  The backbonding in this case is analogous to the CO example, except that the acceptor orbital is a phosphorus 3d orbital rather than a ligand π* orbital.  Here the phosphine ligand acts as a σ-donor and a π-acceptor, forming a dπ-dπ bond. 

The third kind of metal-ligand π-bonding occurs when a '''π-donor ligand''' - an element with both a σ-symmetry electron pair and a filled orthogonal p-orbital - bonds to a metal, as shown above at the right for an O&lt;sup&gt;2-&lt;/sup&gt; ligand.  This occurs in early transition metal complexes. In this example, '''O&lt;sup&gt;2-&lt;/sup&gt;''' is acting as both a '''σ-donor and a π-donor'''.  This interaction is typically drawn as a metal-ligand multiple bond, e.g., the V=O bond in the [[w:vanadyl_ion|vanadyl]] cation [VO]&lt;sup&gt;2+&lt;/sup&gt;.  Typical π-donor ligands are oxide (O&lt;sup&gt;2-&lt;/sup&gt;), nitride (N&lt;sup&gt;3-&lt;/sup&gt;), imide (RN&lt;sup&gt;2-&lt;/sup&gt;), alkoxide (RO&lt;sup&gt;-&lt;/sup&gt;), amide (R&lt;sub&gt;2&lt;/sub&gt;N&lt;sup&gt;-&lt;/sup&gt;), and fluoride (F&lt;sup&gt;-&lt;/sup&gt;).  For late transition metals, strong π-donors form anti-bonding interactions with the filled d-levels, with consequences for spin state, redox potentials, and ligand exchange rates.  π-donor ligands are low in the spectrochemical series.&lt;ref&gt;&quot;Metal–Ligand Multiple Bonds: The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Alkylidene, or Alkylidyne Ligands&quot; W. A. Nugent and J. M. Mayer; Wiley-Interscience, New York, 1988.&lt;/ref&gt; 
[[Image:MetathesisROMPSchrock1993.svg|450px|left|thumb|A chiral Schrock catalyst polymerizes a norbornadiene derivative to a highly stereoregular isotactic polymer.&lt;ref&gt;{{cite journal | last1 = McConville | first1 = David H. | last2 = Wolf | first2 = Jennifer R. | last3 = Schrock | first3 = Richard R. | title = Synthesis of chiral molybdenum ROMP initiators and all-cis highly tactic poly(2,3-(R)2norbornadiene) (R = CF&lt;sub&gt;3&lt;/sub&gt; or CO&lt;sub&gt;2&lt;/sub&gt;Me) | journal = J. Am. Chem. Soc. | volume = 115 | issue=10 | pages = 4413–4414 | year = 1993 | doi = 10.1021/ja00063a090}}&lt;/ref&gt;]][[Image:MetathesisGrubbs1992.svg|350px|thumb|Synthesis of a Grubbs olefin metathesis catalyst.&lt;ref&gt;{{cite journal | last1 = Nguyen | first1 = Sonbinh T. | last2 = Johnson | first2 = Lynda K. | last3 = Grubbs | first3 = Robert H. | last4 = Ziller | first4 = Joseph W. | title = Ring-opening metathesis polymerization (ROMP) of norbornene by a Group VIII carbene complex in protic media | journal = J. Am. Chem. Soc. | volume = 114 | issue=10 | pages = 3974–3975 | year = 1992 | doi = 10.1021/ja00036a053}}&lt;/ref&gt;]]Carbon-containing ligands that are π-donors and their complexes with transition metal ions are very important in [[w:olefin_metathesis|'''olefin metathesis''']], a reaction in which carbon-carbon double bonds are interchanged.  Using these catalysts, cyclic olefins can be transformed into linear polymers in high yield through ring-opening metathesis polymerization (ROMP).  Catalysts of this kind were developed by the groups of Richard Schrock and Robert Grubbs, who shared the 2005 Nobel Prize in Chemistry with Yves Chauvin for their discoveries.  The Schrock catalysts are based on early transition metals such as Mo; they are more reactive but less tolerant of different organic functional groups and protic solvents than the Grubbs catalysts, which are based on Ru complexes.
&lt;br /&gt;
&lt;br /&gt;

==&amp;#160;&amp;#160;5.5 Crystal field stabilization energy, pairing, and Hund's rule==
The splitting of the d-orbitals into different energy levels in transition metal complexes has important consequences for their stability, reactivity, and magnetic properties.  Let us first consider the simple case of the octahedral complexes [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;, where M = Ti, V, Cr.  Because the complexes are octahedral, they all have the same energy level diagram:

[[file:M3+cfse.png|left|500px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[file:Cr2+cfse.png|270px]]
&lt;br /&gt;

The Ti&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, and Cr&lt;sup&gt;3+&lt;/sup&gt; complexes have one, two and three d-electrons respectively, which fill the degenerate t&lt;sub&gt;2g&lt;/sub&gt; orbitals singly.  The spins align parallel according to Hund's rule, which states that the lowest energy state has the highest spin angular momentum.  
&lt;br /&gt;

For each of these complexes we can calculate a '''crystal field stabilization energy, CFSE''', which is the energy difference between the complex in its ground state and in a hypothetical state in which all five d-orbitals are at the energy barycenter.  

:For Ti&lt;sup&gt;3+&lt;/sup&gt;, there is one electron stabilized by 2/5 Δ&lt;sub&gt;O&lt;/sub&gt;, so CFSE = -(1)(2/5)(Δ&lt;sub&gt;O&lt;/sub&gt;) = -2/5 Δ&lt;sub&gt;O&lt;/sub&gt;.  
:Similarly, CFSE = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt; and -6/5 Δ&lt;sub&gt;O&lt;/sub&gt; for V&lt;sup&gt;3+&lt;/sup&gt; and Cr&lt;sup&gt;3+&lt;/sup&gt;, respectively.
&lt;br /&gt;
For Cr&lt;sup&gt;2+&lt;/sup&gt; complexes, which have four d-electrons, the situation is more complicated.  Now we can have a high spin configuration (t&lt;sup&gt;2g&lt;/sup&gt;)&lt;sup&gt;3&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt;, or a low spin configuration (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;4&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;0&lt;/sup&gt; in which two of the electrons are paired.  What are the energies of these two states?
&lt;br /&gt;
:High spin:  CFSE = (-3)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -3/5 Δ&lt;sub&gt;O&lt;/sub&gt;
:Low spin:   CFSE = (-4)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + P = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P, where P is the '''pairing energy'''

:Energy difference = -8/5 Δ&lt;sub&gt;O&lt;/sub&gt; + P - (-3/5 Δ&lt;sub&gt;O&lt;/sub&gt;) = '''-Δ&lt;sub&gt;O&lt;/sub&gt; + P'''
&lt;br /&gt;
The '''pairing energy P''' is the energy penalty for putting two electrons in the same orbital, resulting from the electrostatic repulsion between electrons.  For 3d elements, a typical value of P is about 15,000 cm&lt;sup&gt;-1&lt;/sup&gt;.
&lt;br /&gt;
&lt;br /&gt;

&lt;big&gt;The important result here is that a complex will be '''low spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &gt; P''', and '''high spin''' if '''Δ&lt;sub&gt;O&lt;/sub&gt; &lt; P'''.&lt;/big&gt;  
&lt;br /&gt;
&lt;br /&gt;

Because Δ&lt;sub&gt;O&lt;/sub&gt; depends on both the metals and the ligands, it determines the spin state of the complex.[[file:high-low-spin-Co2+.png|170px|right|thumb|d-orbital energy diagrams for high and low spin Co&lt;sup&gt;2+&lt;/sup&gt; complexes, d&lt;sup&gt;7&lt;/sup&gt;]]
Rules of thumb:
:'''3d''' complexes are '''high spin''' with '''weak field''' ligands and '''low spin''' with '''strong field''' ligands.
:'''High valent 3d''' complexes (e.g., Co&lt;sup&gt;3+&lt;/sup&gt; complexes) tend to be '''low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)
:'''4d and 5d''' complexes are '''always low spin''' (large Δ&lt;sub&gt;O&lt;/sub&gt;)

Note that high and low spin states occur only for 3d metal complexes with between 4 and 7 d-electrons.  Complexes with 1 to 3 d-electrons can accommodate all electrons in individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set. Complexes with 8, 9, or 10 d-electrons will always have completely filled t&lt;sub&gt;2g&lt;/sub&gt; orbitals and 2-4 electrons in the e&lt;sub&gt;g&lt;/sub&gt; set.
&lt;br /&gt;

'''Examples of high and low spin complexes:''' 

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;] contains a d&lt;sup&gt;7&lt;/sup&gt; metal ion with a weak field ligand.  This complex is known to be high spin from magnetic susceptibility measurements, which detect three unpaired electrons per molecule.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;5&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;2&lt;/sup&gt;.  
:We can calculate the CFSE as -(5)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (2)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; = -4/5 Δ&lt;sub&gt;O&lt;/sub&gt;.

:[Co(CN)&lt;sub&gt;6&lt;/sub&gt;&lt;sup&gt;4-&lt;/sup&gt;] is also an octahedral d&lt;sup&gt;7&lt;/sup&gt; complex but it contains CN&lt;sup&gt;-&lt;/sup&gt;, a strong field ligand.  Its orbital occupancy is (t&lt;sub&gt;2g&lt;/sub&gt;)&lt;sup&gt;6&lt;/sup&gt;(e&lt;sub&gt;g&lt;/sub&gt;)&lt;sup&gt;1&lt;/sup&gt; and it therefore has one unpaired electron.  
:In this case the CFSE is -(6)(2/5)Δ&lt;sub&gt;O&lt;/sub&gt; + (1)(3/5)Δ&lt;sub&gt;O&lt;/sub&gt; + 3P = -9/5 Δ&lt;sub&gt;O&lt;/sub&gt; + 3P(For 3 paired electrons).
&lt;br /&gt;

'''Magnetism of transition metal complexes'''&lt;br /&gt;
Compounds with '''unpaired electrons''' have an inherent magnetic moment that arises from the '''electron spin'''.  Such compounds interact strongly with applied magnetic fields.  Their [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] provides a simple way to measure the number of unpaired electrons in a transition metal complex.
&lt;br /&gt;&lt;br /&gt;
If a transition metal complex has no unpaired electrons, it is [[w:diamagnetism|'''diamagnetic''']] and is weakly repelled from the high field region of an inhomogeneous magnetic field.  Complexes with unpaired electrons are typically [[w:paramagnetism|'''paramagnetic''']].  The spins in paramagnets align independently in an applied magnetic field but do not align spontaneously in the absence of a field.  Such compounds are attracted to a magnet, i.e., they are drawn into the high field region of an inhomogeneous field.  The attractive force, which can be measured with a [[w:Gouy_balance|'''Guoy balance''']] or a [[w:magnetometer|'''SQUID magnetometer''']], is proportional to the [[w:Magnetic_susceptibility|'''magnetic susceptibility''']] ('''χ''') of the complex.&lt;br /&gt;
&lt;br /&gt;
The effective '''magnetic moment''' of an ion ('''µ&lt;sub&gt;eff&lt;/sub&gt;'''), in the absence of spin-orbit coupling, is given by the sum of its spin and orbital moments:

:'''µ&lt;sub&gt;eff&lt;/sub&gt; = µ&lt;sub&gt;spin&lt;/sub&gt; + µ&lt;sub&gt;orbital&lt;/sub&gt; = µ&lt;sub&gt;s&lt;/sub&gt; + µ&lt;sub&gt;L&lt;/sub&gt;'''

In octahedral 3d metal complexes, the orbital angular momentum is largely &quot;quenched&quot; by symmetry, so we can approximate:
: '''µ&lt;sub&gt;eff&lt;/sub&gt; ≈ µ&lt;sub&gt;s&lt;/sub&gt;'''  

We can calculate µ&lt;sub&gt;s&lt;/sub&gt; from the number of unpaired electrons (n) using:

:&lt;math&gt;\mu_{eff}= \sqrt{n(n+2)} \mu_B&lt;/math&gt;

Here µ&lt;sub&gt;B&lt;/sub&gt; is the [[w:bohr_magneton|'''Bohr magneton''']] (= eh/4πm&lt;sub&gt;e&lt;/sub&gt;) = 9.3 x 10&lt;sup&gt;-24&lt;/sup&gt; J/T.  This spin-only formula is a good approximation for first-row transition metal complexes, especially high spin complexes.  The table below compares calculated and experimentally measured values of µ&lt;sub&gt;eff&lt;/sub&gt; for octahedral complexes with 1-5 unpaired electrons.

:{|class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
!Ion!!Number of &lt;br/&gt;unpaired&lt;br/&gt;electrons!!Spin-only&lt;br/&gt; moment /μ&lt;sub&gt;B&lt;/sub&gt;!!observed&lt;br/&gt;moment /μ&lt;sub&gt;B&lt;/sub&gt;
|-
|Ti&lt;sup&gt;3+&lt;/sup&gt; ||1||1.73||1.73
|-
|V&lt;sup&gt;4+&lt;/sup&gt;||1 || ||1.68–1.78
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt; ||1 || ||1.70–2.20
|-
|V&lt;sup&gt;3+&lt;/sup&gt;||2||2.83||2.75–2.85
|-
|Ni&lt;sup&gt;2+&lt;/sup&gt;||2|| ||2.8–3.5
|-
|V&lt;sup&gt;2+&lt;/sup&gt; ||3||3.87||3.80–3.90
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt; ||3|| ||3.70–3.90
|-
|Co&lt;sup&gt;2+&lt;/sup&gt; ||3|| ||4.3–5.0
|-
|Mn&lt;sup&gt;4+&lt;/sup&gt; ||3|| ||3.80–4.0
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt; ||4||4.90 ||4.75–4.90
|-
|Fe&lt;sup&gt;2+&lt;/sup&gt; ||4 || ||5.1–5.7
|-
|Mn&lt;sup&gt;2+&lt;/sup&gt; ||5||5.92 ||5.65–6.10
|-
|Fe&lt;sup&gt;3+&lt;/sup&gt; ||5|| ||5.7–6.0
|}
The small deviations from the spin-only formula for these octahedral complexes can result from the neglect of orbital angular momentum or of spin-orbit coupling. Tetrahedral d&lt;sup&gt;3&lt;/sup&gt;, d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;8&lt;/sup&gt; and d&lt;sup&gt;9&lt;/sup&gt; complexes tend to show larger deviations from the spin-only formula than octahedral complexes of the same ion because quenching of the orbital contribution is less effective in the tetrahedral case.&lt;br /&gt;

'''Summary of rules for high and low spin complexes:'''[[file:CFSE_DH.png|right|300px]]
:'''3d complexes:'''  Can be high or low spin, depending on the ligand (d&lt;sup&gt;4&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, d&lt;sup&gt;6&lt;/sup&gt;, d&lt;sup&gt;7&lt;/sup&gt;)
:'''4d and 5d complexes:'''  Always low spin, because Δ&lt;sub&gt;O&lt;/sub&gt; is large
: '''Maximum CFSE''' is for d&lt;sup&gt;3&lt;/sup&gt; and d&lt;sup&gt;8&lt;/sup&gt; cases (e.g., Cr&lt;sup&gt;3+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;) with weak field ligands (H&lt;sub&gt;2&lt;/sub&gt;O, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;,...) and for d&lt;sup&gt;3&lt;/sup&gt;-d&lt;sup&gt;6&lt;/sup&gt; with strong field ligands (Fe&lt;sup&gt;2+&lt;/sup&gt;, Ru&lt;sup&gt;2+&lt;/sup&gt;, Os&lt;sup&gt;2+&lt;/sup&gt;, Co&lt;sup&gt;3+&lt;/sup&gt;, Rh&lt;sup&gt;3+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt;,...)
:[[w:Irving–Williams_series|'''Irving-Williams series.''']]  For M&lt;sup&gt;2+&lt;/sup&gt; complexes, the stability of the complex follows the order Mg&lt;sup&gt;2+&lt;/sup&gt; &lt; Mn&lt;sup&gt;2+&lt;/sup&gt; &lt; Fe&lt;sup&gt;2+&lt;/sup&gt; &lt; Co&lt;sup&gt;2+&lt;/sup&gt; &lt; Ni&lt;sup&gt;2+&lt;/sup&gt; &lt; Cu&lt;sup&gt;2+&lt;/sup&gt; &gt; Zn&lt;sup&gt;2+&lt;/sup&gt;.  This trend represents increasing Lewis acidity as the ions become smaller (going left to right in the periodic table) as well as the trend in CFSE.  This same trend is reflected in the hydration enthalpy of gas-phase M&lt;sup&gt;2+&lt;/sup&gt; ions, as illustrated in the graph at the right.  Note that Ca&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;, and Zn&lt;sup&gt;2+&lt;/sup&gt;, which are d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;(high spin), and d&lt;sup&gt;10&lt;/sup&gt; aquo ions, respectively, all have zero CFSE and fall on the same line.  Ions that deviate the most from the line such as Ni&lt;sup&gt;2+&lt;/sup&gt; (octahedral d&lt;sup&gt;8&lt;/sup&gt;) have the highest CFSE.
&lt;br /&gt;
[[File:Vanadiumoxidationstates.jpg|thumb|right|upright|From left: [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (lilac), [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (green), [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (blue) and [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; (yellow).]]
'''Colors and spectra of transition metal complexes'''&lt;br /&gt;
Transition metal complexes often have beautiful colors because, as noted above, their d-d transition energies can be in the visible part of the spectrum.  With octahedral complexes these colors are faint (the transitions are weak) because they violate the [[w:Laporte_rule|Laporte selection rule]].  According to this rule, g -&gt; g and u -&gt; u transitions are forbidden in centrosymmetric complexes.  d-orbitals have g (gerade) symmetry, so d-d transitions are Laporte-forbidden.  However octahedral complexes can absorb light when they momentarily distort away from centrosymmetry as the molecule vibrates.  Spin flips are also forbidden in optical transitions by the spin selection rule, so the excited state will always have the same spin multiplicity as the ground state.
&lt;br /&gt;
&lt;br /&gt;
The spectra of even the simplest transition metal complexes are rather complicated because of the many possible ways in which the d-electrons can fill the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  For example, if we consider a d&lt;sup&gt;2&lt;/sup&gt; complex such as V&lt;sup&gt;3+&lt;/sup&gt;(aq), we know that the two electrons can reside in any of the five d-orbitals, and can either be spin-up or spin-down.  There are actually 45 different such arrangements (called '''microstates''') that do not violate the Pauli exclusion principle for a d&lt;sup&gt;2&lt;/sup&gt; complex.  Usually we are concerned only with the six of lowest energy, in which both electrons occupy individual orbitals in the t&lt;sub&gt;2g&lt;/sub&gt; set and all their spins are aligned either up or down.&lt;br /&gt;&lt;br /&gt;
[[file:Cr(hexammine)3+.png|300px|left|thumb|The UV-visible spectrum of [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; shows two weak absorption bands, both corresponding to d-d transitions from the t&lt;sub&gt;2g&lt;/sub&gt; to e&lt;sub&gt;g&lt;/sub&gt; orbitals.]]
We can see how these microstates play a role in electronic spectra when we consider the d-d transitions of the [Cr(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion.  This ion is d&lt;sup&gt;3&lt;/sup&gt;, so each of the three t&lt;sub&gt;2g&lt;/sub&gt; orbitals contains one unpaired electron.  We expect to see a transition when one of the three electrons in the t&lt;sub&gt;2g&lt;/sub&gt; orbitals is excited to an empty e&lt;sub&gt;g&lt;/sub&gt; orbital.  Interestingly, we find not one but '''two''' transitions in the visible.&lt;br /&gt;
&lt;br /&gt;
The reason that we see two transitions is that the electron can come from any one of the t&lt;sub&gt;2g&lt;/sub&gt; orbitals and end up in either of the e&lt;sub&gt;g&lt;/sub&gt; orbitals.  Let us assume for the sake of argument that the electron is initially in the d&lt;sub&gt;xy&lt;/sub&gt; orbital.  It can be excited to either the d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; or the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbital:
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;(higher energy)
:d&lt;sub&gt;xy&lt;/sub&gt; --&gt; d&lt;sub&gt;x&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;sub&gt;2&lt;/sub&gt; &amp;nbsp;&amp;nbsp; (lower energy)
The first transition is at higher energy (shorter wavelength) because in the excited state the configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;).  All three of the excited state orbitals have some z-component, so the d-electron density is &quot;piled up&quot; along the z-axis.  The energy of this transition is thus increased by '''electron-electron repulsion'''.  In the second case, the excited state configuration is (d&lt;sub&gt;yz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;xz&lt;/sub&gt;&lt;sup&gt;1&lt;/sup&gt;d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sup&gt;1&lt;/sup&gt;), and the d-electrons are more symmetrically distributed around the metal.  This effect is responsible for a splitting of the d-d bands by about 8,000 cm&lt;sup&gt;-1&lt;/sup&gt;.  We can show that all other possible transitions are equivalent to one of these two by symmetry, and hence we see only two visible absorption bands for Cr&lt;sup&gt;3+&lt;/sup&gt; complexes.


==&amp;#160;&amp;#160;5.6 Non-octahedral complexes==
[[File:octa-to-sq.png|left|600px|thumb|Crystal field energy diagram showing the transition from octahedral to square planar geometry]][[File:Cisplatin-3D-balls.png |right|170px|thumbnail|cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, a 5d&lt;sup&gt;8&lt;/sup&gt; square planar complex]]The most important non-octahedral geometries for transition metal complexes are:
:'''4-coordinate:'''  square planar and tetrahedral
:'''5-coordinate:'''  square pyramidal and trigonal bipyramidal


[[File:Nci-vol-8173-300_barnett_rosenberg.jpg|right|170px|thumb|[[w:Barnett_Rosenberg|Barnett Rosenberg]] (Michigan State University) accidentally discovered the biological effects of square planar cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt; while researching bacterial growth in electric fields.&lt;ref&gt;{{cite journal | author = Rosenberg B, Vancamp L, Trosco JE, Mansour VH | title = Platinum compounds - a new class of potent antitumour agents | journal = Nature | volume = 222 | issue = 5191 | pages = 385-386 | year = 1969 | doi = 10.1038/222385a0 }}&lt;/ref&gt;  The Pt electrode he used reacted with chloride and ammonium ions in the electrolyte to produce the compound at 1-10 ppm concentration.  Further experiments revealed that the cis-isomer (but not the trans-isomer) is a potent anti-cancer drug which is especially effective against testicular cancer.  The drug works by cross-linking guanine-cytosine rich regions of DNA, thus inhibiting cell division.]][[File:Geoffrey_Wilkinson_ca._1976.png|right|170px|thumb|Sir [[w:Geoffrey_Wilkinson|Geoffrey Wilkinson]], an inorganic chemist at Imperial College London, developed Wilkinson's catalyst in 1966. Earlier, as an Assistant Professor at Harvard University, he had elucidated the sandwich structure of [[w:ferrocene|ferrocene]],&lt;ref&gt;{{cite journal |author = G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward |title = The Structure of Iron Bis-Cyclopentadienyl |journal = Journal of the American Chemical Society |year = 1952|volume = 74 |pages = 2125–2126 |doi = 10.1021/ja01128a527 |issue = 8}}&lt;/ref&gt; which had been discovered a few years before but not understood.  Wilkinson was awarded the Nobel Prize in Chemistry in 1973 for his contributions to organometallic chemistry.]]


'''Energies of the d-orbitals in non-octahedral geometries.'''  The figure at the left shows what happens to the d-orbital energy diagram as we progressively distort an octahedral complex by elongating it along the z-axis (a '''tetragonal distortion'''), by removing one of its ligands to make a '''square pyramid''', or by removing both of the ligands along the z-axis to make a '''square planar''' complex.  In all cases, we keep the total bond order the same by making the bonds in the xy plane shorter as the bonds in the z-direction are stretched and/or broken.
&lt;br /&gt;
&lt;br /&gt;
The distortion away from octahedral symmetry breaks the degeneracy of the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; orbitals.  d-orbitals with a z-axis component (d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) go down in energy as orbitals that reside in the xy plane (d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) rise in energy.  The barycenter (the weighted average orbital energy) remains constant.  Also, it is important to note that the splitting between the d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals is constant at Δ&lt;sub&gt;O&lt;/sub&gt; regardless of the nature of the distortion. In the square planar geometry, the energies of the d&lt;sub&gt;xz&lt;/sub&gt; d&lt;sub&gt;yz&lt;/sub&gt;, d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;, d&lt;sub&gt;xy&lt;/sub&gt;, and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals are -0.51, -0.40, +0.21, and +1.21 (in units of Δ&lt;sub&gt;O&lt;/sub&gt;), respectively.
&lt;br /&gt;&lt;br /&gt;
Why would a &quot;happy&quot; octahedral complex want to lose two of its ligands to make a '''square planar''' complex?  This occurs frequently in d&lt;sup&gt;8&lt;/sup&gt; and sometimes in d&lt;sup&gt;9&lt;/sup&gt; complexes with large Δ&lt;sub&gt;O&lt;/sub&gt;, i.e., '''3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands and 4d&lt;sup&gt;8&lt;/sup&gt;, 5d&lt;sup&gt;8&lt;/sup&gt; complexes with any ligands'''.  Examples of such d&lt;sup&gt;8&lt;/sup&gt; complexes are [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, the anti-cancer drug cisplatin (cis-Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;), [Pd(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, and [AuCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;.  At the d&lt;sup&gt;8&lt;/sup&gt; electron count, the lowest four orbitals are filled and the highest orbital (the d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;) is empty, resulting in a large CFSE (2.4 Δ&lt;sub&gt;O&lt;/sub&gt;, vs. 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; for octahedral d&lt;sup&gt;8&lt;/sup&gt;). This difference of 1.2 Δ&lt;sub&gt;O&lt;/sub&gt; more than offsets the pairing energy for 4d&lt;sup&gt;8&lt;/sup&gt; and 5d&lt;sup&gt;8&lt;/sup&gt; complexes, and for 3d&lt;sup&gt;8&lt;/sup&gt; complexes with strong field ligands.  These square planar complexes are diamagnetic and tend to be quite stable.  With weak field ligands, 3d&lt;sup&gt;8&lt;/sup&gt; complexes are octahedral and paramagnetic (e.g., [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which has two unpaired electrons in the e&lt;sub&gt;g&lt;/sub&gt; orbitals).&lt;br /&gt;&lt;br /&gt;

&lt;br /&gt;
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'''Square planar complexes in catalysis:'''&lt;br /&gt;

[[File:Catalitic cycle for hydrogenation with Wilkinson's catalyst.svg|left|400px]]Square planar d&lt;sup&gt;8&lt;/sup&gt; complexes can be oxidized by two electrons to become octahedral (low spin) d&lt;sup&gt;6&lt;/sup&gt; complexes, which also have a large CFSE.  Because the loss of two electrons is accompanied by the gain of two ligands, this process is called '''oxidative addition'''.  The reverse process is called '''reductive elimination.'''  Both processes function together in catalytic cycles, such as the hydrogenation of olefins using [[w:Wilkinson's_catalyst|'''Wilkinson's catalyst''']].&lt;ref&gt;{{cite journal|author=Osborn, J. A.; Jardine, F. H.; Young, J. F.; Wilkinson, G.| title=The Preparation and Properties of Tris(triphenylphosphine)halogenorhodium(I) and Some Reactions Thereof Including Catalytic Homogeneous Hydrogenation of Olefins and Acetylenes and Their Derivatives| journal= Journal of the Chemical Society A | year = 1966 | pages = 1711–1732 | doi = 10.1039/J19660001711}}&lt;/ref&gt;&lt;ref&gt;&quot;Tris(triphenylphosphine)halorhodium(I)&quot;  J. A. Osborn, G. Wilkinson, Inorganic Syntheses, 1967, Volume 10, p. 67. DOI 10.1002/9780470132418.ch12&lt;/ref&gt;  The catalytic cycle is shown at the left.  
&lt;br /&gt;

The catalyst cycles between 4-coordinate Rh(I) (4d&lt;sup&gt;8&lt;/sup&gt;) and 6-coordinate Rh(III) (4d&lt;sup&gt;6&lt;/sup&gt;).  The complex first adds H&lt;sub&gt;2&lt;/sub&gt; oxidatively, to give a six-coordinate complex in which the hydrogen is formally H&lt;sup&gt;-&lt;/sup&gt;.  An olefin molecule displaces a solvent molecule, using its π-electrons to coordinate the metal.  The complex rearranges by inserting the olefin into the metal-hydrogen bond, a process called '''migratory insertion'''.  Finally, the complex returns to the square planar geometry by eliminating the hydrogenated olefin (reductive elimination).  Wilkinson's catalyst is highly active and is widely used for homogeneous hydrogenation, hydroboration, and hydrosilation reactions.&lt;ref&gt;{{cite journal | author = D. A. Evans, G. C. Fu and A. H. Hoveyda | title = Rhodium(I)-catalyzed hydroboration of olefins. The documentation of regio- and stereochemical control in cyclic and acyclic systems | year = 1988 | journal = J. Am. Chem. Soc. | volume = 110 | issue = 20 | pages = 6917–6918 | doi=10.1021/ja00228a068}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | author = I. Ojima, T. Kogure | journal = Tetrahedron Lett. | year = 1972 | volume = 13 | issue = 49 | pages = 5035–5038 | doi = 10.1016/S0040-4039(01)85162-5 | title = Selective reduction of α,β-unsaturated terpene carbonyl compounds using hydrosilane-rhodium(I) complex combinations}}&lt;/ref&gt;  With chiral phosphine ligands, the catalyst can hydrogenate prochiral olefins to give enantiomerically pure products.&lt;ref&gt;{{cite journal | author = W. S. Knowles | title = Asymmetric Hydrogenations (Nobel Lecture 2001) | journal = Advanced Synthesis and Catalysis | year = 2003 | volume = 345 | issue = 12 | pages = 3–13 | doi = 10.1002/adsc.200390028 }}&lt;/ref&gt; With chiral tridentate ligands that occupy three of the four coordination sites of the square planar complex, very high yields of enantiometrically pure hydrogenation products can be produced. Analogous chiral Ir(I) complexes catalyze the hydrogenation of prochiral ketones to chiral primary alcohols, an important step in the production of many chiral pharmaceutical compounds.&lt;ref&gt;{{cite journal | author = J. Yu, J. Long, W. Wu., P. Xue, and X. Zhang | title = Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands | journal = Organic Letters | year = 2017 | volume = 19 | issue = 3 | pages = 690-693 | doi = 10.1021/acs.orglett.6b03862 }}&lt;/ref&gt; 

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[[File:Dicyanoaurate(I)-3D-vdW.png|Dicyanoaurate(I)-3D-vdW|right|200px]]
'''Linear ML&lt;sub&gt;2&lt;/sub&gt; complexes.'''  Cu(I), Ag(I), and Au(I) ions form linear ML&lt;sub&gt;2&lt;/sub&gt; complexes with both weak and strong field ligands. For example, air oxidation of gold or silver metal occurs in the presence of cyanide salts, forming [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; or [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;, and this redox reaction is exploited in mining these precious metals. Insoluble Ag(I) compounds, e.g., AgCl, can be solubilized in ammonia solutions to make soluble linear complexes such as [Ag(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;

The linear coordination geometry arises from hybridization of s and d orbitals.  For example, in the [Au(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; ion shown above, hybrids of the 5d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; and 6s orbitals each contain one electron and are directed along the z-axis, similar to the way in which p&lt;sub&gt;z&lt;/sub&gt; and s orbitals are hybridized in molecules such as HC≡CH. In these linear complexes, the crystal field splits into three levels, with the filled d&lt;sub&gt;xy&lt;/sub&gt; and d&lt;sub&gt;x&lt;sup&gt;2&lt;/sup&gt;-y&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbitals lowest in energy, the filled d&lt;sub&gt;xz&lt;/sub&gt; and d&lt;sub&gt;yz&lt;/sub&gt; at intermediate energy, and the half-filled d&lt;sub&gt;z&lt;sup&gt;2&lt;/sup&gt;&lt;/sub&gt; orbital highest.  Back bonding between the d&lt;sub&gt;xz&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt; orbitals and CN&lt;sup&gt;-&lt;/sup&gt; π* orbitals also occurs, further stabilizing the complex. &lt;ref&gt;M. De Santis et al., The Chemical Bond and s−d Hybridization in Coinage Metal(I) Cyanides, Inorg. Chem. 2019, 58, 11716−11729. https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.9b01694&lt;/ref&gt;&lt;ref&gt;N. Zhang, J. Kou, and C. Sun, Investigation on Gold–Ligand Interaction for Complexes from Gold Leaching: A DFT Study, Molecules 2023, 28, 1508. https://doi.org/10.3390/molecules28031508&lt;/ref&gt;

==&amp;#160;&amp;#160;5.7 Jahn-Teller effect==
[[File:Jahn-Teller effect.svg|left|250px|thumb|Jahn-Teller distortion of a d&lt;sup&gt;9&lt;/sup&gt; octahedral transition metal complex.  The tetragonal distortion lengthens the bonds along the z-axis as the bonds in the x-y plane become shorter.  This change lowers the overall energy, because the two electrons in the d&lt;sub&gt;z2&lt;/sub&gt; orbital go down in energy as the one electron in the d&lt;sub&gt;x2-y2&lt;/sub&gt; orbital goes up.]] The '''Jahn–Teller effect''', sometimes also known as '''Jahn–Teller distortion''', describes the geometrical distortion of molecules and ions that is associated with certain electron configurations. This electronic effect is named after [[w:Hermann Arthur Jahn|Hermann Arthur Jahn]] and [[w:Edward Teller|Edward Teller]], who proved, using [[w:group theory|group theory]], that orbitally degenerate molecules ''cannot'' be stable.&lt;ref&gt;{{cite journal | author = [[w:Hermann Arthur Jahn|H. Jahn]] and [[w:Edward Teller|E. Teller]] | title = Stability of Polyatomic Molecules in Degenerate Electronic States. I. Orbital Degeneracy | year = 1937 | journal = Proceedings of the Royal Society A | volume = 161 | issue = 905 | pages = 220–235 | doi = 10.1098/rspa.1937.0142|bibcode = 1937RSPSA.161..220J }}&lt;/ref&gt; The '''Jahn–Teller theorem''' essentially states that any non-linear molecule with a spatially [[w:degenerate energy level|degenerate]] electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the molecule.
&lt;br /&gt;
We can understand this effect in the context of octahedral metal complexes by considering d-electron configurations in which the '''e&lt;sub&gt;g&lt;/sub&gt;''' orbital set contains '''one or three electrons'''.  The most common of these are high spin d&lt;sup&gt;4&lt;/sup&gt; (e.g., CrF&lt;sub&gt;2&lt;/sub&gt;) , low spin d&lt;sup&gt;7&lt;/sup&gt; (e.g.,NaNiO&lt;sub&gt;2&lt;/sub&gt;), and d&lt;sup&gt;9&lt;/sup&gt; (e.g., Cu&lt;sup&gt;2+&lt;/sup&gt;). If the complex can distort to break the symmetry, then one of the (formerly) degenerate e&lt;sub&gt;g&lt;/sub&gt; orbitals will go down in energy and the other will go up.  More electrons will occupy the lower orbital than the upper one, resulting in an overall lowering of the electronic energy.  A similar distortion can occur in tetrahedral complexes when the t&lt;sub&gt;2&lt;/sub&gt; orbitals are partially filled.  Such geometric distortions that lower the electronic energy are said to be '''electronically driven'''.  Similar electronically driven distortions occur in one-dimensional chain compounds, where they are called [[w:Peierls_transition|Peierls distortions]], and in two-dimensionally bonded sheets, where they are called [[w:charge_density_wave|charge density waves]].
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[[File:Hexaaquacopper(II)-3D-balls.png|thumb|right|200px|The Jahn–Teller effect is responsible for the tetragonal distortion of the hexaaquacopper(II) complex ion, [Cu(OH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, which might otherwise possess octahedral geometry.  The two axial Cu−O distances are 2.38 Å, whereas the four equatorial Cu−O distances are ~1.95 Å.]]
[[File:Cu water.png|thumb|right|200px|The Cu(II) ion can also coordinate five water molecules in an elongated square pyramid with four Cu-Oeq bonds (2x1.98 Å and 2x1.95 Å) and a long Cu-Oax bond (2.35 Å). The four equatorial ligands are distorted from the mean equatorial plane by ± 17°.]]
The Jahn–Teller effect is most often encountered in octahedral complexes, especially six-coordinate copper(II) complexes.&lt;ref&gt;{{cite book | title = Metal-ligand bonding | author = Rob Janes and Elaine A. Moore | publisher = Royal Society of Chemistry | year = 2004 | isbn = 0-85404-979-7 | url = http://books.google.com/?id=qsP7mmhqvj4C&amp;pg=PA23&amp;dq=%22Jahn-Teller+distortion%22 }}&lt;/ref&gt; The ''d''&lt;sup&gt;9&lt;/sup&gt; electronic configuration of this ion gives three electrons in the two degenerate ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the ''z'' axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the ''z'' axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a ''z'' component, thus lowering the energy of the complex. If the undistorted complex would be expected to have an inversion center, this is preserved after the distortion.  
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&lt;br /&gt;
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals. This situation arises in complexes with the configurations ''d''&lt;sup&gt;9&lt;/sup&gt;, low-spin ''d''&lt;sup&gt;7&lt;/sup&gt; or high-spin ''d''&lt;sup&gt;4&lt;/sup&gt; complexes, all of which have doubly degenerate ground states. In such compounds the ''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilization. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals (''i.e.'' configurations such as ''d''&lt;sup&gt;1&lt;/sup&gt; or ''d''&lt;sup&gt;2&lt;/sup&gt;, both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the ''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals, which do not point ''directly'' at the ligands (see the table below).  The same is true in tetrahedral complexes (e.g. manganate ([MnO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, d&lt;sup&gt;1&lt;/sup&gt;): the distortion is very subtle because there is less stabilization to be gained when the ligands are not pointing directly at the orbitals.

The expected effects for octahedral coordination are given in the following table:
&lt;div align=center&gt;
{| class=&quot;wikitable&quot; style=&quot;text-align:center&quot;
|+ Jahn–Teller effect
! Number of d electrons !! 1 !! 2 !! 3 !! colspan=&quot;2&quot; | 4 !!  colspan=&quot;2&quot; | 5  !! colspan=&quot;2&quot; | 6 !! colspan=&quot;2&quot; | 7 !! 8 !! 9 !! 10
|-
! High/Low Spin !! !! !! !! HS !! LS !! HS !! LS !! HS !! LS !! HS !! LS !! !! !!
|-
!Strength of J-T Effect
| style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | w || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; | || style=&quot;width:20px&quot; | s || style=&quot;width:20px&quot; |
|-
   
|}
&lt;/div&gt;

w: weak Jahn–Teller effect (''t&lt;sub&gt;2g&lt;/sub&gt;'' orbitals unevenly occupied)

s: strong Jahn–Teller effect expected (''e&lt;sub&gt;g&lt;/sub&gt;'' orbitals unevenly occupied)

blank: no Jahn–Teller effect expected.

The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes.&lt;ref&gt;Patrick Frank, Maurizio Benfatto, Robert K. Szilagyi, Paola D'Angelo, Stefano Della Longa, and Keith O. Hodgson &quot;The Solution Structure of [Cu(aq)]&lt;sup&gt;2+&lt;/sup&gt; and Its Implications for Rack-Induced Bonding in Blue Copper Protein Active Sites&quot; Inorganic Chemistry 2005, vol 44, pp 1922–1933. DOI 10.1021/ic0400639&lt;/ref&gt; Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be obtained from the fine structure of the low-temperature electron spin resonance spectra. 
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==&amp;#160;&amp;#160;5.8 Tetrahedral complexes==
Tetrahedral complexes are formed with late transition metal ions (Co&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;) and some early transition metals (Ti&lt;sup&gt;4+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt;), especially in situations where the ligands are large.  In these cases the small metal ion cannot easily accommodate a coordination number higher than four.  Examples of tetrahedal ions and molecules are [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, [MnCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;, and TiX&lt;sub&gt;4&lt;/sub&gt; (X = halogen).  Tetrahedral coordination is also observed in some oxo-anions such as [FeO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;, which exists as discrete anions in the salts Na&lt;sub&gt;4&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt; and Sr&lt;sub&gt;2&lt;/sub&gt;FeO&lt;sub&gt;4&lt;/sub&gt;, and in the neutral oxides RuO&lt;sub&gt;4&lt;/sub&gt; and OsO&lt;sub&gt;4&lt;/sub&gt;. The metal carbonyl complexes Ni(CO)&lt;sub&gt;4&lt;/sub&gt; and Co(CO)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt; are also tetrahedral.
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[[file:tetrahedron-in-cube.png|300px|left]][[file:tetrahedral-cfse.png|right|200px]]The splitting of the d-orbitals in a tetrahedral crystal field can be understood by connecting the vertices of a tetrahedron to form a cube, as shown in the picture at the left.  The tetrahedral M-L bonds lie along the body diagonals of the cube.  The d&lt;sub&gt;z&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; and d&lt;sub&gt;x&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt;&lt;sub&gt;-y&lt;/sub&gt;&lt;small&gt;2&lt;/small&gt; orbitals point along the cartesian axes, i.e., towards the faces of the cube, and have the least contact with the ligand lone pairs.  Therefore these two orbitals form a low energy, doubly degenerate e set.  The d&lt;sub&gt;xy&lt;/sub&gt;, d&lt;sub&gt;yz&lt;/sub&gt;, and d&lt;sub&gt;xz&lt;/sub&gt; orbitals point at the edges of the cube and form a triply degenerate t&lt;sub&gt;2&lt;/sub&gt; set.  While the t&lt;sub&gt;2&lt;/sub&gt; orbitals have more overlap with the ligand orbitals than the e set, they are still weakly interacting compared to the e&lt;sub&gt;g&lt;/sub&gt; orbitals of an octahedral complex.  
The resulting crystal field energy diagram is shown at the right.  The splitting energy, Δ&lt;sub&gt;t&lt;/sub&gt;, is about 4/9 the splitting of an octahedral complex formed with the same ligands.  For 3d elements, Δ&lt;sub&gt;t&lt;/sub&gt; is thus small compared to the pairing energy and their tetrahedral complexes are always high spin.  Note that we have dropped the &quot;g&quot; subscript because the tetrahedron does not have a center of symmetry.
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Tetrahedral complexes often have '''vibrant colors''' because they '''lack the center of symmetry''' that forbids a d-d* transition. Because the low energy transition is allowed, these complexes typically absorb in the visible range and have extinction coefficients that are 1-2 orders of magnitude higher than the those of the corresponding octahedral complexes. An illustration of this effect can be seen in Drierite, which contains particles of colorless, anhydrous calcium sulfate (gypsum) that absorbs moisture from gases.  The indicator dye in Drierite is cobalt (II) chloride, which is  is a light pink when wet (octahedral) and deep blue when dry (tetrahedral).  The reversible hydration reaction is: 

:::::Co[CoCl&lt;sub&gt;4&lt;/sub&gt;]  + 12 H&lt;sub&gt;2&lt;/sub&gt;O&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; ⇌ &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 2 [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]Cl&lt;sub&gt;2&lt;/sub&gt;
::('''deep blue''', tetrahedral [CoCl&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt;)&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;('''light pink''', octahedral [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;)
:[[File:Drierite indicateur cropped.jpg|left|Drierite Dry and Wet|450px]][[file:co-cfse.png|200px]]
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==&amp;#160;&amp;#160;5.9 Stability of transition metal complexes==
The crystal field stabilization energy ('''CFSE''') is an important factor in the stability of transition metal complexes.  Complexes with high CFSE tend to be '''thermodynamically''' stable (i.e., they have high values of K&lt;sub&gt;a&lt;/sub&gt;, the equilibrium constant for metal-ligand association) and are also '''kinetically''' inert.  They are kinetically inert because ligand substitution requires that they ''dissociate'' (lose a ligand), ''associate'' (gain a ligand), or ''interchange'' (gain and lose ligands at the same time) in the transition state.  These distortions in coordination geometry lead to a large '''activation energy''' if the CFSE is large, even if the product of the ligand exchange reaction is also a stable complex.  For this reason, complexes of Pt&lt;sup&gt;4+&lt;/sup&gt;, Ir&lt;sup&gt;3+&lt;/sup&gt; (both low spin 5d&lt;sup&gt;6&lt;/sup&gt;), and Pt&lt;sup&gt;2+&lt;/sup&gt; (square planar 5d&lt;sup&gt;8&lt;/sup&gt;) have very slow ligand exchange rates.
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There are two other important factors that contribute to complex stability:
:'''Hard-soft interactions''' of metals and ligands (which relate to the '''energy''' of complex formation)
:The '''chelate effect''', which is an '''entropic''' contributor to complex stability.
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'''Hard-soft interactions'''  &lt;br /&gt;
&lt;u&gt;Hard acids&lt;/u&gt; are typically small, high charge density cations that are weakly polarizable such as H&lt;sup&gt;+&lt;/sup&gt;, Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, Be&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Ti&lt;sup&gt;4+&lt;/sup&gt;, and Cr&lt;sup&gt;6+&lt;/sup&gt;. ''Electropositive metals'' in ''high oxidation states'' are typically hard acids.  These elements are predominantly found in oxide minerals, because O&lt;sup&gt;2-&lt;/sup&gt; is a hard base. &lt;br /&gt;
Some &lt;u&gt;hard bases&lt;/u&gt; include H&lt;sub&gt;2&lt;/sub&gt;O, OH&lt;sup&gt;-&lt;/sup&gt;, O&lt;sup&gt;2-&lt;/sup&gt;, F&lt;sup&gt;-&lt;/sup&gt;, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Cl&lt;sup&gt;-&lt;/sup&gt;, and NH&lt;sub&gt;3&lt;/sub&gt;. &lt;br /&gt;
The hard acid-base interaction is primarily '''electrostatic'''. Complexes of hard acids with hard bases are stable because of the electrostatic component of the CFSE.
&lt;br /&gt;

&lt;u&gt;Soft acids&lt;/u&gt; are large, polarizable, ''electronegative metal'' ions in ''low oxidation states'' such as Ni&lt;sup&gt;0&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;+&lt;/sup&gt;, Ag&lt;sup&gt;+&lt;/sup&gt;, and Au&lt;sup&gt;+&lt;/sup&gt;.
&lt;br /&gt;
&lt;u&gt;Soft bases&lt;/u&gt; are anions/neutral bases such as H&lt;sup&gt;-&lt;/sup&gt;, C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, CO, PR&lt;sub&gt;3&lt;/sub&gt;, R&lt;sub&gt;2&lt;/sub&gt;S, and CN&lt;sup&gt;-&lt;/sup&gt;). Soft acids typically occur in nature as sulfide or arsenide minerals.  &lt;br /&gt;
&lt;br /&gt;
The bonding between soft acids and soft bases is predominantly '''covalent'''.  For example, metal carbonyls bind through a covalent interaction between a zero- or low-valent metal and neutral CO to form Ni(CO)&lt;sub&gt;4&lt;/sub&gt;, Fe(CO)&lt;sub&gt;5&lt;/sub&gt;, Co(CO)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, Mn&lt;sub&gt;2&lt;/sub&gt;(CO)&lt;sub&gt;10&lt;/sub&gt;, W(CO)&lt;sub&gt;6&lt;/sub&gt;, and related compounds.

The preference for hard-hard and soft-soft interactions (&quot;like binds like&quot;) is nicely illustrated in the properties of the copper halides:

::CuF &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;'''CuI'''
:&amp;nbsp;&amp;nbsp;unstable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable

::'''CuF&lt;sub&gt;2&lt;/sub&gt;'''&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;CuI&lt;sub&gt;2&lt;/sub&gt;
:&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;stable &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;unstable

The compounds CuF and CuI&lt;sub&gt;2&lt;/sub&gt; have never been isolated, and are thermodynamically unstable to disproportionation:

:2 CuF(s) → Cu(s) + CuF&lt;sub&gt;2&lt;/sub&gt;(s)
:2 CuI&lt;sub&gt;2&lt;/sub&gt;(s) → 2 CuI(s) + I&lt;sub&gt;2&lt;/sub&gt;(s)

We will learn more about quantifying the energetics of these compounds in Chapter 9.

==&amp;#160;&amp;#160;5.10 Chelate and macrocyclic effects==

[[File:Me-EN.svg|thumb|130px|Ethylenediamine (en) is a bidentate ligand that forms a five-membered ring in coordinating to a metal ion M]]Ligands that contain more than one binding site for a metal ion are called '''chelating''' ligands (from the Greek word χηλή, chēlē, meaning &quot;claw&quot;).  As the name implies, chelating ligands have '''high affinity''' for metal ions relative to ligands with only one binding group (which are called monodentate = &quot;single tooth&quot;) ligands.
&lt;br /&gt;
Consider the two complexation equilibria in aqueous solution, between the cobalt (II) ion, Co&lt;sup&gt;2+&lt;/sup&gt;(aq) and ethylenediamine (en) on the one hand and ammonia, NH&lt;sub&gt;3&lt;/sub&gt;, on the other.

:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 NH&lt;sub&gt;3&lt;/sub&gt; ⇌ [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (1)
:[Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 3 en ⇌ [Co(en)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; + 6 H&lt;sub&gt;2&lt;/sub&gt;O (2)

Electronically, the ammonia and en ligands are very similar, since both bind through N and since the Lewis base strengths of their nitrogen atoms are similar.  This means that ΔH° must be very similar for the two reactions, since six Co-N bonds are formed in each case.  Interestingly however, we observe that the equilibrium constant is ''100,000 times larger'' for the second reaction than it is for the first.
&lt;br /&gt;&lt;br /&gt;
The big difference between these two reactions is that the second one involves &quot;condensation&quot; of ''fewer particles'' to make the complex.  This means that the '''entropy changes''' for the two reactions are different.  The first reaction has a ΔS° value close to zero, because there are the same number of molecules on both sides of the equation.  The second one has a positive ΔS° because four molecules come together but seven molecules are produced.  The difference between them (ΔΔS°) is about +100 J/mol-K.  We can translate this into a ratio of equilibrium constants using:
&lt;br /&gt;

:K&lt;sub&gt;f&lt;/sub&gt;(en)/K&lt;sub&gt;f&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;) = e&lt;sup&gt;-ΔΔG°/RT&lt;/sup&gt; ≈ e&lt;sup&gt;+ΔΔS°/R&lt;/sup&gt; ≈ e&lt;sup&gt;12&lt;/sup&gt; ≈ 10&lt;sup&gt;5&lt;/sup&gt;
&lt;br /&gt;
[[File:EDTA.svg|thumbnail|left|170 px|Ethylenediaminetetraaceticacid acid (EDTA), a hexadentate ligand]][[File:Heme_b.svg|180px|right|thumbnail|Heme b]]
The bottom line is that the chelate effect is '''entropy-driven'''.  It follows that the more binding groups a ligand contains, the more positive the ΔS° and the higher the K&lt;sub&gt;f&lt;/sub&gt; will be for complex formation.  In this regard, the hexadentate ligand ethylenediamine tetraacetic acid (EDTA) is an optimal ligand for making octahedral complexes because it has six binding groups.  In basic solutions where all four of the COOH groups are deprotonated, the '''chelate effect''' of the EDTA&lt;sup&gt;4-&lt;/sup&gt; ligand is approximately 10&lt;sup&gt;15&lt;/sup&gt;.  This means, for a given metal ion, K&lt;sub&gt;f&lt;/sub&gt; is 10&lt;sup&gt;15&lt;/sup&gt; times larger for EDTA&lt;sup&gt;4-&lt;/sup&gt; than it would be for the relevant monodentate ligands at the same concentration.  EDTA&lt;sup&gt;4-&lt;/sup&gt;tightly binds essentially any 2+, 3+, or 4+ ion in the periodic table, and is a very useful ligand for both analytical applications and separations.
 
The '''macrocyclic effect''' follows the same principle as the chelate effect, but the effect is further enhanced by the cyclic conformation of the ligand.  Macrocyclic ligands are not only multi-dentate, but because they are covalently constrained to their cyclic form, they allow less conformational freedom. The ligand is said to be &quot;'''pre-organized'''&quot; for binding, and there is little entropy penalty for wrapping it around the metal ion.  For example heme b is a tetradentate cyclic ligand which is strongly complexes transition metal ions, including (in biological systems) Fe&lt;sup&gt;+2&lt;/sup&gt;. 
&lt;br /&gt;

Some other common chelating and cyclic ligands are shown below:  [[File:Acac.png|right|300px]]
[[File:Jacqueline Barton AIC Gold Medal 2015.jpg|170px|left|thumb|[[w:Jacqueline_Barton|Prof. Jacqueline Barton]] (Caltech) has used metal polypyridyl complexes to study electron transfer reactions that are implicated in the biological sensing and repair of damage in DNA molecules.]]'''Acetylacetonate''' (acac&lt;sup&gt;-&lt;/sup&gt;, right) is an anionic bidentate ligand that coordinates metal ions through two oxygen atoms.  Acac&lt;sup&gt;-&lt;/sup&gt; is a hard base so it prefers hard acid cations.  With divalent metal ions, acac&lt;sup&gt;-&lt;/sup&gt; forms neutral, volatile complexes such as Cu(acac)&lt;sub&gt;2&lt;/sub&gt; and Mo(acac)&lt;sub&gt;2&lt;/sub&gt; that are useful for [[w:Chemical_vapor_deposition|chemical vapor deposition]] (CVD) of metal thin films.  
'''2,2'-Bipyridine''' and related bidentate ligands such as 1,10-phenanthroline (below, center left) form propeller-shaped complexes with metals such as Ru&lt;sup&gt;2+&lt;/sup&gt;. The [[w:Tris(bipyridine)ruthenium(II)_chloride|[Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;]] complex (below left)  is photoluminescent and can also undergo photoredox reactions, making it an interesting compound for both photocatalysis and artificial photosynthesis.  The chiral propellor shapes of metal polypyridyl complexes such as [Ru(bpy)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; coincidentally match the size and helicity of the major groove of DNA.  This has led to a number of interesting studies of electron transfer reactions along the DNA backbone, initiated by photoexcitation of the metal complex.
&lt;br&gt;&lt;br&gt;
'''Crown ethers''' such as 18-crown-6 (below, center right) are cyclic hard bases that can complex alkali metal cations.  Crowns can selectively bind Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, or K&lt;sup&gt;+&lt;/sup&gt; depending on the number of ethylene oxide units in the ring.  
:The chelating properties of crown ethers are mimetic of the natural antibiotic '''valinomycin''' (below right), which selectively transports K&lt;sup&gt;+&lt;/sup&gt; ions across bacterial cell membranes, killing the bacterium by dissipating its membrane potential.  Like crown ethers, valinomycin is a cyclic hard base.

::::&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Trisbipyridylruthenium structure.jpg|130px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:1,10-phenanthroline.svg|150px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:18-crown-6.png|120px]]&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;[[File:Valinomycin.svg|180px]]

==&amp;#160;&amp;#160;5.11 Ligand substitution reactions==
Transition metal complexes can exchange one ligand for another, and these reactions are important in their synthesis, stereochemistry, and catalytic chemistry.  The mechanisms of chemical reactions are intimately connected to reaction kinetics.  As in organic chemistry, the mechanisms of transition metal reactions are typically inferred from experiments that examine the concentration dependence of the incoming and outgoing ligands on the reaction rate, the detection of intermediates, and the stereochemistry of the reactants and products.
&lt;br&gt;&lt;br&gt;
'''Thermodynamic vs. kinetics.'''  When we think about the reactions of transition metal complexes, it is important to recall the distinction between their ''thermodynamics'' and ''kinetics''.  Take for example the formation of the square planar tetracyanonickelate complex:
&lt;br&gt;&lt;br&gt;
::Ni&lt;sup&gt;2+&lt;/sup&gt;(aq) + 4 CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;      K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; M&lt;sup&gt;-4&lt;/sup&gt;
&lt;br&gt;
Thermodynamically, [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is very '''stable''', meaning that the equilibrium above lies very far to the right.  Kinetically, however, the complex is '''labile''', meaning that it can exchange its ligands rapidly.  For example the exchange between a &lt;sup&gt;13&lt;/sup&gt;C labeled CN&lt;sup&gt;-&lt;/sup&gt; ion and a bound CN&lt;sup&gt;-&lt;/sup&gt; ligand occurs on the timescale of tens of milliseconds:
&lt;br&gt;&lt;br&gt;
::[Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; (aq) + *CN&lt;sup&gt;-&lt;/sup&gt;(aq) ⇌ [Ni(CN)&lt;sub&gt;3&lt;/sub&gt;(*CN)]&lt;sup&gt;2-&lt;/sup&gt; + CN&lt;sup&gt;-&lt;/sup&gt;(aq)  &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  k&lt;sub&gt;exchange&lt;/sub&gt; ≈ 10&lt;sup&gt;2&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;s&lt;sup&gt;-1&lt;/sup&gt;
&lt;br&gt;
Conversely, a compound can be thermodynamically '''unstable''' but kinetically '''inert''', meaning that it takes a relatively long time to react.  For example, the [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; ion is unstable in acid, but its hydrolysis reaction with concentrated HCl takes about one week to go to completion at room temperature: 
&lt;br&gt;[[File:Henry Taube - HD.3F.005 (11086397086).jpg|250 px|right|thumb|Henry Taube (Stanford University) received the 1983 Nobel Prize for his work on the electron transfer and ligand exchange reactions of transition metal complexes]]
:: [Co(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 H&lt;sub&gt;3&lt;/sub&gt;O&lt;sup&gt;+&lt;/sup&gt;(aq) ⇌ [Co(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;(aq) + 6 NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;(aq) &amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;  K&lt;sub&gt;eq&lt;/sub&gt; ≈ 10&lt;sup&gt;30&lt;/sup&gt; 
&lt;br&gt;
Henry Taube, who studied the mechanisms of ligand exchange reactions in simple test tube experiments, classified transition metal complexes as '''labile''' if their reaction half-life was one minute or less, and '''inert''' if they took longer to react.  The dynamic range of ligand substitution rates is enormous, spanning at least 15 orders of magnitude.  On the timescale of most laboratory experiments, the Taube definition of lability is a useful one for classifying reactions into those that have low and high activation energies.  As we will see, the '''crystal field stabilization energy (CFSE)''' plays a key role in determining the activation energy and therefore the rate of ligand substitution.
&lt;br&gt;&lt;br&gt;
'''Crystal field stabilization energy and ligand exchange rates.'''  Let's consider a very common and simple ligand exchange reaction, which is the substitution of one water molecule for another in an octahedral [M(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;n+&lt;/sup&gt; complex.  Since the products (except for the label) are the same as the reactants, we know that ΔG° = 0 and K&lt;sub&gt;eq&lt;/sub&gt; = 1 for this reaction.  The progress of the reaction can be monitored by NMR by using isotopically labeled water (typically containing &lt;sup&gt;17&lt;/sup&gt;O or &lt;sup&gt;18&lt;/sup&gt;O):
[[File:octahedral_complex_water_substitution.jpg|center|400px]]
The most striking thing about this (otherwise boring) reaction is the vast difference in rate constants - about 14 orders of magnitude - for different metal ions and oxidation states:
&lt;center&gt;
{| class=&quot;wikitable&quot;
|-
! M&lt;sup&gt;n+&lt;/sup&gt; !! log k (sec&lt;sup&gt;-1&lt;/sup&gt;)
|-
|Cr&lt;sup&gt;3+&lt;/sup&gt;||&lt;center&gt;-6&lt;/center&gt;
|-
|V&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;-2&lt;/center&gt;
|-
|Cr&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|-
|Cu&lt;sup&gt;2+&lt;/sup&gt;|| &lt;center&gt;8&lt;/center&gt;
|}&lt;/center&gt;

[[file:cr3+CFSE.jpg|center|500px]]While at first it may seem strange that the same ion in two different oxidation states (Cr&lt;sup&gt;3+&lt;/sup&gt; vs. Cr&lt;sup&gt;2+&lt;/sup&gt;) would be inert or labile, respectively, we can begin to rationalize the difference by drawing d-orbital splitting diagrams for the complexes.  What we find is that octahedral complexes that have '''high CFSE''' (Cr&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;) tend to be '''inert'''.  Conversely, ions with electrons in high energy e&lt;sub&gt;g&lt;/sub&gt; orbitals (Cr&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;) tend to be labile.  In the case of Cr&lt;sup&gt;3+&lt;/sup&gt; and V&lt;sup&gt;2+&lt;/sup&gt;, the energy penalty for distorting the complex away from octahedral symmetry - to make, for example, a 5- or 7-coordinate intermediate - is particularly high.  This activation energy for ligand substitution is lower for Cr&lt;sup&gt;2+&lt;/sup&gt; and Cu&lt;sup&gt;2+&lt;/sup&gt;, which already have electrons in antibonding e&lt;sub&gt;g&lt;/sub&gt; orbitals.
&lt;br&gt;
Based on the rules we developed for calculating the CFSE of transition metal complexes, we can now predict the trends in ligand substitution rates:

* Octahedral complexes with '''d&lt;sup&gt;3&lt;/sup&gt;''' and '''d&lt;sup&gt;6&lt;/sup&gt;(low spin)''' configurations, such as Cr&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;3&lt;/sup&gt;), Co&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Rh&lt;sup&gt;3+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), Ru&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;), and Os&lt;sup&gt;2+&lt;/sup&gt; (d&lt;sup&gt;6&lt;/sup&gt;) tend to be '''substitution-inert''' because of their high CFSE.
* '''Square planar d&lt;sup&gt;8&lt;/sup&gt;''' complexes, especially those in the 4d and 5d series, are also s'''ubstitution-inert'''.  Examples are complexes of Pd&lt;sup&gt;2+&lt;/sup&gt;, Pt&lt;sup&gt;2+&lt;/sup&gt;, and Au&lt;sup&gt;3+&lt;/sup&gt;.
* Intermediate cases are complexes of Fe&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;3+&lt;/sup&gt;, V&lt;sup&gt;2+&lt;/sup&gt;, Ni&lt;sup&gt;2+&lt;/sup&gt;, and of main group ions (Be&lt;sup&gt;2+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;) that are hard Lewis acids.  These complexes make strong metal-oxygen bonds and have water exchange rates in the range of 10&lt;sup&gt;1&lt;/sup&gt;-10&lt;sup&gt;6&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.
* '''Ions with zero CFSE''' exchange water molecules on a timescale of nanoseconds (k ≈ 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;).  These include ions with d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt; (high spin), and d&lt;sup&gt;10&lt;/sup&gt; electron counts, including alkali metal (Li&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Cs&lt;sup&gt;+&lt;/sup&gt;) and alkali earth (Mg&lt;sup&gt;2+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, Ba&lt;sup&gt;2+&lt;/sup&gt;) cations, Zn&lt;sup&gt;2+&lt;/sup&gt;, Cd&lt;sup&gt;2+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, and Mn&lt;sup&gt;2+&lt;/sup&gt;.  In these cases the CFSE is zero and the energetic cost of breaking octahedral symmetry is relatively low.  
* For p-block elements, faster exchange occurs with larger ions (e.g., Ba&lt;sup&gt;2+&lt;/sup&gt; &gt; Ca&lt;sup&gt;2+&lt;/sup&gt; and Ga&lt;sup&gt;3+&lt;/sup&gt; &gt; Al&lt;sup&gt;3+&lt;/sup&gt;), because Lewis acid strength decreases with increasing ion size.  
* The Cu&lt;sup&gt;2+&lt;/sup&gt; ion (d&lt;sup&gt;9&lt;/sup&gt;), as a '''Jahn-Teller ion''', is already distorted away from octahedral symmetry and is therefore quite '''labile''', exchanging water ligands at a rate of about 10&lt;sup&gt;8&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;.

&lt;br&gt;
'''Ligand Substitution Mechanisms.'''  For an ML&lt;sub&gt;n&lt;/sub&gt; complex undergoing ligand substitution, there are essentially three different reaction mechanisms:
&lt;br&gt;&lt;br&gt;
* In the '''dissociative mechanism''', a ML&lt;sub&gt;n&lt;/sub&gt; complex first '''loses a ligand''' to form an ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate, and the incoming ligand Y reacts with the ML&lt;sub&gt;n-1&lt;/sub&gt; fragment:
&lt;br&gt;
::L&lt;sub&gt;(n-1)&lt;/sub&gt;M-L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M- + L* ⇌ L&lt;sub&gt;(n-1)&lt;/sub&gt;M-Y
&lt;br&gt;
This mechanism is illustrated below for ligand substitution on an octahedral ML&lt;sub&gt;6&lt;/sub&gt; complex. The intermediate state in this example involves a trigonal bipyramidal ML&lt;sub&gt;5&lt;/sub&gt; fragment as well as free L and Y ligands.  

[[File:dissociative_substitution.gif|450px|right|thumb|Illustration of the dissociative ligand substitution mechanism for an ML&lt;sub&gt;6&lt;/sub&gt; complex.  The reaction energy profile is shown at the right.]]If the rate determining step is the dissociation of L from the complex, then the concentration of Y does not affect the rate of reaction, leading to the first-order rate law:
&lt;br&gt;
::Rate = k&lt;sub&gt;1&lt;/sub&gt;[ML&lt;sub&gt;n&lt;/sub&gt;]

In the case of an octahedral complex, this reaction would be first order in ML&lt;sub&gt;6&lt;/sub&gt; and zero order in Y, but only if the highest energy transition state is the one that precedes the formation of the ML&lt;sub&gt;5&lt;/sub&gt; intermediate.  If the two transition states are close in energy (as in the case of the animation at the right), then the rate law becomes more complicated.  In this case, we can simplify the problem by assuming a low steady-state concentration of the ML&lt;sub&gt;n&lt;/sub&gt; intermediate.  The resulting rate law is: 


::&lt;math chem&gt;\ce{Rate} = \frac{k_1 k_2[\ce Y][\ce{ML_\mathit{n}}]}{{k_{-1}[\ce L]}+k_2[\ce Y]}&lt;/math&gt;

which reduces to the simpler first-order rate law when k&lt;sub&gt;2&lt;/sub&gt;[Y] &gt;&gt; k&lt;sub&gt;-1&lt;/sub&gt;[L].  Because the formation of the transition state involves dissociation of a ligand, the entropy of activation is always positive in the dissociative mechanism.
&lt;br&gt;&lt;br&gt;

* In the '''associative mechanism''', the incoming ligand Y attacks the ML&lt;sub&gt;n&lt;/sub&gt; complex, transiently forming an ML&lt;sub&gt;n&lt;/sub&gt;Y intermediate, and the intermediate then loses a ligand L forming the ML&lt;sub&gt;n-1&lt;/sub&gt;Y product.

Complexes that undergo associative substitution are typically either coordinatively unsaturated or contain a ligand that can change its bonding to the metal, e.g. a change in the hapticity or bending of a nitric oxide ligand (NO).  In homogeneous catalysis, the associative pathway is desirable because the binding event, and hence the selectivity of the reaction, depends not only on the nature of the metal catalyst but also on the molecule that is involved in the catalytic cycle.

[[File:Berry_pseudorotation.gif|200 px|right|thumb|Berry pseudorotation mechanism]]Examples of associative mechanisms are commonly found in the chemistry of d&lt;sup&gt;8&lt;/sup&gt; square planar metal complexes, e.g. [[w:Vaska's_complex|Vaska's complex]] (IrCl(CO)[P(C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;) and tetrachloroplatinate(II).  These  compounds (ML&lt;sub&gt;4&lt;/sub&gt;) bind the incoming (substituting) ligand Y to form pentacoordinate intermediates ML&lt;sub&gt;4&lt;/sub&gt;Y, which in a subsequent step dissociate one of their ligands.  Although the incoming ligand is initially bound at an equatorial site, the [[w:Berry_mechanism|Berry pseudorotation]] provides a low energy pathway for all ligands to sample both the equatorial and axial sites.  Ligand dissociation must occur from an equatorial site according to the [[w:principle of microscopic reversibility|principle of microscopic reversibility]].  Dissociation of Y results in no reaction, but dissociation of L results in net substitution, yielding the d&lt;sup&gt;8&lt;/sup&gt; complex ML&lt;sub&gt;3&lt;/sub&gt;Y.  The first step is typically rate determining.  Thus, the entropy of activation is negative, which indicates an increase in order in the transition state.  Associative reactions follow second order kinetics: the rate of the appearance of product depends on the concentration of both ML&lt;sub&gt;4&lt;/sub&gt; and Y.
[[File:AssveRxn.png|520px|center]]

'''The Trans Effect''', which is connected with the associative mechanism, controls the stereochemistry of certain ligand substitution reactions. 
&lt;br&gt;&lt;br&gt;
The trans effect refers to the labilization (making more reactive) of ligands that are '''trans''' to certain other ligands, the latter being referred to as '''trans-directing ligands'''. The labilization of trans ligands is attributed to electronic effects and is most notable in square planar complexes, but it can also be observed with octahedral complexes.&lt;ref name=coe&gt;Coe, B. J.; Glenwright, S. J. Trans-effects in octahedral transition metal complexes. ''Coordination Chemistry Reviews'' '''2000''', ''203'', 5-80.&lt;/ref&gt; The [[w:cis effect|cis effect]] is most often observed in octahedral complexes.

In addition to the ''kinetic trans effect'', trans ligands also have an influence on the ground state of the molecule, the most notable ones being bond lengths and stability. Some authors prefer the term '''trans influence''' to distinguish this from the kinetic effect,&lt;ref name=crabtree&gt;{{Cite book | author = [[w:Robert H. Crabtree|Robert H. Crabtree]] | title = The Organometallic Chemistry of the Transition Metals | year = 2005 | edition = 4th | isbn = 0-471-66256-9 | publisher = Wiley-Interscience | location = New Jersey}}&lt;/ref&gt; while others use more specific terms such as '''structural trans effect''' or '''thermodynamic trans effect'''.&lt;ref name=coe/&gt;

The discovery of the trans effect is attributed to [[w:Ilya Ilich Chernyaev|Ilya Ilich Chernyaev]],&lt;ref&gt;Kauffmann, G. B. I'lya I'lich Chernyaev (1893-1966) and the Trans Effect. ''J. Chem. Educ.'' '''1977''', ''54'', 86-89.&lt;/ref&gt; who recognized it and gave it a name in 1926.&lt;ref&gt;Chernyaev, I. I. The mononitrites of bivalent platinum. I. ''Ann. inst. platine'' (USSR) '''1926''', ''4'', 243-275.&lt;/ref&gt;
&lt;br&gt;&lt;br&gt;
The intensity of the trans effect (as measured by the increase in the rate of substitution of the trans ligand) follows this sequence:

:[[w:fluoride|F&lt;sup&gt;−&lt;/sup&gt;]], [[w:water (molecule)|H&lt;sub&gt;2&lt;/sub&gt;O]], [[w:hydroxide|OH&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:ammonia|NH&lt;sub&gt;3&lt;/sub&gt;]] &lt; [[w:pyridine|py]] &lt; [[w:chloride|Cl&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:bromide|Br&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:iodide|I&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiocyanate|SCN&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitrite|NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]], [[w:thiourea|SC(NH&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;]], [[w:phenyl|Ph&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:sulfite|SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;]] &lt; [[w:phosphine|PR&lt;sub&gt;3&lt;/sub&gt;]], [[w:arsine|AsR&lt;sub&gt;3&lt;/sub&gt;]], [[w:thioether|SR&lt;sub&gt;2&lt;/sub&gt;]], [[w:methyl|CH&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;]] &lt; [[w:hydride|H&lt;sup&gt;−&lt;/sup&gt;]], [[w:nitric oxide|NO]], [[w:carbon monoxide|CO]], [[w:cyanide|CN&lt;sup&gt;−&lt;/sup&gt;]], [[w:ethylene|C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;]]

Note that weak field ligands tend to be poor trans-directing ligands, whereas strong field ligands are strongly trans-directing.
&lt;br&gt;&lt;br&gt;
The classic example of the trans effect is the synthesis of [[w:cisplatin|cisplatin]] and its [[w:Trans-dichlorodiammineplatinum(II)|trans isomer]].&lt;ref&gt;{{cite journal|title=''cis''- and ''trans''-Dichlorodiammineplatinum(II)|journal=Inorg. Synth.|volume=7|year=1963|author=George B. Kauffman, Dwaine O. Cowan|pages=239–245|doi=10.1002/9780470132388.ch63}}&lt;/ref&gt; Starting from PtCl&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, the first NH&lt;sub&gt;3&lt;/sub&gt; ligand is added to any of the four equivalent positions at random. However, since Cl&lt;sup&gt;−&lt;/sup&gt; has a greater trans effect than NH&lt;sub&gt;3&lt;/sub&gt;, the second NH&lt;sub&gt;3&lt;/sub&gt; is added trans to a Cl&lt;sup&gt;−&lt;/sup&gt; and therefore cis to the first NH&lt;sub&gt;3&lt;/sub&gt;.

:[[File:Synthesis Cisplatin (trans effect).svg|frameless|upright=3.0|Synthesis of cisplatin using the trans effect]]

If, on the other hand, one starts from Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;, the ''trans'' product is obtained instead:
:[[File:Synthesis Transplatin (trans effect).svg|frameless|upright=3.0|Synthesis of transplatin using the trans effect]]

The trans effect in square complexes can be explained in terms of the associative mechanism, described above, which goes through a trigonal bipyramidal intermediate. Ligands with a high kinetic trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–d&lt;sub&gt;π&lt;/sub&gt; repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand. The third and final equatorial site is occupied by the departing trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.&lt;ref name=crabtree /&gt;
&lt;br&gt;
&lt;br&gt;
* The '''interchange mechanism''' is similar to the associative and dissociative pathways, except that no distinct ML&lt;sub&gt;n&lt;/sub&gt;Y or ML&lt;sub&gt;n-1&lt;/sub&gt; intermediate is formed.  This concerted mechanism can be thought of as analogous to nucleophilic substitution via the S&lt;sub&gt;N&lt;/sub&gt;2 pathway at a tetrahedral carbon atom in organic chemistry.  The interchange mechanism is further classified as associative (''I''&lt;sub&gt;a&lt;/sub&gt;) or dissociative (''I''&lt;sub&gt;d&lt;/sub&gt;) depending on the relative importance of M-Y and M-L bonding in the transition state.  If the transition state is characterized by the formation of a strong M-Y bond, then the mechanism is ''I''&lt;sub&gt;a&lt;/sub&gt;.  Conversely, if weakening of the M-L bond is more important in reaching the transition state, then the mechanism is ''I''&lt;sub&gt;d&lt;/sub&gt;.  

An example of the ''I''&lt;sub&gt;a&lt;/sub&gt; mechanism is the interchange of bulk and coordinated water in [V(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;. In contrast, the slightly more compact ion [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; ion exchanges water via the  ''I''&lt;sub&gt;d&lt;/sub&gt; mechanism.&lt;ref&gt;{{cite journal |first=Lothar |last=Helm |first2=André E. |last2=Merbach |title=Inorganic and Bioinorganic Solvent Exchange Mechanisms |journal=Chem. Rev. |year=2005 |volume=105 |issue=6 |pages=1923–1959 |doi=10.1021/cr030726o |pmid=15941206}}&lt;/ref&gt;
&lt;br&gt;

'''Effects of ion pairing.'''  Highly charged cationic complexes tend to form ion pairs with anionic ligands, and these ion pairs often undergo reactions via the ''I''&lt;sub&gt;a&lt;/sub&gt; pathway.   The electrostatically held nucleophilic incoming ligand can exchange positions with a ligand in the first coordination sphere, resulting in net substitution. An illustrative process is the &quot;anation&quot; (reaction with an anion) of the chromium(III) hexaaquo complex:
::[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  +  SCN&lt;sup&gt;−&lt;/sup&gt;  ⇌  {[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;
::{[Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;], NCS}&lt;sup&gt;2+&lt;/sup&gt;   ⇌  [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;NCS]&lt;sup&gt;2+&lt;/sup&gt;  +  H&lt;sub&gt;2&lt;/sub&gt;O  
&lt;br&gt;

==&amp;#160;&amp;#160;5.12 f-Block element salts and coordination compounds==

[[File:Rareearthoxides.jpg|thumb|Lanthanide oxides: clockwise from top center: [[w:praseodymium|praseodymium]], [[w:cerium|ceruyn]], [[w:lanthanum|lanthanum]], [[w:neodymium|neodymium]], [[w:samarium|samarium]] and [[w:gadolinium|gadolinium]]]]The 4f and 5f block elements are called the [[w:lanthanide|lanthanides]] and [[w:actinide|actinides]], respectively. The chemistry of the lanthanides is dominated by the +3 oxidation state, and in Ln&lt;sup&gt;III&lt;/sup&gt; compounds the 6s electrons and (usually) one 4f electron are lost and the ions have the configuration [Xe]4f&lt;sup&gt;(''n''−1)&lt;/sup&gt;.&lt;ref&gt;{{cite web|author=Winter, Mark |url=http://www.webelements.com/lanthanum/atoms.html|title=Lanthanum ionisation energies|publisher=WebElements Ltd, UK|access-date=2 September 2010}}&lt;/ref&gt; All the lanthanide elements exhibit the oxidation state +3. In addition, Ce&lt;sup&gt;3+&lt;/sup&gt; can lose its single f electron to form Ce&lt;sup&gt;4+&lt;/sup&gt; with the stable electronic configuration of xenon. Also, Eu&lt;sup&gt;3+&lt;/sup&gt; can gain an electron to form Eu&lt;sup&gt;2+&lt;/sup&gt; with the f&lt;sup&gt;7&lt;/sup&gt; configuration that has the extra stability of a half-filled shell. Other than Ce(IV) and Eu(II), none of the lanthanides are stable in oxidation states other than +3 in aqueous solution. 

In terms of reduction potentials, the Ln&lt;sup&gt;0/3+&lt;/sup&gt; couples are nearly the same for all lanthanides, ranging from −1.99 (for Eu) to −2.35 V (for Pr). Thus these metals are highly reducing, with reducing power similar to alkaline earth metals such as Mg (−2.36 V).
====Ln(III) compounds====
The trivalent lanthanides mostly form ionic salts. The trivalent ions are hard acceptors and form more stable complexes with oxygen-donor ligands than with nitrogen-donor ligands. The larger ions are 9-coordinate in aqueous solution, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;9&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt; but the smaller ions are 8-coordinate, [Ln(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;8&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;. There is some evidence that the later lanthanides have more water molecules in the second coordination sphere.&lt;ref&gt;{{cite book|last=Burgess|first=J.|title=Metal ions in solution|publisher=Ellis Horwood|location= New York|year=1978|isbn=978-0-85312-027-8}}&lt;/ref&gt; Complexation with monodentate ligands is generally weak because it is difficult to displace water molecules from the first coordination sphere. Stronger complexes are formed with chelating ligands because of the [[w:chelate effect|chelate effect]], such as the tetra-anion derived from 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ([[w:DOTA (chelator)|DOTA]]).

:[[File:Lanthanide nitrates.png|thumb|750px|center|Samples of lanthanide nitrates in their hexahydrate form. From left to right: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.]]
{{-}}

====Ln(II) and Ln(IV) compounds====
The most common divalent derivatives of the lanthanides are for Eu(II), which achieves a favorable f&lt;sup&gt;7&lt;/sup&gt; configuration. Divalent halide derivatives are known for all of the lanthanides. They are either conventional salts or are Ln(III) &quot;electride&quot;-like salts. The simple salts include YbI&lt;sub&gt;2&lt;/sub&gt;, EuI&lt;sub&gt;2&lt;/sub&gt;, and SmI&lt;sub&gt;2&lt;/sub&gt;. The electride-like salts, described as Ln&lt;sup&gt;3+&lt;/sup&gt;, 2I&lt;sup&gt;−&lt;/sup&gt;, e&lt;sup&gt;−&lt;/sup&gt;, include LaI&lt;sub&gt;2&lt;/sub&gt;, CeI&lt;sub&gt;2&lt;/sub&gt; and GdI&lt;sub&gt;2&lt;/sub&gt;. Many of the iodides form soluble complexes with ethers, e.g. TmI&lt;sub&gt;2&lt;/sub&gt;(dimethoxyethane)&lt;sub&gt;3&lt;/sub&gt;.&lt;ref name=Nief&gt;{{cite journal|author=Nief, F. |title=Non-classical divalent lanthanide complexes|journal= Dalton Trans.|year= 2010|volume=39|issue=29|pages= 6589–6598|doi=10.1039/c001280g|pmid=20631944}}&lt;/ref&gt; Samarium(II) iodide is a useful reducing agent. Ln(II) complexes can be synthesized by transmetalation reactions. The normal range of oxidation states can be expanded via the use of sterically bulky cyclopentadienyl ligands, in this way many lanthanides can be isolated as Ln(II) compounds.&lt;ref&gt;{{cite journal|last1=Evans|first1=William J.|title=Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States|journal=Organometallics|date=15 September 2016|volume=35|issue=18|pages=3088–3100|doi=10.1021/acs.organomet.6b00466|doi-access=free}}&lt;/ref&gt;

Ce(IV) in ceric ammonium nitrate is a useful oxidizing agent. The Ce(IV) is the exception owing to the tendency to form an unfilled f shell. Otherwise tetravalent lanthanides are rare. However, recently Tb(IV)&lt;ref&gt;{{cite journal |title=Molecular Complex of Tb in the +4 Oxidation State&lt; |author1=Palumbo, C.T. |author2=Zivkovic, I. |author3=Scopelliti, R. |author4=Mazzanti, M. |date=2019 |pages=9827–9831 |volume=141 |journal=Journal of the American Chemical Society |doi=10.1021/jacs.9b05337 |pmid=31194529 |issue=25 |bibcode=2019JAChS.141.9827P |s2cid=189814301 |url=http://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-url=https://web.archive.org/web/20240423040613/https://infoscience.epfl.ch/record/268286/files/Palumbo%20ja-2019-05337d%20manuscriptR1.pdf |archive-date=23 April 2024 }}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Rice|first1=Natalie T.|last2=Popov|first2=Ivan A.|last3=Russo|first3=Dominic R.|last4=Bacsa|first4=John|last5=Batista|first5=Enrique R.|last6=Yang|first6=Ping|last7=Telser|first7=Joshua|last8=La Pierre|first8=Henry S.|date=21 August 2019|title=Design, Isolation, and Spectroscopic Analysis of a Tetravalent Terbium Complex|journal=Journal of the American Chemical Society|volume=141|issue=33|pages=13222–13233|doi=10.1021/jacs.9b06622|pmid=31352780|bibcode=2019JAChS.14113222R |osti=1558225|s2cid=207197096|issn=0002-7863|url=https://figshare.com/articles/journal_contribution/9450461 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal |title= Stabilization of the Oxidation State + IV in Siloxide-Supported Terbium Compounds |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Scopelliti, R. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=3549–3553|volume=59 |journal=Angewandte Chemie International Edition |issue=9 |doi=10.1002/anie.201914733|pmid=31840371 |bibcode=2020ACIE...59.3549W |s2cid=209385870 |url=http://infoscience.epfl.ch/record/275738 }}&lt;/ref&gt; and Pr(IV)&lt;ref&gt;{{cite journal |title= Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. |author1=Willauer, A.R. |author2=Palumbo, C.T. |author3=Fadaei-Tirani, F. |author4=Zivkovic, I. |author5=Douair, I. |author6=Maron, L.  |author7=Mazzanti, M. |date=2020 |pages=489–493|volume=142 |journal=Journal of the American Chemical Society |issue=12 |doi=10.1021/jacs.0c01204|pmid=32134644 |bibcode=2020JAChS.142.5538W |s2cid=212564931 |url=http://infoscience.epfl.ch/record/277306 }}&lt;/ref&gt; complexes have been shown to exist.

===Lanthanide coordination chemistry and catalysis===
When in the form of coordination complexes, lanthanides exist overwhelmingly in their +3 oxidation state, although particularly stable 4f configurations can also give +4 (Ce, Pr, Tb) or +2 (Sm, Eu, Yb) ions. All of these forms are strongly electropositive and thus lanthanide ions are [[w:HSAB theory|hard Lewis acids]].&lt;ref name=&quot;Ortu&quot;&gt;{{ cite journal | title = Rare Earth Starting Materials and Methodologies for Synthetic Chemistry | first1 = Fabrizio | last1 = Ortu | journal = [[w:Chemical Reviews|Chem. Rev.]] | year = 2022 | volume = 122 | issue = 6 | pages = 6040–6116 | doi = 10.1021/acs.chemrev.1c00842 | pmid = 35099940 | pmc = 9007467 }}&lt;/ref&gt; The oxidation states are also very stable; with the exceptions of [[w:SmI2|SmI&lt;sub&gt;2&lt;/sub&gt;]]&lt;ref&gt;{{cite journal|last1=Molander|first1=Gary A.|last2=Harris|first2=Christina R.|title=Sequencing Reactions with Samarium(II) Iodide|journal=Chemical Reviews|date=1 January 1996|volume=96|issue=1|pages=307–338|doi=10.1021/cr950019y|pmid=11848755}}&lt;/ref&gt; and [[w:Ceric ammonium nitrate|cerium(IV) salts]],&lt;ref&gt;{{cite journal|last1=Nair|first1=Vijay|last2=Balagopal|first2=Lakshmi|last3=Rajan|first3=Roshini|last4= Mathew|first4=Jessy|title=Recent Advances in Synthetic Transformations Mediated by Cerium(IV) Ammonium Nitrate|journal=Accounts of Chemical Research|date=1 January 2004|volume=37|issue=1|pages=21–30|doi=10.1021/ar030002z|pmid=14730991}}&lt;/ref&gt; lanthanides are not used for redox chemistry. 4f electrons have a high probability of being found close to the nucleus and are thus strongly affected as the nuclear charge increases across the series; this results in a corresponding decrease in ionic radii referred to as the [[w:lanthanide contraction|lanthanide contraction]].

The low probability of the 4f electrons existing at the outer region of the atom or ion permits little effective overlap between the orbitals of a lanthanide ion and any binding ligand. Thus lanthanide complexes typically have little or no covalent character and are not influenced by orbital geometries. The lack of orbital interaction also means that varying the metal typically has little effect on the complex (other than size), especially when compared to transition metals. Complexes are held together by weaker electrostatic forces which are omni-directional and thus the ligands alone dictate the symmetry and coordination of complexes. Steric factors therefore dominate, with coordinative saturation of the metal being balanced against inter-ligand repulsion. This results in a diverse range of coordination geometries, many of which are irregular,&lt;ref&gt;{{cite journal|last1=Dehnicke|first1=Kurt|last2=Greiner|first2=Andreas|title=Unusual Complex Chemistry of Rare-Earth Elements: Large Ionic Radii—Small Coordination Numbers|journal=Angewandte Chemie International Edition|year=2003|volume=42|issue=12|pages=1340–1354|doi=10.1002/anie.200390346|pmid=12671966 |bibcode=2003ACIE...42.1340D }}&lt;/ref&gt; and also manifests itself in the highly fluxional nature of the complexes. As there is no energetic reason to be locked into a single geometry, rapid intramolecular and intermolecular ligand exchange will take place. This typically results in complexes that rapidly fluctuate between all possible configurations.

Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarize bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the [[w:Luche reduction|Luche reduction]]. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%.&lt;ref&gt;{{cite book|last=Aspinall|first=Helen C.|title=Chemistry of the f-block elements|year=2001|publisher=Gordon &amp; Breach|location=Amsterdam [u.a.]|isbn=978-90-5699-333-7}}&lt;/ref&gt; The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex&lt;ref&gt;{{cite journal |last1=Kobayashi|first1=Shū|last2=Hamada|first2=Tomoaki|last3=Nagayama|first3=Satoshi|last4=Manabe|first4=Kei |title=Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media|journal=Organic Letters|date=1 January 2001|volume=3|issue=2|pages=165–167|doi=10.1021/ol006830z|pmid=11430025|url=https://figshare.com/articles/journal_contribution/3737823|url-access=subscription}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Aspinall|first1=Helen C.|last2=Dwyer|first2=Jennifer L.|last3=Greeves|first3=Nicholas|last4=Steiner|first4=Alexander
|title=Li&lt;sub&gt;3&lt;/sub&gt;[Ln(binol)&lt;sub&gt;3&lt;/sub&gt;]·6THF: New Anhydrous Lithium Lanthanide Binaphtholates and Their Use in Enantioselective Alkyl Addition to Aldehydes|journal=Organometallics|date=1 April 1999|volume=18|issue=8|pages=1366–1368|doi=10.1021/om981011s}}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Parac-Vogt|first1=Tatjana N.|last2=Pachini|first2=Sophia|last3=Nockemann|first3=Peter|last4=VanmHecke|first4=Kristof|last5=Van Meervelt|first5=Luc|last6=Binnemans|first6=Koen|title=Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency|journal=European Journal of Organic Chemistry|date=1 November 2004|volume=2004|issue=22|pages=4560–4566|doi=10.1002/ejoc.200400475|s2cid=96125063 |url=https://lirias.kuleuven.be/handle/123456789/33568|type=Submitted manuscript|url-access=subscription}}&lt;/ref&gt; and change the nuclearity of metal clusters.&lt;ref&gt;{{cite journal|last1=Lipstman|first1=Sophia|last2=Muniappan|first2=Sankar|last3=George|first3= Sumod|last4=Goldberg|first4=Israel|title=Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids|journal=Dalton Transactions|date=1 January 2007|volume=30 |issue=30|pages=3273–81|doi=10.1039/B703698A|pmid=17893773 |bibcode=2007DTr....30.3273L }}&lt;/ref&gt;&lt;ref&gt;{{cite journal|last1=Bretonnière|first1=Yann|last2=Mazzanti|first2=Marinella|last3=Pécaut|first3=Jacques|last4=Dunand|first4=Frank A.|last5=Merbach|first5=André E.|title=Solid-State and Solution Properties of the Lanthanide Complexes of a New Heptadentate Tripodal Ligand: A Route to Gadolinium Complexes with an Improved Relaxation Efficiency|journal=Inorganic Chemistry|date=1 December 2001|volume=40|issue=26|pages=6737–6745|doi=10.1021/ic010591+|pmid=11735486 |url=http://infoscience.epfl.ch/record/78253 }}&lt;/ref&gt;

Despite this, the use of lanthanide coordination complexes as homogeneous catalysts is largely restricted to the laboratory and there are currently few examples them being used on an industrial scale.&lt;ref&gt;{{cite journal|last1=Trinadhachari|first1=Ganala Naga|last2=Kamat|first2=Anand Gopalkrishna|last3=Prabahar|first3=Koilpillai Joseph|last4=Handa|first4=Vijay Kumar|last5=Srinu|first5=Kukunuri Naga Venkata Satya|last6=Babu|first6=Korupolu Raghu|last7=Sanasi|first7=Paul Douglas|title=Commercial Scale Process of Galanthamine Hydrobromide Involving Luche Reduction: Galanthamine Process Involving Regioselective 1,2-Reduction of α,β-Unsaturated Ketone|journal=Organic Process Research &amp; Development|date=15 March 2013|volume=17|issue=3|pages=406–412|doi=10.1021/op300337y}}&lt;/ref&gt; Lanthanides exist in many forms other than coordination complexes and many of these are industrially useful. In particular lanthanide  oxides are used as heterogeneous catalysts in various industrial processes.

==&amp;#160;&amp;#160;5.13 Discussion questions==
*Discuss chelating ligands and what they do, using some new examples.
*Explain (using some new examples) how we know if an octahedral complex of a metal ion will be high spin or low spin, and what measurements we can do to confirm it.

==&amp;#160;&amp;#160;5.14 Problems==

1.	Predict the molecular geometry of the following complexes, and determine whether each will be diamagnetic or paramagnetic:


(a) [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b) [Ru(ox)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;  (ox = oxalate, C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)

(c) [Ag(CN)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;-&lt;/sup&gt;

(d) [W(CO)&lt;sub&gt;6&lt;/sub&gt;]

(e) [Ir(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


2.    For each of the following transition metal complexes, give (i) the d-electron count), (ii) the approximate molecular geometry of the complex, and (iii) an energy level diagram showing the splitting and filling of the d-orbitals. 

(a)[Os(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt;

(b)''cis-''PtCl&lt;sub&gt;2&lt;/sub&gt;(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;

(c) [Cu(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt;


3.	Octahedral transition metal complexes can be either high or low spin. Is the same true of tetrahedral and square planar complexes? Explain why or why not.


4.	For each of the transition metal complexes in the table below, give the d electron count, number of unpaired electrons, and electronic configurations. Give the number of electrons in the t&lt;sub&gt;2g&lt;/sub&gt; and e&lt;sub&gt;g&lt;/sub&gt; sets of 3d orbitals that are consistent with the observed magnetic moments.

{| class=&quot;wikitable&quot;
|-
! Compound !! µ (BM)
!d electron count
!number of unpaired electrons
!electonic configuration
|-
| a. [Fe(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; || 1.8
|
|
|
|-
| b. [Fe(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;5&lt;/sub&gt;(H&lt;sub&gt;2&lt;/sub&gt;O)]&lt;sup&gt;3+&lt;/sup&gt; || 6.1
|
|
|
|-
| c. [Fe(NCS)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt; || 5.0
|
|
|
|-
| d. [Cr(acac)&lt;sub&gt;3&lt;/sub&gt;] || 3.9
|
|
|
|}


5.   For each of the following pairs, identify the complex with the higher crystal field stabilization energy (and show your work).

(a) [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3-&lt;/sup&gt; vs. [Mn(CN)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;4-&lt;/sup&gt;&lt;br /&gt;

(b) [Ni(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;  vs. [Cd(en)&lt;sub&gt;2&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;, where en = H&lt;sub&gt;2&lt;/sub&gt;NCH&lt;sub&gt;2&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;&lt;br /&gt;

(c) [Cr(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;3+&lt;/sup&gt;  vs.  [Mn(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt;


6.	In a solution made by combining FeCl&lt;sub&gt;3&lt;/sub&gt; with excess ethylenediaminetetraacetic acid (EDTA) at neutral pH, the concentration of Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) ions is on the order of 10&lt;sup&gt;-17&lt;/sup&gt; M.  However, in a solution of ethylenediamine and acetic acid at comparable concentration, the Fe&lt;sup&gt;3+&lt;/sup&gt;(aq) concentration is about 10&lt;sup&gt;-7&lt;/sup&gt;, i.e., 10&lt;sup&gt;10&lt;/sup&gt; times higher.  Explain. 


7.	The complex [VO(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is blue, while the analogous complex with another monodentate neutral ligand L, [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is yellow.  How many of the following statements are true? Explain briefly.

(a) L is a stronger field ligand than H&lt;sub&gt;2&lt;/sub&gt;O.

(b) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is a high-spin complex.

(c) [VO(L)&lt;sub&gt;5&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; absorbs yellow light.

(d) Both complexes have one 3d electron associated with the metal.


8.	OH&lt;sup&gt;-&lt;/sup&gt; and NH&lt;sub&gt;3&lt;/sub&gt; are both Brønsted bases, and both can form complexes with metal ions.  Explain how OH&lt;sup&gt;-&lt;/sup&gt; can be a much stronger Brønsted base than NH&lt;sub&gt;3&lt;/sub&gt;, and at the same time much lower in the spectrochemical series.


9.   A solution of [Ni(H&lt;sub&gt;2&lt;/sub&gt;O)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; is faint green and paramagnetic (µ = 2.90 BM), whereas a solution of [Ni(CN)&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2-&lt;/sup&gt; is yellow and diamagnetic.  

(a) Draw the molecular geometry and the d-orbital energy level diagrams for each complex, showing the electronic occupancy of the d-orbitals. 

(b) Explain the differences in magnetism and color. 


10.	W. Deng and K. W. Hipps (J. Phys. Chem. B 2003, 107, 10736-10740) reported an STM study of the electronic properties of Ni(II)tetraphenyl porphyrin (NiTPP), a red-purple, neutral diamagnetic complex that is made by reacting Ni(II) perchlorate with tetraphenylporphine.  When NiTPP is reacted with sodium thiocyanate it forms another complex that is paramagnetic.  Draw the structures of NiTPP and the product complex, and the crystal field energy level diagram that explains each.  What value of the magnetic moment (in units of μB) would you expect for the paramagnetic complex?
&lt;br /&gt;
&lt;br /&gt;

[[file:aqua-exchange.png|right|450px]]
11.     Transition metal complexes can undergo ligand exchange reactions, in which a free ligand or solvent molecule substitutes for one of the bound ligands. Because the reactant and product complexes often have different colors, the rate of ligand exchange can be easily measured in &quot;test tube&quot; reactions. The exchange of chemically identical ligands (e.g., a bound water molecule for a free water molecule) can also be measured by NMR spectroscopy and other methods. Interestingly, the rates water exchange vary over a range of ''14 orders of magnitude'' for different metal ions and oxidation states. In some cases it takes weeks for one water molecule to exchange for another.  In other cases, the timescale of the exchange is nanoseconds.

(a) There is an overall trend (see figure at right) in which the exchange rate is slower for higher oxidation states of the metal.  Explain this trend. What does the crystal field stabilization energy have to do with the kinetics of the reaction?

(b) Apart from your answer to (a), explain any trends you observe for the rate of water exchange among divalent metal ions.

(c) Cu&lt;sup&gt;2+&lt;/sup&gt; has an especially fast water exchange rate.  Why?

(d) What are the geometries and d-electron counts of the aquo complexes of the slowest divalent, trivalent, and tetravalent metal ions in the figure? Do they have particularly high or low CFSE's? Explain.


12.    Ligand exchange rates for main group ions increase going down a group, e.g., Al&lt;sup&gt;3+&lt;/sup&gt; &lt; Ga&lt;sup&gt;3+&lt;/sup&gt; &lt; In&lt;sup&gt;3+&lt;/sup&gt;.  For transition metal ions, we see the opposite trend, e.g., Fe&lt;sup&gt;2+&lt;/sup&gt; &gt; Ru&lt;sup&gt;2+&lt;/sup&gt; &gt; Os&lt;sup&gt;2+&lt;/sup&gt;.  Explain why these trends are different.


13.	Seppelt and coworkers reported the very unusual ion [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; in the salt [AuXe&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; (Sb&lt;sub&gt;2&lt;/sub&gt;F&lt;sub&gt;11&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;)&lt;sub&gt;2&lt;/sub&gt; (Science 2000, 290, 117-118).  This was the first report of a compound containing a bond between a metal and a noble gas atom.  Draw a d-orbital energy diagram for this ion and predict whether it should be diamagnetic or paramagnetic.  Would you expect to be able to form a similar complex using Cu in place of Au, or Kr in place of Xe? Why or why not?


14.   For the reaction ''cis''-Mo(CO)&lt;sub&gt;4&lt;/sub&gt;L&lt;sub&gt;2&lt;/sub&gt; + CO → Mo(CO)&lt;sub&gt;5&lt;/sub&gt;L + L, the reaction rate is found to vary by a factor of 500 for two different ligands L, but it is relatively insensitive to the pressure of CO gas. (a) What kind of mechanism does this reaction have? (b) What are the signs of the activation volume and the activation entropy?


15.  In Rosenberg's initial discovery of the biological effects of ''cis-''Pt(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Cl&lt;sub&gt;2&lt;/sub&gt;, the compound was made accidentally by partial dissolution of a Pt anode in an electrolyte solution that contained glucose and magnesium chloride.&lt;ref&gt;{{Cite journal | last1 = Rosenberg | first1 = B. | last2 = Van Camp | first2 = L. | last3 = Krigas | first3 = T. | doi = 10.1038/205698a0 | title = Inhibition of Cell Division in Escherichia coli by Electrolysis Products from a Platinum Electrode | journal = Nature | volume = 205 | issue = 4972 | pages = 698–9 | year = 1965 | pmid =  14287410| pmc = }}&lt;/ref&gt; The electrolysis reaction also produced small amounts of ammonium ions. Explain mechanistically why the ''cis-''isomer is formed selectively under these conditions.

==&amp;#160;&amp;#160;5.15 References==
{{reflist|colwidth=30em}}

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      <text bytes="61104" sha1="7fu1pjmkxwtvcrlu7jh04leodlmhz82" xml:space="preserve">This is for the AQA AS Computer Science Specification.

This is where suggestions can be made about what some of the questions might be and how we can solve them.

'''Please be respectful and do not vandalise or tamper with the page, as this would affect students' preparation for their exams!'''

== Read / Write to binary fil ==
Modify the program in order to allow the user to read / write the transmission (from form of spaces and equals signs) to a binary format (in order to reduce space taken to store)

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# These functions need to be added to relavent subroutines if support for a binary file is required:
# BinaryEncode result passed as parameter to BinaryWrite with filename, called from SendMorseCode (pass MorseCodeString to BinaryEncode)
# BinaryRead result (parameter is file name) passed as parameter to BinaryDecode, and the return is to be used as variable Transmission in GetTransmission()
# Python binary file handling reads / writes in bytes. Therefore, for optimum usage, we need to be making full use of each byte. Letting a space be a 0 and an equals sign be 1, each 8 characters from the currently supported text file become 1 byte. Leftmost character = first value in each byte, 8n th = last byte of array
def BinaryEncode(Message):
    Bytes = []
    Current = 128
    Count = 0
    for Character in Message:
        if Current == 0.5:
            Bytes.append(int(Count))
            Count = 0
            Current = 128
        if Character == '=':
            Count += Current
        Current = Current / 2
    if Count != 0:
        Bytes.append(int(Count))
    return bytes(Bytes) # base10 -&gt; base2 value

def BinaryWrite(Bytes, FileName):
    FileHandle = open(FileName, 'wb')
    FileHandle.write(Bytes)
    FileHandle.flush()
    FileHandle.close()

def BinaryRead(FileName):
    FileHandle = open(FileName, 'rb')
    ByteValues = list(FileHandle.read()) # base2 -&gt; base10 value
    FileHandle.close()
    return ByteValues

def BinaryDecode(Bytes):
    Message = str()
    for Byte in Bytes:
        for BitValue in [128, 64, 32, 16, 8, 4, 2, 1]:
            if Byte &gt;= BitValue:
                Byte -= BitValue
                Message += '='
            else:
                Message += ' '
    return Message

# Example usage (using message from preliminary material
Bin = (BinaryEncode(&quot;===   =   = ===       === = = === &quot;))
BinaryWrite(Bin, 'binfile')
print(BinaryDecode(BinaryRead('binfile')))

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Substitution Cipher ==

This question refers to the subroutines '''GetTransmission''' and '''ReceiveMorseCode'''. The question requires the creation of subroutines '''GetKey''' and '''DecryptTransmission'''.

The '''Skeleton Program''' is to be adapted so that messages encrypted with a substitution cipher can be '''received''' and '''decrypted'''. The method of decryption will be to apply a '''decryption key''' to the message.

In a substitution cipher, every character is replaced with another character. For example, every letter A could be substituted with the number 7.

The '''decryption key''' will be stored in a text file, consisting of 36 characters. The first 26 characters will represent the letters A – Z and the next 10 will represent the numbers from 0 – 9. 

A new subroutine GetKey needs to be created, which will read and return the key from a '''file specified by the user'''. If no key is specified, the subroutine should return the key: ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789. This key should be interpreted to mean that every character represents itself.

A new subroutine DecryptTransmission needs to be created, which will apply the decryption key to the transmission. It will be called by a new line in ReceiveMorseCode, to be inserted '''before''' print(PlainText):

PlainText = DecryptTransmission(PlainText).

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def ReceiveMorseCode(Dash, Letter, Dot): 
  PlainText = EMPTYSTRING
  MorseCodeString = EMPTYSTRING
  Transmission = GetTransmission() 
  LastChar = len(Transmission) - 1
  i = 0
  while i &lt; LastChar:
    i, CodedLetter = GetNextLetter(i, Transmission)
    MorseCodeString = MorseCodeString + SPACE + CodedLetter
    PlainTextLetter = Decode(CodedLetter, Dash, Letter, Dot)
    PlainText = PlainText + PlainTextLetter
  print(MorseCodeString)
  PlainText = DecryptTransmission(PlainText)
  print(PlainText)

def GetKey():
    theline = ''
    with open('keykey.txt', 'r') as decryptionkey:
        for line in decryptionkey:
            theline = line
    return theline

def DecryptTransmission(gibberish):
    keys = GetKey()
    #print(keys)
    keylst = []
    for i in keys:
        keylst.append(i)
    actualword = list('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
    decryptedmessage = ''
    
    for lettertodecrypt in gibberish:
        if lettertodecrypt in keys:
          decryptedmessage += actualword[keylst.index(lettertodecrypt)]
        elif lettertodecrypt == ' ':
          decryptedmessage += ' '
        else:
            print('Invalid')
    
    return decryptedmessage
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a menu option ==
The program currently just prints the menu again when an incorrect option is input; add validation so the program prints a message when an invalid option is input.
{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
switch (MenuOption)
{
    case &quot;R&quot;:
        ReceiveMorseCode(Dash, Letter, Dot);
        break;
    case &quot;S&quot;:
        SendMorseCode(MorseCode);
        break;
    case &quot;X&quot;:
        ProgramEnd = true;
        break;
    default:
        Console.WriteLine(&quot;You have made an invalid selection. Try again&quot;);
        break;
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if (MenuOption = 'R') or (MenuOption ='r') then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if (MenuOption = 'S') or (MenuOption='s') then
        SendMorseCode(MorseCode)
      else if (MenuOption = 'X') or (menuOption='x') then
        ProgramEnd := True
      else
        writeln('you did not enter a valid option.');
        readln;
    end;
end
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetMenuOption():
  MenuOption = EMPTYSTRING
  Correct = False
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;)
    if MenuOption == 'R' or MenuOption == 'S' or MenuOption == 'X':
      Correct = True
    else:
{{CPTAnswerTab|C#}}

      MenuOption = input(&quot;Invalid choice. Re-Enter your choice: &quot;)
  return MenuOption

## Change from lower to upper case with ascii incase they lead you up to it or tell you to use ascii instead of .upper()
def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = raw_input(&quot;Enter your choice: &quot;)
    Ascii = ord(MenuOption)
    if Ascii&gt;=97:
      Ascii=Ascii-32
    MenuOption=chr(Ascii)
  return MenuOption
  
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Translate transmission directly to English (bypass file)  ==
Update receive signal to allow direct input rather than txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
private static string GetTransmission()
        {
            string choice = EMPTYSTRING;//declares to empty
            Console.WriteLine (&quot;Would you like to load a file (Y/N)&quot;);//outputs the line
            choice = Console.ReadLine().ToUpper();//assigns the value
            string Transmission;//declares
            if (choice == &quot;Y&quot;)
            {
                string FileName = EMPTYSTRING; //declare
                Console.Write(&quot;Enter file name: &quot;);//outputty
                FileName = (Console.ReadLine() + &quot;.txt&quot;);//assigns
                try//error handling
                {
                    Transmission = File.ReadAllText(FileName);//assings varaible to text from the file in bin
                    Transmission = StripLeadingSpaces(Transmission);//removes spaces at the start of the transmission
                    if (Transmission.Length &gt; 0)//chekcs length
                    {
                        Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                        Transmission = Transmission + EOL; //adds the global to it
                    }
                }
                catch
                {
                    ReportError(&quot;No transmission found&quot;); //catches if the try errors calling sub
                    //give instructions
                    Console.WriteLine(&quot;Please enter a valid text file name that is in the bin/debug&quot;);
                    Transmission = EMPTYSTRING;//assigns it to empty
                }
            }
            else
            {
                Console.WriteLine(&quot;Please enter your transmission&quot;);//outputs
                Transmission = Console.ReadLine();//assigns
                Transmission = StripLeadingSpaces(Transmission);//strips spaces at the start
                if (Transmission.Length &gt; 0)//chekcs length
                {
                    Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                    Transmission = Transmission + EOL; //adds the global to it
                }
            }
            return Transmission;//returns transmission
        }
THIS REQUIRES AN INPUT OF TRANSMISSION RATHER THAN DIRECT MORSE
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmissionFromFile() : String;
var
  FileName : String;
  FileHandle : Textfile;
  Transmission : String;
begin
  write('Enter file name: ');
  readln(FileName);
  try
    assign(FileHandle,FileName);
    reset(FileHandle);
    readln(FileHandle, Transmission);
    close(FileHandle);
    Transmission := StripLeadingSpaces(Transmission);
    if length(Transmission) &gt; 0 then
      begin
        Transmission := StripTrailingSpaces(Transmission);
        Transmission := Transmission + EOL;
      end;
  except
    on E: exception do
      begin
        ReportError('No transmission found');
        Transmission := EMPTYSTRING;
      end;
  end ;
  GetTransmissionFromFile := Transmission;
end;

Function GetTransmissionFromInput() : String;
var
  transmission : String;
begin
  writeln('please enter your transmission (using = to signify on and a space to represent off) ');
  readln(transmission);
  Transmission :=StripLeadingSpaces(Transmission);
  if length(Transmission) &gt; 0 then
    begin
      Transmission := StripTrailingSpaces(Transmission);
      Transmission := Transmission + EOL;
    end;
  GetTransmissionFromInput := Transmission;
end;

Function GetAnyTransmission() : string;
var
  choice: string;
  valid: integer;
begin
  repeat
    begin
      writeln('Do you want to receive transmission from a file?(Y/N) ');
      readln (choice);
      if (Choice = 'Y') or (Choice = 'y') or (Choice = 'yes') or (Choice= 'YES') or (Choice= 'Yes') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromFile();
        end
      else if (Choice ='N') or (Choice = 'n') or (Choice = 'no') or (Choice= 'NO') or (Choice ='No') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromInput();
        end
      else
        begin
          valid := 0;
          writeln('You have not entered a valid response');
        end;
      end;
    until Valid = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetTransmission():
  choice = input(&quot;Would you like to load a file? (Y/N): &quot;)

  if choice == &quot;Y&quot;:
    FileName = input(&quot;Enter file name: &quot;)

    try:
      FileHandle = open(FileName, 'r')
      Transmission = FileHandle.readline()
      FileHandle.close()
      Transmission = StripLeadingSpaces(Transmission)
      if len(Transmission) &gt; 0:
        Transmission = StripTrailingSpaces(Transmission)
        Transmission = Transmission + EOL
    except:
      ReportError(&quot;No transmission found&quot;)
      Transmission = EMPTYSTRING
  else:
    Transmission = input(&quot;Enter your transmission String: &quot;)
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
      
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Dim choice As String
        Console.WriteLine(&quot;Do you wish to load a file?&quot;)
        choice = Console.ReadLine
        If choice = &quot;yes &quot; Then
            Console.Write(&quot;Enter file name: &quot;)
            Try
                Filename = Console.ReadLine()
                Dim Reader As New StreamReader(Filename)
                Transmission = Reader.ReadLine
                Reader.Close()
                Transmission = StripLeadingSpaces(Transmission)
                If Transmission.Length() &gt; 0 Then
                    Transmission = StripTrailingSpaces(Transmission)
                    Transmission = Transmission + EOL
                End If
            Catch
                ReportError(&quot;No transmission found&quot;)
                Transmission = EMPTYSTRING
            End Try
        Else
            Console.WriteLine(&quot;please enter the morse code string&quot;)
            Transmission = Console.ReadLine
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        End If
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save a .txt file when sending Morse Code ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
static void sendMorseCode(String[] morseCode) throws IOException {
		Console.write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
		String plainText = Console.readLine();
		plainText=plainText.toUpperCase();
		int plainTextLength = plainText.length();
		String morseCodeString = EMPTYSTRING;
		int index;
		for (int i = 0; i &lt; plainTextLength; i++) {
			char plainTextLetter = plainText.charAt(i);
			if (plainTextLetter == SPACE) {
				index = 0;
			} else {
				index = (int) plainTextLetter - (int) 'A' + 1;
			}
			String codedLetter = morseCode[index];
			morseCodeString = morseCodeString + codedLetter + SPACE;
		}
		Console.writeLine(morseCodeString);
		System.out.println(&quot;Do you want to save you message \n 1:Y \n 2:N&quot;);
		String choice = scan.next();
		switch(choice) {
		case &quot;Y&quot;:
			filewriter(morseCodeString);

			break;
		case &quot;N&quot;:
			break;
		default:
			System.out.println(&quot;That was not an option /n Your data will be stored&quot;);
			filewriter(morseCodeString);

			break;
		}
	}
	public static void filewriter(String sendMorseCode) throws IOException {
		System.out.println(&quot;Enter the name of the file&quot;);
		String filename = scan.next();
		FileWriter fw = new FileWriter(filename);
		PrintWriter end = new PrintWriter(fw);
		end.print(sendMorseCode);
		end.close();
		fw.close();
	}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
  #SBaker May 18 4.	Save a text file when sending Morse Code
  #we need to format MorseCodeString into the output format
  outputString = ''
  for letter in MorseCodeString:
    if letter == '.':
      outputString = outputString + &quot;= &quot;
    elif letter == '-':
      outputString = outputString + &quot;=== &quot;
    elif letter == ' ':
      outputString = outputString + &quot;  &quot;
  FileName = input(&quot;Enter file name: &quot;)
  try:
    FileHandle = open(FileName, 'w')
    FileHandle.write(outputString)
    FileHandle.close()
  except:
    ReportError(&quot;No file found&quot;)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainText = PlainText.ToUpper()

        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;Would you like to save this to a text file?&quot;)
        Dim save As String = Console.ReadLine()
        If save = &quot;Y&quot; Or save = &quot;y&quot; Then
            Dim fileTitle As String
            Console.WriteLine(&quot;What would you like to call the file?&quot;)
            fileTitle = Console.ReadLine()
            Dim fileLoc As String
            fileLoc = &quot;H:\Documents\2018 June\VB\&quot; + fileTitle + &quot;.txt&quot;
            Dim fs As New FileStream(fileLoc, FileMode.CreateNew, FileAccess.Write)
            Dim sw As New StreamWriter(fs)
            sw.WriteLine(MorseCodeString)
            sw.Flush()
        Else
            Console.WriteLine(&quot;Okay.&quot;)
            Console.ReadLine()
        End If
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Create and save transmission signal when sending ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add EncodeMorseCode(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void EncodeMorseCode(string MorseCode)        // Function to convert MorseCodeString to the '=' and (Space) format in Preliminary Material
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string ShouldSave = Console.ReadLine();                 // Check whether user wants to save to file
        if (ShouldSave[0] == 'y' || ShouldSave[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();       // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))             // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;                     // Append .txt if not present
                }
                                                        
                StreamWriter CodedFileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)

                // Use the built-in .Replace(old, new) method to swap out the relevant characters in C#.
                string CodedOutput = MorseCode.Replace(&quot;-&quot;, &quot;=== &quot;).Replace(&quot;.&quot;, &quot;= &quot;).Replace(&quot;  &quot;, &quot;   &quot;).Replace(&quot;      &quot;, &quot;       &quot;);
                // This now effectively formats the MorseCodeString message to the '=' and ' ' format

                CodedFileSaver.Write(CodedOutput);

                CodedFileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling
            }
            Console.WriteLine(&quot;Coded File successfully written&quot;);
        }
     }

// S Wood - Teach

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveTransmission(Transmission : string);
var
  FileHandle : TextFile;
begin
  AssignFile(FileHandle, 'Message.txt');
  try
    rewrite (FileHandle);
    writeln (FileHandle, Transmission);
    CloseFile (FileHandle);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter, TransmissionString : String;
  PlainTextLength, i, Index, k : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  TransmissionString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      for k := 1 to length(CodedLetter) do
      begin
        case CodedLetter[k] of
          ' ': TransmissionString += ' ';
          '.': TransmissionString += '=';
          '-': TransmissionString += '==='
        end;
      TransmissionString += ' ';
      end;
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      if i &lt;&gt; PlainTextLength then
        TransmissionString += '  ';
    end;
  writeln(MorseCodeString);
  SaveTransmission(TransmissionString);
  writeln ('Message encoded and saved in Message.txt');
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
for (int i = 0; i &lt; morseCodeString.length(); i++) {
            char c = morseCodeString.charAt(i);
            if (c == '-') {
                morseCodeTransmission = morseCodeTransmission + &quot; ===&quot;;
            }
            if (c == '.') {
                morseCodeTransmission = morseCodeTransmission + &quot; =&quot;;
            }
            if (c == ' ') {
                morseCodeTransmission = morseCodeTransmission + &quot;  &quot;;
            }
        }

        System.out.println(&quot;Name the file you would like to save this too&quot;);

        String fileName = Console.readLine();
        if (!fileName.contains(&quot;.txt&quot;)) {
            fileName = fileName + &quot;.txt&quot;;
        }
        try {
            BufferedWriter fileHandle = new BufferedWriter(new FileWriter(fileName));
            fileHandle.write(morseCodeTransmission);
            fileHandle.close();
        } catch (IOException e) {
        }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if '    '+FileName[-4].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Dim save As Integer
        Dim file As StreamWriter
        Dim file2 As String
        Dim morsecodesymbol As String
        Dim morsecodesymbolR As String
        Dim morsecodemessage As String

        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else

                If Asc(PlainTextLetter) &lt; 65 Then
                    Index = Asc(PlainTextLetter) - 21
                Else
                    Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
                End If
            End If

            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE + SPACE + SPACE

        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;would you like to save your message in a document? If so then please press 1 if not press 2&quot;)
        Try
            save = Console.ReadLine
        Catch ex As Exception
            Console.WriteLine(&quot;you have messed up the saving program, please do as asked&quot;)
        End Try
        If save = 1 Then
            Console.WriteLine(&quot;your file will be saved please choose a name&quot;)
            file2 = Console.ReadLine &amp; &quot;.txt&quot;
            For i = 0 To MorseCodeString.Length - 1
                morsecodesymbol = MorseCodeString(i)
                If morsecodesymbol = &quot;-&quot; Then
                    morsecodesymbolR = &quot;===&quot;
                ElseIf morsecodesymbol = &quot;.&quot; Then
                    morsecodesymbolR = &quot;=&quot;
                ElseIf morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot; &quot;
                ElseIf morsecodesymbol = SPACE And morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot;     &quot;
                End If
                morsecodemessage = morsecodemessage &amp; &quot; &quot; &amp; morsecodesymbolR
            Next
            File = New StreamWriter(file2)
            File.Write(morsecodemessage)
            File.Close()
        End If

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Add Morse code for numbers/symbols ==
Allow the user to convert numbers and punctuation (for which there is Morse code available) into Morse code.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def SendReceiveMessages(): # All lists here have been modified to support numbers &amp; some punctuation ( .,?! ) by adding indexes 27 onwards. This has been modified so that sending &amp; receiving (if only sending required, only the MorseCode list requires changing) works.
  Dash = [20,23,0,45,24,1,0,17,31,21,28,25,0,15,11,42,0,0,46,22,13,48,30,10,0,0,44,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,27,0,38,40,37,0,29] 
  Dot = [5,18,33,0,2,9,0,26,32,19,0,3,0,7,4,43,0,0,12,8,14,6,0,16,0,0,34,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,36,35,0,0,46,39,47] 
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', ',', '?', '!'] 
  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..', '-----', '.----', '..---', '...--', '....-', '.....', '-....', '--...', '---..', '----.', '.-.-.-', '--..--', '..--..', '-.-.--'] 
  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True

def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
        Index = 0
    elif PlainTextLetter.isalpha(): # Character in position is a letter
      Index = ord(PlainTextLetter.upper()) - ord('A') + 1
    elif PlainTextLetter.isnumeric(): # Character in position is a number
      # 0 needs to be at index 27, so subtract unicode value of 0 and add 27 to get index of all numbers
      Index = ord(PlainTextLetter) - ord('0') + 27 
    else: # Is not a number / letter / space, assume it is a symbol. If statements for all supported symbols, setting index to position in MorseCode list
      if PlainTextLetter == '.':
        Index = 37 
      elif PlainTextLetter == ',': 
        Index = 38
      elif PlainTextLetter == '?':
        Index = 39
      elif PlainTextLetter == '!':
        Index = 40
      else: # Unsupported character, replace with space (could also output error here if needed)
        Index = 0 
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendReceiveMessages()
        Dim Dash = {20, 23, 0, 0, 24, 1, 0, 17, 31, 21, 28, 25, 0, 15, 11, 37, 45, 0, 40, 22, 13, 341, 30, 10, 0, 0, 44, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 46, 0, 0, 0, 0, 0, 0, 0}
        Dim Letter = {&quot; &quot;, &quot;A&quot;, &quot;B&quot;, &quot;C&quot;, &quot;D&quot;, &quot;E&quot;, &quot;F&quot;, &quot;G&quot;, &quot;H&quot;, &quot;I&quot;, &quot;J&quot;, &quot;K&quot;, &quot;L&quot;, &quot;M&quot;, &quot;N&quot;, &quot;O&quot;, &quot;P&quot;, &quot;Q&quot;, &quot;R&quot;, &quot;S&quot;, &quot;T&quot;, &quot;U&quot;, &quot;V&quot;, &quot;W&quot;, &quot;X&quot;, &quot;Y&quot;, &quot;Z&quot;, &quot;0&quot;, &quot;1&quot;, &quot;2&quot;, &quot;3&quot;, &quot;4&quot;, &quot;5&quot;, &quot;6&quot;, &quot;7&quot;, &quot;8&quot;, &quot;9&quot;, &quot;OT&quot;, &quot;ö&quot;, &quot;/&quot;, &quot;Ä&quot;, &quot;ü&quot;, &quot;+&quot;, &quot;üe&quot;, &quot;ZT&quot;, &quot;Á&quot;, &quot;,&quot;, &quot;@&quot;, &quot;.&quot;, &quot;?&quot;}
        Dim Dot = {5, 18, 33, 0, 2, 9, 0, 26, 32, 19, 0, 3, 0, 7, 4, 38, 0, 0, 12, 8, 14, 6, 0, 16, 39, 0, 34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 43, 48, 49, 0, 47}
        Dim MorseCode = {&quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot;, &quot;-----&quot;, &quot;.----&quot;, &quot;..---&quot;, &quot;...--&quot;, &quot;....-&quot;, &quot;.....&quot;, &quot;-....&quot;, &quot;--....&quot;, &quot;---...&quot;, &quot;----..&quot;, &quot;-----.&quot;, &quot;----&quot;, &quot;---.&quot;, &quot;-··-·&quot;, &quot;.-.-&quot;, &quot;..--&quot;, &quot;.-.-.&quot;, &quot;..--.&quot;, &quot;--..-&quot;, &quot;.--.-&quot;, &quot;--..--&quot;, &quot;.--.-.&quot;, &quot;.-.-..&quot;, &quot;..--..&quot;}

- Symbols work in progress numbers work!

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a message to send ==
Currently lowercase characters crash the program, add functionality to translate lowercase letters and correctly translate numbers/symbols

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
// Does not have numbers or symbols. Any other instances in the code where it does not allow lower case use the code equalsIgnoreCase(
// The code below shows it working in the menu of the Program
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Currently only supports lowercase letters &amp; prevents invalid characters. Needs modifying to support numbers.
def SendMorseCode(MorseCode):
  Error = True # Input validation
  while Error: # Repeat the code in this section until input is valid
    Error = False # Assume no errors until one is detected
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter.upper()) - ord('A') + 1 # .upper() added to support lowercase characters
      try: # Attempt to find morse code for current character
        CodedLetter = MorseCode[Index]
        MorseCodeString = MorseCodeString + CodedLetter + SPACE
      except: # Has been an issue finding morse code for character - inform user of this &amp; re-run loop to allow a new input
        print(&quot;Invalid character in message.&quot;)
        Error = True # Set error to true so loop re-runs
        break # Break for loop to go back to start of Error loop (and ask for a new input)
  print(MorseCodeString)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Automatically append '.txt' to file. ==
Code that makes it obsolete for the user to add the '.txt' extension to their file name

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
FileName = FileName.Contains(&quot;.txt&quot;) ? FileName : FileName + &quot;.txt&quot;;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmission(): String;
var
  FileName, FileNameOriginal: String;
  FileHandle: Textfile;
  Transmission: String;
begin
  write('Enter file name: ');
  readln(FileNameOriginal);    {Variable was originally set as FileName but was changed for Concentrate}
  FileName := Concat(FileNameOriginal,'.txt');

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
   
  static void sendMorseCode(String[] morseCode) throws IOException
  {
    Console.write(&quot;Enter your message (letters and spaces only): &quot;);
    String plainText = Console.readLine();
    plainText = plainText.toUpperCase();
    int plainTextLength = plainText.length();
    String morseCodeString = EMPTYSTRING;
    int index;
    for (int i = 0; i &lt; plainTextLength; i++)
    {
      char plainTextLetter = plainText.charAt(i);
      if (plainTextLetter == SPACE)
      {
        index = 0;
      }
      else
      {
        index = (int)plainTextLetter - (int)'A' + 1;
      }
      String codedLetter = morseCode[index];
      morseCodeString = morseCodeString + codedLetter + SPACE;
    }
    Console.writeLine(morseCodeString);
    Save(morseCodeString);
  }
  
  
  public static void Save(String pop) throws IOException {
	  System.out.println(&quot;Enter file name: &quot;);
	  Scanner scan = new Scanner(System.in);
	  String f = scan.next();
	  FileWriter file = new FileWriter(f+&quot;.txt&quot;, true);
	  PrintWriter print = new PrintWriter(file);
	  print.println(pop);
	  print.flush();
	  print.close();
  }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def GetTransmission():
  FileName = input(&quot;Enter file name: &quot;)
  if FileName[-4:] != '.txt': # If last 4 characters match .txt - the 4 spaces appended to the start of string are to prevent the string being shorted than the indexes being checked
        FileName += '.txt' # Append .txt to end of file name
  try:
    FileHandle = open(FileName, 'r')
    Transmission = FileHandle.readline()
    FileHandle.close()
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
  except:
    ReportError(&quot;No transmission found&quot;)
    Transmission = EMPTYSTRING
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Console.Write(&quot;Enter file name: &quot;)
        Try
            Filename = Console.ReadLine()
            Filename = Filename + &quot;.txt&quot;
            Dim Reader As New StreamReader(Filename)
            Transmission = Reader.ReadLine
            Reader.Close()
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        Catch
            ReportError(&quot;No transmission found&quot;)
            Transmission = EMPTYSTRING
        End Try
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save message in a text file ==
Code that save the translated code in a text file

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveMorseToFile(MorseString : string);   //added to save morse
var
  FileMorse:TextFile;
begin
  AssignFile(FileMorse, 'MorseFile.txt');
  try
    rewrite(FileMorse);
    writeln(FileMorse, MorseString);
    CloseFile(FileMorse);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
  SaveMorseToFile(MorseCodeString);//Saves it to a file
  writeln('Saved to MorseFile.txt');
end;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void write(String morseCodeString) throws IOException 
	{
		FileWriter fw = new FileWriter (&quot;morse.txt&quot;);
		PrintWriter output = new PrintWriter (fw);
		output.println(morseCodeString);
		output.close();
		output.flush();
		System.out.println(&quot;Printed in morse.txt&quot;);
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if FileName[-4:].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== List Characters ==
Output a list of all of the characters from the list next to their Morse code representation.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// NEW SUBROUTINE- Letter and MorseCode lists are passed as parameters/arguments
private static void ListMorseCode(char[] Letter, string[] MorseCode)
{
    for (int index = 0; index &lt; Letter.Length; index++)      // for loop - loops through all elements in the Letter Array
    {
        Console.WriteLine(Letter[index] + &quot;   &quot; + MorseCode[index]);     // Output the text character, followed by a few spaces, and then the Morse code representation
    }
}

// AMENDED SUBROUTINE
private static void DisplayMenu()
{
    Console.WriteLine();
    Console.WriteLine(&quot;Main Menu&quot;);
    Console.WriteLine(&quot;=========&quot;);
    Console.WriteLine(&quot;R - Receive Morse code&quot;);
    Console.WriteLine(&quot;S - Send Morse code&quot;);
    Console.WriteLine(&quot;L - List Morse code characters&quot;);         // Added - display menu option for this modification
    Console.WriteLine(&quot;X - Exit program&quot;);
    Console.WriteLine();
}

// AMENDED SUBROUTINE
private static void SendReceiveMessages()
{
    int[] Dash = new int[] { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
    int[] Dot = new int[] { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
    char[] Letter = new char[] { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
    string[] MorseCode = new string[] { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot; };
    bool ProgramEnd = false;
    string MenuOption = EMPTYSTRING;
    while (!ProgramEnd)
    {
        DisplayMenu();
        MenuOption = GetMenuOption();
        if (MenuOption == &quot;R&quot;)
        {
            ReceiveMorseCode(Dash, Letter, Dot);
        }
        else if (MenuOption == &quot;S&quot;)
        {
            SendMorseCode(MorseCode);
        }
        else if (MenuOption == &quot;X&quot;)
        {
            ProgramEnd = true;
        }
        else if (MenuOption == &quot;L&quot;)             // Added - if menu option selected is the 'L' (list Morse code)
        {
            ListMorseCode(Letter, MorseCode);   // Run ListMorseCode subroutine, passing lists Letter and MorseCode
        }
    }
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure DisplayMenu();
begin
  writeln;
  writeln('Main Menu');
  writeln('=========');
  writeln('R - Receive Morse code');
  writeln('S - Send Morse code');
  writeln('L - List Morse code characters');//Added menu option for this
  writeln('X - Exit program');
  writeln;
end;

Procedure ListCharacters(Letter:Array of char; MorseCode:Array of String);   //new procedure for listing
var
  z : integer;
begin
  for z:=0 to 26 do
    writeln(Letter[z],'   ',MorseCode[z]);
end;

Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if MenuOption = 'R' then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if MenuOption = 'S' then
        SendMorseCode(MorseCode)
      else if MenuOption = 'X' then
        ProgramEnd := True
      else if MenuOption = 'L' then
        ListCharacters(Letter, MorseCode); //Added to lead to new procedure
    end;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Added subroutines

def ListMorseCode(Letter, MorseCode): # New subroutine - Letter and MorseCode lists are passed as parameters
  for Pos in range(len(Letter)): # Loop through all positions in the length of the list
    print(Letter[Pos]+&quot;   &quot;+MorseCode[Pos]) # Output the text character, followed by a few spaces, and then the Morse code representation

# Existing modified subroutines

def DisplayMenu():
  print()
  print(&quot;Main Menu&quot;)
  print(&quot;=========&quot;)
  print(&quot;R - Receive Morse code&quot;)
  print(&quot;S - Send Morse code&quot;)
  print(&quot;L - List Morse code characters&quot;) # Added - display menu option for this modification
  print(&quot;X - Exit program&quot;)
  print()

def SendReceiveMessages():
  Dash = [20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0]
  Dot = [5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0]
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..']

  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True
    elif MenuOption == 'L': # Added - if menu option selected is the 'L' (list Morse code)
      ListMorseCode(Letter, MorseCode) # Run ListMorseCode subroutine, passing lists Letter and MorseCode

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Accept multiple lines of text to convert to Morse code ==
Description of question

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter,x : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
  continue : integer;
begin
  continue:= 0;
  repeat
    write('Enter your message (uppercase letters and spaces only): ');
    readln(PlainText);
    PlainTextLength := length(PlainText);
    MorseCodeString := EMPTYSTRING;
    for i := 1 to PlainTextLength do
      begin
        PlainTextLetter := PlainText[i];
        if PlainTextLetter = SPACE then
          Index := 0
        else
          Index := ord(PlainTextLetter) - ord('A') + 1;
        CodedLetter := MorseCode[Index];
        MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      end;
    writeln(MorseCodeString);
    write('Continue (Y or N): ');
    readln(x);
    if (x = 'Y') or (x ='y') then //start of continue
        continue:= 0
      else if (x = 'N') or (x = 'n') then
        continue:= 1
      else
        begin
          writeln('Interpreting answer as no');//could be made to loop if needed
          continue:=1;
        end;
  until continue = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  Continue = 0
  while Continue != 1:
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter) - ord('A') + 1
      CodedLetter = MorseCode[Index]
      MorseCodeString = MorseCodeString + CodedLetter + SPACE
    print(MorseCodeString)
    x = input(&quot;Continue Y/N?: &quot;)
    if x == &quot;Y&quot; or x == &quot;y&quot;:
      Continue = 0
    elif x == &quot;N&quot; or x == &quot;n&quot;:
      Continue = 1
    else:
      print(&quot;Interpreting answer as no&quot;)
      Continue = 1
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Accept lowercase letters ==
This will accept the input of lowercase characters

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// AMENDED SUBROUTINE - Allows Lowercase values in Send string now. (ASCII values used)
private static void SendMorseCode(string[] MorseCode)
{
    Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
    string PlainText = Console.ReadLine();
    int PlainTextLength = PlainText.Length;
    string MorseCodeString = EMPTYSTRING;
    char PlainTextLetter = SPACE;
    int Index = 0;

    int ascii;              // declare new value 'ascii' to store that value.

    for (int i = 0; i &lt; PlainTextLength; i++)
    {
        PlainTextLetter = PlainText[i];
        if (PlainTextLetter == SPACE)
        {
            Index = 0;
        }
        else
        {
            if ((int)PlainTextLetter &gt;= 97)             // if ASCII Value of that letter is 97 or above, it is assumed to be lowercase.
                ascii = (int)PlainTextLetter - 32;      // if lowercase then subtract 32 from its ASCII value
            else
                ascii = (int)PlainTextLetter;           // else it is uppercase, then use that ASCII value.

            Index = ascii - (int)'A' + 1;               // use the 'ascii' value to calculate, just incase lowercase has been used.
        }
        string CodedLetter = MorseCode[Index];
        MorseCodeString = MorseCodeString + CodedLetter + SPACE;
    }
    Console.WriteLine(MorseCodeString);
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index, assci : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        begin   //added to allow lower case letters
          if ord(PlainTextLetter) &gt;= 97 then
            assci:= ord(PlainTextLetter) - 32
          else
            assci:=  ord(PlainTextLetter);
          Index := assci - ord('A') + 1;
        end;                             //should work
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
write ('This is a question: ');
readln(Variable);
Variable := AnsiUpperCase(Variable);
{This can be added for the MenuOption (in GetMenuOption) and Plaintext (in SendMorseCode)}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static char getMenuOption() {
		boolean valid = false;
		char menuOption = ' ';
		while(!valid) {
		String option = EMPTYSTRING;
		Console.write(&quot;Enter menu option&quot;);
		try {
			option = Console.readLine();
		} catch (Exception e) {
			System.out.println(&quot;Invalid input&quot;);
		}
		if (option.equalsIgnoreCase(&quot;R&quot;))
			menuOption = 'R'; valid = true;
		if (option.equalsIgnoreCase(&quot;S&quot;))
			menuOption = 'S'; valid = true;
		if (option.equalsIgnoreCase(&quot;X&quot;)) {
			menuOption = 'X'; valid = true;
		}
		else if (!valid) {
				System.out.println(&quot;Invalid input&quot;);
			}
		}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()#Changed
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
      Index = 0
    else: 
      Index = ord(PlainTextLetter) - ord('A') + 1
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;).upper()#Changed
  return MenuOption
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter)
                If Index &gt; 96 And Index &lt; 123 Then
                    Index -= 32
                End If
                Index = Index - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        SaveMorseCode(MorseCodeString)
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}</text>
      <sha1>7fu1pjmkxwtvcrlu7jh04leodlmhz82</sha1>
    </revision>
    <revision>
      <id>4636878</id>
      <parentid>4636877</parentid>
      <timestamp>2026-05-21T13:42:11Z</timestamp>
      <contributor>
        <username>NDG</username>
        <id>3510220</id>
      </contributor>
      <minor />
      <comment>Reverted edits by [[Special:Contribs/~2026-30562-12|~2026-30562-12]] ([[User talk:~2026-30562-12|talk]]) to last version by Kai Burghardt: test edits, please use the sandbox</comment>
      <origin>4392737</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="61105" sha1="2xk8fj7k9cbf9gb0l0byqau871al9kv" xml:space="preserve">This is for the AQA AS Computer Science Specification.

This is where suggestions can be made about what some of the questions might be and how we can solve them.

'''Please be respectful and do not vandalise or tamper with the page, as this would affect students' preparation for their exams!'''

== Read / Write to binary file ==
Modify the program in order to allow the user to read / write the transmission (from form of spaces and equals signs) to a binary format (in order to reduce space taken to store)

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# These functions need to be added to relavent subroutines if support for a binary file is required:
# BinaryEncode result passed as parameter to BinaryWrite with filename, called from SendMorseCode (pass MorseCodeString to BinaryEncode)
# BinaryRead result (parameter is file name) passed as parameter to BinaryDecode, and the return is to be used as variable Transmission in GetTransmission()
# Python binary file handling reads / writes in bytes. Therefore, for optimum usage, we need to be making full use of each byte. Letting a space be a 0 and an equals sign be 1, each 8 characters from the currently supported text file become 1 byte. Leftmost character = first value in each byte, 8n th = last byte of array
def BinaryEncode(Message):
    Bytes = []
    Current = 128
    Count = 0
    for Character in Message:
        if Current == 0.5:
            Bytes.append(int(Count))
            Count = 0
            Current = 128
        if Character == '=':
            Count += Current
        Current = Current / 2
    if Count != 0:
        Bytes.append(int(Count))
    return bytes(Bytes) # base10 -&gt; base2 value

def BinaryWrite(Bytes, FileName):
    FileHandle = open(FileName, 'wb')
    FileHandle.write(Bytes)
    FileHandle.flush()
    FileHandle.close()

def BinaryRead(FileName):
    FileHandle = open(FileName, 'rb')
    ByteValues = list(FileHandle.read()) # base2 -&gt; base10 value
    FileHandle.close()
    return ByteValues

def BinaryDecode(Bytes):
    Message = str()
    for Byte in Bytes:
        for BitValue in [128, 64, 32, 16, 8, 4, 2, 1]:
            if Byte &gt;= BitValue:
                Byte -= BitValue
                Message += '='
            else:
                Message += ' '
    return Message

# Example usage (using message from preliminary material
Bin = (BinaryEncode(&quot;===   =   = ===       === = = === &quot;))
BinaryWrite(Bin, 'binfile')
print(BinaryDecode(BinaryRead('binfile')))

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Substitution Cipher ==

This question refers to the subroutines '''GetTransmission''' and '''ReceiveMorseCode'''. The question requires the creation of subroutines '''GetKey''' and '''DecryptTransmission'''.

The '''Skeleton Program''' is to be adapted so that messages encrypted with a substitution cipher can be '''received''' and '''decrypted'''. The method of decryption will be to apply a '''decryption key''' to the message.

In a substitution cipher, every character is replaced with another character. For example, every letter A could be substituted with the number 7.

The '''decryption key''' will be stored in a text file, consisting of 36 characters. The first 26 characters will represent the letters A – Z and the next 10 will represent the numbers from 0 – 9. 

A new subroutine GetKey needs to be created, which will read and return the key from a '''file specified by the user'''. If no key is specified, the subroutine should return the key: ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789. This key should be interpreted to mean that every character represents itself.

A new subroutine DecryptTransmission needs to be created, which will apply the decryption key to the transmission. It will be called by a new line in ReceiveMorseCode, to be inserted '''before''' print(PlainText):

PlainText = DecryptTransmission(PlainText).

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def ReceiveMorseCode(Dash, Letter, Dot): 
  PlainText = EMPTYSTRING
  MorseCodeString = EMPTYSTRING
  Transmission = GetTransmission() 
  LastChar = len(Transmission) - 1
  i = 0
  while i &lt; LastChar:
    i, CodedLetter = GetNextLetter(i, Transmission)
    MorseCodeString = MorseCodeString + SPACE + CodedLetter
    PlainTextLetter = Decode(CodedLetter, Dash, Letter, Dot)
    PlainText = PlainText + PlainTextLetter
  print(MorseCodeString)
  PlainText = DecryptTransmission(PlainText)
  print(PlainText)

def GetKey():
    theline = ''
    with open('keykey.txt', 'r') as decryptionkey:
        for line in decryptionkey:
            theline = line
    return theline

def DecryptTransmission(gibberish):
    keys = GetKey()
    #print(keys)
    keylst = []
    for i in keys:
        keylst.append(i)
    actualword = list('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
    decryptedmessage = ''
    
    for lettertodecrypt in gibberish:
        if lettertodecrypt in keys:
          decryptedmessage += actualword[keylst.index(lettertodecrypt)]
        elif lettertodecrypt == ' ':
          decryptedmessage += ' '
        else:
            print('Invalid')
    
    return decryptedmessage
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a menu option ==
The program currently just prints the menu again when an incorrect option is input; add validation so the program prints a message when an invalid option is input.
{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
switch (MenuOption)
{
    case &quot;R&quot;:
        ReceiveMorseCode(Dash, Letter, Dot);
        break;
    case &quot;S&quot;:
        SendMorseCode(MorseCode);
        break;
    case &quot;X&quot;:
        ProgramEnd = true;
        break;
    default:
        Console.WriteLine(&quot;You have made an invalid selection. Try again&quot;);
        break;
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if (MenuOption = 'R') or (MenuOption ='r') then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if (MenuOption = 'S') or (MenuOption='s') then
        SendMorseCode(MorseCode)
      else if (MenuOption = 'X') or (menuOption='x') then
        ProgramEnd := True
      else
        writeln('you did not enter a valid option.');
        readln;
    end;
end
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetMenuOption():
  MenuOption = EMPTYSTRING
  Correct = False
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;)
    if MenuOption == 'R' or MenuOption == 'S' or MenuOption == 'X':
      Correct = True
    else:
{{CPTAnswerTab|C#}}

      MenuOption = input(&quot;Invalid choice. Re-Enter your choice: &quot;)
  return MenuOption

## Change from lower to upper case with ascii incase they lead you up to it or tell you to use ascii instead of .upper()
def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = raw_input(&quot;Enter your choice: &quot;)
    Ascii = ord(MenuOption)
    if Ascii&gt;=97:
      Ascii=Ascii-32
    MenuOption=chr(Ascii)
  return MenuOption
  
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Translate transmission directly to English (bypass file)  ==
Update receive signal to allow direct input rather than txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
private static string GetTransmission()
        {
            string choice = EMPTYSTRING;//declares to empty
            Console.WriteLine (&quot;Would you like to load a file (Y/N)&quot;);//outputs the line
            choice = Console.ReadLine().ToUpper();//assigns the value
            string Transmission;//declares
            if (choice == &quot;Y&quot;)
            {
                string FileName = EMPTYSTRING; //declare
                Console.Write(&quot;Enter file name: &quot;);//outputty
                FileName = (Console.ReadLine() + &quot;.txt&quot;);//assigns
                try//error handling
                {
                    Transmission = File.ReadAllText(FileName);//assings varaible to text from the file in bin
                    Transmission = StripLeadingSpaces(Transmission);//removes spaces at the start of the transmission
                    if (Transmission.Length &gt; 0)//chekcs length
                    {
                        Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                        Transmission = Transmission + EOL; //adds the global to it
                    }
                }
                catch
                {
                    ReportError(&quot;No transmission found&quot;); //catches if the try errors calling sub
                    //give instructions
                    Console.WriteLine(&quot;Please enter a valid text file name that is in the bin/debug&quot;);
                    Transmission = EMPTYSTRING;//assigns it to empty
                }
            }
            else
            {
                Console.WriteLine(&quot;Please enter your transmission&quot;);//outputs
                Transmission = Console.ReadLine();//assigns
                Transmission = StripLeadingSpaces(Transmission);//strips spaces at the start
                if (Transmission.Length &gt; 0)//chekcs length
                {
                    Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                    Transmission = Transmission + EOL; //adds the global to it
                }
            }
            return Transmission;//returns transmission
        }
THIS REQUIRES AN INPUT OF TRANSMISSION RATHER THAN DIRECT MORSE
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmissionFromFile() : String;
var
  FileName : String;
  FileHandle : Textfile;
  Transmission : String;
begin
  write('Enter file name: ');
  readln(FileName);
  try
    assign(FileHandle,FileName);
    reset(FileHandle);
    readln(FileHandle, Transmission);
    close(FileHandle);
    Transmission := StripLeadingSpaces(Transmission);
    if length(Transmission) &gt; 0 then
      begin
        Transmission := StripTrailingSpaces(Transmission);
        Transmission := Transmission + EOL;
      end;
  except
    on E: exception do
      begin
        ReportError('No transmission found');
        Transmission := EMPTYSTRING;
      end;
  end ;
  GetTransmissionFromFile := Transmission;
end;

Function GetTransmissionFromInput() : String;
var
  transmission : String;
begin
  writeln('please enter your transmission (using = to signify on and a space to represent off) ');
  readln(transmission);
  Transmission :=StripLeadingSpaces(Transmission);
  if length(Transmission) &gt; 0 then
    begin
      Transmission := StripTrailingSpaces(Transmission);
      Transmission := Transmission + EOL;
    end;
  GetTransmissionFromInput := Transmission;
end;

Function GetAnyTransmission() : string;
var
  choice: string;
  valid: integer;
begin
  repeat
    begin
      writeln('Do you want to receive transmission from a file?(Y/N) ');
      readln (choice);
      if (Choice = 'Y') or (Choice = 'y') or (Choice = 'yes') or (Choice= 'YES') or (Choice= 'Yes') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromFile();
        end
      else if (Choice ='N') or (Choice = 'n') or (Choice = 'no') or (Choice= 'NO') or (Choice ='No') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromInput();
        end
      else
        begin
          valid := 0;
          writeln('You have not entered a valid response');
        end;
      end;
    until Valid = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetTransmission():
  choice = input(&quot;Would you like to load a file? (Y/N): &quot;)

  if choice == &quot;Y&quot;:
    FileName = input(&quot;Enter file name: &quot;)

    try:
      FileHandle = open(FileName, 'r')
      Transmission = FileHandle.readline()
      FileHandle.close()
      Transmission = StripLeadingSpaces(Transmission)
      if len(Transmission) &gt; 0:
        Transmission = StripTrailingSpaces(Transmission)
        Transmission = Transmission + EOL
    except:
      ReportError(&quot;No transmission found&quot;)
      Transmission = EMPTYSTRING
  else:
    Transmission = input(&quot;Enter your transmission String: &quot;)
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
      
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Dim choice As String
        Console.WriteLine(&quot;Do you wish to load a file?&quot;)
        choice = Console.ReadLine
        If choice = &quot;yes &quot; Then
            Console.Write(&quot;Enter file name: &quot;)
            Try
                Filename = Console.ReadLine()
                Dim Reader As New StreamReader(Filename)
                Transmission = Reader.ReadLine
                Reader.Close()
                Transmission = StripLeadingSpaces(Transmission)
                If Transmission.Length() &gt; 0 Then
                    Transmission = StripTrailingSpaces(Transmission)
                    Transmission = Transmission + EOL
                End If
            Catch
                ReportError(&quot;No transmission found&quot;)
                Transmission = EMPTYSTRING
            End Try
        Else
            Console.WriteLine(&quot;please enter the morse code string&quot;)
            Transmission = Console.ReadLine
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        End If
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save a .txt file when sending Morse Code ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
static void sendMorseCode(String[] morseCode) throws IOException {
		Console.write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
		String plainText = Console.readLine();
		plainText=plainText.toUpperCase();
		int plainTextLength = plainText.length();
		String morseCodeString = EMPTYSTRING;
		int index;
		for (int i = 0; i &lt; plainTextLength; i++) {
			char plainTextLetter = plainText.charAt(i);
			if (plainTextLetter == SPACE) {
				index = 0;
			} else {
				index = (int) plainTextLetter - (int) 'A' + 1;
			}
			String codedLetter = morseCode[index];
			morseCodeString = morseCodeString + codedLetter + SPACE;
		}
		Console.writeLine(morseCodeString);
		System.out.println(&quot;Do you want to save you message \n 1:Y \n 2:N&quot;);
		String choice = scan.next();
		switch(choice) {
		case &quot;Y&quot;:
			filewriter(morseCodeString);

			break;
		case &quot;N&quot;:
			break;
		default:
			System.out.println(&quot;That was not an option /n Your data will be stored&quot;);
			filewriter(morseCodeString);

			break;
		}
	}
	public static void filewriter(String sendMorseCode) throws IOException {
		System.out.println(&quot;Enter the name of the file&quot;);
		String filename = scan.next();
		FileWriter fw = new FileWriter(filename);
		PrintWriter end = new PrintWriter(fw);
		end.print(sendMorseCode);
		end.close();
		fw.close();
	}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
  #SBaker May 18 4.	Save a text file when sending Morse Code
  #we need to format MorseCodeString into the output format
  outputString = ''
  for letter in MorseCodeString:
    if letter == '.':
      outputString = outputString + &quot;= &quot;
    elif letter == '-':
      outputString = outputString + &quot;=== &quot;
    elif letter == ' ':
      outputString = outputString + &quot;  &quot;
  FileName = input(&quot;Enter file name: &quot;)
  try:
    FileHandle = open(FileName, 'w')
    FileHandle.write(outputString)
    FileHandle.close()
  except:
    ReportError(&quot;No file found&quot;)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainText = PlainText.ToUpper()

        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;Would you like to save this to a text file?&quot;)
        Dim save As String = Console.ReadLine()
        If save = &quot;Y&quot; Or save = &quot;y&quot; Then
            Dim fileTitle As String
            Console.WriteLine(&quot;What would you like to call the file?&quot;)
            fileTitle = Console.ReadLine()
            Dim fileLoc As String
            fileLoc = &quot;H:\Documents\2018 June\VB\&quot; + fileTitle + &quot;.txt&quot;
            Dim fs As New FileStream(fileLoc, FileMode.CreateNew, FileAccess.Write)
            Dim sw As New StreamWriter(fs)
            sw.WriteLine(MorseCodeString)
            sw.Flush()
        Else
            Console.WriteLine(&quot;Okay.&quot;)
            Console.ReadLine()
        End If
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Create and save transmission signal when sending ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add EncodeMorseCode(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void EncodeMorseCode(string MorseCode)        // Function to convert MorseCodeString to the '=' and (Space) format in Preliminary Material
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string ShouldSave = Console.ReadLine();                 // Check whether user wants to save to file
        if (ShouldSave[0] == 'y' || ShouldSave[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();       // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))             // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;                     // Append .txt if not present
                }
                                                        
                StreamWriter CodedFileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)

                // Use the built-in .Replace(old, new) method to swap out the relevant characters in C#.
                string CodedOutput = MorseCode.Replace(&quot;-&quot;, &quot;=== &quot;).Replace(&quot;.&quot;, &quot;= &quot;).Replace(&quot;  &quot;, &quot;   &quot;).Replace(&quot;      &quot;, &quot;       &quot;);
                // This now effectively formats the MorseCodeString message to the '=' and ' ' format

                CodedFileSaver.Write(CodedOutput);

                CodedFileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling
            }
            Console.WriteLine(&quot;Coded File successfully written&quot;);
        }
     }

// S Wood - Teach

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveTransmission(Transmission : string);
var
  FileHandle : TextFile;
begin
  AssignFile(FileHandle, 'Message.txt');
  try
    rewrite (FileHandle);
    writeln (FileHandle, Transmission);
    CloseFile (FileHandle);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter, TransmissionString : String;
  PlainTextLength, i, Index, k : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  TransmissionString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      for k := 1 to length(CodedLetter) do
      begin
        case CodedLetter[k] of
          ' ': TransmissionString += ' ';
          '.': TransmissionString += '=';
          '-': TransmissionString += '==='
        end;
      TransmissionString += ' ';
      end;
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      if i &lt;&gt; PlainTextLength then
        TransmissionString += '  ';
    end;
  writeln(MorseCodeString);
  SaveTransmission(TransmissionString);
  writeln ('Message encoded and saved in Message.txt');
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
for (int i = 0; i &lt; morseCodeString.length(); i++) {
            char c = morseCodeString.charAt(i);
            if (c == '-') {
                morseCodeTransmission = morseCodeTransmission + &quot; ===&quot;;
            }
            if (c == '.') {
                morseCodeTransmission = morseCodeTransmission + &quot; =&quot;;
            }
            if (c == ' ') {
                morseCodeTransmission = morseCodeTransmission + &quot;  &quot;;
            }
        }

        System.out.println(&quot;Name the file you would like to save this too&quot;);

        String fileName = Console.readLine();
        if (!fileName.contains(&quot;.txt&quot;)) {
            fileName = fileName + &quot;.txt&quot;;
        }
        try {
            BufferedWriter fileHandle = new BufferedWriter(new FileWriter(fileName));
            fileHandle.write(morseCodeTransmission);
            fileHandle.close();
        } catch (IOException e) {
        }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if '    '+FileName[-4].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Dim save As Integer
        Dim file As StreamWriter
        Dim file2 As String
        Dim morsecodesymbol As String
        Dim morsecodesymbolR As String
        Dim morsecodemessage As String

        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else

                If Asc(PlainTextLetter) &lt; 65 Then
                    Index = Asc(PlainTextLetter) - 21
                Else
                    Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
                End If
            End If

            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE + SPACE + SPACE

        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;would you like to save your message in a document? If so then please press 1 if not press 2&quot;)
        Try
            save = Console.ReadLine
        Catch ex As Exception
            Console.WriteLine(&quot;you have messed up the saving program, please do as asked&quot;)
        End Try
        If save = 1 Then
            Console.WriteLine(&quot;your file will be saved please choose a name&quot;)
            file2 = Console.ReadLine &amp; &quot;.txt&quot;
            For i = 0 To MorseCodeString.Length - 1
                morsecodesymbol = MorseCodeString(i)
                If morsecodesymbol = &quot;-&quot; Then
                    morsecodesymbolR = &quot;===&quot;
                ElseIf morsecodesymbol = &quot;.&quot; Then
                    morsecodesymbolR = &quot;=&quot;
                ElseIf morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot; &quot;
                ElseIf morsecodesymbol = SPACE And morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot;     &quot;
                End If
                morsecodemessage = morsecodemessage &amp; &quot; &quot; &amp; morsecodesymbolR
            Next
            File = New StreamWriter(file2)
            File.Write(morsecodemessage)
            File.Close()
        End If

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Add Morse code for numbers/symbols ==
Allow the user to convert numbers and punctuation (for which there is Morse code available) into Morse code.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def SendReceiveMessages(): # All lists here have been modified to support numbers &amp; some punctuation ( .,?! ) by adding indexes 27 onwards. This has been modified so that sending &amp; receiving (if only sending required, only the MorseCode list requires changing) works.
  Dash = [20,23,0,45,24,1,0,17,31,21,28,25,0,15,11,42,0,0,46,22,13,48,30,10,0,0,44,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,27,0,38,40,37,0,29] 
  Dot = [5,18,33,0,2,9,0,26,32,19,0,3,0,7,4,43,0,0,12,8,14,6,0,16,0,0,34,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,36,35,0,0,46,39,47] 
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', ',', '?', '!'] 
  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..', '-----', '.----', '..---', '...--', '....-', '.....', '-....', '--...', '---..', '----.', '.-.-.-', '--..--', '..--..', '-.-.--'] 
  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True

def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
        Index = 0
    elif PlainTextLetter.isalpha(): # Character in position is a letter
      Index = ord(PlainTextLetter.upper()) - ord('A') + 1
    elif PlainTextLetter.isnumeric(): # Character in position is a number
      # 0 needs to be at index 27, so subtract unicode value of 0 and add 27 to get index of all numbers
      Index = ord(PlainTextLetter) - ord('0') + 27 
    else: # Is not a number / letter / space, assume it is a symbol. If statements for all supported symbols, setting index to position in MorseCode list
      if PlainTextLetter == '.':
        Index = 37 
      elif PlainTextLetter == ',': 
        Index = 38
      elif PlainTextLetter == '?':
        Index = 39
      elif PlainTextLetter == '!':
        Index = 40
      else: # Unsupported character, replace with space (could also output error here if needed)
        Index = 0 
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendReceiveMessages()
        Dim Dash = {20, 23, 0, 0, 24, 1, 0, 17, 31, 21, 28, 25, 0, 15, 11, 37, 45, 0, 40, 22, 13, 341, 30, 10, 0, 0, 44, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 46, 0, 0, 0, 0, 0, 0, 0}
        Dim Letter = {&quot; &quot;, &quot;A&quot;, &quot;B&quot;, &quot;C&quot;, &quot;D&quot;, &quot;E&quot;, &quot;F&quot;, &quot;G&quot;, &quot;H&quot;, &quot;I&quot;, &quot;J&quot;, &quot;K&quot;, &quot;L&quot;, &quot;M&quot;, &quot;N&quot;, &quot;O&quot;, &quot;P&quot;, &quot;Q&quot;, &quot;R&quot;, &quot;S&quot;, &quot;T&quot;, &quot;U&quot;, &quot;V&quot;, &quot;W&quot;, &quot;X&quot;, &quot;Y&quot;, &quot;Z&quot;, &quot;0&quot;, &quot;1&quot;, &quot;2&quot;, &quot;3&quot;, &quot;4&quot;, &quot;5&quot;, &quot;6&quot;, &quot;7&quot;, &quot;8&quot;, &quot;9&quot;, &quot;OT&quot;, &quot;ö&quot;, &quot;/&quot;, &quot;Ä&quot;, &quot;ü&quot;, &quot;+&quot;, &quot;üe&quot;, &quot;ZT&quot;, &quot;Á&quot;, &quot;,&quot;, &quot;@&quot;, &quot;.&quot;, &quot;?&quot;}
        Dim Dot = {5, 18, 33, 0, 2, 9, 0, 26, 32, 19, 0, 3, 0, 7, 4, 38, 0, 0, 12, 8, 14, 6, 0, 16, 39, 0, 34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 43, 48, 49, 0, 47}
        Dim MorseCode = {&quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot;, &quot;-----&quot;, &quot;.----&quot;, &quot;..---&quot;, &quot;...--&quot;, &quot;....-&quot;, &quot;.....&quot;, &quot;-....&quot;, &quot;--....&quot;, &quot;---...&quot;, &quot;----..&quot;, &quot;-----.&quot;, &quot;----&quot;, &quot;---.&quot;, &quot;-··-·&quot;, &quot;.-.-&quot;, &quot;..--&quot;, &quot;.-.-.&quot;, &quot;..--.&quot;, &quot;--..-&quot;, &quot;.--.-&quot;, &quot;--..--&quot;, &quot;.--.-.&quot;, &quot;.-.-..&quot;, &quot;..--..&quot;}

- Symbols work in progress numbers work!

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a message to send ==
Currently lowercase characters crash the program, add functionality to translate lowercase letters and correctly translate numbers/symbols

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
// Does not have numbers or symbols. Any other instances in the code where it does not allow lower case use the code equalsIgnoreCase(
// The code below shows it working in the menu of the Program
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Currently only supports lowercase letters &amp; prevents invalid characters. Needs modifying to support numbers.
def SendMorseCode(MorseCode):
  Error = True # Input validation
  while Error: # Repeat the code in this section until input is valid
    Error = False # Assume no errors until one is detected
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter.upper()) - ord('A') + 1 # .upper() added to support lowercase characters
      try: # Attempt to find morse code for current character
        CodedLetter = MorseCode[Index]
        MorseCodeString = MorseCodeString + CodedLetter + SPACE
      except: # Has been an issue finding morse code for character - inform user of this &amp; re-run loop to allow a new input
        print(&quot;Invalid character in message.&quot;)
        Error = True # Set error to true so loop re-runs
        break # Break for loop to go back to start of Error loop (and ask for a new input)
  print(MorseCodeString)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Automatically append '.txt' to file. ==
Code that makes it obsolete for the user to add the '.txt' extension to their file name

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
FileName = FileName.Contains(&quot;.txt&quot;) ? FileName : FileName + &quot;.txt&quot;;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmission(): String;
var
  FileName, FileNameOriginal: String;
  FileHandle: Textfile;
  Transmission: String;
begin
  write('Enter file name: ');
  readln(FileNameOriginal);    {Variable was originally set as FileName but was changed for Concentrate}
  FileName := Concat(FileNameOriginal,'.txt');

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
   
  static void sendMorseCode(String[] morseCode) throws IOException
  {
    Console.write(&quot;Enter your message (letters and spaces only): &quot;);
    String plainText = Console.readLine();
    plainText = plainText.toUpperCase();
    int plainTextLength = plainText.length();
    String morseCodeString = EMPTYSTRING;
    int index;
    for (int i = 0; i &lt; plainTextLength; i++)
    {
      char plainTextLetter = plainText.charAt(i);
      if (plainTextLetter == SPACE)
      {
        index = 0;
      }
      else
      {
        index = (int)plainTextLetter - (int)'A' + 1;
      }
      String codedLetter = morseCode[index];
      morseCodeString = morseCodeString + codedLetter + SPACE;
    }
    Console.writeLine(morseCodeString);
    Save(morseCodeString);
  }
  
  
  public static void Save(String pop) throws IOException {
	  System.out.println(&quot;Enter file name: &quot;);
	  Scanner scan = new Scanner(System.in);
	  String f = scan.next();
	  FileWriter file = new FileWriter(f+&quot;.txt&quot;, true);
	  PrintWriter print = new PrintWriter(file);
	  print.println(pop);
	  print.flush();
	  print.close();
  }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def GetTransmission():
  FileName = input(&quot;Enter file name: &quot;)
  if FileName[-4:] != '.txt': # If last 4 characters match .txt - the 4 spaces appended to the start of string are to prevent the string being shorted than the indexes being checked
        FileName += '.txt' # Append .txt to end of file name
  try:
    FileHandle = open(FileName, 'r')
    Transmission = FileHandle.readline()
    FileHandle.close()
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
  except:
    ReportError(&quot;No transmission found&quot;)
    Transmission = EMPTYSTRING
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Console.Write(&quot;Enter file name: &quot;)
        Try
            Filename = Console.ReadLine()
            Filename = Filename + &quot;.txt&quot;
            Dim Reader As New StreamReader(Filename)
            Transmission = Reader.ReadLine
            Reader.Close()
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        Catch
            ReportError(&quot;No transmission found&quot;)
            Transmission = EMPTYSTRING
        End Try
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save message in a text file ==
Code that save the translated code in a text file

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveMorseToFile(MorseString : string);   //added to save morse
var
  FileMorse:TextFile;
begin
  AssignFile(FileMorse, 'MorseFile.txt');
  try
    rewrite(FileMorse);
    writeln(FileMorse, MorseString);
    CloseFile(FileMorse);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
  SaveMorseToFile(MorseCodeString);//Saves it to a file
  writeln('Saved to MorseFile.txt');
end;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void write(String morseCodeString) throws IOException 
	{
		FileWriter fw = new FileWriter (&quot;morse.txt&quot;);
		PrintWriter output = new PrintWriter (fw);
		output.println(morseCodeString);
		output.close();
		output.flush();
		System.out.println(&quot;Printed in morse.txt&quot;);
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if FileName[-4:].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== List Characters ==
Output a list of all of the characters from the list next to their Morse code representation.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// NEW SUBROUTINE- Letter and MorseCode lists are passed as parameters/arguments
private static void ListMorseCode(char[] Letter, string[] MorseCode)
{
    for (int index = 0; index &lt; Letter.Length; index++)      // for loop - loops through all elements in the Letter Array
    {
        Console.WriteLine(Letter[index] + &quot;   &quot; + MorseCode[index]);     // Output the text character, followed by a few spaces, and then the Morse code representation
    }
}

// AMENDED SUBROUTINE
private static void DisplayMenu()
{
    Console.WriteLine();
    Console.WriteLine(&quot;Main Menu&quot;);
    Console.WriteLine(&quot;=========&quot;);
    Console.WriteLine(&quot;R - Receive Morse code&quot;);
    Console.WriteLine(&quot;S - Send Morse code&quot;);
    Console.WriteLine(&quot;L - List Morse code characters&quot;);         // Added - display menu option for this modification
    Console.WriteLine(&quot;X - Exit program&quot;);
    Console.WriteLine();
}

// AMENDED SUBROUTINE
private static void SendReceiveMessages()
{
    int[] Dash = new int[] { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
    int[] Dot = new int[] { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
    char[] Letter = new char[] { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
    string[] MorseCode = new string[] { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot; };
    bool ProgramEnd = false;
    string MenuOption = EMPTYSTRING;
    while (!ProgramEnd)
    {
        DisplayMenu();
        MenuOption = GetMenuOption();
        if (MenuOption == &quot;R&quot;)
        {
            ReceiveMorseCode(Dash, Letter, Dot);
        }
        else if (MenuOption == &quot;S&quot;)
        {
            SendMorseCode(MorseCode);
        }
        else if (MenuOption == &quot;X&quot;)
        {
            ProgramEnd = true;
        }
        else if (MenuOption == &quot;L&quot;)             // Added - if menu option selected is the 'L' (list Morse code)
        {
            ListMorseCode(Letter, MorseCode);   // Run ListMorseCode subroutine, passing lists Letter and MorseCode
        }
    }
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure DisplayMenu();
begin
  writeln;
  writeln('Main Menu');
  writeln('=========');
  writeln('R - Receive Morse code');
  writeln('S - Send Morse code');
  writeln('L - List Morse code characters');//Added menu option for this
  writeln('X - Exit program');
  writeln;
end;

Procedure ListCharacters(Letter:Array of char; MorseCode:Array of String);   //new procedure for listing
var
  z : integer;
begin
  for z:=0 to 26 do
    writeln(Letter[z],'   ',MorseCode[z]);
end;

Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if MenuOption = 'R' then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if MenuOption = 'S' then
        SendMorseCode(MorseCode)
      else if MenuOption = 'X' then
        ProgramEnd := True
      else if MenuOption = 'L' then
        ListCharacters(Letter, MorseCode); //Added to lead to new procedure
    end;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Added subroutines

def ListMorseCode(Letter, MorseCode): # New subroutine - Letter and MorseCode lists are passed as parameters
  for Pos in range(len(Letter)): # Loop through all positions in the length of the list
    print(Letter[Pos]+&quot;   &quot;+MorseCode[Pos]) # Output the text character, followed by a few spaces, and then the Morse code representation

# Existing modified subroutines

def DisplayMenu():
  print()
  print(&quot;Main Menu&quot;)
  print(&quot;=========&quot;)
  print(&quot;R - Receive Morse code&quot;)
  print(&quot;S - Send Morse code&quot;)
  print(&quot;L - List Morse code characters&quot;) # Added - display menu option for this modification
  print(&quot;X - Exit program&quot;)
  print()

def SendReceiveMessages():
  Dash = [20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0]
  Dot = [5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0]
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..']

  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True
    elif MenuOption == 'L': # Added - if menu option selected is the 'L' (list Morse code)
      ListMorseCode(Letter, MorseCode) # Run ListMorseCode subroutine, passing lists Letter and MorseCode

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Accept multiple lines of text to convert to Morse code ==
Description of question

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter,x : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
  continue : integer;
begin
  continue:= 0;
  repeat
    write('Enter your message (uppercase letters and spaces only): ');
    readln(PlainText);
    PlainTextLength := length(PlainText);
    MorseCodeString := EMPTYSTRING;
    for i := 1 to PlainTextLength do
      begin
        PlainTextLetter := PlainText[i];
        if PlainTextLetter = SPACE then
          Index := 0
        else
          Index := ord(PlainTextLetter) - ord('A') + 1;
        CodedLetter := MorseCode[Index];
        MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      end;
    writeln(MorseCodeString);
    write('Continue (Y or N): ');
    readln(x);
    if (x = 'Y') or (x ='y') then //start of continue
        continue:= 0
      else if (x = 'N') or (x = 'n') then
        continue:= 1
      else
        begin
          writeln('Interpreting answer as no');//could be made to loop if needed
          continue:=1;
        end;
  until continue = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  Continue = 0
  while Continue != 1:
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter) - ord('A') + 1
      CodedLetter = MorseCode[Index]
      MorseCodeString = MorseCodeString + CodedLetter + SPACE
    print(MorseCodeString)
    x = input(&quot;Continue Y/N?: &quot;)
    if x == &quot;Y&quot; or x == &quot;y&quot;:
      Continue = 0
    elif x == &quot;N&quot; or x == &quot;n&quot;:
      Continue = 1
    else:
      print(&quot;Interpreting answer as no&quot;)
      Continue = 1
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Accept lowercase letters ==
This will accept the input of lowercase characters

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// AMENDED SUBROUTINE - Allows Lowercase values in Send string now. (ASCII values used)
private static void SendMorseCode(string[] MorseCode)
{
    Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
    string PlainText = Console.ReadLine();
    int PlainTextLength = PlainText.Length;
    string MorseCodeString = EMPTYSTRING;
    char PlainTextLetter = SPACE;
    int Index = 0;

    int ascii;              // declare new value 'ascii' to store that value.

    for (int i = 0; i &lt; PlainTextLength; i++)
    {
        PlainTextLetter = PlainText[i];
        if (PlainTextLetter == SPACE)
        {
            Index = 0;
        }
        else
        {
            if ((int)PlainTextLetter &gt;= 97)             // if ASCII Value of that letter is 97 or above, it is assumed to be lowercase.
                ascii = (int)PlainTextLetter - 32;      // if lowercase then subtract 32 from its ASCII value
            else
                ascii = (int)PlainTextLetter;           // else it is uppercase, then use that ASCII value.

            Index = ascii - (int)'A' + 1;               // use the 'ascii' value to calculate, just incase lowercase has been used.
        }
        string CodedLetter = MorseCode[Index];
        MorseCodeString = MorseCodeString + CodedLetter + SPACE;
    }
    Console.WriteLine(MorseCodeString);
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index, assci : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        begin   //added to allow lower case letters
          if ord(PlainTextLetter) &gt;= 97 then
            assci:= ord(PlainTextLetter) - 32
          else
            assci:=  ord(PlainTextLetter);
          Index := assci - ord('A') + 1;
        end;                             //should work
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
write ('This is a question: ');
readln(Variable);
Variable := AnsiUpperCase(Variable);
{This can be added for the MenuOption (in GetMenuOption) and Plaintext (in SendMorseCode)}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static char getMenuOption() {
		boolean valid = false;
		char menuOption = ' ';
		while(!valid) {
		String option = EMPTYSTRING;
		Console.write(&quot;Enter menu option&quot;);
		try {
			option = Console.readLine();
		} catch (Exception e) {
			System.out.println(&quot;Invalid input&quot;);
		}
		if (option.equalsIgnoreCase(&quot;R&quot;))
			menuOption = 'R'; valid = true;
		if (option.equalsIgnoreCase(&quot;S&quot;))
			menuOption = 'S'; valid = true;
		if (option.equalsIgnoreCase(&quot;X&quot;)) {
			menuOption = 'X'; valid = true;
		}
		else if (!valid) {
				System.out.println(&quot;Invalid input&quot;);
			}
		}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()#Changed
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
      Index = 0
    else: 
      Index = ord(PlainTextLetter) - ord('A') + 1
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;).upper()#Changed
  return MenuOption
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter)
                If Index &gt; 96 And Index &lt; 123 Then
                    Index -= 32
                End If
                Index = Index - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        SaveMorseCode(MorseCodeString)
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}</text>
      <sha1>2xk8fj7k9cbf9gb0l0byqau871al9kv</sha1>
    </revision>
    <revision>
      <id>4636879</id>
      <parentid>4636878</parentid>
      <timestamp>2026-05-21T13:42:24Z</timestamp>
      <contributor>
        <username>~2026-30562-12</username>
        <id>3591367</id>
      </contributor>
      <comment>/* Read / Write to binary file */</comment>
      <origin>4636879</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="61104" sha1="7fu1pjmkxwtvcrlu7jh04leodlmhz82" xml:space="preserve">This is for the AQA AS Computer Science Specification.

This is where suggestions can be made about what some of the questions might be and how we can solve them.

'''Please be respectful and do not vandalise or tamper with the page, as this would affect students' preparation for their exams!'''

== Read / Write to binary fil ==
Modify the program in order to allow the user to read / write the transmission (from form of spaces and equals signs) to a binary format (in order to reduce space taken to store)

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# These functions need to be added to relavent subroutines if support for a binary file is required:
# BinaryEncode result passed as parameter to BinaryWrite with filename, called from SendMorseCode (pass MorseCodeString to BinaryEncode)
# BinaryRead result (parameter is file name) passed as parameter to BinaryDecode, and the return is to be used as variable Transmission in GetTransmission()
# Python binary file handling reads / writes in bytes. Therefore, for optimum usage, we need to be making full use of each byte. Letting a space be a 0 and an equals sign be 1, each 8 characters from the currently supported text file become 1 byte. Leftmost character = first value in each byte, 8n th = last byte of array
def BinaryEncode(Message):
    Bytes = []
    Current = 128
    Count = 0
    for Character in Message:
        if Current == 0.5:
            Bytes.append(int(Count))
            Count = 0
            Current = 128
        if Character == '=':
            Count += Current
        Current = Current / 2
    if Count != 0:
        Bytes.append(int(Count))
    return bytes(Bytes) # base10 -&gt; base2 value

def BinaryWrite(Bytes, FileName):
    FileHandle = open(FileName, 'wb')
    FileHandle.write(Bytes)
    FileHandle.flush()
    FileHandle.close()

def BinaryRead(FileName):
    FileHandle = open(FileName, 'rb')
    ByteValues = list(FileHandle.read()) # base2 -&gt; base10 value
    FileHandle.close()
    return ByteValues

def BinaryDecode(Bytes):
    Message = str()
    for Byte in Bytes:
        for BitValue in [128, 64, 32, 16, 8, 4, 2, 1]:
            if Byte &gt;= BitValue:
                Byte -= BitValue
                Message += '='
            else:
                Message += ' '
    return Message

# Example usage (using message from preliminary material
Bin = (BinaryEncode(&quot;===   =   = ===       === = = === &quot;))
BinaryWrite(Bin, 'binfile')
print(BinaryDecode(BinaryRead('binfile')))

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Substitution Cipher ==

This question refers to the subroutines '''GetTransmission''' and '''ReceiveMorseCode'''. The question requires the creation of subroutines '''GetKey''' and '''DecryptTransmission'''.

The '''Skeleton Program''' is to be adapted so that messages encrypted with a substitution cipher can be '''received''' and '''decrypted'''. The method of decryption will be to apply a '''decryption key''' to the message.

In a substitution cipher, every character is replaced with another character. For example, every letter A could be substituted with the number 7.

The '''decryption key''' will be stored in a text file, consisting of 36 characters. The first 26 characters will represent the letters A – Z and the next 10 will represent the numbers from 0 – 9. 

A new subroutine GetKey needs to be created, which will read and return the key from a '''file specified by the user'''. If no key is specified, the subroutine should return the key: ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789. This key should be interpreted to mean that every character represents itself.

A new subroutine DecryptTransmission needs to be created, which will apply the decryption key to the transmission. It will be called by a new line in ReceiveMorseCode, to be inserted '''before''' print(PlainText):

PlainText = DecryptTransmission(PlainText).

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def ReceiveMorseCode(Dash, Letter, Dot): 
  PlainText = EMPTYSTRING
  MorseCodeString = EMPTYSTRING
  Transmission = GetTransmission() 
  LastChar = len(Transmission) - 1
  i = 0
  while i &lt; LastChar:
    i, CodedLetter = GetNextLetter(i, Transmission)
    MorseCodeString = MorseCodeString + SPACE + CodedLetter
    PlainTextLetter = Decode(CodedLetter, Dash, Letter, Dot)
    PlainText = PlainText + PlainTextLetter
  print(MorseCodeString)
  PlainText = DecryptTransmission(PlainText)
  print(PlainText)

def GetKey():
    theline = ''
    with open('keykey.txt', 'r') as decryptionkey:
        for line in decryptionkey:
            theline = line
    return theline

def DecryptTransmission(gibberish):
    keys = GetKey()
    #print(keys)
    keylst = []
    for i in keys:
        keylst.append(i)
    actualword = list('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
    decryptedmessage = ''
    
    for lettertodecrypt in gibberish:
        if lettertodecrypt in keys:
          decryptedmessage += actualword[keylst.index(lettertodecrypt)]
        elif lettertodecrypt == ' ':
          decryptedmessage += ' '
        else:
            print('Invalid')
    
    return decryptedmessage
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a menu option ==
The program currently just prints the menu again when an incorrect option is input; add validation so the program prints a message when an invalid option is input.
{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
switch (MenuOption)
{
    case &quot;R&quot;:
        ReceiveMorseCode(Dash, Letter, Dot);
        break;
    case &quot;S&quot;:
        SendMorseCode(MorseCode);
        break;
    case &quot;X&quot;:
        ProgramEnd = true;
        break;
    default:
        Console.WriteLine(&quot;You have made an invalid selection. Try again&quot;);
        break;
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if (MenuOption = 'R') or (MenuOption ='r') then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if (MenuOption = 'S') or (MenuOption='s') then
        SendMorseCode(MorseCode)
      else if (MenuOption = 'X') or (menuOption='x') then
        ProgramEnd := True
      else
        writeln('you did not enter a valid option.');
        readln;
    end;
end
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetMenuOption():
  MenuOption = EMPTYSTRING
  Correct = False
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;)
    if MenuOption == 'R' or MenuOption == 'S' or MenuOption == 'X':
      Correct = True
    else:
{{CPTAnswerTab|C#}}

      MenuOption = input(&quot;Invalid choice. Re-Enter your choice: &quot;)
  return MenuOption

## Change from lower to upper case with ascii incase they lead you up to it or tell you to use ascii instead of .upper()
def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = raw_input(&quot;Enter your choice: &quot;)
    Ascii = ord(MenuOption)
    if Ascii&gt;=97:
      Ascii=Ascii-32
    MenuOption=chr(Ascii)
  return MenuOption
  
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Translate transmission directly to English (bypass file)  ==
Update receive signal to allow direct input rather than txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
private static string GetTransmission()
        {
            string choice = EMPTYSTRING;//declares to empty
            Console.WriteLine (&quot;Would you like to load a file (Y/N)&quot;);//outputs the line
            choice = Console.ReadLine().ToUpper();//assigns the value
            string Transmission;//declares
            if (choice == &quot;Y&quot;)
            {
                string FileName = EMPTYSTRING; //declare
                Console.Write(&quot;Enter file name: &quot;);//outputty
                FileName = (Console.ReadLine() + &quot;.txt&quot;);//assigns
                try//error handling
                {
                    Transmission = File.ReadAllText(FileName);//assings varaible to text from the file in bin
                    Transmission = StripLeadingSpaces(Transmission);//removes spaces at the start of the transmission
                    if (Transmission.Length &gt; 0)//chekcs length
                    {
                        Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                        Transmission = Transmission + EOL; //adds the global to it
                    }
                }
                catch
                {
                    ReportError(&quot;No transmission found&quot;); //catches if the try errors calling sub
                    //give instructions
                    Console.WriteLine(&quot;Please enter a valid text file name that is in the bin/debug&quot;);
                    Transmission = EMPTYSTRING;//assigns it to empty
                }
            }
            else
            {
                Console.WriteLine(&quot;Please enter your transmission&quot;);//outputs
                Transmission = Console.ReadLine();//assigns
                Transmission = StripLeadingSpaces(Transmission);//strips spaces at the start
                if (Transmission.Length &gt; 0)//chekcs length
                {
                    Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                    Transmission = Transmission + EOL; //adds the global to it
                }
            }
            return Transmission;//returns transmission
        }
THIS REQUIRES AN INPUT OF TRANSMISSION RATHER THAN DIRECT MORSE
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmissionFromFile() : String;
var
  FileName : String;
  FileHandle : Textfile;
  Transmission : String;
begin
  write('Enter file name: ');
  readln(FileName);
  try
    assign(FileHandle,FileName);
    reset(FileHandle);
    readln(FileHandle, Transmission);
    close(FileHandle);
    Transmission := StripLeadingSpaces(Transmission);
    if length(Transmission) &gt; 0 then
      begin
        Transmission := StripTrailingSpaces(Transmission);
        Transmission := Transmission + EOL;
      end;
  except
    on E: exception do
      begin
        ReportError('No transmission found');
        Transmission := EMPTYSTRING;
      end;
  end ;
  GetTransmissionFromFile := Transmission;
end;

Function GetTransmissionFromInput() : String;
var
  transmission : String;
begin
  writeln('please enter your transmission (using = to signify on and a space to represent off) ');
  readln(transmission);
  Transmission :=StripLeadingSpaces(Transmission);
  if length(Transmission) &gt; 0 then
    begin
      Transmission := StripTrailingSpaces(Transmission);
      Transmission := Transmission + EOL;
    end;
  GetTransmissionFromInput := Transmission;
end;

Function GetAnyTransmission() : string;
var
  choice: string;
  valid: integer;
begin
  repeat
    begin
      writeln('Do you want to receive transmission from a file?(Y/N) ');
      readln (choice);
      if (Choice = 'Y') or (Choice = 'y') or (Choice = 'yes') or (Choice= 'YES') or (Choice= 'Yes') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromFile();
        end
      else if (Choice ='N') or (Choice = 'n') or (Choice = 'no') or (Choice= 'NO') or (Choice ='No') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromInput();
        end
      else
        begin
          valid := 0;
          writeln('You have not entered a valid response');
        end;
      end;
    until Valid = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetTransmission():
  choice = input(&quot;Would you like to load a file? (Y/N): &quot;)

  if choice == &quot;Y&quot;:
    FileName = input(&quot;Enter file name: &quot;)

    try:
      FileHandle = open(FileName, 'r')
      Transmission = FileHandle.readline()
      FileHandle.close()
      Transmission = StripLeadingSpaces(Transmission)
      if len(Transmission) &gt; 0:
        Transmission = StripTrailingSpaces(Transmission)
        Transmission = Transmission + EOL
    except:
      ReportError(&quot;No transmission found&quot;)
      Transmission = EMPTYSTRING
  else:
    Transmission = input(&quot;Enter your transmission String: &quot;)
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
      
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Dim choice As String
        Console.WriteLine(&quot;Do you wish to load a file?&quot;)
        choice = Console.ReadLine
        If choice = &quot;yes &quot; Then
            Console.Write(&quot;Enter file name: &quot;)
            Try
                Filename = Console.ReadLine()
                Dim Reader As New StreamReader(Filename)
                Transmission = Reader.ReadLine
                Reader.Close()
                Transmission = StripLeadingSpaces(Transmission)
                If Transmission.Length() &gt; 0 Then
                    Transmission = StripTrailingSpaces(Transmission)
                    Transmission = Transmission + EOL
                End If
            Catch
                ReportError(&quot;No transmission found&quot;)
                Transmission = EMPTYSTRING
            End Try
        Else
            Console.WriteLine(&quot;please enter the morse code string&quot;)
            Transmission = Console.ReadLine
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        End If
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save a .txt file when sending Morse Code ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
static void sendMorseCode(String[] morseCode) throws IOException {
		Console.write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
		String plainText = Console.readLine();
		plainText=plainText.toUpperCase();
		int plainTextLength = plainText.length();
		String morseCodeString = EMPTYSTRING;
		int index;
		for (int i = 0; i &lt; plainTextLength; i++) {
			char plainTextLetter = plainText.charAt(i);
			if (plainTextLetter == SPACE) {
				index = 0;
			} else {
				index = (int) plainTextLetter - (int) 'A' + 1;
			}
			String codedLetter = morseCode[index];
			morseCodeString = morseCodeString + codedLetter + SPACE;
		}
		Console.writeLine(morseCodeString);
		System.out.println(&quot;Do you want to save you message \n 1:Y \n 2:N&quot;);
		String choice = scan.next();
		switch(choice) {
		case &quot;Y&quot;:
			filewriter(morseCodeString);

			break;
		case &quot;N&quot;:
			break;
		default:
			System.out.println(&quot;That was not an option /n Your data will be stored&quot;);
			filewriter(morseCodeString);

			break;
		}
	}
	public static void filewriter(String sendMorseCode) throws IOException {
		System.out.println(&quot;Enter the name of the file&quot;);
		String filename = scan.next();
		FileWriter fw = new FileWriter(filename);
		PrintWriter end = new PrintWriter(fw);
		end.print(sendMorseCode);
		end.close();
		fw.close();
	}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
  #SBaker May 18 4.	Save a text file when sending Morse Code
  #we need to format MorseCodeString into the output format
  outputString = ''
  for letter in MorseCodeString:
    if letter == '.':
      outputString = outputString + &quot;= &quot;
    elif letter == '-':
      outputString = outputString + &quot;=== &quot;
    elif letter == ' ':
      outputString = outputString + &quot;  &quot;
  FileName = input(&quot;Enter file name: &quot;)
  try:
    FileHandle = open(FileName, 'w')
    FileHandle.write(outputString)
    FileHandle.close()
  except:
    ReportError(&quot;No file found&quot;)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainText = PlainText.ToUpper()

        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;Would you like to save this to a text file?&quot;)
        Dim save As String = Console.ReadLine()
        If save = &quot;Y&quot; Or save = &quot;y&quot; Then
            Dim fileTitle As String
            Console.WriteLine(&quot;What would you like to call the file?&quot;)
            fileTitle = Console.ReadLine()
            Dim fileLoc As String
            fileLoc = &quot;H:\Documents\2018 June\VB\&quot; + fileTitle + &quot;.txt&quot;
            Dim fs As New FileStream(fileLoc, FileMode.CreateNew, FileAccess.Write)
            Dim sw As New StreamWriter(fs)
            sw.WriteLine(MorseCodeString)
            sw.Flush()
        Else
            Console.WriteLine(&quot;Okay.&quot;)
            Console.ReadLine()
        End If
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Create and save transmission signal when sending ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add EncodeMorseCode(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void EncodeMorseCode(string MorseCode)        // Function to convert MorseCodeString to the '=' and (Space) format in Preliminary Material
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string ShouldSave = Console.ReadLine();                 // Check whether user wants to save to file
        if (ShouldSave[0] == 'y' || ShouldSave[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();       // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))             // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;                     // Append .txt if not present
                }
                                                        
                StreamWriter CodedFileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)

                // Use the built-in .Replace(old, new) method to swap out the relevant characters in C#.
                string CodedOutput = MorseCode.Replace(&quot;-&quot;, &quot;=== &quot;).Replace(&quot;.&quot;, &quot;= &quot;).Replace(&quot;  &quot;, &quot;   &quot;).Replace(&quot;      &quot;, &quot;       &quot;);
                // This now effectively formats the MorseCodeString message to the '=' and ' ' format

                CodedFileSaver.Write(CodedOutput);

                CodedFileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling
            }
            Console.WriteLine(&quot;Coded File successfully written&quot;);
        }
     }

// S Wood - Teach

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveTransmission(Transmission : string);
var
  FileHandle : TextFile;
begin
  AssignFile(FileHandle, 'Message.txt');
  try
    rewrite (FileHandle);
    writeln (FileHandle, Transmission);
    CloseFile (FileHandle);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter, TransmissionString : String;
  PlainTextLength, i, Index, k : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  TransmissionString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      for k := 1 to length(CodedLetter) do
      begin
        case CodedLetter[k] of
          ' ': TransmissionString += ' ';
          '.': TransmissionString += '=';
          '-': TransmissionString += '==='
        end;
      TransmissionString += ' ';
      end;
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      if i &lt;&gt; PlainTextLength then
        TransmissionString += '  ';
    end;
  writeln(MorseCodeString);
  SaveTransmission(TransmissionString);
  writeln ('Message encoded and saved in Message.txt');
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
for (int i = 0; i &lt; morseCodeString.length(); i++) {
            char c = morseCodeString.charAt(i);
            if (c == '-') {
                morseCodeTransmission = morseCodeTransmission + &quot; ===&quot;;
            }
            if (c == '.') {
                morseCodeTransmission = morseCodeTransmission + &quot; =&quot;;
            }
            if (c == ' ') {
                morseCodeTransmission = morseCodeTransmission + &quot;  &quot;;
            }
        }

        System.out.println(&quot;Name the file you would like to save this too&quot;);

        String fileName = Console.readLine();
        if (!fileName.contains(&quot;.txt&quot;)) {
            fileName = fileName + &quot;.txt&quot;;
        }
        try {
            BufferedWriter fileHandle = new BufferedWriter(new FileWriter(fileName));
            fileHandle.write(morseCodeTransmission);
            fileHandle.close();
        } catch (IOException e) {
        }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if '    '+FileName[-4].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Dim save As Integer
        Dim file As StreamWriter
        Dim file2 As String
        Dim morsecodesymbol As String
        Dim morsecodesymbolR As String
        Dim morsecodemessage As String

        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else

                If Asc(PlainTextLetter) &lt; 65 Then
                    Index = Asc(PlainTextLetter) - 21
                Else
                    Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
                End If
            End If

            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE + SPACE + SPACE

        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;would you like to save your message in a document? If so then please press 1 if not press 2&quot;)
        Try
            save = Console.ReadLine
        Catch ex As Exception
            Console.WriteLine(&quot;you have messed up the saving program, please do as asked&quot;)
        End Try
        If save = 1 Then
            Console.WriteLine(&quot;your file will be saved please choose a name&quot;)
            file2 = Console.ReadLine &amp; &quot;.txt&quot;
            For i = 0 To MorseCodeString.Length - 1
                morsecodesymbol = MorseCodeString(i)
                If morsecodesymbol = &quot;-&quot; Then
                    morsecodesymbolR = &quot;===&quot;
                ElseIf morsecodesymbol = &quot;.&quot; Then
                    morsecodesymbolR = &quot;=&quot;
                ElseIf morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot; &quot;
                ElseIf morsecodesymbol = SPACE And morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot;     &quot;
                End If
                morsecodemessage = morsecodemessage &amp; &quot; &quot; &amp; morsecodesymbolR
            Next
            File = New StreamWriter(file2)
            File.Write(morsecodemessage)
            File.Close()
        End If

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Add Morse code for numbers/symbols ==
Allow the user to convert numbers and punctuation (for which there is Morse code available) into Morse code.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def SendReceiveMessages(): # All lists here have been modified to support numbers &amp; some punctuation ( .,?! ) by adding indexes 27 onwards. This has been modified so that sending &amp; receiving (if only sending required, only the MorseCode list requires changing) works.
  Dash = [20,23,0,45,24,1,0,17,31,21,28,25,0,15,11,42,0,0,46,22,13,48,30,10,0,0,44,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,27,0,38,40,37,0,29] 
  Dot = [5,18,33,0,2,9,0,26,32,19,0,3,0,7,4,43,0,0,12,8,14,6,0,16,0,0,34,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,36,35,0,0,46,39,47] 
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', ',', '?', '!'] 
  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..', '-----', '.----', '..---', '...--', '....-', '.....', '-....', '--...', '---..', '----.', '.-.-.-', '--..--', '..--..', '-.-.--'] 
  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True

def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
        Index = 0
    elif PlainTextLetter.isalpha(): # Character in position is a letter
      Index = ord(PlainTextLetter.upper()) - ord('A') + 1
    elif PlainTextLetter.isnumeric(): # Character in position is a number
      # 0 needs to be at index 27, so subtract unicode value of 0 and add 27 to get index of all numbers
      Index = ord(PlainTextLetter) - ord('0') + 27 
    else: # Is not a number / letter / space, assume it is a symbol. If statements for all supported symbols, setting index to position in MorseCode list
      if PlainTextLetter == '.':
        Index = 37 
      elif PlainTextLetter == ',': 
        Index = 38
      elif PlainTextLetter == '?':
        Index = 39
      elif PlainTextLetter == '!':
        Index = 40
      else: # Unsupported character, replace with space (could also output error here if needed)
        Index = 0 
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendReceiveMessages()
        Dim Dash = {20, 23, 0, 0, 24, 1, 0, 17, 31, 21, 28, 25, 0, 15, 11, 37, 45, 0, 40, 22, 13, 341, 30, 10, 0, 0, 44, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 46, 0, 0, 0, 0, 0, 0, 0}
        Dim Letter = {&quot; &quot;, &quot;A&quot;, &quot;B&quot;, &quot;C&quot;, &quot;D&quot;, &quot;E&quot;, &quot;F&quot;, &quot;G&quot;, &quot;H&quot;, &quot;I&quot;, &quot;J&quot;, &quot;K&quot;, &quot;L&quot;, &quot;M&quot;, &quot;N&quot;, &quot;O&quot;, &quot;P&quot;, &quot;Q&quot;, &quot;R&quot;, &quot;S&quot;, &quot;T&quot;, &quot;U&quot;, &quot;V&quot;, &quot;W&quot;, &quot;X&quot;, &quot;Y&quot;, &quot;Z&quot;, &quot;0&quot;, &quot;1&quot;, &quot;2&quot;, &quot;3&quot;, &quot;4&quot;, &quot;5&quot;, &quot;6&quot;, &quot;7&quot;, &quot;8&quot;, &quot;9&quot;, &quot;OT&quot;, &quot;ö&quot;, &quot;/&quot;, &quot;Ä&quot;, &quot;ü&quot;, &quot;+&quot;, &quot;üe&quot;, &quot;ZT&quot;, &quot;Á&quot;, &quot;,&quot;, &quot;@&quot;, &quot;.&quot;, &quot;?&quot;}
        Dim Dot = {5, 18, 33, 0, 2, 9, 0, 26, 32, 19, 0, 3, 0, 7, 4, 38, 0, 0, 12, 8, 14, 6, 0, 16, 39, 0, 34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 43, 48, 49, 0, 47}
        Dim MorseCode = {&quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot;, &quot;-----&quot;, &quot;.----&quot;, &quot;..---&quot;, &quot;...--&quot;, &quot;....-&quot;, &quot;.....&quot;, &quot;-....&quot;, &quot;--....&quot;, &quot;---...&quot;, &quot;----..&quot;, &quot;-----.&quot;, &quot;----&quot;, &quot;---.&quot;, &quot;-··-·&quot;, &quot;.-.-&quot;, &quot;..--&quot;, &quot;.-.-.&quot;, &quot;..--.&quot;, &quot;--..-&quot;, &quot;.--.-&quot;, &quot;--..--&quot;, &quot;.--.-.&quot;, &quot;.-.-..&quot;, &quot;..--..&quot;}

- Symbols work in progress numbers work!

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a message to send ==
Currently lowercase characters crash the program, add functionality to translate lowercase letters and correctly translate numbers/symbols

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
// Does not have numbers or symbols. Any other instances in the code where it does not allow lower case use the code equalsIgnoreCase(
// The code below shows it working in the menu of the Program
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Currently only supports lowercase letters &amp; prevents invalid characters. Needs modifying to support numbers.
def SendMorseCode(MorseCode):
  Error = True # Input validation
  while Error: # Repeat the code in this section until input is valid
    Error = False # Assume no errors until one is detected
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter.upper()) - ord('A') + 1 # .upper() added to support lowercase characters
      try: # Attempt to find morse code for current character
        CodedLetter = MorseCode[Index]
        MorseCodeString = MorseCodeString + CodedLetter + SPACE
      except: # Has been an issue finding morse code for character - inform user of this &amp; re-run loop to allow a new input
        print(&quot;Invalid character in message.&quot;)
        Error = True # Set error to true so loop re-runs
        break # Break for loop to go back to start of Error loop (and ask for a new input)
  print(MorseCodeString)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Automatically append '.txt' to file. ==
Code that makes it obsolete for the user to add the '.txt' extension to their file name

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
FileName = FileName.Contains(&quot;.txt&quot;) ? FileName : FileName + &quot;.txt&quot;;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmission(): String;
var
  FileName, FileNameOriginal: String;
  FileHandle: Textfile;
  Transmission: String;
begin
  write('Enter file name: ');
  readln(FileNameOriginal);    {Variable was originally set as FileName but was changed for Concentrate}
  FileName := Concat(FileNameOriginal,'.txt');

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
   
  static void sendMorseCode(String[] morseCode) throws IOException
  {
    Console.write(&quot;Enter your message (letters and spaces only): &quot;);
    String plainText = Console.readLine();
    plainText = plainText.toUpperCase();
    int plainTextLength = plainText.length();
    String morseCodeString = EMPTYSTRING;
    int index;
    for (int i = 0; i &lt; plainTextLength; i++)
    {
      char plainTextLetter = plainText.charAt(i);
      if (plainTextLetter == SPACE)
      {
        index = 0;
      }
      else
      {
        index = (int)plainTextLetter - (int)'A' + 1;
      }
      String codedLetter = morseCode[index];
      morseCodeString = morseCodeString + codedLetter + SPACE;
    }
    Console.writeLine(morseCodeString);
    Save(morseCodeString);
  }
  
  
  public static void Save(String pop) throws IOException {
	  System.out.println(&quot;Enter file name: &quot;);
	  Scanner scan = new Scanner(System.in);
	  String f = scan.next();
	  FileWriter file = new FileWriter(f+&quot;.txt&quot;, true);
	  PrintWriter print = new PrintWriter(file);
	  print.println(pop);
	  print.flush();
	  print.close();
  }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def GetTransmission():
  FileName = input(&quot;Enter file name: &quot;)
  if FileName[-4:] != '.txt': # If last 4 characters match .txt - the 4 spaces appended to the start of string are to prevent the string being shorted than the indexes being checked
        FileName += '.txt' # Append .txt to end of file name
  try:
    FileHandle = open(FileName, 'r')
    Transmission = FileHandle.readline()
    FileHandle.close()
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
  except:
    ReportError(&quot;No transmission found&quot;)
    Transmission = EMPTYSTRING
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Console.Write(&quot;Enter file name: &quot;)
        Try
            Filename = Console.ReadLine()
            Filename = Filename + &quot;.txt&quot;
            Dim Reader As New StreamReader(Filename)
            Transmission = Reader.ReadLine
            Reader.Close()
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        Catch
            ReportError(&quot;No transmission found&quot;)
            Transmission = EMPTYSTRING
        End Try
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save message in a text file ==
Code that save the translated code in a text file

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveMorseToFile(MorseString : string);   //added to save morse
var
  FileMorse:TextFile;
begin
  AssignFile(FileMorse, 'MorseFile.txt');
  try
    rewrite(FileMorse);
    writeln(FileMorse, MorseString);
    CloseFile(FileMorse);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
  SaveMorseToFile(MorseCodeString);//Saves it to a file
  writeln('Saved to MorseFile.txt');
end;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void write(String morseCodeString) throws IOException 
	{
		FileWriter fw = new FileWriter (&quot;morse.txt&quot;);
		PrintWriter output = new PrintWriter (fw);
		output.println(morseCodeString);
		output.close();
		output.flush();
		System.out.println(&quot;Printed in morse.txt&quot;);
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if FileName[-4:].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== List Characters ==
Output a list of all of the characters from the list next to their Morse code representation.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// NEW SUBROUTINE- Letter and MorseCode lists are passed as parameters/arguments
private static void ListMorseCode(char[] Letter, string[] MorseCode)
{
    for (int index = 0; index &lt; Letter.Length; index++)      // for loop - loops through all elements in the Letter Array
    {
        Console.WriteLine(Letter[index] + &quot;   &quot; + MorseCode[index]);     // Output the text character, followed by a few spaces, and then the Morse code representation
    }
}

// AMENDED SUBROUTINE
private static void DisplayMenu()
{
    Console.WriteLine();
    Console.WriteLine(&quot;Main Menu&quot;);
    Console.WriteLine(&quot;=========&quot;);
    Console.WriteLine(&quot;R - Receive Morse code&quot;);
    Console.WriteLine(&quot;S - Send Morse code&quot;);
    Console.WriteLine(&quot;L - List Morse code characters&quot;);         // Added - display menu option for this modification
    Console.WriteLine(&quot;X - Exit program&quot;);
    Console.WriteLine();
}

// AMENDED SUBROUTINE
private static void SendReceiveMessages()
{
    int[] Dash = new int[] { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
    int[] Dot = new int[] { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
    char[] Letter = new char[] { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
    string[] MorseCode = new string[] { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot; };
    bool ProgramEnd = false;
    string MenuOption = EMPTYSTRING;
    while (!ProgramEnd)
    {
        DisplayMenu();
        MenuOption = GetMenuOption();
        if (MenuOption == &quot;R&quot;)
        {
            ReceiveMorseCode(Dash, Letter, Dot);
        }
        else if (MenuOption == &quot;S&quot;)
        {
            SendMorseCode(MorseCode);
        }
        else if (MenuOption == &quot;X&quot;)
        {
            ProgramEnd = true;
        }
        else if (MenuOption == &quot;L&quot;)             // Added - if menu option selected is the 'L' (list Morse code)
        {
            ListMorseCode(Letter, MorseCode);   // Run ListMorseCode subroutine, passing lists Letter and MorseCode
        }
    }
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure DisplayMenu();
begin
  writeln;
  writeln('Main Menu');
  writeln('=========');
  writeln('R - Receive Morse code');
  writeln('S - Send Morse code');
  writeln('L - List Morse code characters');//Added menu option for this
  writeln('X - Exit program');
  writeln;
end;

Procedure ListCharacters(Letter:Array of char; MorseCode:Array of String);   //new procedure for listing
var
  z : integer;
begin
  for z:=0 to 26 do
    writeln(Letter[z],'   ',MorseCode[z]);
end;

Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if MenuOption = 'R' then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if MenuOption = 'S' then
        SendMorseCode(MorseCode)
      else if MenuOption = 'X' then
        ProgramEnd := True
      else if MenuOption = 'L' then
        ListCharacters(Letter, MorseCode); //Added to lead to new procedure
    end;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Added subroutines

def ListMorseCode(Letter, MorseCode): # New subroutine - Letter and MorseCode lists are passed as parameters
  for Pos in range(len(Letter)): # Loop through all positions in the length of the list
    print(Letter[Pos]+&quot;   &quot;+MorseCode[Pos]) # Output the text character, followed by a few spaces, and then the Morse code representation

# Existing modified subroutines

def DisplayMenu():
  print()
  print(&quot;Main Menu&quot;)
  print(&quot;=========&quot;)
  print(&quot;R - Receive Morse code&quot;)
  print(&quot;S - Send Morse code&quot;)
  print(&quot;L - List Morse code characters&quot;) # Added - display menu option for this modification
  print(&quot;X - Exit program&quot;)
  print()

def SendReceiveMessages():
  Dash = [20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0]
  Dot = [5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0]
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..']

  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True
    elif MenuOption == 'L': # Added - if menu option selected is the 'L' (list Morse code)
      ListMorseCode(Letter, MorseCode) # Run ListMorseCode subroutine, passing lists Letter and MorseCode

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Accept multiple lines of text to convert to Morse code ==
Description of question

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter,x : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
  continue : integer;
begin
  continue:= 0;
  repeat
    write('Enter your message (uppercase letters and spaces only): ');
    readln(PlainText);
    PlainTextLength := length(PlainText);
    MorseCodeString := EMPTYSTRING;
    for i := 1 to PlainTextLength do
      begin
        PlainTextLetter := PlainText[i];
        if PlainTextLetter = SPACE then
          Index := 0
        else
          Index := ord(PlainTextLetter) - ord('A') + 1;
        CodedLetter := MorseCode[Index];
        MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      end;
    writeln(MorseCodeString);
    write('Continue (Y or N): ');
    readln(x);
    if (x = 'Y') or (x ='y') then //start of continue
        continue:= 0
      else if (x = 'N') or (x = 'n') then
        continue:= 1
      else
        begin
          writeln('Interpreting answer as no');//could be made to loop if needed
          continue:=1;
        end;
  until continue = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  Continue = 0
  while Continue != 1:
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter) - ord('A') + 1
      CodedLetter = MorseCode[Index]
      MorseCodeString = MorseCodeString + CodedLetter + SPACE
    print(MorseCodeString)
    x = input(&quot;Continue Y/N?: &quot;)
    if x == &quot;Y&quot; or x == &quot;y&quot;:
      Continue = 0
    elif x == &quot;N&quot; or x == &quot;n&quot;:
      Continue = 1
    else:
      print(&quot;Interpreting answer as no&quot;)
      Continue = 1
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Accept lowercase letters ==
This will accept the input of lowercase characters

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// AMENDED SUBROUTINE - Allows Lowercase values in Send string now. (ASCII values used)
private static void SendMorseCode(string[] MorseCode)
{
    Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
    string PlainText = Console.ReadLine();
    int PlainTextLength = PlainText.Length;
    string MorseCodeString = EMPTYSTRING;
    char PlainTextLetter = SPACE;
    int Index = 0;

    int ascii;              // declare new value 'ascii' to store that value.

    for (int i = 0; i &lt; PlainTextLength; i++)
    {
        PlainTextLetter = PlainText[i];
        if (PlainTextLetter == SPACE)
        {
            Index = 0;
        }
        else
        {
            if ((int)PlainTextLetter &gt;= 97)             // if ASCII Value of that letter is 97 or above, it is assumed to be lowercase.
                ascii = (int)PlainTextLetter - 32;      // if lowercase then subtract 32 from its ASCII value
            else
                ascii = (int)PlainTextLetter;           // else it is uppercase, then use that ASCII value.

            Index = ascii - (int)'A' + 1;               // use the 'ascii' value to calculate, just incase lowercase has been used.
        }
        string CodedLetter = MorseCode[Index];
        MorseCodeString = MorseCodeString + CodedLetter + SPACE;
    }
    Console.WriteLine(MorseCodeString);
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index, assci : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        begin   //added to allow lower case letters
          if ord(PlainTextLetter) &gt;= 97 then
            assci:= ord(PlainTextLetter) - 32
          else
            assci:=  ord(PlainTextLetter);
          Index := assci - ord('A') + 1;
        end;                             //should work
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
write ('This is a question: ');
readln(Variable);
Variable := AnsiUpperCase(Variable);
{This can be added for the MenuOption (in GetMenuOption) and Plaintext (in SendMorseCode)}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static char getMenuOption() {
		boolean valid = false;
		char menuOption = ' ';
		while(!valid) {
		String option = EMPTYSTRING;
		Console.write(&quot;Enter menu option&quot;);
		try {
			option = Console.readLine();
		} catch (Exception e) {
			System.out.println(&quot;Invalid input&quot;);
		}
		if (option.equalsIgnoreCase(&quot;R&quot;))
			menuOption = 'R'; valid = true;
		if (option.equalsIgnoreCase(&quot;S&quot;))
			menuOption = 'S'; valid = true;
		if (option.equalsIgnoreCase(&quot;X&quot;)) {
			menuOption = 'X'; valid = true;
		}
		else if (!valid) {
				System.out.println(&quot;Invalid input&quot;);
			}
		}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()#Changed
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
      Index = 0
    else: 
      Index = ord(PlainTextLetter) - ord('A') + 1
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;).upper()#Changed
  return MenuOption
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter)
                If Index &gt; 96 And Index &lt; 123 Then
                    Index -= 32
                End If
                Index = Index - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        SaveMorseCode(MorseCodeString)
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}</text>
      <sha1>7fu1pjmkxwtvcrlu7jh04leodlmhz82</sha1>
    </revision>
    <revision>
      <id>4636880</id>
      <parentid>4636879</parentid>
      <timestamp>2026-05-21T13:42:38Z</timestamp>
      <contributor>
        <username>~2026-30562-12</username>
        <id>3591367</id>
      </contributor>
      <comment>/* Read / Write to binary fil */</comment>
      <origin>4636880</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="61105" sha1="2xk8fj7k9cbf9gb0l0byqau871al9kv" xml:space="preserve">This is for the AQA AS Computer Science Specification.

This is where suggestions can be made about what some of the questions might be and how we can solve them.

'''Please be respectful and do not vandalise or tamper with the page, as this would affect students' preparation for their exams!'''

== Read / Write to binary file ==
Modify the program in order to allow the user to read / write the transmission (from form of spaces and equals signs) to a binary format (in order to reduce space taken to store)

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# These functions need to be added to relavent subroutines if support for a binary file is required:
# BinaryEncode result passed as parameter to BinaryWrite with filename, called from SendMorseCode (pass MorseCodeString to BinaryEncode)
# BinaryRead result (parameter is file name) passed as parameter to BinaryDecode, and the return is to be used as variable Transmission in GetTransmission()
# Python binary file handling reads / writes in bytes. Therefore, for optimum usage, we need to be making full use of each byte. Letting a space be a 0 and an equals sign be 1, each 8 characters from the currently supported text file become 1 byte. Leftmost character = first value in each byte, 8n th = last byte of array
def BinaryEncode(Message):
    Bytes = []
    Current = 128
    Count = 0
    for Character in Message:
        if Current == 0.5:
            Bytes.append(int(Count))
            Count = 0
            Current = 128
        if Character == '=':
            Count += Current
        Current = Current / 2
    if Count != 0:
        Bytes.append(int(Count))
    return bytes(Bytes) # base10 -&gt; base2 value

def BinaryWrite(Bytes, FileName):
    FileHandle = open(FileName, 'wb')
    FileHandle.write(Bytes)
    FileHandle.flush()
    FileHandle.close()

def BinaryRead(FileName):
    FileHandle = open(FileName, 'rb')
    ByteValues = list(FileHandle.read()) # base2 -&gt; base10 value
    FileHandle.close()
    return ByteValues

def BinaryDecode(Bytes):
    Message = str()
    for Byte in Bytes:
        for BitValue in [128, 64, 32, 16, 8, 4, 2, 1]:
            if Byte &gt;= BitValue:
                Byte -= BitValue
                Message += '='
            else:
                Message += ' '
    return Message

# Example usage (using message from preliminary material
Bin = (BinaryEncode(&quot;===   =   = ===       === = = === &quot;))
BinaryWrite(Bin, 'binfile')
print(BinaryDecode(BinaryRead('binfile')))

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Substitution Cipher ==

This question refers to the subroutines '''GetTransmission''' and '''ReceiveMorseCode'''. The question requires the creation of subroutines '''GetKey''' and '''DecryptTransmission'''.

The '''Skeleton Program''' is to be adapted so that messages encrypted with a substitution cipher can be '''received''' and '''decrypted'''. The method of decryption will be to apply a '''decryption key''' to the message.

In a substitution cipher, every character is replaced with another character. For example, every letter A could be substituted with the number 7.

The '''decryption key''' will be stored in a text file, consisting of 36 characters. The first 26 characters will represent the letters A – Z and the next 10 will represent the numbers from 0 – 9. 

A new subroutine GetKey needs to be created, which will read and return the key from a '''file specified by the user'''. If no key is specified, the subroutine should return the key: ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789. This key should be interpreted to mean that every character represents itself.

A new subroutine DecryptTransmission needs to be created, which will apply the decryption key to the transmission. It will be called by a new line in ReceiveMorseCode, to be inserted '''before''' print(PlainText):

PlainText = DecryptTransmission(PlainText).

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def ReceiveMorseCode(Dash, Letter, Dot): 
  PlainText = EMPTYSTRING
  MorseCodeString = EMPTYSTRING
  Transmission = GetTransmission() 
  LastChar = len(Transmission) - 1
  i = 0
  while i &lt; LastChar:
    i, CodedLetter = GetNextLetter(i, Transmission)
    MorseCodeString = MorseCodeString + SPACE + CodedLetter
    PlainTextLetter = Decode(CodedLetter, Dash, Letter, Dot)
    PlainText = PlainText + PlainTextLetter
  print(MorseCodeString)
  PlainText = DecryptTransmission(PlainText)
  print(PlainText)

def GetKey():
    theline = ''
    with open('keykey.txt', 'r') as decryptionkey:
        for line in decryptionkey:
            theline = line
    return theline

def DecryptTransmission(gibberish):
    keys = GetKey()
    #print(keys)
    keylst = []
    for i in keys:
        keylst.append(i)
    actualword = list('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
    decryptedmessage = ''
    
    for lettertodecrypt in gibberish:
        if lettertodecrypt in keys:
          decryptedmessage += actualword[keylst.index(lettertodecrypt)]
        elif lettertodecrypt == ' ':
          decryptedmessage += ' '
        else:
            print('Invalid')
    
    return decryptedmessage
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a menu option ==
The program currently just prints the menu again when an incorrect option is input; add validation so the program prints a message when an invalid option is input.
{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
switch (MenuOption)
{
    case &quot;R&quot;:
        ReceiveMorseCode(Dash, Letter, Dot);
        break;
    case &quot;S&quot;:
        SendMorseCode(MorseCode);
        break;
    case &quot;X&quot;:
        ProgramEnd = true;
        break;
    default:
        Console.WriteLine(&quot;You have made an invalid selection. Try again&quot;);
        break;
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if (MenuOption = 'R') or (MenuOption ='r') then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if (MenuOption = 'S') or (MenuOption='s') then
        SendMorseCode(MorseCode)
      else if (MenuOption = 'X') or (menuOption='x') then
        ProgramEnd := True
      else
        writeln('you did not enter a valid option.');
        readln;
    end;
end
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetMenuOption():
  MenuOption = EMPTYSTRING
  Correct = False
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;)
    if MenuOption == 'R' or MenuOption == 'S' or MenuOption == 'X':
      Correct = True
    else:
{{CPTAnswerTab|C#}}

      MenuOption = input(&quot;Invalid choice. Re-Enter your choice: &quot;)
  return MenuOption

## Change from lower to upper case with ascii incase they lead you up to it or tell you to use ascii instead of .upper()
def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = raw_input(&quot;Enter your choice: &quot;)
    Ascii = ord(MenuOption)
    if Ascii&gt;=97:
      Ascii=Ascii-32
    MenuOption=chr(Ascii)
  return MenuOption
  
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Translate transmission directly to English (bypass file)  ==
Update receive signal to allow direct input rather than txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
private static string GetTransmission()
        {
            string choice = EMPTYSTRING;//declares to empty
            Console.WriteLine (&quot;Would you like to load a file (Y/N)&quot;);//outputs the line
            choice = Console.ReadLine().ToUpper();//assigns the value
            string Transmission;//declares
            if (choice == &quot;Y&quot;)
            {
                string FileName = EMPTYSTRING; //declare
                Console.Write(&quot;Enter file name: &quot;);//outputty
                FileName = (Console.ReadLine() + &quot;.txt&quot;);//assigns
                try//error handling
                {
                    Transmission = File.ReadAllText(FileName);//assings varaible to text from the file in bin
                    Transmission = StripLeadingSpaces(Transmission);//removes spaces at the start of the transmission
                    if (Transmission.Length &gt; 0)//chekcs length
                    {
                        Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                        Transmission = Transmission + EOL; //adds the global to it
                    }
                }
                catch
                {
                    ReportError(&quot;No transmission found&quot;); //catches if the try errors calling sub
                    //give instructions
                    Console.WriteLine(&quot;Please enter a valid text file name that is in the bin/debug&quot;);
                    Transmission = EMPTYSTRING;//assigns it to empty
                }
            }
            else
            {
                Console.WriteLine(&quot;Please enter your transmission&quot;);//outputs
                Transmission = Console.ReadLine();//assigns
                Transmission = StripLeadingSpaces(Transmission);//strips spaces at the start
                if (Transmission.Length &gt; 0)//chekcs length
                {
                    Transmission = StripTrailingSpaces(Transmission);//strips spaces from the end of the text
                    Transmission = Transmission + EOL; //adds the global to it
                }
            }
            return Transmission;//returns transmission
        }
THIS REQUIRES AN INPUT OF TRANSMISSION RATHER THAN DIRECT MORSE
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmissionFromFile() : String;
var
  FileName : String;
  FileHandle : Textfile;
  Transmission : String;
begin
  write('Enter file name: ');
  readln(FileName);
  try
    assign(FileHandle,FileName);
    reset(FileHandle);
    readln(FileHandle, Transmission);
    close(FileHandle);
    Transmission := StripLeadingSpaces(Transmission);
    if length(Transmission) &gt; 0 then
      begin
        Transmission := StripTrailingSpaces(Transmission);
        Transmission := Transmission + EOL;
      end;
  except
    on E: exception do
      begin
        ReportError('No transmission found');
        Transmission := EMPTYSTRING;
      end;
  end ;
  GetTransmissionFromFile := Transmission;
end;

Function GetTransmissionFromInput() : String;
var
  transmission : String;
begin
  writeln('please enter your transmission (using = to signify on and a space to represent off) ');
  readln(transmission);
  Transmission :=StripLeadingSpaces(Transmission);
  if length(Transmission) &gt; 0 then
    begin
      Transmission := StripTrailingSpaces(Transmission);
      Transmission := Transmission + EOL;
    end;
  GetTransmissionFromInput := Transmission;
end;

Function GetAnyTransmission() : string;
var
  choice: string;
  valid: integer;
begin
  repeat
    begin
      writeln('Do you want to receive transmission from a file?(Y/N) ');
      readln (choice);
      if (Choice = 'Y') or (Choice = 'y') or (Choice = 'yes') or (Choice= 'YES') or (Choice= 'Yes') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromFile();
        end
      else if (Choice ='N') or (Choice = 'n') or (Choice = 'no') or (Choice= 'NO') or (Choice ='No') then
        begin
          valid := 1;
          GetAnyTransmission := GetTransmissionFromInput();
        end
      else
        begin
          valid := 0;
          writeln('You have not entered a valid response');
        end;
      end;
    until Valid = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def GetTransmission():
  choice = input(&quot;Would you like to load a file? (Y/N): &quot;)

  if choice == &quot;Y&quot;:
    FileName = input(&quot;Enter file name: &quot;)

    try:
      FileHandle = open(FileName, 'r')
      Transmission = FileHandle.readline()
      FileHandle.close()
      Transmission = StripLeadingSpaces(Transmission)
      if len(Transmission) &gt; 0:
        Transmission = StripTrailingSpaces(Transmission)
        Transmission = Transmission + EOL
    except:
      ReportError(&quot;No transmission found&quot;)
      Transmission = EMPTYSTRING
  else:
    Transmission = input(&quot;Enter your transmission String: &quot;)
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
      
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Dim choice As String
        Console.WriteLine(&quot;Do you wish to load a file?&quot;)
        choice = Console.ReadLine
        If choice = &quot;yes &quot; Then
            Console.Write(&quot;Enter file name: &quot;)
            Try
                Filename = Console.ReadLine()
                Dim Reader As New StreamReader(Filename)
                Transmission = Reader.ReadLine
                Reader.Close()
                Transmission = StripLeadingSpaces(Transmission)
                If Transmission.Length() &gt; 0 Then
                    Transmission = StripTrailingSpaces(Transmission)
                    Transmission = Transmission + EOL
                End If
            Catch
                ReportError(&quot;No transmission found&quot;)
                Transmission = EMPTYSTRING
            End Try
        Else
            Console.WriteLine(&quot;please enter the morse code string&quot;)
            Transmission = Console.ReadLine
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        End If
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save a .txt file when sending Morse Code ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
static void sendMorseCode(String[] morseCode) throws IOException {
		Console.write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
		String plainText = Console.readLine();
		plainText=plainText.toUpperCase();
		int plainTextLength = plainText.length();
		String morseCodeString = EMPTYSTRING;
		int index;
		for (int i = 0; i &lt; plainTextLength; i++) {
			char plainTextLetter = plainText.charAt(i);
			if (plainTextLetter == SPACE) {
				index = 0;
			} else {
				index = (int) plainTextLetter - (int) 'A' + 1;
			}
			String codedLetter = morseCode[index];
			morseCodeString = morseCodeString + codedLetter + SPACE;
		}
		Console.writeLine(morseCodeString);
		System.out.println(&quot;Do you want to save you message \n 1:Y \n 2:N&quot;);
		String choice = scan.next();
		switch(choice) {
		case &quot;Y&quot;:
			filewriter(morseCodeString);

			break;
		case &quot;N&quot;:
			break;
		default:
			System.out.println(&quot;That was not an option /n Your data will be stored&quot;);
			filewriter(morseCodeString);

			break;
		}
	}
	public static void filewriter(String sendMorseCode) throws IOException {
		System.out.println(&quot;Enter the name of the file&quot;);
		String filename = scan.next();
		FileWriter fw = new FileWriter(filename);
		PrintWriter end = new PrintWriter(fw);
		end.print(sendMorseCode);
		end.close();
		fw.close();
	}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
  #SBaker May 18 4.	Save a text file when sending Morse Code
  #we need to format MorseCodeString into the output format
  outputString = ''
  for letter in MorseCodeString:
    if letter == '.':
      outputString = outputString + &quot;= &quot;
    elif letter == '-':
      outputString = outputString + &quot;=== &quot;
    elif letter == ' ':
      outputString = outputString + &quot;  &quot;
  FileName = input(&quot;Enter file name: &quot;)
  try:
    FileHandle = open(FileName, 'w')
    FileHandle.write(outputString)
    FileHandle.close()
  except:
    ReportError(&quot;No file found&quot;)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainText = PlainText.ToUpper()

        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;Would you like to save this to a text file?&quot;)
        Dim save As String = Console.ReadLine()
        If save = &quot;Y&quot; Or save = &quot;y&quot; Then
            Dim fileTitle As String
            Console.WriteLine(&quot;What would you like to call the file?&quot;)
            fileTitle = Console.ReadLine()
            Dim fileLoc As String
            fileLoc = &quot;H:\Documents\2018 June\VB\&quot; + fileTitle + &quot;.txt&quot;
            Dim fs As New FileStream(fileLoc, FileMode.CreateNew, FileAccess.Write)
            Dim sw As New StreamWriter(fs)
            sw.WriteLine(MorseCodeString)
            sw.Flush()
        Else
            Console.WriteLine(&quot;Okay.&quot;)
            Console.ReadLine()
        End If
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Create and save transmission signal when sending ==
-Convert generated Morse into transmission signal.

-Write the transmission signal into txt file.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

    // Add EncodeMorseCode(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void EncodeMorseCode(string MorseCode)        // Function to convert MorseCodeString to the '=' and (Space) format in Preliminary Material
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string ShouldSave = Console.ReadLine();                 // Check whether user wants to save to file
        if (ShouldSave[0] == 'y' || ShouldSave[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();       // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))             // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;                     // Append .txt if not present
                }
                                                        
                StreamWriter CodedFileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)

                // Use the built-in .Replace(old, new) method to swap out the relevant characters in C#.
                string CodedOutput = MorseCode.Replace(&quot;-&quot;, &quot;=== &quot;).Replace(&quot;.&quot;, &quot;= &quot;).Replace(&quot;  &quot;, &quot;   &quot;).Replace(&quot;      &quot;, &quot;       &quot;);
                // This now effectively formats the MorseCodeString message to the '=' and ' ' format

                CodedFileSaver.Write(CodedOutput);

                CodedFileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling
            }
            Console.WriteLine(&quot;Coded File successfully written&quot;);
        }
     }

// S Wood - Teach

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveTransmission(Transmission : string);
var
  FileHandle : TextFile;
begin
  AssignFile(FileHandle, 'Message.txt');
  try
    rewrite (FileHandle);
    writeln (FileHandle, Transmission);
    CloseFile (FileHandle);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter, TransmissionString : String;
  PlainTextLength, i, Index, k : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  TransmissionString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      for k := 1 to length(CodedLetter) do
      begin
        case CodedLetter[k] of
          ' ': TransmissionString += ' ';
          '.': TransmissionString += '=';
          '-': TransmissionString += '==='
        end;
      TransmissionString += ' ';
      end;
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      if i &lt;&gt; PlainTextLength then
        TransmissionString += '  ';
    end;
  writeln(MorseCodeString);
  SaveTransmission(TransmissionString);
  writeln ('Message encoded and saved in Message.txt');
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
for (int i = 0; i &lt; morseCodeString.length(); i++) {
            char c = morseCodeString.charAt(i);
            if (c == '-') {
                morseCodeTransmission = morseCodeTransmission + &quot; ===&quot;;
            }
            if (c == '.') {
                morseCodeTransmission = morseCodeTransmission + &quot; =&quot;;
            }
            if (c == ' ') {
                morseCodeTransmission = morseCodeTransmission + &quot;  &quot;;
            }
        }

        System.out.println(&quot;Name the file you would like to save this too&quot;);

        String fileName = Console.readLine();
        if (!fileName.contains(&quot;.txt&quot;)) {
            fileName = fileName + &quot;.txt&quot;;
        }
        try {
            BufferedWriter fileHandle = new BufferedWriter(new FileWriter(fileName));
            fileHandle.write(morseCodeTransmission);
            fileHandle.close();
        } catch (IOException e) {
        }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if '    '+FileName[-4].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Dim save As Integer
        Dim file As StreamWriter
        Dim file2 As String
        Dim morsecodesymbol As String
        Dim morsecodesymbolR As String
        Dim morsecodemessage As String

        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else

                If Asc(PlainTextLetter) &lt; 65 Then
                    Index = Asc(PlainTextLetter) - 21
                Else
                    Index = Asc(PlainTextLetter) - Asc(&quot;A&quot;) + 1
                End If
            End If

            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE + SPACE + SPACE

        Next
        Console.WriteLine(MorseCodeString)
        Console.WriteLine(&quot;would you like to save your message in a document? If so then please press 1 if not press 2&quot;)
        Try
            save = Console.ReadLine
        Catch ex As Exception
            Console.WriteLine(&quot;you have messed up the saving program, please do as asked&quot;)
        End Try
        If save = 1 Then
            Console.WriteLine(&quot;your file will be saved please choose a name&quot;)
            file2 = Console.ReadLine &amp; &quot;.txt&quot;
            For i = 0 To MorseCodeString.Length - 1
                morsecodesymbol = MorseCodeString(i)
                If morsecodesymbol = &quot;-&quot; Then
                    morsecodesymbolR = &quot;===&quot;
                ElseIf morsecodesymbol = &quot;.&quot; Then
                    morsecodesymbolR = &quot;=&quot;
                ElseIf morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot; &quot;
                ElseIf morsecodesymbol = SPACE And morsecodesymbol = SPACE Then
                    morsecodesymbolR = &quot;     &quot;
                End If
                morsecodemessage = morsecodemessage &amp; &quot; &quot; &amp; morsecodesymbolR
            Next
            File = New StreamWriter(file2)
            File.Write(morsecodemessage)
            File.Close()
        End If

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Add Morse code for numbers/symbols ==
Allow the user to convert numbers and punctuation (for which there is Morse code available) into Morse code.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def SendReceiveMessages(): # All lists here have been modified to support numbers &amp; some punctuation ( .,?! ) by adding indexes 27 onwards. This has been modified so that sending &amp; receiving (if only sending required, only the MorseCode list requires changing) works.
  Dash = [20,23,0,45,24,1,0,17,31,21,28,25,0,15,11,42,0,0,46,22,13,48,30,10,0,0,44,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,27,0,38,40,37,0,29] 
  Dot = [5,18,33,0,2,9,0,26,32,19,0,3,0,7,4,43,0,0,12,8,14,6,0,16,0,0,34,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,36,35,0,0,46,39,47] 
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', ',', '?', '!'] 
  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..', '-----', '.----', '..---', '...--', '....-', '.....', '-....', '--...', '---..', '----.', '.-.-.-', '--..--', '..--..', '-.-.--'] 
  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True

def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
        Index = 0
    elif PlainTextLetter.isalpha(): # Character in position is a letter
      Index = ord(PlainTextLetter.upper()) - ord('A') + 1
    elif PlainTextLetter.isnumeric(): # Character in position is a number
      # 0 needs to be at index 27, so subtract unicode value of 0 and add 27 to get index of all numbers
      Index = ord(PlainTextLetter) - ord('0') + 27 
    else: # Is not a number / letter / space, assume it is a symbol. If statements for all supported symbols, setting index to position in MorseCode list
      if PlainTextLetter == '.':
        Index = 37 
      elif PlainTextLetter == ',': 
        Index = 38
      elif PlainTextLetter == '?':
        Index = 39
      elif PlainTextLetter == '!':
        Index = 40
      else: # Unsupported character, replace with space (could also output error here if needed)
        Index = 0 
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
 Sub SendReceiveMessages()
        Dim Dash = {20, 23, 0, 0, 24, 1, 0, 17, 31, 21, 28, 25, 0, 15, 11, 37, 45, 0, 40, 22, 13, 341, 30, 10, 0, 0, 44, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 46, 0, 0, 0, 0, 0, 0, 0}
        Dim Letter = {&quot; &quot;, &quot;A&quot;, &quot;B&quot;, &quot;C&quot;, &quot;D&quot;, &quot;E&quot;, &quot;F&quot;, &quot;G&quot;, &quot;H&quot;, &quot;I&quot;, &quot;J&quot;, &quot;K&quot;, &quot;L&quot;, &quot;M&quot;, &quot;N&quot;, &quot;O&quot;, &quot;P&quot;, &quot;Q&quot;, &quot;R&quot;, &quot;S&quot;, &quot;T&quot;, &quot;U&quot;, &quot;V&quot;, &quot;W&quot;, &quot;X&quot;, &quot;Y&quot;, &quot;Z&quot;, &quot;0&quot;, &quot;1&quot;, &quot;2&quot;, &quot;3&quot;, &quot;4&quot;, &quot;5&quot;, &quot;6&quot;, &quot;7&quot;, &quot;8&quot;, &quot;9&quot;, &quot;OT&quot;, &quot;ö&quot;, &quot;/&quot;, &quot;Ä&quot;, &quot;ü&quot;, &quot;+&quot;, &quot;üe&quot;, &quot;ZT&quot;, &quot;Á&quot;, &quot;,&quot;, &quot;@&quot;, &quot;.&quot;, &quot;?&quot;}
        Dim Dot = {5, 18, 33, 0, 2, 9, 0, 26, 32, 19, 0, 3, 0, 7, 4, 38, 0, 0, 12, 8, 14, 6, 0, 16, 39, 0, 34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 43, 48, 49, 0, 47}
        Dim MorseCode = {&quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot;, &quot;-----&quot;, &quot;.----&quot;, &quot;..---&quot;, &quot;...--&quot;, &quot;....-&quot;, &quot;.....&quot;, &quot;-....&quot;, &quot;--....&quot;, &quot;---...&quot;, &quot;----..&quot;, &quot;-----.&quot;, &quot;----&quot;, &quot;---.&quot;, &quot;-··-·&quot;, &quot;.-.-&quot;, &quot;..--&quot;, &quot;.-.-.&quot;, &quot;..--.&quot;, &quot;--..-&quot;, &quot;.--.-&quot;, &quot;--..--&quot;, &quot;.--.-.&quot;, &quot;.-.-..&quot;, &quot;..--..&quot;}

- Symbols work in progress numbers work!

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Validation of a message to send ==
Currently lowercase characters crash the program, add functionality to translate lowercase letters and correctly translate numbers/symbols

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
// Does not have numbers or symbols. Any other instances in the code where it does not allow lower case use the code equalsIgnoreCase(
// The code below shows it working in the menu of the Program
static void sendReceiveMessages() throws IOException {
		int[] dash = { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
		int[] dot = { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
		char[] letter = { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
				'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
		String[] morseCode = { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;,
				&quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;,
		&quot;--..&quot; };
		boolean programEnd = false;
		while (!programEnd) {
			displayMenu();
			String menuOption = scan.next();
			if (menuOption.equalsIgnoreCase(&quot;r&quot;)) {
				receiveMorseCode(dash, letter, dot);
			} else if (menuOption.equalsIgnoreCase(&quot;s&quot;)) {
				sendMorseCode(morseCode);
			} else if (menuOption.equalsIgnoreCase(&quot;x&quot;)) {
				programEnd = true;
			}else {
				System.out.println(&quot;That was an Incorrect Input&quot;);
			}
		}
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Currently only supports lowercase letters &amp; prevents invalid characters. Needs modifying to support numbers.
def SendMorseCode(MorseCode):
  Error = True # Input validation
  while Error: # Repeat the code in this section until input is valid
    Error = False # Assume no errors until one is detected
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;)
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter.upper()) - ord('A') + 1 # .upper() added to support lowercase characters
      try: # Attempt to find morse code for current character
        CodedLetter = MorseCode[Index]
        MorseCodeString = MorseCodeString + CodedLetter + SPACE
      except: # Has been an issue finding morse code for character - inform user of this &amp; re-run loop to allow a new input
        print(&quot;Invalid character in message.&quot;)
        Error = True # Set error to true so loop re-runs
        break # Break for loop to go back to start of Error loop (and ask for a new input)
  print(MorseCodeString)
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Automatically append '.txt' to file. ==
Code that makes it obsolete for the user to add the '.txt' extension to their file name

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;
FileName = FileName.Contains(&quot;.txt&quot;) ? FileName : FileName + &quot;.txt&quot;;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Function GetTransmission(): String;
var
  FileName, FileNameOriginal: String;
  FileHandle: Textfile;
  Transmission: String;
begin
  write('Enter file name: ');
  readln(FileNameOriginal);    {Variable was originally set as FileName but was changed for Concentrate}
  FileName := Concat(FileNameOriginal,'.txt');

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
   
  static void sendMorseCode(String[] morseCode) throws IOException
  {
    Console.write(&quot;Enter your message (letters and spaces only): &quot;);
    String plainText = Console.readLine();
    plainText = plainText.toUpperCase();
    int plainTextLength = plainText.length();
    String morseCodeString = EMPTYSTRING;
    int index;
    for (int i = 0; i &lt; plainTextLength; i++)
    {
      char plainTextLetter = plainText.charAt(i);
      if (plainTextLetter == SPACE)
      {
        index = 0;
      }
      else
      {
        index = (int)plainTextLetter - (int)'A' + 1;
      }
      String codedLetter = morseCode[index];
      morseCodeString = morseCodeString + codedLetter + SPACE;
    }
    Console.writeLine(morseCodeString);
    Save(morseCodeString);
  }
  
  
  public static void Save(String pop) throws IOException {
	  System.out.println(&quot;Enter file name: &quot;);
	  Scanner scan = new Scanner(System.in);
	  String f = scan.next();
	  FileWriter file = new FileWriter(f+&quot;.txt&quot;, true);
	  PrintWriter print = new PrintWriter(file);
	  print.println(pop);
	  print.flush();
	  print.close();
  }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

def GetTransmission():
  FileName = input(&quot;Enter file name: &quot;)
  if FileName[-4:] != '.txt': # If last 4 characters match .txt - the 4 spaces appended to the start of string are to prevent the string being shorted than the indexes being checked
        FileName += '.txt' # Append .txt to end of file name
  try:
    FileHandle = open(FileName, 'r')
    Transmission = FileHandle.readline()
    FileHandle.close()
    Transmission = StripLeadingSpaces(Transmission)
    if len(Transmission) &gt; 0:
      Transmission = StripTrailingSpaces(Transmission)
      Transmission = Transmission + EOL
  except:
    ReportError(&quot;No transmission found&quot;)
    Transmission = EMPTYSTRING
  return Transmission

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Function GetTransmission() As String
        Dim Filename As String
        Dim Transmission As String
        Console.Write(&quot;Enter file name: &quot;)
        Try
            Filename = Console.ReadLine()
            Filename = Filename + &quot;.txt&quot;
            Dim Reader As New StreamReader(Filename)
            Transmission = Reader.ReadLine
            Reader.Close()
            Transmission = StripLeadingSpaces(Transmission)
            If Transmission.Length() &gt; 0 Then
                Transmission = StripTrailingSpaces(Transmission)
                Transmission = Transmission + EOL
            End If
        Catch
            ReportError(&quot;No transmission found&quot;)
            Transmission = EMPTYSTRING
        End Try
        Return Transmission
    End Function
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Save message in a text file ==
Code that save the translated code in a text file

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:
    private static void SaveToFile(string MorseCodeString)     // ADDED - SAVE TO FILE
    {
        Console.WriteLine(&quot;Would You like to save the message to a file (Y/N)?&quot;);
        string SaveChoice = Console.ReadLine();                 // Check whether user wants to save to file
        if (SaveChoice[0] == 'y' || SaveChoice[0] == 'Y')       // [0] to only account for first character of input (both cases checked)
        {
            try
            {
                Console.WriteLine(&quot;Enter the name of the file to save the message to: &quot;);
                string FileName = Console.ReadLine();                   // User input file name

                if (!FileName.Contains(&quot;.txt&quot;))     // If it doesn't contain '.txt' then add the &quot;.txt&quot; to FileName
                {
                    FileName += &quot;.txt&quot;;             // Append .txt if not present
                }

                StreamWriter FileSaver = new StreamWriter(FileName);    // Open file in write mode (new StreamWriter)
                FileSaver.Write(MorseCodeString);                       // Write the MorseCodeString to the File chosen

                FileSaver.Close();
            }
            catch
            {
                ReportError(&quot;Error when writing to file.&quot;);     // Error handling message
            }
            Console.WriteLine(&quot;File successfully written&quot;);
        }
    }

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SaveMorseToFile(MorseString : string);   //added to save morse
var
  FileMorse:TextFile;
begin
  AssignFile(FileMorse, 'MorseFile.txt');
  try
    rewrite(FileMorse);
    writeln(FileMorse, MorseString);
    CloseFile(FileMorse);
  except
    on E: exception do
      writeln ('Exception: ', E.Message);
  end;
end;

Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        Index := ord(PlainTextLetter) - ord('A') + 1;
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
  SaveMorseToFile(MorseCodeString);//Saves it to a file
  writeln('Saved to MorseFile.txt');
end;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static void write(String morseCodeString) throws IOException 
	{
		FileWriter fw = new FileWriter (&quot;morse.txt&quot;);
		PrintWriter output = new PrintWriter (fw);
		output.println(morseCodeString);
		output.close();
		output.flush();
		System.out.println(&quot;Printed in morse.txt&quot;);
	}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
# Add SaveToFile(MorseCodeString) to last line of the SendMorseCode() subroutine, and also define the following subroutines:

def SaveToFile(MorseCodeString): # ADDED - SAVE TO FILE
  ShouldSave = input(&quot;Would You like to save the message to a file (Y/N)?&quot;) # Check whether user wants to save to file
  if ShouldSave[0].lower() == 'y': # .lower to make casing irrelevant, [0] to only account for first character (e.g. yes will also be accepted)
    try: 
      FileName = input(&quot;Enter the name of the file to save the message to: &quot;) # User input file name

      if FileName[-4:].lower() != '.txt': # Check if file extension is .txt. The '    ' at start is 4 spaces in order to prevent error from index not existing (if file name was under 4 characters)
        FileName += '.txt' # Append .txt if not present
      FileHandle = open(FileName, 'w') # Open file in write mode
      FileHandle.write(EncodeMorseCode(MorseCodeString)) # Write the encoded message to file
      FileHandle.close() 
    except:
      ReportError(&quot;Error when writing to file.&quot;) # Error handling

def EncodeMorseCode(MorseCode): # Function to convert morse code to format saved in file
  Output = MorseCode.replace('-', '=== ').replace('.', '= ').replace('  ', '   ').replace('      ', '       ') # Format message to required format
  return Output # Return message to be saved to file

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== List Characters ==
Output a list of all of the characters from the list next to their Morse code representation.

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// NEW SUBROUTINE- Letter and MorseCode lists are passed as parameters/arguments
private static void ListMorseCode(char[] Letter, string[] MorseCode)
{
    for (int index = 0; index &lt; Letter.Length; index++)      // for loop - loops through all elements in the Letter Array
    {
        Console.WriteLine(Letter[index] + &quot;   &quot; + MorseCode[index]);     // Output the text character, followed by a few spaces, and then the Morse code representation
    }
}

// AMENDED SUBROUTINE
private static void DisplayMenu()
{
    Console.WriteLine();
    Console.WriteLine(&quot;Main Menu&quot;);
    Console.WriteLine(&quot;=========&quot;);
    Console.WriteLine(&quot;R - Receive Morse code&quot;);
    Console.WriteLine(&quot;S - Send Morse code&quot;);
    Console.WriteLine(&quot;L - List Morse code characters&quot;);         // Added - display menu option for this modification
    Console.WriteLine(&quot;X - Exit program&quot;);
    Console.WriteLine();
}

// AMENDED SUBROUTINE
private static void SendReceiveMessages()
{
    int[] Dash = new int[] { 20, 23, 0, 0, 24, 1, 0, 17, 0, 21, 0, 25, 0, 15, 11, 0, 0, 0, 0, 22, 13, 0, 0, 10, 0, 0, 0 };
    int[] Dot = new int[] { 5, 18, 0, 0, 2, 9, 0, 26, 0, 19, 0, 3, 0, 7, 4, 0, 0, 0, 12, 8, 14, 6, 0, 16, 0, 0, 0 };
    char[] Letter = new char[] { ' ', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
    string[] MorseCode = new string[] { &quot; &quot;, &quot;.-&quot;, &quot;-...&quot;, &quot;-.-.&quot;, &quot;-..&quot;, &quot;.&quot;, &quot;..-.&quot;, &quot;--.&quot;, &quot;....&quot;, &quot;..&quot;, &quot;.---&quot;, &quot;-.-&quot;, &quot;.-..&quot;, &quot;--&quot;, &quot;-.&quot;, &quot;---&quot;, &quot;.--.&quot;, &quot;--.-&quot;, &quot;.-.&quot;, &quot;...&quot;, &quot;-&quot;, &quot;..-&quot;, &quot;...-&quot;, &quot;.--&quot;, &quot;-..-&quot;, &quot;-.--&quot;, &quot;--..&quot; };
    bool ProgramEnd = false;
    string MenuOption = EMPTYSTRING;
    while (!ProgramEnd)
    {
        DisplayMenu();
        MenuOption = GetMenuOption();
        if (MenuOption == &quot;R&quot;)
        {
            ReceiveMorseCode(Dash, Letter, Dot);
        }
        else if (MenuOption == &quot;S&quot;)
        {
            SendMorseCode(MorseCode);
        }
        else if (MenuOption == &quot;X&quot;)
        {
            ProgramEnd = true;
        }
        else if (MenuOption == &quot;L&quot;)             // Added - if menu option selected is the 'L' (list Morse code)
        {
            ListMorseCode(Letter, MorseCode);   // Run ListMorseCode subroutine, passing lists Letter and MorseCode
        }
    }
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure DisplayMenu();
begin
  writeln;
  writeln('Main Menu');
  writeln('=========');
  writeln('R - Receive Morse code');
  writeln('S - Send Morse code');
  writeln('L - List Morse code characters');//Added menu option for this
  writeln('X - Exit program');
  writeln;
end;

Procedure ListCharacters(Letter:Array of char; MorseCode:Array of String);   //new procedure for listing
var
  z : integer;
begin
  for z:=0 to 26 do
    writeln(Letter[z],'   ',MorseCode[z]);
end;

Procedure SendReceiveMessages();
const
  Dash: array[0..26] of Integer = (20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0);
  Dot : array[0..26] of Integer = (5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0);
  Letter : array[0..26] of Char= (' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
  MorseCode : array[0..26] of String= (' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..');
var
  ProgramEnd : Boolean;
  MenuOption : String;
begin
  ProgramEnd := False;
  while not(ProgramEnd) do
    begin
      DisplayMenu();
      MenuOption := GetMenuOption();
      if MenuOption = 'R' then
        ReceiveMorseCode(Dash, Letter, Dot)
      else if MenuOption = 'S' then
        SendMorseCode(MorseCode)
      else if MenuOption = 'X' then
        ProgramEnd := True
      else if MenuOption = 'L' then
        ListCharacters(Letter, MorseCode); //Added to lead to new procedure
    end;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;

# Added subroutines

def ListMorseCode(Letter, MorseCode): # New subroutine - Letter and MorseCode lists are passed as parameters
  for Pos in range(len(Letter)): # Loop through all positions in the length of the list
    print(Letter[Pos]+&quot;   &quot;+MorseCode[Pos]) # Output the text character, followed by a few spaces, and then the Morse code representation

# Existing modified subroutines

def DisplayMenu():
  print()
  print(&quot;Main Menu&quot;)
  print(&quot;=========&quot;)
  print(&quot;R - Receive Morse code&quot;)
  print(&quot;S - Send Morse code&quot;)
  print(&quot;L - List Morse code characters&quot;) # Added - display menu option for this modification
  print(&quot;X - Exit program&quot;)
  print()

def SendReceiveMessages():
  Dash = [20,23,0,0,24,1,0,17,0,21,0,25,0,15,11,0,0,0,0,22,13,0,0,10,0,0,0]
  Dot = [5,18,0,0,2,9,0,26,0,19,0,3,0,7,4,0,0,0,12,8,14,6,0,16,0,0,0]
  Letter = [' ','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

  MorseCode = [' ','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..']

  ProgramEnd = False
  while not ProgramEnd:
    DisplayMenu() 
    MenuOption = GetMenuOption()
    if MenuOption == 'R':
      ReceiveMorseCode(Dash, Letter, Dot)
    elif MenuOption == 'S':
      SendMorseCode(MorseCode) 
    elif MenuOption == 'X':
      ProgramEnd = True
    elif MenuOption == 'L': # Added - if menu option selected is the 'L' (list Morse code)
      ListMorseCode(Letter, MorseCode) # Run ListMorseCode subroutine, passing lists Letter and MorseCode

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

== Accept multiple lines of text to convert to Morse code ==
Description of question

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter,x : String;
  PlainTextLength, i, Index : Integer;
  PlainTextLetter : Char;
  continue : integer;
begin
  continue:= 0;
  repeat
    write('Enter your message (uppercase letters and spaces only): ');
    readln(PlainText);
    PlainTextLength := length(PlainText);
    MorseCodeString := EMPTYSTRING;
    for i := 1 to PlainTextLength do
      begin
        PlainTextLetter := PlainText[i];
        if PlainTextLetter = SPACE then
          Index := 0
        else
          Index := ord(PlainTextLetter) - ord('A') + 1;
        CodedLetter := MorseCode[Index];
        MorseCodeString := MorseCodeString + CodedLetter + SPACE;
      end;
    writeln(MorseCodeString);
    write('Continue (Y or N): ');
    readln(x);
    if (x = 'Y') or (x ='y') then //start of continue
        continue:= 0
      else if (x = 'N') or (x = 'n') then
        continue:= 1
      else
        begin
          writeln('Interpreting answer as no');//could be made to loop if needed
          continue:=1;
        end;
  until continue = 1;
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  Continue = 0
  while Continue != 1:
    PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()
    PlainTextLength = len(PlainText)
    MorseCodeString = EMPTYSTRING
    for i in range(PlainTextLength):
      PlainTextLetter = PlainText[i]
      if PlainTextLetter == SPACE:
        Index = 0
      else: 
        Index = ord(PlainTextLetter) - ord('A') + 1
      CodedLetter = MorseCode[Index]
      MorseCodeString = MorseCodeString + CodedLetter + SPACE
    print(MorseCodeString)
    x = input(&quot;Continue Y/N?: &quot;)
    if x == &quot;Y&quot; or x == &quot;y&quot;:
      Continue = 0
    elif x == &quot;N&quot; or x == &quot;n&quot;:
      Continue = 1
    else:
      print(&quot;Interpreting answer as no&quot;)
      Continue = 1
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}

== Accept lowercase letters ==
This will accept the input of lowercase characters

{{CPTAnswerTab|C#}}
&lt;syntaxhighlight lang=&quot;c#&quot;&gt;

// AMENDED SUBROUTINE - Allows Lowercase values in Send string now. (ASCII values used)
private static void SendMorseCode(string[] MorseCode)
{
    Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;);
    string PlainText = Console.ReadLine();
    int PlainTextLength = PlainText.Length;
    string MorseCodeString = EMPTYSTRING;
    char PlainTextLetter = SPACE;
    int Index = 0;

    int ascii;              // declare new value 'ascii' to store that value.

    for (int i = 0; i &lt; PlainTextLength; i++)
    {
        PlainTextLetter = PlainText[i];
        if (PlainTextLetter == SPACE)
        {
            Index = 0;
        }
        else
        {
            if ((int)PlainTextLetter &gt;= 97)             // if ASCII Value of that letter is 97 or above, it is assumed to be lowercase.
                ascii = (int)PlainTextLetter - 32;      // if lowercase then subtract 32 from its ASCII value
            else
                ascii = (int)PlainTextLetter;           // else it is uppercase, then use that ASCII value.

            Index = ascii - (int)'A' + 1;               // use the 'ascii' value to calculate, just incase lowercase has been used.
        }
        string CodedLetter = MorseCode[Index];
        MorseCodeString = MorseCodeString + CodedLetter + SPACE;
    }
    Console.WriteLine(MorseCodeString);
}

&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
Procedure SendMorseCode(MorseCode : Array of String);
var
  PlainText, MorseCodeString, CodedLetter : String;
  PlainTextLength, i, Index, assci : Integer;
  PlainTextLetter : Char;
begin
  write('Enter your message (uppercase letters and spaces only): ');
  readln(PlainText);
  PlainTextLength := length(PlainText);
  MorseCodeString := EMPTYSTRING;
  for i := 1 to PlainTextLength do
    begin
      PlainTextLetter := PlainText[i];
      if PlainTextLetter = SPACE then
        Index := 0
      else
        begin   //added to allow lower case letters
          if ord(PlainTextLetter) &gt;= 97 then
            assci:= ord(PlainTextLetter) - 32
          else
            assci:=  ord(PlainTextLetter);
          Index := assci - ord('A') + 1;
        end;                             //should work
      CodedLetter := MorseCode[Index];
      MorseCodeString := MorseCodeString + CodedLetter + SPACE;
    end;
  writeln(MorseCodeString);
end;
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Delphi/Pascal}}
&lt;syntaxhighlight lang=&quot;pascal&quot;&gt;
write ('This is a question: ');
readln(Variable);
Variable := AnsiUpperCase(Variable);
{This can be added for the MenuOption (in GetMenuOption) and Plaintext (in SendMorseCode)}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Java}}
&lt;syntaxhighlight lang=&quot;java&quot;&gt;
static char getMenuOption() {
		boolean valid = false;
		char menuOption = ' ';
		while(!valid) {
		String option = EMPTYSTRING;
		Console.write(&quot;Enter menu option&quot;);
		try {
			option = Console.readLine();
		} catch (Exception e) {
			System.out.println(&quot;Invalid input&quot;);
		}
		if (option.equalsIgnoreCase(&quot;R&quot;))
			menuOption = 'R'; valid = true;
		if (option.equalsIgnoreCase(&quot;S&quot;))
			menuOption = 'S'; valid = true;
		if (option.equalsIgnoreCase(&quot;X&quot;)) {
			menuOption = 'X'; valid = true;
		}
		else if (!valid) {
				System.out.println(&quot;Invalid input&quot;);
			}
		}
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|Python}}
&lt;syntaxhighlight lang=&quot;python&quot;&gt;
def SendMorseCode(MorseCode):
  PlainText = input(&quot;Enter your message (uppercase letters and spaces only): &quot;).upper()#Changed
  PlainTextLength = len(PlainText)
  MorseCodeString = EMPTYSTRING
  for i in range(PlainTextLength):
    PlainTextLetter = PlainText[i]
    if PlainTextLetter == SPACE:
      Index = 0
    else: 
      Index = ord(PlainTextLetter) - ord('A') + 1
    CodedLetter = MorseCode[Index]
    MorseCodeString = MorseCodeString + CodedLetter + SPACE
  print(MorseCodeString)

def GetMenuOption():
  MenuOption = EMPTYSTRING
  while len(MenuOption) != 1:
    MenuOption = input(&quot;Enter your choice: &quot;).upper()#Changed
  return MenuOption
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{CPTAnswerTab|VB.NET}}
&lt;syntaxhighlight lang=&quot;vbnet&quot;&gt;
Sub SendMorseCode(ByVal MorseCode() As String)
        Dim PlainText As String
        Dim PlainTextLength As Integer
        Dim MorseCodeString As String
        Dim PlainTextLetter As Char
        Dim CodedLetter As String
        Dim Index As Integer
        Console.Write(&quot;Enter your message (uppercase letters and spaces only): &quot;)
        PlainText = Console.ReadLine()
        PlainTextLength = PlainText.Length()
        MorseCodeString = EMPTYSTRING
        For i = 0 To PlainTextLength - 1
            PlainTextLetter = PlainText(i)
            If PlainTextLetter = SPACE Then
                Index = 0
            Else
                Index = Asc(PlainTextLetter)
                If Index &gt; 96 And Index &lt; 123 Then
                    Index -= 32
                End If
                Index = Index - Asc(&quot;A&quot;) + 1
            End If
            CodedLetter = MorseCode(Index)
            MorseCodeString = MorseCodeString + CodedLetter + SPACE
        Next
        Console.WriteLine(MorseCodeString)
        SaveMorseCode(MorseCodeString)
    End Sub
&lt;/syntaxhighlight&gt;
{{CPTAnswerTabEnd}}

{{BookCat}}</text>
      <sha1>2xk8fj7k9cbf9gb0l0byqau871al9kv</sha1>
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  </page>
  <page>
    <title>Unicode/Character reference/3F000-3FFFF</title>
    <ns>0</ns>
    <id>427007</id>
    <revision>
      <id>4636909</id>
      <parentid>4619643</parentid>
      <timestamp>2026-05-21T18:20:05Z</timestamp>
      <contributor>
        <username>~2026-25678-06</username>
        <id>3579663</id>
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      <origin>4636909</origin>
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      <text bytes="56324" sha1="s8znq9j5sowhyjdz5846jr6nfbx1iun" xml:space="preserve">{{:Unicode/Character reference}}

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|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Seal (ctd.)'''
|----- style=&quot;background:#ccccff&quot;
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!style=&quot;background:#ffffff&quot;|3F01x
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!style=&quot;background:#ffffff&quot;|3F02x
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!style=&quot;background:#ffffff&quot;|3F03x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F05x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F08x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F09x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Ax
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Bx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Cx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Dx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Ex
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Fx
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F10x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F11x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F12x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F13x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F14x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F15x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F16x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F17x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F18x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F19x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Ax
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Bx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Cx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Dx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Ex
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
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!style=&quot;background:#ffffff&quot;|3F1Fx
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
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!style=&quot;background:#ffffff&quot;|3F20x
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!style=&quot;background:#ffffff&quot;|3F21x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F22x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
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!style=&quot;background:#ffffff&quot;|3F23x
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!style=&quot;background:#ffffff&quot;|3F24x
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!style=&quot;background:#ffffff&quot;|3F25x
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!style=&quot;background:#ffffff&quot;|3F26x
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!style=&quot;background:#ffffff&quot;|3F27x
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!style=&quot;background:#ffffff&quot;|3F28x
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!style=&quot;background:#ffffff&quot;|3F29x
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!style=&quot;background:#ffffff&quot;|3F2Ax
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!style=&quot;background:#ffffff&quot;|3F2Cx
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!style=&quot;background:#ffffff&quot;|3F2Dx
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!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
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!style=&quot;background:#ffffff&quot;|3F32x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FAAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FABx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FACx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FADx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FAEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FAFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Enclosed Alphanumeric Extended-A'''
|----- style=&quot;background:#ccccff&quot;
!width=&quot;4%&quot;|U+!!width=&quot;6%&quot;|0!!width=&quot;6%&quot;|1!!width=&quot;6%&quot;|2!!width=&quot;6%&quot;|3!!width=&quot;6%&quot;|4!!width=&quot;6%&quot;|5!!width=&quot;6%&quot;|6!!width=&quot;6%&quot;|7!!width=&quot;6%&quot;|8!!width=&quot;6%&quot;|9!!width=&quot;6%&quot;|A!!width=&quot;6%&quot;|B!!width=&quot;6%&quot;|C!!width=&quot;6%&quot;|D!!width=&quot;6%&quot;|E!!width=&quot;6%&quot;|F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Enclosed Alphanumeric Extended-A'''
|----- style=&quot;background:#ccccff&quot;
!width=&quot;4%&quot;|U+!!width=&quot;6%&quot;|0!!width=&quot;6%&quot;|1!!width=&quot;6%&quot;|2!!width=&quot;6%&quot;|3!!width=&quot;6%&quot;|4!!width=&quot;6%&quot;|5!!width=&quot;6%&quot;|6!!width=&quot;6%&quot;|7!!width=&quot;6%&quot;|8!!width=&quot;6%&quot;|9!!width=&quot;6%&quot;|A!!width=&quot;6%&quot;|B!!width=&quot;6%&quot;|C!!width=&quot;6%&quot;|D!!width=&quot;6%&quot;|E!!width=&quot;6%&quot;|F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FDFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE5x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE7x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FE9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FEAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FEBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FECx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FEDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FEEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FEFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FF0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FF1x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FF2x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FF3x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FF4x
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| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Seal Script (ctd.)'''
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F00x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F02x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F03x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F04x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F05x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F08x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F09x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Ax
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Bx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F0Cx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F10x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F11x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F12x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F13x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F14x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F15x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F16x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F17x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F18x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F19x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Ax
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Bx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Cx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Dx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Ex
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F1Fx
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F20x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F21x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F22x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F23x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3F9Dx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA1x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FA9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FAAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FABx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FACx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FADx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FAEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FAFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB1x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB7x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FB9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FBFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Enclosed Alphanumeric Extended-A'''
|----- style=&quot;background:#ccccff&quot;
!width=&quot;4%&quot;|U+!!width=&quot;6%&quot;|0!!width=&quot;6%&quot;|1!!width=&quot;6%&quot;|2!!width=&quot;6%&quot;|3!!width=&quot;6%&quot;|4!!width=&quot;6%&quot;|5!!width=&quot;6%&quot;|6!!width=&quot;6%&quot;|7!!width=&quot;6%&quot;|8!!width=&quot;6%&quot;|9!!width=&quot;6%&quot;|A!!width=&quot;6%&quot;|B!!width=&quot;6%&quot;|C!!width=&quot;6%&quot;|D!!width=&quot;6%&quot;|E!!width=&quot;6%&quot;|F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FC9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCCx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCDx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FCFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3FD3x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Seal Script (ctd.)'''
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EEEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EEFx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF0x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF1x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF2x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF3x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF4x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF5x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF6x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF7x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF8x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EF9x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EFAx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EFBx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EFCx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EFEx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3EFFx
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
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    <title>Unicode/Character reference/3D000-3DFFF</title>
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{|border=&quot;1&quot; cellpadding=&quot;2&quot; cellspacing=&quot;0&quot; style=&quot;border-collapse:collapse&quot;
|-
| colspan=&quot;17&quot; style=&quot;background:#f8f8f8;text-align:center&quot; | '''Seal Script'''
|----- style=&quot;background:#ccccff&quot;
!width=&quot;4%&quot;|U+!!width=&quot;6%&quot;|0!!width=&quot;6%&quot;|1!!width=&quot;6%&quot;|2!!width=&quot;6%&quot;|3!!width=&quot;6%&quot;|4!!width=&quot;6%&quot;|5!!width=&quot;6%&quot;|6!!width=&quot;6%&quot;|7!!width=&quot;6%&quot;|8!!width=&quot;6%&quot;|9!!width=&quot;6%&quot;|A!!width=&quot;6%&quot;|B!!width=&quot;6%&quot;|C!!width=&quot;6%&quot;|D!!width=&quot;6%&quot;|E!!width=&quot;6%&quot;|F
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|3D00x
|{{H:title|dotted=no|SEAL CHARACTER-3D000|&amp;#x3d000;}}||{{H:title|dotted=no|SEAL CHARACTER-3D001|&amp;#x3d001;}}||{{H:title|dotted=no|SEAL CHARACTER-3D002|&amp;#x3d002;}}||{{H:title|dotted=no|SEAL CHARACTER-3D003|&amp;#x3d003;}}||{{H:title|dotted=no|SEAL CHARACTER-3D004|&amp;#x3d004;}}||{{H:title|dotted=no|SEAL CHARACTER-3D005|&amp;#x3d005;}}||{{H:title|dotted=no|SEAL CHARACTER-3D006|&amp;#x3d006;}}||{{H:title|dotted=no|SEAL CHARACTER-3D007|&amp;#x3d007;}}||{{H:title|dotted=no|SEAL CHARACTER-3D008|&amp;#x3d008;}}||{{H:title|dotted=no|SEAL CHARACTER-3D009|&amp;#x3d009;}}||{{H:title|dotted=no|SEAL CHARACTER-3D00A|&amp;#x3d00a;}}||{{H:title|dotted=no|SEAL CHARACTER-3D00B|&amp;#x3d00b;}}||{{H:title|dotted=no|SEAL CHARACTER-3D00C|&amp;#x3d00c;}}||{{H:title|dotted=no|SEAL CHARACTER-3D00D|&amp;#x3d00d;}}||{{H:title|dotted=no|SEAL CHARACTER-3D00E|&amp;#x3d00e;}}||{{H:title|dotted=no|SEAL CHARACTER-3D00F|&amp;#x3d00f;}}
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|3D01x
|{{H:title|dotted=no|SEAL CHARACTER-3D010|&amp;#x3d010;}}||{{H:title|dotted=no|SEAL CHARACTER-3D011|&amp;#x3d011;}}||{{H:title|dotted=no|SEAL CHARACTER-3D012|&amp;#x3d012;}}||{{H:title|dotted=no|SEAL CHARACTER-3D013|&amp;#x3d013;}}||{{H:title|dotted=no|SEAL CHARACTER-3D014|&amp;#x3d014;}}||{{H:title|dotted=no|SEAL CHARACTER-3D015|&amp;#x3d015;}}||{{H:title|dotted=no|SEAL CHARACTER-3D016|&amp;#x3d016;}}||{{H:title|dotted=no|SEAL CHARACTER-3D017|&amp;#x3d017;}}||{{H:title|dotted=no|SEAL CHARACTER-3D018|&amp;#x3d018;}}||{{H:title|dotted=no|SEAL CHARACTER-3D019|&amp;#x3d019;}}||{{H:title|dotted=no|SEAL CHARACTER-3D01A|&amp;#x3d01a;}}||{{H:title|dotted=no|SEAL CHARACTER-3D01B|&amp;#x3d01b;}}||{{H:title|dotted=no|SEAL CHARACTER-3D01C|&amp;#x3d01c;}}||{{H:title|dotted=no|SEAL CHARACTER-3D01D|&amp;#x3d01d;}}||{{H:title|dotted=no|SEAL CHARACTER-3D01E|&amp;#x3d01e;}}||{{H:title|dotted=no|SEAL CHARACTER-3D01F|&amp;#x3d01f;}}
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|3D02x
|{{H:title|dotted=no|SEAL CHARACTER-3D020|&amp;#x3d020;}}||{{H:title|dotted=no|SEAL CHARACTER-3D021|&amp;#x3d021;}}||{{H:title|dotted=no|SEAL CHARACTER-3D022|&amp;#x3d022;}}||{{H:title|dotted=no|SEAL CHARACTER-3D023|&amp;#x3d023;}}||{{H:title|dotted=no|SEAL CHARACTER-3D024|&amp;#x3d024;}}||{{H:title|dotted=no|SEAL CHARACTER-3D025|&amp;#x3d025;}}||{{H:title|dotted=no|SEAL CHARACTER-3D026|&amp;#x3d026;}}||{{H:title|dotted=no|SEAL CHARACTER-3D027|&amp;#x3d027;}}||{{H:title|dotted=no|SEAL CHARACTER-3D028|&amp;#x3d028;}}||{{H:title|dotted=no|SEAL CHARACTER-3D029|&amp;#x3d029;}}||{{H:title|dotted=no|SEAL CHARACTER-3D02A|&amp;#x3d02a;}}||{{H:title|dotted=no|SEAL CHARACTER-3D02B|&amp;#x3d02b;}}||{{H:title|dotted=no|SEAL CHARACTER-3D02C|&amp;#x3d02c;}}||{{H:title|dotted=no|SEAL CHARACTER-3D02D|&amp;#x3d02d;}}||{{H:title|dotted=no|SEAL CHARACTER-3D02E|&amp;#x3d02e;}}||{{H:title|dotted=no|SEAL CHARACTER-3D02F|&amp;#x3d02f;}}
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|3D03x
|{{H:title|dotted=no|SEAL CHARACTER-3D030|&amp;#x3d030;}}||{{H:title|dotted=no|SEAL CHARACTER-3D031|&amp;#x3d031;}}||{{H:title|dotted=no|SEAL CHARACTER-3D032|&amp;#x3d032;}}||{{H:title|dotted=no|SEAL CHARACTER-3D033|&amp;#x3d033;}}||{{H:title|dotted=no|SEAL CHARACTER-3D034|&amp;#x3d034;}}||{{H:title|dotted=no|SEAL CHARACTER-3D035|&amp;#x3d035;}}||{{H:title|dotted=no|SEAL CHARACTER-3D036|&amp;#x3d036;}}||{{H:title|dotted=no|SEAL CHARACTER-3D037|&amp;#x3d037;}}||{{H:title|dotted=no|SEAL CHARACTER-3D038|&amp;#x3d038;}}||{{H:title|dotted=no|SEAL CHARACTER-3D039|&amp;#x3d039;}}||{{H:title|dotted=no|SEAL CHARACTER-3D03A|&amp;#x3d03a;}}||{{H:title|dotted=no|SEAL CHARACTER-3D03B|&amp;#x3d03b;}}||{{H:title|dotted=no|SEAL CHARACTER-3D03C|&amp;#x3d03c;}}||{{H:title|dotted=no|SEAL CHARACTER-3D03D|&amp;#x3d03d;}}||{{H:title|dotted=no|SEAL CHARACTER-3D03E|&amp;#x3d03e;}}||{{H:title|dotted=no|SEAL CHARACTER-3D03F|&amp;#x3d03f;}}
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|3D04x
|{{H:title|dotted=no|SEAL CHARACTER-3D040|&amp;#x3d040;}}||{{H:title|dotted=no|SEAL CHARACTER-3D041|&amp;#x3d041;}}||{{H:title|dotted=no|SEAL CHARACTER-3D042|&amp;#x3d042;}}||{{H:title|dotted=no|SEAL CHARACTER-3D043|&amp;#x3d043;}}||{{H:title|dotted=no|SEAL CHARACTER-3D044|&amp;#x3d044;}}||{{H:title|dotted=no|SEAL CHARACTER-3D045|&amp;#x3d045;}}||{{H:title|dotted=no|SEAL CHARACTER-3D046|&amp;#x3d046;}}||{{H:title|dotted=no|SEAL CHARACTER-3D047|&amp;#x3d047;}}||{{H:title|dotted=no|SEAL CHARACTER-3D048|&amp;#x3d048;}}||{{H:title|dotted=no|SEAL CHARACTER-3D049|&amp;#x3d049;}}||{{H:title|dotted=no|SEAL CHARACTER-3D04A|&amp;#x3d04a;}}||{{H:title|dotted=no|SEAL CHARACTER-3D04B|&amp;#x3d04b;}}||{{H:title|dotted=no|SEAL CHARACTER-3D04C|&amp;#x3d04c;}}||{{H:title|dotted=no|SEAL CHARACTER-3D04D|&amp;#x3d04d;}}||{{H:title|dotted=no|SEAL CHARACTER-3D04E|&amp;#x3d04e;}}||{{H:title|dotted=no|SEAL CHARACTER-3D04F|&amp;#x3d04f;}}
|----- align=&quot;center&quot; style=&quot;background:#c8a36f&quot;
!style=&quot;background:#ffffff&quot;|3D05x
|{{H:title|dotted=no|SEAL CHARACTER-3D050|&amp;#x3d050;}}||{{H:title|dotted=no|SEAL CHARACTER-3D051|&amp;#x3d051;}}||{{H:title|dotted=no|SEAL CHARACTER-3D052|&amp;#x3d052;}}||{{H:title|dotted=no|SEAL CHARACTER-3D053|&amp;#x3d053;}}||{{H:title|dotted=no|SEAL CHARACTER-3D054|&amp;#x3d054;}}||{{H:title|dotted=no|SEAL CHARACTER-3D055|&amp;#x3d055;}}||{{H:title|dotted=no|SEAL CHARACTER-3D056|&amp;#x3d056;}}||{{H:title|dotted=no|SEAL CHARACTER-3D057|&amp;#x3d057;}}||{{H:title|dotted=no|SEAL CHARACTER-3D058|&amp;#x3d058;}}||{{H:title|dotted=no|SEAL CHARACTER-3D059|&amp;#x3d059;}}||{{H:title|dotted=no|SEAL CHARACTER-3D05A|&amp;#x3d05a;}}||{{H:title|dotted=no|SEAL CHARACTER-3D05B|&amp;#x3d05b;}}||{{H:title|dotted=no|SEAL CHARACTER-3D05C|&amp;#x3d05c;}}||{{H:title|dotted=no|SEAL CHARACTER-3D05D|&amp;#x3d05d;}}||{{H:title|dotted=no|SEAL CHARACTER-3D05E|&amp;#x3d05e;}}||{{H:title|dotted=no|SEAL CHARACTER-3D05F|&amp;#x3d05f;}}
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D06x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D07x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D08x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D09x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D0Ax
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D0Bx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D0Cx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D0Dx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D0Ex
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D0Fx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D10x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D11x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D12x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D13x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D14x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D15x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D16x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D17x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D18x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D19x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D1Ax
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D1Bx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D1Cx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D1Dx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D1Ex
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D1Fx
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D20x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D21x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D22x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D23x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D24x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D25x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D26x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D27x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D28x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D29x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D2Ax
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D2Bx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D2Cx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D2Dx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D2Ex
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D2Fx
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D30x
|&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;||&amp;nbsp;
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D31x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D32x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D33x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D34x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D35x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D36x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D37x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D38x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D39x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D3Ax
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D3Bx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D3Cx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D3Dx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D3Ex
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D3Fx
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|----- style=&quot;background:#ccccff&quot;
!U+||0||1||2||3||4||5||6||7||8||9||A||B||C||D||E||F
|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D41x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D42x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D43x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D44x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D45x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D46x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D47x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3D48x
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
!style=&quot;background:#ffffff&quot;|3DCDx
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- style=&quot;background:#ccccff&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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|----- align=&quot;center&quot; style=&quot;background:#777777&quot;
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  <page>
    <title>Minecraft/Wool</title>
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    <id>448153</id>
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      <timestamp>2026-05-21T16:41:11Z</timestamp>
      <contributor>
        <username>Nautekul</username>
        <id>3577226</id>
      </contributor>
      <minor />
      <comment>Minor change, better grammar</comment>
      <origin>4636901</origin>
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      <text bytes="652" sha1="qju7pbcej4s6ilysenrw4noyhy6apg3" xml:space="preserve">{{minecraft/block|flammable=yes|blastres=1|drops=wool|bestool=shears|stack=64}}
'''Wool''' is very useful. Without it, you will be unable to make beds or carpets. Wool is also a useful decorative material, and can be dyed in a variety of colors.

==Obtaining==
{{minecraft/crafting|makes=wool|5=String|6=String|8=String|9=String}}

Wool is also obtained from killing or shearing [[Minecraft/Sheep|sheep]].

==Recepies==
{{minecraft/crafting|makes=a [[../Bed|bed]]|4=Wool|5=Wool|6=Wool|7=Plank|8=Plank|9=Plank}}
{{minecraft/crafting|makes=4 [[../Carpet|carpets]]|7=Wool|8=Wool}}

==Achievements==
{{minecraft/achievement|Rainbow selection}}

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      <contributor>
        <username>Mfield</username>
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      <minor />
      <comment>Mfield moved page [[User talk:AmongUsGambit]] to [[User talk:Renamed user 3025e60144edfdbf0ef0a67954f4a778]] without leaving a redirect: Automatically moved page while renaming the user &quot;[[Special:CentralAuth/AmongUsGambit|AmongUsGambit]]&quot; to &quot;[[Special:CentralAuth/Renamed user 3025e60144edfdbf0ef0a67954f4a778|Renamed user 3025e60144edfdbf0ef0a67954f4a778]]&quot;</comment>
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      <text bytes="585" sha1="ml0yq37k21x231dn7ljunqbt1tswem5" xml:space="preserve">{{tmbox|type=notice|text='''Please, can you [[Using Wikibooks|help]] improve [[WB:WIW|Wikibooks]]''' by [[Special:Contributions/AmongUsGambit|doing future experiments]] with the [[Help:Contents|wiki software]] in the [{{fullurl:Wikibooks:Sandbox|action=edit}} sandbox] instead? Your fellow contributors consider test edits in the sandbox constructive. You can ask questions or ask for help in the [[WB:HELP|Assistance Reading Room]].&lt;br /&gt; Thanks. }}
--[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 20:38, 18 October 2022 (UTC)</text>
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  <page>
    <title>Mirad Grammar/Flaws in Mirad</title>
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      <text bytes="2773" sha1="jlfa2lteomwo7xfexoefwycbadlvjuc" xml:space="preserve">: Mirad has some flaws that may need to be fixed:

::1. Ambiguities caused by different possible readings of morpheme boundaries.  Here are a few examples:
:::* '''zoyuzben''' can be interpreted as '''zo-yuz-ben''' (''circulating behind'') or '''zoy-uz-ben''' (''turning back'').
:::* '''meima''' can be interpreted as the hybrid combination '''mem''' + '''mim''' (''land-sea, amphibious'') or the adjectival form of '''meim''' (''rural'') in the taxonomic series '''meam''', '''meem''', '''meim'''.... (''countryside'').

::2. Use of the letter '''r''' for three different functions:
:::* Words related to the universe and nature such as '''mar'''....''star'' or '''mur'''....''moon''.
:::* The infinitive form of verbs, such as '''xer'''....''to do''.
:::* A sense intensifier in words, such as '''frua'''....''ghastly'' or '''yonbyexren'''....''exploding'', or numbers like '''ara'''....''one thousand''.
:::* Instruments, tools, machines, and vehicles, such as '''pur'''....''car'', '''sir'''....''machine'', or '''drar'''....''pencil''.
::: The semantic use of '''r''' for universe/nature-related words and the grammatical use or '''r''' as an intensified are not incompatible and do not need to be fixed.  But the use of '''r''' for tools and the like needs to be changed to a different letter, perhaps, '''c'''.
::: Also the '''r''' used for the infinitive form of verbs needs to be changed as well.
::3. The Mirad equivalents of the numeric prefixes '''penta-''' and '''hexa-''' can be confused with the adverbs '''yon''' (''apart'') and '''yan''' (''together'').  For this reason, '''yon-''' as in '''yongun''' (''pentagon'') and '''yangun''' (''hexagon'') have to be changed to '''yoon-''' and '''yaon-''', respectively.  
::4. Words beginning with '''jy''' have been changed to '''jw''' for easier pronunication. For example, '''jyob''' is listed in the dictionary as '''jwob'''. 
::5. Simple vowels following a glide vowel make syllabication ambiguous, so when it needs to be established for pronunciation or syllabification that a post-glided vowel is followed by a simple vowel, a hyphen must be used, eg.:
:::* '''zoyaber''' (''put back on'') is ambiguous:  Is it '''zoy+aber''' or '''zo-yaber'''?  In this case, a hyphen must be inserted to show the first alternative: '''zoy-aber'''.  Otherwise, the word could mean ''to rise behind''.  If Mirad vowels used Cyrillic characters as in the earlier version, Unilingua, this problem would not exist.  So, for now, '''y-''' is meant to represent a post-syllabic glide in cases where ambiguity exists.

:: If you see other irregularities, mistakes, misspellings, or points of confusion, let it be known on the talk page.
&lt;noinclude&gt;{{Chapter navigation with TOC|Mirad-English_Dictionary}}&lt;/noinclude&gt;
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  <page>
    <title>Manshu/Chapter 2</title>
    <ns>0</ns>
    <id>464539</id>
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      <contributor>
        <username>~2026-30590-08</username>
        <id>3591734</id>
      </contributor>
      <comment>/* The Láncāngjiāng (瀾滄江; ie. Mekong) River and Yǒngchāng (永昌; ie. Bǎoshān) */</comment>
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      <text bytes="47536" sha1="d6hhecs4xb1zgxs51aj8sy64y7xqyu4" xml:space="preserve">{{Nav}}

{{incomplete translation}}
{{translation header
 | language = zh
 | original = 
 | title    = [[../]]
 | author   = Fan Chuo
 | override_editor   = Palace Museum Library
 | translator = Walter Stanish and Taitesena
 | section  = Chapter 2
 | previous = [[../Chapter 1/]]
 | next     = [[../Chapter 3/]]
 | notes    = 
}}

[[zh:蛮书/卷02]]

==Translator's note==
In general I am confident of a reasonable translation. The sections are of my own construction. Maps are yet to draw, and cross-referencing with existing identifications of some foreign names will be required.

==Translation==

===Around ''Tuò​dōng​chéng'' (柘東城; ie. Kunming)===
[[File:金碧广场.jpg|thumb|center|800px|The modern 'Golden Horse and Jade Chicken Square' (金馬碧雞廣場) in central Kunming, known succinctly to locals as 'Gold Jade Square' (金碧廣場) and named after the ancient names for the nearby mountains which are described in this section.]]

{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 2: ''Geography''; or ''Mountains and rivers''; or ''Mountains, River-plains, Rivers, and Headwaters'' (山川江源; ''shānchuān jiāng yuán'') — Part 1: Around ''Tuò​dōng​chéng'' (柘東城; ie. Kunming)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|金馬山在柘東城螺山南二十余裏，高百余丈，與碧雞山東南西北相對。
|'''Jīnmǎ​shān​''' (金馬山; lit. 'Golden Horse Mountain') is 20 ''li'' further south from '''Luó​shān​''' (螺山; lit. 'Snail Mountain'&lt;ref&gt;Perhaps this may refer to mountains to the south-southeast of Kunming, between the Chenggong/Dounan area of south-eastern Kunming (recently extensively developed but historically very much inhabited) and the Fuxian Lake basin, or it may be an old name for what is now known as ''Changchongshan''' (长虫山), which dominates the view north from central Kunming and offers sweeping views of the Dianchi Lake (滇池) basin. In any case, a further clue to its identity is shortly revealed in its name — ie. that within the name, apparently the 'snail' rather than 'spiral' sense of the character 螺 is used.&lt;/ref&gt;) of '''Tuò​dōng​chéng''' (柘東城; ie. Kunming&lt;ref&gt;See chapter one for an explanation — basically the character 柘 should reasonably be equated semantically in this text when writing 柘東城 with the more usual 拓 for the same, a well known historic name for Kunming.&lt;/ref&gt;), and is 100 or more ''zhang'' in height (ie. over 330m&lt;ref&gt;Assuming one ''zhang'' (丈) is 3.3m.&lt;/ref&gt;). On each side it is identical to&lt;ref&gt;Alternatively, 'opposes' or 'is equivalent to'.&lt;/ref&gt; '''Bìjī​shān​''' (碧雞山; lit. Jade-green Chicken Mountain).
|-
|土俗傳雲，昔有金馬，往往出見，山上亦有神祠。
|Endemic tradition states that there was once a golden horse which would frequently appear, thus atop the mountain there exists a shrine [to the creature].
|-
|從漢界入蠻路，出此山之下。
|From the Chinese controlled boundary, the '''Road to the Barbarian Lands''' (蠻路&lt;ref&gt;Presumably the road southward down the eastern edge of the lake defining the basin known within this text as 昆池 ('''Kūn​chí''') and in modern times as '''Dianchí''' (滇池). The combined traffic in this direction would have been along at least two routes known for trade since ancient times, both that presumably 'better known' southeastward to Vietnam via Tonghai, Jianshui, and possibly Gejiu and Mengzi, and a presumably lesser known series of routes running south to Xishuangbanna via Pu'er (modern Ning'er) and Simao (modern Pu'er) toward the Tai lands of the modern Jinghong basin thence southward to Burma, Laos and Thailand.&lt;/ref&gt;) winds beneath this mountain.
|-
|螺山遍地悉是螺蛤，故以名焉。
|'''Luó​shān​''' (螺山; lit. 'Snail Mountain') is covered with&lt;ref&gt;遍地悉是 — literally 'all places totally are'.&lt;/ref&gt; snails,&lt;ref&gt;螺蛤&lt;/ref&gt; hence the name.&lt;ref&gt;故以名焉 — literally an amusing collection of characters, rather like 'cause thus name how'.&lt;/ref&gt;
|-
|碧雞山在昆池西岸上，與柘東城隔水相對。
|'''Bìjī​shān​''' (碧雞山; lit. Jade-green Chicken Mountain; ie. modern Xishan?) is on the western shore of '''Kūn​chí​''' (昆池; ie. Dianchi&lt;ref&gt;Presumably 昆池 ('''Kūn​chí''') refers to modern '''Dianchí''' (滇池) rather than '''Green Lake''' (翠湖), which has no major hill to its west and but minor ones to its north, east and south.&lt;/ref&gt;), across the water from '''Tuodongcheng''' (柘東城; ie. Kunming).
|-
|從東來者岡頭數十裏已見此山。
|When coming from the east,&lt;ref&gt;Presumably this basically means &quot;when coming the city&quot;.&lt;/ref&gt; the ridgetop&lt;ref&gt;Perhaps referring to the relative pass, or saddle-like ridge depression on the extreme north of the range, approximately directly west of the modern extent of water and to the south of which ascends the modern road to the '''Dragon's Gate''' (龙门) past numerous temple buildings, as this would have been a natural means of westerly progression for travellers.&lt;/ref&gt; is 10 ''li'' distant, then you are amongst&lt;ref&gt;Actually, the text writes 已見此山 — &quot;you can already see the mountains&quot;, though this makes little sense semantically since they are visible from a great distance. It makes more sense to take an 'are within' or 'are amongst' sense with the text here, particularly as the shape of the water means the route is somewhat indirect, veering west then south, thus giving more purpose to the statement.&lt;/ref&gt; the mountains.
|-
|山勢特秀，池水清淡，水中有碧雞山石，山有洞庭樹，年月久遠，空有余本。
|The mountain is particularly elegant in shape, the lakewater clear, and the stones of '''Bìjī​shān​''' (碧雞山; lit. Jade-green Chicken Mountain; ie. modern Xishan?) amongst it. The mountain has caves, pavillions and forest. The passage of time is distant, and the airs are abundant.&lt;ref&gt;This appears to be a classical Chinese literary / Daoist reference of some kind; a Daoist sense of the character 本 in particular. Essentially it's getting at the naturally pregnant / abundant nature of the place.&lt;/ref&gt;
|}

===The ''Diàn​cāng​shān​'' (玷蒼山; ie. Dali) Region===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 2: ''Geography''; or ''Mountains and rivers''; or ''Mountains, River-plains, Rivers, and Headwaters'' (山川江源; ''shānchuān jiāng yuán'') — The ''Diàn​cāng​shān​'' (玷蒼山; ie. Dali) Region
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|玷蒼山&lt;span style=&quot;color:#aaa&quot;&gt;(案：玷《唐書》作點)&lt;/span&gt;，南自石橋，北抵登川，長一百五十余裏，名為玷蒼。
|'''Diàn​cāng​shān​''' (玷蒼山; lit. 'The Mountains of the Dian Mountain Range'; ie. modern Cangshan?&lt;ref&gt;Modern '''Cangshan''' (苍山) to the west of Dali meets most of the descriptive parameters and would seem to be a logical progression in the context of the text.&lt;/ref&gt;) &lt;span style=&quot;color:#aaa&quot;&gt;(Note: The character 玷 is written with additional dots at left in the ''Tangshu'' (唐書).)&lt;/span&gt; sports a stone bridge to its south, '''Dēng​chuān​''' (登川; lit. 'Trodden River Plains') at its northern foot, a length of 150 ''li'' and is known as '''Diàn​cāng​''' (玷蒼; lit. 'Dian Mountain Range').
|-
|直南北，勸；不甚正。
|The range runs directly north to south,&lt;ref&gt;Meeting the Dali Cangshan assumption.&lt;/ref&gt; and does not deviate.&lt;ref&gt;My reading here appears essentially correct and reasonable in context, however when reading more festidiously the characters 勸不甚正 could be interpreted more literally, perhaps &quot;as such, no correction [in navigation path when passing the mountains] is necessary&quot;.&lt;/ref&gt;
|-
|東向洱河，城郭邑居，棋布山底。
|At the eastern face is the '''ěr​hé​ River''' (洱河; lit. 'Ear River'&lt;ref&gt;Further encouraging the Dali Cangshan assumption; the lake in to which all rivers on this range drain is today known as 耳海.&lt;/ref&gt;), residential villages outside the city walls, and the base of '''Qí​bù​ Mountain''' (棋布山; lit. 'Checker-cloth Mountain'&lt;ref&gt;The checker notion may refer to sparse forest cover, since there is a snowline here.&lt;/ref&gt;).
|-
|西面陡絕，下臨平川。
|The west face is extremely precipitous, and abuts '''Píng​chuān''' (平川; lit. 'Flat and rivered area'&lt;ref&gt;Definitely ''not'' referring to the site of modern Pingchuan village (平川镇) in Bingchuan county (宾川县), Dali prefecture (大理州) since this is far to the east, across the lake, in completely different topography.&lt;/ref&gt;) at its base.
|-
|山頂高數千余丈，石棱青蒼，不通人路。
|The summit is extremely high,&lt;ref&gt;The actual number given is 1000 ''zhang'', or 3.3km assuming a normal 3.3 meter value for the ''zhang'' unit. This is obviously not meant to be taken literally and is figurative: (1) the round number; (2) the fact that the text will be discussing things from a relative base of the Erhai valley as opposed to modern sea level (which wouldn't be far off!); (3) previous, similar references in the same text have been similarly determined to be figurative.&lt;/ref&gt; from which dark&lt;ref&gt;青蒼 — apparently no particular color in the grey/black/green/dark range.&lt;/ref&gt; stone protrudes, and it is impassable.
|-
|冬中有時墮雪。
|In winter, snow falls on occasion.
|-
|囊蔥山在西洱河東隅，河流俯嚙山根。
|'''Náng​cōng​shān​''' (囊蔥山; lit. 'Pocket of [Green Onion/shallot/eschallot/scallion]&lt;ref&gt;An edible wild onion or onion-like species, quite possibly ''Allium chinense'' (commonly known as, variously Chinese onion, Chinese scallion, Japanese scallion, Kiangsi scallion, and Oriental onion). This implies the presence of wild plants on the mountain, which is not too unlikely climatically and could be validated through further study.&lt;/ref&gt; Mountain') is on the eastern corner of the western '''ěr​hé​ River''' (洱河; lit. 'Ear River'),&lt;ref&gt;Note that it is not totally clear from the text whether in fact this is referring to the western portion of the river or an entirely different river with the name '''West Ear River''' (西洱河). However, the western portion seems likely.&lt;/ref&gt; which tumbles down to gnaw at the base of the mountains.&lt;ref&gt;山根 — literally 'mountain root'.&lt;/ref&gt;
|-
|土山無樹石，高處不過數十丈。
|The earthen mountain sports neither forest nor stone, and its height does not exceed [approximately] 33 meters.&lt;ref&gt;Again, this figure is based on one ''zhang'' (丈) being 3.3m.&lt;/ref&gt;
|-
|面對賓居、越析，山下有路，從渠斂趙出登川。
|It faces the visitor without motion,&lt;ref&gt;A tad vague on this part, but it's thereabouts.&lt;/ref&gt; towering and segregating. A road passes beneath, from '''Qú​liǎn​​''' (從渠; lit. 'Dam ditch'&lt;ref&gt;Implying a reasonable period of nontrivial, settled agriculture.&lt;/ref&gt;) beyond to '''Dēng​chuān​''' (登川; lit. 'Trodden River Plains').
|}

===West of ''Yǒng​chāng'' (永昌; ie. Bǎoshān): the ''Gāo​lí​qí​shān​ Mountains'' (高黎其山) and the ''Nù​jiāng​ River'' (怒江; ie. Upper Salween)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 2: ''Geography''; or ''Mountains and rivers''; or ''Mountains, River-plains, Rivers, and Headwaters'' (山川江源; ''shānchuān jiāng yuán'') — West of ''Yǒng​chāng'' (永昌; ie. Baoshan): the ''Gāo​lí​qí​shān​ Mountains'' (高黎其山) and the ''Nù​jiāng​ River'' (怒江; ie. Upper Salween)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|高黎其山在永昌西，下臨怒江。
|'''Gāo​lí​qí​shān​ Mountains''' (高黎其山; lit. 'Tall Black Mountain(s)'&lt;ref&gt;Presumably some relation to the modern Gaoligongshan.&lt;/ref&gt;) is located to the west of [the presumed town or city of] '''Yǒng​chāng​''' (永昌; lit. 'Perpetual Prosperity'), and overlooks the '''Nù​jiāng​ River''' (怒江; lit. 'Raging River'; ie. Upper Salween&lt;ref&gt;Well known identification.&lt;/ref&gt;).
|-
|左右平川，謂之穹賧，湯浪加萌所居也。
|To either side&lt;ref&gt;The text states 'left and right' but as we are not oriented, this seems a smoother translation.&lt;/ref&gt; are flat river-plains, known for their perfectly clear skies [and by extension, uncomfortably harsh sun, which is soon to be emphasized using the same character sequence]. Dwellings appear where the current slows.&lt;ref&gt;Alternatively, one could read more literally as &quot;[The town or village of] '''Shāng​làng​''' (湯浪) is located where the current slows.&quot; however this seems less likely to me (though do not hold this opinion up as unassailable, by any means!) for a few reasons: (1) There is no precedent for discussing a particular location, rather the established context is a range of locations either side of the mountains. (2) The use of 也 is (to my inexperienced eyes) a classical Chinese flourish in this later-period text which alludes to the elevation of the prior phrase to literary modes of interpretation (note that ''Shāng​làng​'' (湯浪) quite possibly rhymed in the Tang Dynasty). (3) The double verb phrase 加萌 — roughly 'to be added forth by sprouting' also suggests literary modes of expression, to my eyes. (4) The same phrase is mentioned shortly and also does not strike me as a place name in that context.&lt;/ref&gt;
|-
|草木不枯，有瘴氣。
|The vegetation is habitually verdant,&lt;ref&gt;The text actually states 'never dries', implying an absence of deciduous foliage, ie. total dominance of evergreen vegetation. This may perhaps be safely read to suggest 'evergreen pine forest' or 'subtropical rainforest'.&lt;/ref&gt; and features a sickening miasma.&lt;ref&gt;Almost certainly a reference to the then highly lethal disease Malaria, which was apparently one of many diseases misunderstood by pre-modern peoples (ie. prior to the discovery of bacteria and advances in toxicology) to be contracted through the inhalation of foul smells.&lt;/ref&gt;
|-
|自永昌之越賧，途經此山，一驛在山之半，一驛在山之巔。
|From '''Yǒng​chāng​''' (永昌; lit. 'Perpetual Prosperity') it is better to&lt;ref&gt;This is my in-context (ie. versus the miasma) reading of 自永昌之越賧 and is not completely certain — an alternate reading would be &quot;From Yongchang to Yuedan&quot;, though Yuedan (lit. 'More fine') makes little sense as a place name and seems an unlikely option.&lt;/ref&gt; pass through these mountains. There is a postal relay station half-way through the mountains, and one upon the summit.
|-
|朝濟怒江登山，暮方到山頂。
|In the morning one crosses the '''Nù​jiāng​ River''' (怒江; lit. 'Raging River'; ie. Upper Salween) and climbs the mountain, but only reaches the summit in the evening.
|-
|冬中山上積雪苦寒，夏秋又苦穹賧、湯浪毒暑酷熱。
|In winter the mountain is covered in snow and is bitterly cold. During summer and autumn the sky is clear and the sun once again relentless, the rushing torrent [exhaling]&lt;ref&gt;This word inserted for ease of translation; phrases this flowery rarely exist in modern English!&lt;/ref&gt; its poisonous and torrid heat.
|-
|河賧賈客在尋傳羈離未還者為之謠曰：「冬時欲歸來，高黎其上雪。秋夏欲歸來，無梆穹賧熱。春時欲歸來，平中絡賂絕。」&lt;span style=&quot;color:#aaa&quot;&gt;(絡賂，財之名也)&lt;/span&gt;
|The clear river merchants (河賧賈客)&lt;ref&gt;Apparently some form of reference to merchants operating over the mountains in this area.&lt;/ref&gt; seek to set out during the 6th solar month (ie. 7th July—6th August). Those who have been state: &quot;In winter we seek to return, as the '''Gāo​lí​qí​shān​ Mountain(s)''' (高黎其山; lit. 'Tall Black Mountain(s)') summit will be snowed-in. In summer and autumn we seek to return, as we do not wish to see the ascendance of the harsh sun and clear skies. What profits we make&lt;ref&gt;The actual characters are 平中 — admittedly 'the balance' would be a closer translation but reads poorly in context.&lt;/ref&gt; are entirely lost&lt;ref&gt;絕&lt;/ref&gt; to the net of bribery.&quot;&lt;ref&gt;While our author's character has earlier seemed hard in places, the inclusion of this rather personal description could be seen as an honest attempt to report the misgivings of (potential) subjects with respect to local corruption or tolls.&lt;/ref&gt;&lt;span style=&quot;color:#aaa&quot;&gt;(Note: &quot;The net of bribery&quot; (絡賂) refers to fiscal matters.)&lt;/span&gt;
|-
|大雪山在永呂西北，從騰充過寶山城，又過金寶城以北大賧，周迥百余裏，悉皆野蠻，無君長也。
|'''Dà​xuě​shān​''' (大雪山; lit. 'Great Snowy Mountain(s)') is to the northwest of '''Yǒng​lǚ​''' (永呂; lit. 'Perpetual High Pitch'&lt;ref&gt;Apparently the character 呂 within the place name refers specifically to one of the twelve semitones in the traditional Chinese musical tone system. This is quite an eloquent name which makes sense as high mountains feature wind which can be understood to create a high pitched, constant tone.&lt;/ref&gt;), from '''Téng​chōng''' (騰充; lit. 'Satisfying [Rapid Movement]'&lt;ref&gt;Modern place name remains constant. '''Tengchong''' is an ancient Han Chinese outpost in Yunnan which was used for '''Southern Silk Road''' trade with Burma for Jade, and beyond to '''India''' and possibly further afield.&lt;/ref&gt;), from '''Téng​chōng''' (騰充) to '''Bǎo​shān​ City''' (寶山城) one again passes through '''Jīn​bǎo​ City''' (金寶城) to the north of the great clear skies.&lt;ref&gt;This part is iffy. Perhaps 大賧 is a place name after all?&lt;/ref&gt; The whole trip is over 100 ''li'', through wholly uncivilized lands without a single gentleman to develop them.
|-
|地有瘴毒，河賧人至彼中瘴者，十有八九死。
|The land is infected with a miasma,&lt;ref&gt;Again, probably a reference to Malaria.&lt;/ref&gt; which most&lt;ref&gt;至 in a less common sense.&lt;/ref&gt; of the peoples of the clear skies region&lt;ref&gt;河賧人&lt;/ref&gt; suffer from,&lt;ref&gt;彼中瘴者 — [those] [suffer - a rarer sense of 中] [miasma] [is/are/ongoing effect]&lt;/ref&gt; of whom eight or nine out of ten die. 
|-
|閣羅鳳嘗使領軍將於大賧中築城，管制野蠻。
|'''Géluófèng''' (閣羅鳳; ie. the second King of Nanzhao, essentially the author's sworn enemy&lt;ref&gt;'''Géluófèng''' (閣羅鳳; 712-779) was Nanzhao's second king who reigned from 748-779. In 750 he retaliated for the murder of Nanzhao envoys by Chinese officials, beginning the acceleration of large-scale hostilities that would eventually lead to all out war and the taking of Sichuan and Chengdu by Nanzhao.&lt;/ref&gt;) led his troops to [make or take] a fortification in the clear skies region, in order to control the local barbarians.
|-
|不逾周歲，死者過半，遂罷棄，不復往來。
|After less than a year, more than half the garrison were dead, and it was thus entirely abandoned with no further expeditions since.
|-
|其山上肥沃，種瓜瓠長丈余，冬瓜亦然，皆三尺圍。
|The mountain top is fertile, growing copious melons and gourds of one ''zhang''&lt;ref&gt;ie. 3.3m&lt;/ref&gt; in length, as well as wax gourd (冬瓜&lt;ref&gt;Cucurbitaceae, Benincasa hispida / white gourd / white hairy melon / Chinese squash / 'winter melon'.&lt;/ref&gt;) which is always three ''chǐ​'' (ie. 1 meter) in circumference.
|-
|又多薏苡，無農桑，收此充糧。
|In addition, there is a lot of Job's tear (薏苡&lt;ref&gt;''Coix lacryma'', erroneously called Chinese pearl barley.&lt;/ref&gt;), there are no mulberry farms&lt;ref&gt;Significant to the Chinese observers with regards to sericulture (silk-making).&lt;/ref&gt;, and [yet] this is adequate annual provisioning.&lt;ref&gt;There are alternate readings like 'for the grain tax' though unlikely in context.&lt;/ref&gt;
|-
|三面皆占大雪山，其高處造天。
|From three sides great snowy mountains may be observed — that high place is heavenly.
|-
|往往有吐蕃至賧貨易，雲此山有路，去贊普牙帳不遠。
|Frequently, Tibetans&lt;ref&gt;The text uses the term Tubo or Tufan, which is an old name for Tibet or the Tibetan Tubo dynasty, which reigned from the 7th—11th centuries AD (ie. at the time of our text).&lt;/ref&gt; come to trade in fine goods by a road across the mountains,&lt;ref&gt;This much is clear.&lt;/ref&gt; acquiring all types of ivory and screens&lt;ref&gt;By which internal, Chinese style carved or (less likely) painted screens with wooden or (less likely) metal frames are probably referred to.&lt;/ref&gt; for little.&lt;ref&gt;&quot;For little&quot; is acquired by dubious interpretation: 不遠 — &quot;not [much]&quot;, perhaps.&lt;/ref&gt;
|}

===north of kunming (xichang area)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 2: ''Geography''; or ''Mountains and rivers''; or ''Mountains, River-plains, Rivers, and Headwaters'' (山川江源; ''shānchuān jiāng yuán'') — north of kunming (xichang area)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|又有水，源出臺登山，南流過巂州，西南至會州諾賧與東瀘，&lt;span style=&quot;color:#aaa&quot;&gt;(此處似有脫漏)&lt;/span&gt;古諾水也。
|There is another river, originating high in the mountains, flowing south toward '''Guīzhōu''' (巂州; ie. modern Xichang&lt;ref&gt;Modern 四川省西昌市 — - a region in far-southern Sichuan, approximately directly north of modern Kunming, across the Jinshajiang or upper Yangtze. For background see the corresponding [https://zh.wikipedia.org/wiki/%E5%B7%82%E5%B7%9E Chinese Wikipedia] or [http://baike.baidu.com/link?url=Y9E6Mvwr7UqiBiumiv40wiT_CQicxbj3PfRZt38W2v48wb6Aj3KZHxFD2CxfNad87BhQclIq3BnfSKi7mwo4pa Baidu Baike] entries.&lt;/ref&gt;). Further southwest is '''Huì​zhōu​''' (會州), '''Nuòdǎn​​''' (諾賧)&lt;ref&gt;This particular part is a little unclear. It seems there may be a grammatical intepretation issue, however I cannot see an alternate interpretation. Treat with caution.&lt;/ref&gt; and the '''East River''' (東瀘), which is the same as the ancient '''Nuòshuǐ​ [River]''' (諾水; lit. Jinshajiang / Upper Yangtse?).
|-
|源出蕃中節度北，謂之諾矣江，南郎部落，又東折流至尋傳部落，與磨些江合。
|Originating&lt;ref&gt;源出&lt;/ref&gt; roughly&lt;ref&gt;度 — apparently this is a valid reading.&lt;/ref&gt; in Tibet's&lt;ref&gt;蕃中&lt;/ref&gt; north, known as the '''Nuò​yǐ​jiāng​ [River]''' (諾矣江), it moves south to the '''Yang tribe''' (郎部落),&lt;ref&gt;This portion seems questionable to me, but I cannot find a more logical reading.&lt;/ref&gt; then turns to flow east to find the '''Zhuàn tribe''' (傳部落), and combine with several tributaries.
|-
|源出吐蕃中節度西其籠川犛牛石下，故謂之犛牛河。
|Originating under the '''Lí​niúshí Mountain​​''' (犛牛石; lit. 'Black Ox Cliff') of western Tibet's '''Lǒng​chuān''' (籠川; lit. 'Dragon [Watered-]Plain'), it was formerly known as '''Lí​niú River''' (犛牛河; lit. 'Black Ox River').
|-
|環繞弄視川，南流過&lt;鳥戔&gt;橋上下磨些部落，即謂之磨些江。
|It skirts the Sichuan basin, running south over and beyond the '''Small Bird Bridge''' (&lt;鳥戔&gt;&lt;ref&gt;This notation refers to a character that is comprised of 鳥 on the left and 戔 on the right, but is not easily reproducible electronically.&lt;/ref&gt;橋) to the '''Mó​xiē​ Tribe''' (磨些部落), and is known as the '''Mó​xiē​ River''' (磨些江).&lt;ref&gt;Actually I had interpreted this as 'several tribes' but the repetition in the river name accords for a different interpretation, as presented.&lt;/ref&gt;
|-
|至尋傳與東瀘水合，東北過會同川，總名瀘水。
|'''Xúnzhuàn''' (尋傳; lit. 'Searching Station') is found within the eastern portion of '''Lúshuǐ''' (瀘水)&lt;ref&gt;In modern times this refers to Lushui county, Nujiang Lisu Autonomous Prefecture (怒江傈僳族自治州), in northwest Yunnan, near Tibet and Burma's northernmost Kachin state. However, in context this identification is possibly doubtful.&lt;/ref&gt; from where a northeasterly passage is possible&lt;ref&gt;This grammatical interpretation is not confident.&lt;/ref&gt; to '''Tóngchuān''' (同川; lit. 'The river-plain of copper'). All these places are part of '''Lúshuǐ''' (瀘水).&lt;ref&gt;The text actually says they all fall under the name, but the adaptation seems to add clarity.&lt;/ref&gt;
|-
|蜀忠武侯諸葛亮伐南蠻，五月渡瀘水處，在弄棟城北，今謂之南瀘。
|'''Zhūgě Liàng''' (諸葛亮&lt;ref&gt;Zhuge Liang (181-234), military leader and prime minister of Shu Han 蜀漢/蜀汉 during the Three Kingdoms period.&lt;/ref&gt;) attacked the southern barbarians, and in the fifth month of the lunar year (ie. approximately May of the year 225&lt;ref&gt;For more information on this campaign, see [https://en.wikipedia.org/wiki/Zhuge_Liang%27s_Southern_Campaign Zhuge Liang's Southern Campaign] at English Wikipedia.&lt;/ref&gt;) crossed the '''Lúshuǐ''' (瀘水)&lt;ref&gt;The formerly questionable potential identification with Nujiang now becomes highly doubtful, in fact almost certainly incorrect.&lt;/ref&gt; river at a place to the north of '''Lòngdòngchéng''' (弄棟城; lit. 'The town with a lane or alley of buildings'&lt;ref&gt;The single lane notion may be read to suggest a torturous or steep geography, yet was probably a town of some decent size in order to achieve the 城 designation.&lt;/ref&gt;), which is known in the present-day&lt;ref&gt;ie. At the time of writing, which is now 1000 years ago.&lt;/ref&gt; as '''Nánlú''' (南瀘; lit. 'The place south of the Lu [River]').
|-
|兩岸葭，大如臂脛。
|Both banks of the river were huge, like limbs.&lt;ref&gt;Presumably referring to cliffs, rocks, outcrops, some other topographic anomaly.&lt;/ref&gt;
|-
|川中氣候常熱，雖至冬，行過者皆袒衣流汗。
|The local microclimate in the river-valley&lt;ref&gt;An alternate translation would be '... in the Sichuan basin' though this appears to be too broad/out of context.&lt;/ref&gt; is always warm right through to the winter, and those traversing sweat and are compelled to dress loosely.
|-
|又東北入戎州界為馬湖，至關邊縣門，與朱提江合，流戎門南城入外江。
|To the northeast one may enter the border of '''Róngzhōu''' (戎州; lit. 'Military Prefecture'&lt;ref&gt;Note that this may not be an actual place name .. further research will be required to determine how specific this reference is.&lt;/ref&gt;) and its '''Wèimǎhú''' (為馬湖; lit. 'Horse-watering Lake'&lt;ref&gt;Presumably.&lt;/ref&gt;), thence '''Guānbiānxiànmén''' (關邊縣門; lit. 'Border-Pass-County Gate'&lt;ref&gt;Presumably a locally significant natural pass with military benefit for defence purposes.&lt;/ref&gt;), which together with the '''Zhūtíjiāng [River]''' (朱提江; lit. 'River of the Vermillion Stroke'&lt;ref&gt;Really a rather literal translation &amp;mdash; looser and more natural for modern English may be 'Vermillion River'.&lt;/ref&gt;) flows to a confluence&lt;ref&gt;入外江 &amp;mdash; literally to 'enter an external or foreign stream'.&lt;/ref&gt; at '''Róngménnánchéng'''' (戎門南城; lit. '[a or the] city to the south of the military gate').&lt;ref&gt;All rather indistinct, but carefully translated nonetheless to hopefully provide clarity of reference where present in the original.&lt;/ref&gt;
|}

===around kunming===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 2: ''Geography''; or ''Mountains and rivers''; or ''Mountains, River-plains, Rivers, and Headwaters'' (山川江源; ''shānchuān jiāng yuán'') — around kunming
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|昆池在柘東城西，南百余裏，四十五裏&lt;span style=&quot;color:#aaa&quot;&gt;(案：此四字疑衍文)&lt;/span&gt;。
|'''Kunchi''' (昆池; lit. 'The Pond of Kun'; ie. modern Dianchi&lt;ref&gt;滇池&lt;/ref&gt;) is to the west&lt;ref&gt;In fact, geographically the lake very likely (as estimated with modern waterline) extended both to the southwest through south-southeast of the city. The city at this point was more compact and roughly centered around what is modern Kunming's Green Lake (翠湖) area. A compounding reason the writer refers to the west as the direction in which to find the lake, excluding the south, is that this is the northernmost point of the lake from which the subsequent measurement (to the south) enumerating the lake's scale is extended.&lt;/ref&gt; of '''Tuodongcheng''' (柘東城; ie. modern Kunming), and extends some 100 or so ''li'' southward, [and] 45 ''li'' [east to west].&lt;ref&gt;The original literally says &quot;[Dianchi] is west of [Kunming], 100 or so ''li'' south, 45 ''li''.&quot;. Presumably this means &quot;... from which it is 100 li [north-to-]south, and 45 li [east-to-west].&quot;. No other interpretation presents itself as meaningful in context.&lt;/ref&gt;&lt;span style=&quot;color:#aaa&quot;&gt;(Untranslated comment from later attempt at interpretation.)&lt;/span&gt;
|-
|水源從金馬山東北來。
|The water's source is the northeast of '''Jinmashan [Mountain]''' (金馬山; lit. 'Golden Horse Mountain'; ie. apparently an ancient toponym referring to the north-south range at the east of the Kunming plateau, but presumably particularly the higher peaks between modern Chengjiang (澄江) and southern Kunming's Dounan (斗南).&lt;ref&gt;The initial component of 金马碧鸡 (lit. &quot;Golden Horse [Mountain] [and] Jade Chicken [Mountain]&quot;) referring to the west and east mountains on either side of Kunming, said to be facing one another, and named according to legend explained in the previous chapter of this translation.&lt;/ref&gt;).&lt;ref&gt;The specification of this (north-eastern side of the eastern range) as the water source is interesting, though probably not entirely accurate as the watershed obviously includes all sides of the lake-valley plateau. In former times, however, it is known that numerous surface streams (now dammed or sealed) flowed toward to the lake from the northern portion of the plateau, and the city of Kunming itself was connected to the lake by river-canal in the area that is now Daguanlou Park (大观楼公园). Numerous Qing-dynasty images are available of boats here, which made overnight trips south down the lake to Kunyang (昆阳). Given that these streams were possibly higher in volume and closer to Kunming, it is understandable that ancient geographical reckoning may have considered these northern streams the primary or sole source of the lake water. Interestingly also, in recent years a historical hydrographic study has been made of Fuxian Lake (抚仙湖) &amp;mdash; the neighbouring lake to the southeast and on the other side of the Jimashan Mountain &amp;mdash; in conjunction with the University of New South Wales in Sydney, Australia, finding that its depth began to steadily increase a few hundred years BCE (I can't recall the reason, though perhaps this was due to the collapse or sedimentation of an underground cavern previously draining water elsewhere or pure climate change?) however I am not aware of any similar study of the historical water levels of Kunming's lake &amp;mdash; here known as Kunchi (昆池) and now known as Dianchi (滇池), which could affect interpretation.&lt;/ref&gt;
|-
|柘東城北十數余裏，官路有橋渡此。
|Over 10 ''li'' north '''Tuodong [City]''' (ie. 柘東城; modern Kunming) city, there is a river-spanning bridge&lt;ref&gt;橋渡 &amp;mdash; literally '[bridge] + [cross a river]'&lt;/ref&gt; on the military road.&lt;ref&gt;官路 &amp;mdash; this may be incorrect but seems the most likely. Alternate translations would include abbreviated place names beginning with the character 官 but no such places come to mind, are referenced nearby in this text.&lt;/ref&gt;
|-
|水闊二丈余，清深迅急，至碧雞山下，為昆州，因水為名也，土蠻亦呼名滇池&lt;span style=&quot;color:#aaa&quot;&gt;(案：今晉寧川中，自有大池，在東南，當是滇池。水不可呼池，乃蠻不能別)&lt;/span&gt;。
|The water is over two ''zhang'' in width (ie. 10 or 20 meters or so&lt;ref&gt;I should look this up specifically!&lt;/ref&gt;), clear, deep and flows rapidly to the base of '''Bijishan [Mountain]''' (碧雞山; lit. 'Jade[-Coloured] Chicken Mountain'). It is part of the '''Kunzhou''' (昆州; lit. 'Kun [river valley or flatland]') [political/administrative region], which is named after the [lake] water, which the local barbarians know as '''Dianchi''' (滇池&lt;ref&gt;Amusingly, with reference to modern toponyms, it seems that the barbarian name rather than the Han Chinese name was the one that stuck!&lt;/ref&gt;). &lt;span style=&quot;color:#aaa&quot;&gt;(Later intepreter's note states that this refers to the modern Jinning estuary zone, a point from which the lake (modern Dianchi, or the Kunchi/[Barbarian tongue] Dianchi of this text) is located to the southeast, and draws questionable&lt;ref&gt;By self-admission.&lt;/ref&gt; inferences about the local water flow.&lt;ref&gt;Common to certain geographical references in this text, this interpretation does not appear to make perfect sense given the directions specified in the text anyway. Given that we were focused on the north a mere few characters ago, jumping to the southernmost point of the lake seems extremely obtuse. This interpretation may have occurred via modern comprehension of the fact that there is apparently an outflow beginning in this area, taking water to the northwest through a tributary to the upper Yangtse. Personally I would class this whole section of text as evidencing little but alleged etymology, general river flow volume and a baseline contemporary engineering capacity in the general Kunming lake-plateau region with reference to bridge spans.&lt;/ref&gt;)&lt;/span&gt;
|-
|滇池水亦名東昆池，西南繞山，又西北池流為河，過安寧城下。
|'''Dianchi [Lake]''''s water is also known as '''Eastern Kunchi [Lake]''' (東昆池), it is ringed by mountains to the southwest, flows in to a river to the northwest through the '''Northwestern Lake''' (西北池)&lt;ref&gt;As per the previous interpretive note, this remains unclear. It could be a reference to the outflow northwest of Jinning/Kunyang, or it could be a reference to the northernmost portion of the lake's modern shores between modern Kunming and Xishan. Either way, it is referring to the western edge of the lake or some very nearby area.&lt;/ref&gt; and flows beneath '''Anning [City]''' (安寧城).
|-
|亙水東西，有橋三十，一闊長三百余步。
|From east to west the waters have thirty bridges, as broad as one zhang and three hundred or so steps.
|-
|徒行七日程與瀘水合。
|It is a seven day journey to '''Lushui''' (瀘水).
|-
|又量水川在滇池南兩日程，漢舊黎州也。
|'''Liangshuichuan''' (量水川; lit. 'Measured-Water Riverplain'&lt;ref&gt;Possibly the measure character refers to the same grammatical/semantic shift as 又, in which case the place is called Shuichuan (水川) and not Liangshuichuan, in which case the literal meaning is merely 'Water Delta' or 'River-plain of water'.&lt;/ref&gt;) is two days travel to the south of '''Dianchi [Lake]''' (滇池) and belonged to the '''Lizhou Region''' (黎州) during the '''Shu Kingdom of the Han Dynasty''' (漢舊).&lt;ref&gt;ie. Zhugeliang's time.&lt;/ref&gt;
|-
|川中有大池，其水東泄。
|Within the river-plain&lt;ref&gt;川中&lt;/ref&gt; lies a large water-body&lt;ref&gt;大池 &amp;mdash; conventionally variously translated with overspecificity as a lake, pond or pool.&lt;/ref&gt;, from which water flows rapidly to the east.&lt;ref&gt;It may be useful to identify general candidates for this probably still identifiable geographic feature and to verify any potential identification with research in to established identifications of Lizhou.&lt;/ref&gt;
|-
|流處出一石竇中，流水甚廣，石竇甚狹。
|The water comes out of a stone spring, flowing remarkably broadly though the space from which it emerges from the stone is tiny.
|-
|土蠻雲，忽竇空，百姓憂溺。
|According to the local barbarians, the space opened suddenly, and the population were threatened with drowning.&lt;ref&gt;Or perhaps a more ''potential'' take: &quot;... can open suddenly and threaten to drown the population.&quot;&lt;/ref&gt;
|-
|新豐川亦有大池甚廣。
|'''Xinfengchuan''' (新豐川; lit. 'New Bountiful River-plain') also has a great and very broad lake.
|}

===The ''Láncāngjiāng'' (瀾滄江; ie. Mekong) River and ''Yǒngchāng'' (永昌; ie. ''Bǎoshān'')===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 2: ''Geography''; or ''Mountains and rivers''; or ''Mountains, River-plains, Rivers, and Headwaters'' (山川江源; ''shānchuān jiāng yuán'') — The ''Láncāngjiāng'' (瀾滄江; ie. Mekong) River and ''Yǒngchāng'' (永昌; ie. ''Bǎoshān'')
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|瀾滄江，源出吐蕃中大雪山下莎川。
|The '''Láncāngjiāng [River]''' (瀾滄江; ie. Mekong river), originates from great snowy mountains in '''Tubo [Region]''' (吐蕃; ie. the Kham Tibetan region&lt;ref&gt;The far southeastern portion of the Tibetan cultural zone, incorporating portions of modern Sichuan, Tibet and Yunnan provinces.&lt;/ref&gt;, descending via '''Shāchuān''' (莎川; roughly 'Verdant Sands River-valley'&lt;ref&gt;By admittedly obtuse but fair reading of the component radicals of ''shā'' (莎) — ie. vegetation and sand.&lt;/ref&gt;).
|-
|東南過聿賫城西，謂之瀨水河，又過順蠻部落。
|It flows southeast &amp;mdash; to the west of '''聿賫城 [City]''' (聿賫城&lt;ref&gt;I must remember to look this up...&lt;/ref&gt;) at a place known as '''Laishuihe''' (瀨水河), continuing onward past the '''Shunman [Barbarian Tribe]''' (順蠻部落; lit. 'Shun Barbarian Tribe'&lt;ref&gt;The ''man'' (蠻) part in the inline translation means barbarian.&lt;/ref&gt;).
|-
|南流過劍川大山之西。
|It flows southward to the great mountains west of '''Jianchuan''' (劍川&lt;ref&gt;This area is currently the subject of a very important archaeological dig revealing the earliest significant population showing evidence of intensive rice agriculture (it also has very early, possibly the earliest stilt houses in the entire region). Its location on a small, fertile, elevated lake plateau between much of Yunnan and the Tibetan empire made it an ancient center of trade and presumably cultural and technological exchange.&lt;/ref&gt;), 
|-
|瀾滄江南流入海。
|The '''Lancangjiang''' (瀾滄江; ie. Mekong) [then/thereafter] flows south to the ocean.&lt;ref&gt;This is a huge generalization. While roughly true it neglects thousands of kilometers of malarial jungle, three prominent eastward turns (one nearby, one in Laos and one in Cambodia) and the huge Tonle Sap Lake. It is unlikely therefore that this statement reflects actual travel experience but rather a combination of assumption and literary reference. Some four hundred odd years later, literary records evidence an established trade route from Thailand's then kingdom of Ayutthaya to Yunnan overland along this very arduous route.&lt;/ref&gt;
|-
|龍尾城西第七驛有橋，即永昌也。
|The seventh traveller's rest stop to the west of '''Longweicheng''' (龍尾城; ie. modern Xiaguan) has a bridge and is known as '''Yǒngchāng''' (永昌; lit. 'perpetual [goodness as embodied by sunlight]'; modern 保山/Bǎoshān&lt;ref&gt;Presumably this may mean seven days' journey.&lt;/ref&gt;).
|-
|兩岸高險，水迅激。
|The two cliffs [at Yongchang] are extremely high and the water flows rapidly.
|-
|橫亙大竹索為梁，上布簀，簀上實板，仍通以竹屋蓋橋。
|All the way across span great bamboo beams&lt;ref&gt;大竹; lit. 'Great Bamboo'. Apparently literal use, and not referring to modern Dazhu county in Dazhou (达州達州), Sichuan (四川).&lt;/ref&gt; covered with reed mats,&lt;ref&gt;上布簀 - literally 'above' [is] 'cloth' [of the type] 'reed mat'&lt;/ref&gt; atop which are layered good and strong wooden planks,&lt;ref&gt;'Good and strong wooden planks' seems the best translation for 實 ('good'/'solid'/'true') in the 實板 sense used.&lt;/ref&gt; and by means of a bamboo structure effect a covered bridge.&lt;ref&gt;This last part is a little interpretive, as the precise sense of 仍通以 is unclear to me. In any event, the content is essentially correct.&lt;/ref&gt;
|-
|其穿索石孔，孔明所鑿也。
|It passes through the stone hole bored by '''Zhuge Liang''' (孔明).
|-
|昔諸葛征永昌，於此築城。
|Previously, he journeyed to&lt;ref&gt;Probably meaning went on an aggressive military campaign to...&lt;/ref&gt; '''Yongchang''' (ie. modern Baoshan) from these fortifications.
|-
|今江西山上有廢城遺跡及古碑猶存，亦有神祠廟存焉。
|Today, within the mountains to the west of the river remnants of a ruined town&lt;ref&gt;廢城 — could be a 'ruined city wall' but town seems more in keeping with the prior sense of the translation in explaining the place as one that was inhabited for periods of time and used as an ancient fortification.&lt;/ref&gt; and an ancient stelae&lt;ref&gt;古碑&lt;/ref&gt; are still extant,&lt;ref&gt;猶存 — literally 'still survive'.&lt;/ref&gt; as is a temple to the ancestors.&lt;ref&gt;神祠廟 — One could take 神 to mean gods, and 祠 to mean Confucian-style ancestor worship. That may be a little liberal, but at a minimum the sense of a temple is apparently accurate, as is the Confucian component. It is interesting to note, given the early period in history discussed, that Confucius (551–479 BCE) was from Qufu in Shandong (山东曲阜), which is virtually the opposite side of China, and that Zhugeliang hailed from the same region, a mere 50km to the east of Qufu in modern Yinan county (沂南县).&lt;/ref&gt;
|-
|又麗水，一名祿{曰鬥}江&lt;span style=&quot;color:#aaa&quot;&gt;(案：「{曰鬥}」字，字書不載)&lt;/span&gt;。
|Another magnificent river is the '''Lucky [Raging Gorge] River''' (祿{曰鬥}江&lt;ref&gt;The character {曰鬥} is of unknown pronunciation but presumably refers in its initial radical 「曰」to 'speech' or rather the idea of the creation of noise, and in its latter 「鬥」 (&quot;gate&quot; or &quot;pass&quot;) radical to the a river passing betwixt a deep or tight gorge. Thus, a combined meaning has here been assumed from component radicals.&lt;/ref&gt;).&lt;span style=&quot;color:#aaa&quot;&gt;(Previous transliterator's note: The character to which {曰鬥} refers is unknown.)&lt;/span&gt;
|-
|源自邏些城三危山下。
|It originates from beneath '''Sanwei Mountain''' (三危山; lit. 'Three Dangers Mountain') at '''Luoxie [City]''' (邏些城; lit. '[Walled]&lt;ref&gt;Probably.&lt;/ref&gt; Settlement of the Few [Patrols or Routes]').
|-
|南流過麗水城西，又南至蒼望。
|To the south it flows beyond the west of '''Lishui [City]''' (麗水城; lit. '[City of] Beautiful Waters'), and proceeds further southward toward the Cang Mountain [range].&lt;ref&gt;蒼 is used here to refer to the range and could potentially be interpreted in a generic fashion but is here from context clearly the local toponym.&lt;/ref&gt;
|-
|又東南過道雙王道勿川。
|Continuing southeast [southwest] it passes the '''Dàoshuāng''' king's '''Dàowù''' valley.&lt;ref&gt;In the '''New Book of Tang ('''新唐书), there are 35 tribes listed in the Pyu Kingdom's adminstration. Among these are the 道双，道勿 and 道瓮''.'' It is likely that '''道''' is a tribal prefix for a frontier group. The '''Míchén''' king in 802AD went to the Tang and had a member of the 道勿 tribe enoffed as the heir according to the Imperial Archives Volume 965.&lt;/ref&gt;
|-
|西過彌諾道立柵，又西與彌諾江合流。
|To the west it passes '''Mínuòdàolì'''  &lt;ref&gt;Minuo is associated with the Chindwin while 道 is a tribal prefix. This means that the Pyu administered the Minuo and the Dao Li tribe around present day Mandaly. &lt;/ref&gt; and further west joins its waters with the '''Minuo River''' (彌諾江; ie. Chindwin River).
|-
|過驃國南入於海。
|It crosses through the '''Country of the Piao''' (驃國&lt;ref&gt;Probably easily resolvable, possibly related to Pyu as in Mon-Khmer language family predecessor kingdoms in Burma.&lt;/ref&gt;) and thence in to the ocean.&lt;ref&gt;This probably refers to second hand or tertiary information about the distant delta of the river, which would have been a significant and dangerous journey for the highland Yunnanese (eg. Nanzhao) or other Chinese peoples owing to the ease of death from then relatively untreatable and misunderstood malaria.&lt;/ref&gt;
|-
|水中有蛟龍、鱷魚、烏鲗魚。
|Among its waters swim large&lt;ref&gt;Literally 'dragon sized' (蛟龍).&lt;/ref&gt; shrimp, crocodiles,&lt;ref&gt;鱷魚&lt;/ref&gt; and black cuttlefish.&lt;ref&gt;Loose translation of 烏鲗魚 which may have no modern equivalent.&lt;/ref&gt;
|-
|又有水獸似牛，遊泳則波濤沸湧，狀如海潮。
|There are also water-beasts that are like buffalo,&lt;ref&gt;Here possibly referring to now extinct rhinoceros or hippopotamus endemic to the area?&lt;/ref&gt; which when they swim create waves in the water&lt;ref&gt;This part is rather vague and may require further attention.&lt;/ref&gt; like the tide.
|-
|《禹貢》：導黑水至於三危，蓋此是也。
|[A quote from] ''Yugong'' (禹貢&lt;ref&gt;Not sure if this is a book or a person!&lt;/ref&gt;): Guide&lt;ref&gt;導&lt;/ref&gt; the black waters&lt;ref&gt;黑水&lt;/ref&gt; to enter&lt;ref&gt;至於&lt;/ref&gt; '''The Three Dangers''' (三危; ''sanwei''), this is as it should be.
|-
|或雲源當是大月河，恐非也。
|Otherwise the source in Yunnan is thought to be the '''Great Moon River''' (大月河), which is afraid of nothing.&lt;ref&gt;恐非也 — [afraid] [not] [is/indeed]&lt;/ref&gt;
|-
|又彌諾江在麗水西，源出西北小婆羅門國。
|The '''Minuojiang''' (彌諾江) lies to the west of '''Lishui''' (麗水), appearing from the northwest in the '''Little Brahmin Country''' (小婆羅門國&lt;ref&gt;In the Hukawng Valley where the Chindwin originates and which is north of Anxi as mentioned elsewhere in the text. &lt;/ref&gt;)
|-
|南流過湧腋苴川，又東南至兜彌伽木柵，分流繞柵，居沙灘南北一百裏，東西六十裏。
|Southward it flows through [past] the '''Yongyeju Valley''' (湧腋苴川; &lt;ref&gt;This is the Kabaw Valley. To be consistent with geography I amended it to imply it flows past the valley rather than through it. Fan Chuo later in the document mentions that he recorded various words of the barbarians. The Ju (苴) means beautiful in the Bai language at the time. The current characters for this toponym are not reliable to reconstruct it as the Bai language back then cannot be reconsntructed as of yet. The Chindwin does pass the Kabaw Valley.&lt;/ref&gt;), then onward to the southeast to the border&lt;ref&gt;柵 — more literally fence.&lt;/ref&gt; of '''Doumijia''' (兜彌伽木; MC: Tuwmjiegja &lt;ref&gt;This series of characters looks suspiciously like a transliteration from a non Chinese (possibly Tibeto-Burman) language but more likely a Indianized name. Such as Dhumika (Smoky)&lt;/ref&gt;) wooden stockade, then splits to wind around the border and stop within a sandy water body that is 100 ''li'' in north-to-south by 60 ''li'' east-west.&lt;ref&gt;This is the Mingin sandbank where the Chindwin River splits around it before connecting back together and flowing into the Irrawaddy. &lt;/ref&gt;
|-
|合流正東，過彌臣國，南入於海。
|Due east it converges together and passes the '''State of Míchén'''  (臣國&lt;ref&gt;An identification for this should be possible. In following the Khmer identification of the prior portion of the text, this would very likely be the fellow Indianized kingdom of Chenla/Zhenla or the Chams, who were only conquered by the invading Vietnamese/Chinese armies in central Vietnam later on around the dawn of the Ming Dynasty.&lt;/ref&gt;). South it enters at the sea.
|}

==References and notes==
{{reflist}}</text>
      <sha1>d6hhecs4xb1zgxs51aj8sy64y7xqyu4</sha1>
    </revision>
  </page>
  <page>
    <title>Manshu/Chapter 6</title>
    <ns>0</ns>
    <id>464543</id>
    <revision>
      <id>4637005</id>
      <parentid>4636722</parentid>
      <timestamp>2026-05-22T10:49:05Z</timestamp>
      <contributor>
        <username>Taitesena</username>
        <id>3485636</id>
      </contributor>
      <comment>/* 镇西节度 （Zhènxī jié dù) */</comment>
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      <format>text/x-wiki</format>
      <text bytes="53724" sha1="timpxy2wtyspthej2ixpuljhcq2mx06" xml:space="preserve">{{incomplete translation}}
{{translation header
 | language = zh
 | original = 
 | title    = [[../]]
 | author   = Fan Chuo
 | override_editor   = Palace Museum Library
 | translator = Walter Stanish and Taitesena
 | section  = Chapter 6
 | previous = [[../Chapter 5/]]
 | next     =[[../Chapter 7/]]
 | notes    = '''Manshu''' (蠻書), written by [[Author:Fan Chuo|Fan Chuo]] in the 9th century, is a Chinese historical text regarding the geopolitics of southwest China, particularly Nanzhao. It is an important historical source for the period. This translation is based upon a digitized version of the recompiled 1774 movable type edition edited by the 武英 (Palace Museum Library).
}}

[[zh:蛮书/卷06]]

==Translation==
===''Yúnnán City'' (雲南城; ie. modern Yunnanyi)===
[[File:Architectural View, Yunnanyi.svg|center|thumb|600px|View of a former private inter-house passageway raised above the cobbled street in the caravan town of Yunnanyi, Yunnan, China.]]
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 1 — ''Yúnnán City'' (雲南城; ie. modern Yunnanyi)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|雲南城，天寶中閣羅鳳所規置也。
|'''Yúnnán City''' (雲南城; ie. modern Yunnanyi) was established by '''Gé​luó​fèng​''' (閣羅鳳) in the ''Tianbao'' era (ie. 742-756).
|-
|嘗為信州地。
|It has since come to be known as '''Xìn​zhōu​''' (信州).
|-
|城池郭邑皆如漢制。
|All of the villages about the wall are similar to those of the Han Chinese.
|-
|州中南北二十余裏，東西四十五裏。
|The center of the prefecture is over 20 ''li'' (ie. ~6.5km) from north to south, and 45 ''li'' (ie. ~14.5km) from east to west.
|-
|帶邑及過山雖有三千余戶，田疇多廢，閭裏少人。
|Although the villages of the region cross the mountains and have over 3000 households, many fields lay fallow, and few people may be found at the village gates.
|-
|諸葛亮分永昌東北置雲南郡，斯即其故地也。
|'''Zhū​gě​ Liàng''' (諸葛亮)&lt;ref&gt;'''Zhū​gě​ Liàng''' (諸葛亮; 181-234), military leader and prime minister of '''Shu Han''' (蜀漢) during the '''Three Kingdoms''' period. Also the main hero of the fictional ''Romance of Three Kingdoms'' (三國演義) where he is portrayed as a sage and military genius/mastermind.&lt;/ref&gt; divided the north-east of '''Yǒng​chāng​''' (永昌; ie. modern Baoshan) in to the '''Yún​nán​ Region''' (雲南郡) &amp;mdash; this is its former location.
|-
|西隔山有品𧸘&lt;ref&gt;&lt;貝僉&gt;&lt;/ref&gt;賧，亦名清字川，嘗為波州。
|To the west is the sibling town of '''Pǐnbiandǎn​''' (品𧸘賧; lit. 'Goods Market River' or 'Goods Market Toll-point'), also known as '''Qīng​zì​chuān​''' (清字川; lit. 'Clear Character River-plain'), the former '''Bō​zhōu​''' (波州).
|-
|大池繞山，長二十余裏，波州廢地在池東南隅。
|A great pond encircles the mountain, over 20 ''li'' (ie. 6.5km) in length, with the discarded lands of '''Bō​zhōu​''' (波州) at its southeast corner.
|-
|故渭北節度段子英，此州人也。
|The famous hero of the former '''Wèi​běi​ Commandery''' (渭北節度) was from this region.
|-
|故居、墳墓皆在。
|His former residence and grave still remain.
|-
|雲南東第二程有欠舍川，大都部落第三程至石鼓驛，舊化川也。
|The second location east of '''Yúnnán''' (雲南; ie. modern Yunnanyi) is '''Qiàn​shè​chuān​''' (欠舍川; lit. 'Poorly Populated River-valley'), most tribes' third location is '''Dàn​gǔyì​''' (石鼓驛; lit. 'Grain-drum Relay Station'), the former '''Huà​chuān​''' (舊化川; lit. 'Dynamic River-valley').
|-
|第四程至曲驛，有大覽賧、小覽賧，漢舊覽州也。
|The fourth stop is '''Qū​yì''' (曲驛; lit. 'Crooked Relay Station'), which includes '''Dà​lǎn​dǎn​''' (大覽賧; lit. 'Great View Toll Station (or River-view)') and '''Xiǎo​​lǎn​dǎn​''' (小覽賧; lit. 'Small View Toll Station (or River-view)')), and was formerly known to Han Chinese as '''Lǎn​zhōu​''' (覽州; lit. 'Scenic River-valley Region').
|}

===''Nòngdōng City'' (弄棟城)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 2 — ''Nòngdōng City'' (弄棟城)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|弄棟城在故姚州川中，南北百余裏，東西三十余裏。
|'''Nòngdōng City''' (弄棟城) is on the former '''Yáo​zhōu​''' (姚州) river. It measures over 100 ''li'' (ie. ~32km) from north to south, and over 30 ''li'' (ie. ~10km) from east to west.
|-
|廢城在東巖山上。
|An abandoned city lies on the eastern cliff.
|-
|當川中有平巖，周回五六頃，新築弄棟城在其上。
|The same river-plain has '''Píng​yán​''' (平巖), which is 5 or 6 ''qǐng'' (ie. ~33-40 hectares) in size. The newly built '''Nòngdōng City''' (弄棟城) lies above it.
|-
|管雜蠻數部落，悉無漢人。
|It overlooks various barbarian tribes, and there are no Han Chinese people.
|-
|姚州百姓陷蠻者，皆被移隸遠處。
|The common people of '''Yáo​zhōu​''' (姚州) were captured by barbarians, and all were relocated a long distance away.
|}

===''Tuodong City'' (柘東城)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 3 — ''Tuodong City'' (柘東城)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|柘東城，廣德二年鳳伽異所置也。
|'''Tuodong City''' (柘東城) was established by '''Fèng​jiā​yì​''' (鳳伽異) in the second year of the ''Guangde'' reign (ie. ~764).
|-
|其地漢舊昆川，故謂昆池。
|The area's Han Chinese hail from '''Kūn​chuān​''' (昆川; lit. 'Descendant River-plain'), and it was formerly known as '''Kūn​chí​''' (昆池; lit. 'Descendant Pond').
|-
|東北有井邑城隍，城西有漢城，土俗相傳雲是莊蹻故城。
|To the northeast lies (the fixed shrine to) the '''Chéng​ Huáng''' (城隍; lit. 'City God') of the (city-internal) '''Jǐng​yì​''' (井邑; lit. 'Well Village'),&lt;ref&gt;This may be a reference to the area immediately adjacent to the northeast corner of modern Kunming's old central swamp, known as '''Cuihu''' (翠湖; lit. 'Jade-green Lake'), since this is known to have been a major historical fresh water source for the city and to be in a naturally low-lying and water-collecting basin beside '''Wuhua Mountain''' (无花山), which now gives its name to a major part of the city.&lt;/ref&gt; to the west lies '''Hàn​chéng​''' (漢城; lit. 'the Han Chinese city'), which indigenous lore asserts was the location of the ancient city known as '''Zhuāng​qiāo​''' (莊蹻; lit. 'Manor Bridge').
|-
|城之東十余裏有穀昌村，漢穀昌王故地也。
|Some 10 ''li'' (ie. ~3.3km) to the east&lt;ref&gt;Perhaps in the general area of the west-facing hills around the modern location of '''Tanhua Temple Park''', just east of the Second Eastern Ring Road of Kunming?&lt;/ref&gt; lies '''Gǔ​chāng​cūn​''' (穀昌村; lit. 'Flourishing-Grain Village'), the former location of the Han Chinese '''Flourishing-Grain King''' (穀昌王).
|-
|貞元十年，南詔破西戎，遷施、順、磨些諸種數萬戶以實其地。
|In the 10th year of the ''Zhenyuan'' reign (ie. ~795), '''Nán​zhào​''' (南詔) defeated the '''Xī​róng''' (西戎),&lt;ref&gt;This is the second reference in the text to this alleged historic ethnic group, which is perhaps better associated with regions further north (Sichuan, etc.). It again occurs within a general historic context and may conceivably have been written from additional or earlier sources, now lost. Given the lack of clarification in the current text, it is difficult to know precisely which group it may refer to.&lt;/ref&gt; and ordered over 10,000 households to resettle here.&lt;ref&gt;This part not entirely clear.&lt;/ref&gt;
|-
|又從永昌以望苴子、望外喻等千余戶分隸城傍，以靜道路。
|Again from '''Yǒng​chāng''' (永昌; ie. the modern Baoshan area), '''Wàng​jū​zi​''' (望苴子), '''Wàng​wài​yù​''' (望外喻) and more than 1000 households moved to the city via the pacified road.
|}

===''Jìnníng Prefecture'' (晉寧州)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 4 — ''Jìnníng Prefecture'' (晉寧州)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|晉寧州，漢滇河故地也。
|'''Jìnníng Prefecture''' (晉寧州; lit. 'Peaceful Visit (or Flow, or Growth) River-Valley') is the location formerly known to Han Chinese as the '''Diān​hé​''' (滇河; lit. 'River of Level Waters').&lt;ref&gt;This probably refers to the historical state of the primary outflow river of '''Dianchi Lake''' (滇池), ''Tángláng Chuān''' (螳螂川; lit. 'Tanglang Creek'), located in the southwest of the lake near modern '''Jìnníng''' (晋宁).&lt;/ref&gt;
|-
|在柘東城南八十裏晉平川，幅員數百裏，西爨王墓，累累相望。
|'''Jìn​píng​chuān​''' (晉平川; lit. 'Flat River-plain of Growth') is 80 ''li'' (ie. ~km) south of '''Tuodong City''' (柘東城), its size is&lt;ref&gt;Or possibly, is a few multiples of...&lt;/ref&gt; 100 ''li'' (ie. ~32.3km), and the tomb of the '''King of the Western Cuàn​''' (西爨王) faces countless other graves.
|}

===''Shíchéngchuān'' (石城川)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 5 — ''Shíchéngchuān'' (石城川)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|石城川，味縣故地也。
|'''Shíchéngchuān''' (石城川; lit. 'Stone City River-plain'&lt;ref&gt;Or possibly '''Shíchéngchuān''' (石城川; lit. '(Large portion of) Grain City River-plain'), though this seems far less likely.&lt;/ref&gt;) is the location of ancient '''Wèi​xiàn​''' (味縣; lit. 'Fragrant&lt;ref&gt;Or less likely, 'Tasty' (good chefs?).&lt;/ref&gt; County').
|-
|貞觀中，為郎州，開元初改為南寧州。
|In the ''Zhen'guan'' era&lt;ref&gt;The reign of '''Emperor Tàizōng''' (太宗).&lt;/ref&gt; (ie. 627–649), it became '''Láng​zhōu​''' (郎州; lit. 'River-plain Region of (Youth or (the) Minister)'), and at the beginning of the ''Kāiyuán'' (ie. 713–741) era it was renamed to '''Nán​níng​zhōu​''' (南寧州; lit. 'Pacified Southern River-plain Region').
|-
|州城即諸葛亮戰處故城也。
|The prefectural capital is at the former battle-site of '''Zhū​gě​ Liàng​''' (諸葛亮).
|-
|城中有諸葛亮所撰文，立二碑，背上篆文曰：「此碑如倒，蠻為漢奴。」
|Within the city is a written composition of '''Zhū​gě​ Liàng​''' (諸葛亮), recorded upon two standing stelae, which state: &quot;This stone records the fall of the barbarians and their enslavement by the Han Chinese.&quot; 
|-
|近年蠻夷以木搘柱&lt;span style=&quot;color:#aaa&quot;&gt;(案：《新唐書》謂諸葛亮碑在柘東城，與此不合，蓋《唐書》之誤)。&lt;/span&gt;
|In recent years, the Barbarians have propped up the stelae with wood. &lt;span style=&quot;color:#aaa&quot;&gt;(Former transliterator's note: In the ''History of the Later Tang Dynasty'' (新唐書), it states that the '''Zhū​gě​ Liàng​''' (諸葛亮) stelae are in '''Tuodōng​chéng''' (柘東城), which conflicts with this section of the current text and covers an error in the ''History of the Early Tang Dynasty'' (舊唐書).)&lt;/span&gt;
|-
|臣今春見安南兵馬使郭延宗曾奉使至柘東，停住一月日，館穀勤厚，贈遺不輕&lt;span style=&quot;color:#aaa&quot;&gt;(案：以上五句與上下文不相屬，疑亦錯簡在此)&lt;/span&gt;。
|This Spring I witnessed military horses from '''Ān​nám​''' (安南; ie. modern Hanoi, Vietnam) come to offer tribute in '''Tuodōng​''' (柘東), where they remained for a little over a month&lt;ref&gt;Seemingly a reasonable interpretation of 一月日; alternatively this could be specifying a day in the first lunar month (ie. February/March period), which would in fact perfectly accord with the aforementioned spring season.&lt;/ref&gt;, working diligently&lt;ref&gt;This seems the spirit, however the first two characters of the phrase 館穀勤厚 are hard for me to interpret clearly in context and are mostly glossed over in this translation.&lt;/ref&gt; and bestowing non-trifling volumes of tributary presents. &lt;span style=&quot;color:#aaa&quot;&gt;(Former transliterator's note: The five previous sentences appear to be out of context, therefore it is suspected that this part of the text&lt;ref&gt;The note literally says 'this piece of written bamboo' (簡).&lt;/ref&gt; was introduced out of order.)&lt;/span&gt;
|-
|又有夔鹿弄川，漢同勞縣故地也&lt;span style=&quot;color:#aaa&quot;&gt;(案：《舊唐書·地理誌》郎州有同樂縣，「同勞」疑即「同樂」之誤)&lt;/span&gt;。
|There is also '''Kuí​lù​lòng​chuān​''' (夔鹿弄川; lit. 'Spirit&lt;ref&gt;Modern dictionaries suggest that 夔 may refer to two different types of deities/spirits, either a one-legged mountain daemon or the Chinese mythical figure who invented music and dancing. Quote from [https://en.wikipedia.org/wiki/Kui_(Chinese_mythology) English Wikipedia]: &quot;Classic texts use this name for the legendary musician Kui who invented music and dancing; for the one-legged mountain demon or rain-god Kui variously said to resemble a Chinese dragon, a drum, or a monkey with a human face; and for the Kuiniu wild yak or buffalo.&quot;&lt;/ref&gt;-deer Alley River-plain'), the area formerly known to Han Chinese as '''Tóng​láo​xiàn​''' (同勞縣; lit. 'Working Together County'). &lt;span style=&quot;color:#aaa&quot;&gt;(Former transliterator's note: In the ''Geography'' chapter of the ''History of the Early Tang Dynasty'' (舊唐書), '''Lángzhōu​''' (郎州) has a ​'''Tóng​lè​''' (同樂縣; lit. 'Happiness Together County'), and as such the '''Tóng​láo''' (同勞) here is suspected to be an erroneous (reproduction of an earlier intact and clear) reference to that place.)&lt;/span&gt;
|-
|在龍河遇川南百余裏。
|It is over 100 ''li'' (ie. ~32.5km) south of '''Lóng​hé​yù​chuān​''' (龍河遇川; lit. 'Dragon River Meeting River-plain Region').
|-
|石城南面有新豐川，漢南寧州新豐縣故地也。
|To the south of '''Shíchéng''' (石城) lies '''Fēng​chuān​''' (豐川), the location of the historical region known to Han Chinese '''Xīn​fēng​ Xiàn​''' (新豐縣; lit. 'New Plentiful County') of '''Nánníng​zhōu​''' (南寧州; lit. 'Peaceful Southern Prefecture').
|-
|廢城墻塹猶在，大小石城川同。
|The abandoned city walls and moat remain, and their size is comparable to that of '''Shíchéngchuān''' (石城川).
|-
|升麻川西川南有曲軛川，漢南寧州同起縣也。
|South of the western river-plain of '''Shēng​má​chuān​''' (升麻川; lit. 'Hoisted Hemp River-valley') lies '''Qū​'è​chuān​''' (曲軛川; lit. 'Crooked Yoke River-valley'), established at the same time as '''Nánníng​zhōu​''' (南寧州).
|}

===''Ānníng Town'' (安寧鎮)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 6 — ''Ānníng Town'' (安寧鎮)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|安寧鎮，去柘東城西一日程，連然縣故地也。
|From '''Ānníng Town''' (安寧鎮) it is one day's journey to '''Tuodong City''' (柘東城), and it is the former '''Lián​rán​xiàn​''' (連然縣; lit. 'County of the Just Military-Company').
|-
|通海鎮，去安寧西第三程至龍封驛。
|From '''Tōng​hǎi​zhèn​''' (通海鎮; lit. 'Town Connecting to the Oceans') toward '''Ānníng''' (安寧) it takes three days' journey westward&lt;ref&gt;If this is referring to the same place as modern '''Tonghai''' (通海), then this sounds about right, having cycled and walked much of the terrain personally. The probable route would be from '''Tonghai''' (通海) at the south of across to the far south of '''Dianchi Lake''' (滇池), either via '''Yuxi''' (玉溪) then north, or first north a little along the west of the eastern ('''Fuxian Lake''' (抚仙湖) and adjacent) lake complex then more directly across the mountains via a pass near '''Shizhaishan''' (石寨山), then north-west along the modern '''Tanglangchuan River''' (螳螂川) to '''Anning''' (安宁). However, if this is the case, then there remain two issues. (1) It is unclear why '''Lóng​fēng​yì​''' (龍封驛) is mentioned, or where its location is (perhaps if, as suggested, '''Lóng​fēng​yì​''' (龍封驛) was just after a miasmic swamp then that swamp was in the area of modern '''Kunyang''' (昆阳) and '''Lóng​fēng​yì​''' (龍封驛) lay on the '''Tanglangchuan River''' (螳螂川) after turning northwest from '''Dianchi Lake''' (滇池)?). This is believable. (2) Why does it say eight days' journey? This would be too much, unless it perhaps refers to a less direct, less miasmic and more leisurely route to '''Tuodong''' (柘東; ie. modern Kunming), perhaps via the eastern edge of '''Fuxian Lake''' (抚仙湖) and then perhaps even via '''Yangzonghai''' (阳宗海)?&lt;/ref&gt; in order to reach '''Lóng​fēng​yì​''' (龍封驛; lit. 'Dragon Letter Relay-station').&lt;ref&gt;Perhaps if, as suggested, '''Lóng​fēng​yì​''' (龍封驛) was just after a miasmic swamp then that swamp was in the area of modern '''Kunyang''' (昆阳) and '''Lóng​fēng​yì​''' (龍封驛) lay on the '''Tanglangchuan River''' (螳螂川) after turning northwest from '''Dianchi Lake''' (滇池)?&lt;/ref&gt;
|-
|驛前臨瘴川，去柘東城八日程，漢俞元縣故地也。
|The area just before the '''Lóng​fēng​yì​''' (龍封驛) relay station is a miasmic swamp, from which it takes eight days' journey to reach '''Tuodong''' (柘東). It was formerly known to Han Chinese as '''Shù​yuán​xiàn​''' (俞元縣; lit. 'Primary Point County' or perhaps&lt;ref&gt;The first character in particular has a rash of potential meanings. One can imagine that the point was of military and political significance as a gateway to the fertile lake-plateaux of central Yunnan.&lt;/ref&gt; 'Good Foundation County').
|-
|量水川&lt;span style=&quot;color:#aaa&quot;&gt;(案：《舊唐書·地理誌》黎州有梁水縣，「量水」蓋即「梁水」轉音之訛)&lt;/span&gt;，漢舊黎州。
|'''Liàng​shuǐ​chuān​''' (量水川; lit. 'River-plain of Plentiful Water') &lt;span style=&quot;color:#aaa&quot;&gt;(Former transliterator's note: In the ''Geography'' chapter of the ''History of the Early Tang Dynasty'' (舊唐書),&lt;ref&gt;It is perhaps interesting and potentially significant to note that a transliterator somewhere along the line used a different formatting methodology for the name of the text here; ie. &amp;mdash; 《舊唐書·地理誌》 instead of just《唐書》or 《唐書·地理誌》... though the difference is probably only modern, it gives us a little insight in to the quality of the process (ie. imperfect consistency).&lt;/ref&gt; '''Lízhōu​''' (黎州; lit. 'Black Prefecture') has a '''Liáng​shuǐ​xiàn​''' (梁水縣; lit. 'Water Bridge County'), it is thus suspected that「量水」was here erroneously phonetically altered to「梁水」)&lt;/span&gt;, the former Han Chinese region of '''Lí​zhōu​''' (黎州; lit. 'Black Prefecture').
|-
|今吐蕃呼為量水川。
|The Tibetans&lt;ref&gt;Perhaps referring to any ethnic group with a Tibeto-Burman language family, rather than Tibetans per-se.&lt;/ref&gt; refer to it&lt;ref&gt;This statement is fertile ground for historical phonological and semantic analysis.&lt;/ref&gt; as '''Liàng​shuǐ​chuān​''' (量水川; lit. 'River-plain of Plentiful Water').
|-
|通海城南十四日程至步頭，從步頭船行沿江三十五日出南蠻，夷人不解舟船，多取通海城路賈勇步入真、登州、林西原，取峰州路行。
|14 days' journey south of '''Tōng​hǎi​''' (通海城) city one arrives at '''Bù​tóu​''' (步頭; lit. 'Walk's Beginning'), from there it is 35 days' journey by boat to emerge at the '''Nán​mán​''' (南蠻; lit. 'Southern Barbarians') (lands), where they have no conception of and are fascinated by boats. Many people take the '''Tōng​hǎi​''' (通海城) road to '''Gǔyǒng''' (賈勇) then journey onward to '''Zhēn​''' (真),&lt;ref&gt;Apparently a place name though considered unlikely/spurious and not mentioned in Chapter 1.&lt;/ref&gt; '''Dēngzhōu​''' (登州; ie. probably somewhere near modern ''Mau Dong / Mau A'' (in north-west Vietnam, on the Red River)).&lt;ref&gt;According to analysis described within a footnote in Chapter 1.&lt;/ref&gt;), '''Lín​xī​yuán​''' (林西原; lit. '(Water?) Source to the West of the Forest') and '''Fēngzhōu'''/'''Phong Châu''' (峯州 or 峰州; modern ''Việt Trì'').&lt;ref&gt;Again, according to analysis in the footnotes of Chapter 1.&lt;/ref&gt;&lt;ref&gt;It is interesting to note that here the foreign routes associated with the Red River (红河) are described both differently and in reverse to Chapter 1, with different place names being mentioned and different details omitted. It is therefore arguably quite likely that this portion and the Chapter 1 portion were written at different times, against different sources or copied from different former texts. It also confirms that Tonghai was a rather important hub for long distance journeys, as both its name and topographic situation would suggest.&lt;/ref&gt;
|-
|量水川西南至龍河，又南與青木香山路直，南至昆侖國矣。
|To the southwest of '''Liàng​shuǐ​chuān​''' (量水川; lit. 'River-plain of Plentiful Water') lies the '''Lóng​hé​ River''' (龍河; lit. 'Dragon River'), and going still southward through verdantly forested and fragrant mountain roads, in the south one arrives at the country of '''Kunlun''' (昆侖國; lit. 'Country of the Wheel of Descendance'; ie. Southeast Asian Brahmanist lands (probably period Thailand or Cambodia)&lt;ref&gt;In [https://books.google.com.hk/books?id=colwNdOiiCQC&amp;pg=PA33&amp;lpg=PA33&amp;dq=kunlunguo&amp;source=bl&amp;ots=XHDG5zY3s_&amp;sig=bQJKu4v4G3jLlqK6r7AfBdL0B8Y&amp;hl=zh-TW&amp;sa=X&amp;ved=0ahUKEwi83MCrmunNAhXGJJQKHd9jB88Q6AEIHzAD The Blacks of Premodern China (p33)] (University of Pennsylvania Press, 2009) Don J. Wyatt reviews in English various attempts to identify this region, essentially concluding that it has no specific geolocation whatsoever but could be thought to encompass any one of many Southeast Asian, South Asian and even East African regions. Here it likely refers to Thailand or Cambodia. It is perhaps useful to note that the literal translation is strongly suggestive of ''karma'' and rebirth and therefore Buddhist (or perhaps Hindu) influence.&lt;/ref&gt;).
|}

===''Níngběi City'' (寧北城)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 7 — ''Níngběi City'' (寧北城)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|寧北城，在漢碟榆縣之東境也。
|'''Níngběi City''' (寧北城) is on the eastern border of the Chinese '''Dié​yú​xiàn​ County''' (碟榆縣; lit. 'Elm Dish County'&lt;ref&gt;Possibly implying a lack of easy production or trade access to stoneware?&lt;/ref&gt;).
|-
|本無城池，今以浪人詔矣羅君舊宅為理所。
|Before there was a city, it was the former residence of '''Yǐ​luó​jūn​''' (矣羅君) of (the Kingdom of) '''Làng​rén​zhào​''' (浪人詔)
|-
|東地有野共川，北地有虺川，又北有虺川，又北有郎婆川，又北有桑川，即至鐵橋城北九賧川。
|'''Yě​gòng​chuān​''' (野共川) lies to the east, '''Huǐ​chuān​''' (虺川) lies to the north, further north lies '''Huǐ​chuān​''' (虺川&lt;ref&gt;There must be a mistake of duplication in the source text here. Probably one place name is lost. Different versions of the source should be reviewed to recover the content.&lt;/ref&gt;), still further north lies '''Láng​pó​chuān​''' (郎婆川), still further north lies '''Sāng​chuān​''' (桑川; lit. 'Mulberry River-plain'), after which one arrives at '''Nine-river Plain''' (九賧川) north of '''Tiěqiáo (Iron Bridge) City''' (鐵橋城).
|-
|又西北有羅眉川，又西牟郎共城，又西至傍彌潛城。
|Further north-west lies '''Luó​méi​chuān​''' (羅眉川; lit. 'Gathering Rise/Apex River-plain'), further west is '''Móu​láng​gòng​ City''' (牟郎共城), and still further west one appraoches '''Mí​qián​chéng​''' (彌潛城; lit. 'Completely Hidden City').
|-
|西有鹽井，鹽井西有斂尋城。
|To the west is '''Salt Well''' (鹽井), and west of that lies '''Liǎn​xún​ City''' (斂尋城; lit. 'Restrained Gathering City').
|-
|皆施蠻、順蠻部落今所居之地也。
|All are barbarous, obeying the barbarian tribes in residence.
|-
|又西北至聿賫城，又西北至弄視川。
|Further north-west one arrives at '''Yù​jī​ City''' (聿賫城), and still further northwest one arrives at '''Lòng​shì​chuān​''' (弄視川).
|}

===''Tiěqiáo (Iron Bridge) City'' (鐵橋城)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 8 — ''Tiěqiáo (Iron Bridge) City'' (鐵橋城)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|鐵橋城在劍川北三日程，川中平路有驛。
|'''Tiěqiáo (Iron Bridge) City''' (鐵橋城) is three days' journey to the north of '''Jiàn​chuān​''' (劍川), and there is a (postal) relay-station in the middle of the flat road on in the midst of the river-plain.&lt;ref&gt;Note that this places it approximately at the location of Zhongdian (now known as Xianggelila / Shangri-la).&lt;/ref&gt;
|-
|貞元十年，南詔蒙異牟尋用軍破東西兩城，斬斷鐵橋，大籠官已下投水死者以萬計。
|In the 10th year of the ''Zhenyuan'' era (ie. ~795), '''Méng​yì​móu​''' (蒙異牟&lt;ref&gt;Perhaps the final character of the name is in fact part of the verb to seek but I considered it less likely than being part of the (two character) name.&lt;/ref&gt;) of '''Nán​zhào​''' (南詔) sought military supplies&lt;ref&gt;Probably food, men and horses.&lt;/ref&gt; to attack the cities to the east and west (of the bridge), and to close the bridge...
|-
|今西城南詔置兵守禦，東城至神川以來，半為散地。
|'''Nán​zhào​''' (南詔) has installed a military garrison on the '''Western City''' (西城), and the '''Eastern City''' (東城) has since stretched haphazardly to '''Shén​chuān​''' (神川).
|-
|見管浪加萌、於浪、傳兗、長裈、磨些、撲子、河人、弄棟等十余種。
|They manage ten types (of Barbarians) including the '''Làng​jiā​méng​''' (浪加萌), '''Yū​làng​''' (於浪), '''Chuányǎn​''' (傳兗), '''Cháng​kūn​''' (長裈), '''Mó​xiē​''' (磨些), '''Pū​zi​''' (撲子), '''Hé​rén​''' (河人), '''Lòng​dòng​''' (弄棟) and others.
|}

===''Kūn​míng​ City'' (昆明城)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 9 — ''Kūn​míng​ City'' (昆明城)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|昆明城，在東瀘之西，去龍口十六日程。
|The city of '''Kūn​míng​''' (昆明城; lit. 'City of Brilliant Descent') is west of the '''Dōng​lú​''' (東瀘; lit. 'East Lu (River)'), some 16 days' journey from '''Lóng​kǒu​''' (龍口; lit. 'Dragon's Mouth'; ie. modern Xiaguan).
|-
|正北有諱苴川，正南至松外城，又正南至龍怯河，西南至小婆城，又西南至大婆城，西北至三探覽城，又西北至鐵橋東城。
|Directly north is '''Huì​jū​chuān​''' (諱苴川; lit. 'Hemp Taboo River-valley'), directly south is '''Sōng​wài​ City''' (松外城; lit. 'City Outside the Pines'), directly south again is the '''Lóng​qiè​ River''' (龍怯河; lit. 'Cowardly Dragon River'), southwest is '''Xiǎo​pó​chéng​''' (小婆城; lit. 'Little Grandma City'), southwest again is '''Dà​pó​ City''' (大婆城; lit. 'Big Grandma City'), southwest again is '''Sān​tàn​lǎn​ City''' (三探覽城; lit. 'Thrice-scouted View City'), and northwest again is the '''Tiě​qiáo​dōng​ City''' (鐵橋東城; lit. 'City East of the Iron Bridge').
|-
|其鐵橋上下乃昆明、雙舍，至松外已東，邊近瀘水，並磨些種落所居之地。
|Both sides of the '''Tiě​qiáo''' (鐵橋; lit. 'Iron Bridge') is '''Kūn​míng​''' (昆明), two residential areas, after which one arrives at the east of '''Sōng​wài''' (松外), the edge of which is close to '''Lú​shuǐ''' (瀘水; lit. '(the) Lu River')&lt;ref&gt;Note that the spatial relations in this sentence are not completely clear and may be revised in a subsequent reading.&lt;/ref&gt; and the site of the '''Mó​xiē​''' (磨些) (barbarians') '''Zhòng​luò​''' (種落) village.
|}

===''Yǒng​chāng​ City'' (永昌城; ie. modern Baoshan)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 10 — ''Yongchang City'' (永昌城; ie. modern Baoshan)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|永昌城，古哀牢地，在玷蒼山西六日程。
|'''Yǒng​chāng​ City''' (永昌城), which is the ancient location of the '''Āi​láo​''' (哀牢) (people or culture), is six days' journey to the west of '''Diàn​cāng​shān​''' (玷蒼山; ie. the modern Cāng​shān​ range running north-south to the west of the Erhai basin / modern Dali).
|-
|西北去廣蕩城六十日程。
|It is sixty days' journey northwest to '''Guǎng​dàng​ City''' (廣蕩城; lit. 'Broad Sweep City'&lt;ref&gt;Perhaps referencing somewhere in Tibet, even Lhasa?&lt;/ref&gt;).
|-
|廣蕩城接吐蕃界。
|'''Guǎng​dàng​ City''' (廣蕩城) is on the '''Tǔ​bō​''' (吐蕃; ie. Tibetan Tubo dynasty&lt;ref&gt;7th-11th century&lt;/ref&gt;) border.
|-
|隔候雪山，西邊大洞川，亦有諸葛武侯城。
|Behind are snowy mountains, and at its western side lies '''Dà​dòng​chuān​''' (大洞川; lit. 'Great Cave River-plain') and the '''Zhū​gě​ Post-Military City''' (諸葛武侯城; lit. 'Zhū​gě​ Post-Military City'&lt;ref&gt;Possibly referring to some post-warfare haunt of Zhuge Liang, though I am not familiar enough with his story to know... though it is ''strongly'' doubtful he came this far out of Yunnan and in to Tibetan lands. Another option is that 諸葛武 is a name, though this also makes little sense.&lt;/ref&gt;).
|-
|城中有神廟，土俗鹹共敬畏，禱祝不闕。
|A temple lies at the heart of the city that the indigenous peasants&lt;ref&gt;My interpretation of 鹹共.&lt;/ref&gt; revere, praying conscientiously.
|-
|蠻夷騎馬，遙望廟即下馬趨走。
|When the local barbarians ride horses, they dismount immediately upon seeing a temple in the distance, then approach by a rapid walk.
|-
|西南管柘南城，土俗相傳，呼為要鎮。
|'''Tuonán City''' (柘南城) in the '''Southwestern Commandery'''&lt;ref&gt;Some kind of contemporary unit of governance, anyway. There is probably an accepted translation for the period, however I am completely uninterested in government and lack formal education in the academic traditions of Chinese translation thus unaware of such lexicons.&lt;/ref&gt; (西南管) was once known as '''Yāo​zhèn​''' (要鎮; lit. 'Coerced Village'&lt;ref&gt;Note that the semantics here are probably not Chinese, ie. we should discard the literal meaning. It is far more likely, coming from a Tibeto-Burman language, to be a rough phonetic import of the time. More fertile research ground here for historical phonologists/linguists!&lt;/ref&gt;) by indigenous received custom.
|-
|正南過唐封川，至茫天連。
|Directly southward one passes '''Táng​fēng​chuān​''' (唐封川; lit.&lt;ref&gt;Perhaps!&lt;/ref&gt; 'Well Sealed River-plain') and arrives at (the region of) '''Máng​tiān​lián​''' (茫天連; lit. 'Vast, joined skies').&lt;ref&gt;Probably referring to modern Myanmar: not only does this generally fit with the vague gesturings of the text, but in addition it makes perfect sense that travelers from Yunnan would consider significant the difference in tropical skies with respect to clouds and the reduced presence of mountains.&lt;/ref&gt;
|-
|自瀾滄江已西，越賧撲子，其種並是望苴子。
|West of the '''Lán​cāng​jiāng''' (瀾滄江; lit. 'Vast Swelling River'; ie. Mekong River) are more '''River Pū​zi''' (賧撲子) tribes, also known as '''Wàng​jū​zi​''' (望苴子&lt;ref&gt;Note that as with the city '''Yangxiefai''', the period pronunciation here may be closer to '''Wangxiezi'''.&lt;/ref&gt;).&lt;ref&gt;Not super clear on two parts of this sentence, first part being 越賧, second part being 其種並是, however this currently seems the most appropriate interpretation, which is supported by the earlier list of ethnicities in this chapter which included '''Pū​zi''' (撲子).&lt;/ref&gt;
|-
|俗尚勇力，土又多馬。
|It is their custom to value courage and strength, and the region has many horses.
|-
|開元已前閉絕，與六詔不通。
|They vanished before the ''Kaiyuan'' era (ie. prior to 713) but were different to the '''Six Zhào​''' (六詔).
|-
|盛羅皮始罷柘俞城，閣羅鳳已後，漸就柔服。
|'''Shèng​luó​pí​''' (盛羅皮) ... '''Gé​luó​fèng​''' (閣羅鳳) ...
|-
|通計南詔兵數三萬，而永西居其一。
|(Knowing that?) '''Nán​zhào​''' (南詔) had 30,000 soldiers, and was always the major power in the west.
|-
|又雜種有金齒、漆齒、銀齒、繡腳、穿鼻、裸形、磨些、望外喻等，皆三譯四譯，言語乃與河賧相通。
|They had many types (of soldiers in the army), including '''Jīn​chǐ​''' (金齒; lit. 'Gold-tooth'), '''Qī​chǐ​''' (漆齒; lit. 'Painted or lacquered tooth'), '''Yín​chǐ​''' (銀齒; lit. 'Silver tooth'), '''Xiù​jiǎo​''' (繡腳; lit. 'Embroidered leg'), '''Chuān​bí​''' (穿鼻; lit. 'Pierced nose'), '''Luǒ​xíng​''' (裸形; lit. 'Naked'), '''Mó​xiē​''' (磨些), '''Wàng​wài​yù​''' (望外喻; lit. 'Beyond the moon'&lt;ref&gt;Could possibly refer to the area beyond the mountain in the central upper Salween (Nujiang) River, which has a very moon-like hole in it.&lt;/ref&gt;) and others, each communicating via 3 or 4 interpreters, and thus mutually comprehensible to the '''Hé​dǎn​''' (河賧; lit. 'River Barbarians').
|}

===銀生城 (Yín​shēng​ City)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 11 — ...
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|銀生城在撲賧之南，去龍尾城十日程，東南有通鐙川，又直南通河普川，又正南通羌浪川，卻是邊海無人之境也。
|'''Yín​shēng​ City''' (銀生城; lit. 'Source of Silver City') is south of '''Pū​dǎn​''' (撲賧).&lt;ref&gt;Could be a place name, could be a river name, could be a tribal name.&lt;/ref&gt; It is 12 days' journey to '''Lóng​wěi​chéng​''' (龍尾城; lit. 'Dragon Tail City'; ie. modern Xiaguan). Southeast lies '''Dèng​chuān​''' (鐙川), directly south of which one may reach '''Hé​pǔ​chuān​''' (河普川), further directly&lt;ref&gt;It may be significant to note that this sub-phrase uses 正 whereas the last one used 直 ... it is unclear to me how or whether the expected interpretation should differ, so I leave this note to draw attention to the difference for future readers.&lt;/ref&gt; south of which is '''Qiāng​làng​chuān​''' (羌浪川), whose border regions are nevertheless wholly uninhabited.
|-
|東至送江川，南至邛鵝川，又南至林記川，又東南至大銀孔，又南有婆羅門、波斯、阇婆、勃泥昆侖數種。
|East is '''Sòngjiāng​chuān​''' (送江川; lit. 'Delivery-River Plain'), south is '''Qióng'​é​chuān​''' (邛鵝川; lit. 'Goose Mound River Plain'), still further south is '''Lín​jì​chuān​''' (林記川; lit. 'Memorial Forest River-Plain'), still further southeast is '''Dà​yín​kǒng​''' (大銀孔; lit. 'Great Silver Hole'&lt;ref&gt;Strongly implying an established underground silver mining operation.&lt;/ref&gt;), still further south is '''Pó​luó​mén​''' (婆羅門; lit. 'Brahman' implying 'Indian or Hindu lands'), '''Bō​sī​''' (波斯; ie. Persia), '''Shé​pó​''' (阇婆&lt;ref&gt;Unidentified. Could be Sri Lanka or a South Asian empire of the time.&lt;/ref&gt;), '''Bó​ní​''' (勃泥&lt;ref&gt;Unidentified. Could be Nepal if (a) it existed then; and (b) the characters were crossed in transliteration. Could also be any number of other polities.&lt;/ref&gt;), '''Kūn​lún​''' (昆侖&lt;ref&gt;Unidentified. Mythical South Asian location, probably.&lt;/ref&gt;) and other places.
|-
|外通交易之處，多諸珍寶，以黃金麝香為貴貨。
|With regard to foreign trade, all manner of treasures are traded for gold and musk.
|-
|撲子、長鬃等數十種蠻。
|There are ten types of barbarians including the '''Pū​zi​''' (撲子) and the '''Cháng​zōng​''' (長鬃; lit. 'Long mane').
|-
|又開南城在龍尾城南十一日程，管柳追和都督城，又威遠城、奉逸城、利潤城，內有鹽井一百來所。
|'''Kāinán City''' (開南城) is 11 days' journey south of '''Lóng​wěi​ City''' (龍尾城; ie. modern Xiaguan), a local provincial regional administrative center. There are also '''Wēi​yuǎn​ City''' (威遠城&lt;ref&gt;There is allegedly a modern Weiyuan county in Neijiang (內江), Sichuan.&lt;/ref&gt;), '''Fèng​yì​ City''' (奉逸城) and '''Lì​rùn​ City''' (利潤城), which in aggregate have up to 100 salt wells.
|-
|茫乃道並黑齒等類十部落，皆屬焉。
|The '''Máng​nǎi​ Road''' (茫乃道&lt;ref&gt;Apparently this toponym is a phonetic transliteration from a non-Chinese language as the semantics of the component characters appear relatively nonsensical.&lt;/ref&gt;) joins the '''Black Tooth''' (黑齒) to some ten or so tribes, all of whom are subordinate.
|-
|陸路去永昌十日程，水路下彌臣國三十日程。
|It is 11 days' overland journey to '''Yǒng​chāng​''' (永昌; ie. modern Baoshan), and 30 days' journey by water (ie. (river and?) ocean) to '''Mí​chén​guó​''' (彌臣國; lit. 'The Country of Michen'; ie. possibly Arakan; Sanskrit lit. 'Hill Country'&lt;ref&gt;[http://www.world10k.com/blog/?p=1252 One Chinese analysis] of the possible identity of this ancient toponym is as follows.&lt;br/&gt;&lt;br/&gt;
&amp;nbsp;&lt;span style=&quot;color:#aaa&quot;&gt;彌臣&lt;/span&gt;&lt;br/&gt;
'''The Country of Mí​chén​'''&lt;br/&gt;
&amp;nbsp;&lt;span style=&quot;color:#aaa&quot;&gt;《蠻書》卷一０，“小婆羅門國與驃國及彌臣國接界，在永昌北七十四日程”。&lt;/span&gt;&lt;br/&gt;
As per the 10th scroll of the ''Manshu'', &quot;The little Brahmanic country of ... from which it is 74 days' journey north to Yongchang &lt;span style=&quot;color:#aaa&quot;&gt;(ie. modern Baoshan)&lt;/span&gt;&quot;.&lt;br/&gt;
&amp;nbsp;&lt;span style=&quot;color:#aaa&quot;&gt;《唐會要》卷三三，“驃一作僄，其西別有彌臣國”。&lt;/span&gt;&lt;br/&gt;
As per the 33rd scroll of the ''Tánghuìyào'', &quot;...&quot;.&lt;br/&gt;
&amp;nbsp;&lt;span style=&quot;color:#aaa&quot;&gt;在今緬甸的西南部一帶。&lt;/span&gt;&lt;br/&gt;
Located in the southwestern part of modern Myanmar (Burma).&lt;br/&gt;
&amp;nbsp;&lt;span style=&quot;color:#aaa&quot;&gt;故地眾說紛紜：或謂指阿拉干（Arakan）地區，《琉璃宮史》稱該處為Macchagiri或Majjhagiri，giri梵文意為山、山國，彌臣則Maccha的譯音；一說在伊洛瓦底（Irrawaddy）江下游，指勃生（Bassein）或勃固（Pegu）一帶；也有的認為位薩爾溫（Salween）江口附近，波斯史籍稱為Musha或Musa。&lt;/span&gt;&lt;br/&gt;
...&lt;br/&gt;
&amp;nbsp;&lt;span style=&quot;color:#aaa&quot;&gt;另見《蠻書》卷二、六、七；《唐會西》卷一００；《御覽》卷七八九、九七一；《寰宇記》卷一七七；《冊府》卷九六五、九七二；《華夷圖》；《新唐書》卷二二二下；《通考》卷三三０；《讀史紀》卷一一九；《續通志》卷六四０。&lt;/span&gt;&lt;br/&gt;
The toponym occurs in...&lt;br/&gt;
 - the ''Manshu'' (蠻書) &lt;span style=&quot;color:#aaa&quot;&gt;(ie. this book)&lt;/span&gt; in chapters 2, 6 and 7;&lt;br/&gt;
 - &lt;span style=&quot;color:#aaa&quot;&gt;(again, later in)&lt;/span&gt; the ''Tánghuìyào'' (唐會要) [https://zh.wikisource.org/wiki/%E5%94%90%E6%9C%83%E8%A6%81/%E5%8D%B7100 in scroll 100];&lt;br/&gt;
&amp;nbsp;&amp;nbsp;封彌臣國嗣王樂道勿禮為彌臣國王焉。&lt;br/&gt;
 - the ''Yùlǎn'' (御覽) in scrolls [https://zh.wikisource.org/wiki/%E5%A4%AA%E5%B9%B3%E5%BE%A1%E8%A6%BD/0789#.E5.BD.8C.E8.AB.BE.E5.9C.8B.E3.80.81.E5.BD.8C.E8.87.A3.E5.9C.8B 789] and [https://zh.wikisource.org/wiki/%E5%A4%AA%E5%B9%B3%E5%BE%A1%E8%A6%BD/0971#.E6.AA.B3.E6.A6.94 971];&lt;br/&gt;
 - the ''Huányǔjì'' (寰宇記) &lt;span style=&quot;color:#aaa&quot;&gt;(apparently referring to the ''Universal Geography of the Taiping Era (976-983)'' or ''Tàipínghuányǔjì'' (太平寰宇记))&lt;/span&gt; in scroll 177 &lt;span style=&quot;color:#aaa&quot;&gt;(which does not presently seem to exist in online copies such as [https://zh.wikisource.org/zh-hant/%E5%A4%AA%E5%B9%B3%E5%AF%B0%E5%AE%87%E8%A8%98 that at Wikisource] or [http://ctext.org/wiki.pl?if=gb&amp;res=637263 that at ctext.org])&lt;/span&gt;;&lt;br/&gt;
 - the ''Cèfǔ'' (冊府) &lt;span style=&quot;color:#aaa&quot;&gt;(apparently referring to [https://en.wikipedia.org/wiki/Cefu_Yuangui 冊府元龜])&lt;/span&gt; in scrolls [http://ctext.org/wiki.pl?if=gb&amp;chapter=657319 965] and [http://ctext.org/wiki.pl?if=gb&amp;chapter=142837 972];&lt;br/&gt;
 - the ''Huáyítú'' (華夷圖) &lt;span style=&quot;color:#aaa&quot;&gt;(apparently referring to ''[https://en.wikipedia.org/wiki/Sihai_Huayi_Zongtu Complete Map of the Four Seas, China, and the Barbarians]'')&lt;/span&gt;;&lt;br/&gt;
 - the ''Xīntángshū'' (新唐書) in [https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7222%E4%B8%8B#.E9.A9.83 the final portion of scroll 222];&lt;br/&gt;
 - in ''Tōngkǎo'' (通考) in scroll 330;&lt;br/&gt;
 - in the ''Dúshǐjì'' (讀史紀) in scroll 119;&lt;br/&gt;
 - and finally in the ''Xùtōngzhì'' (續通志) in scroll 640.&lt;br/&gt;
&lt;/ref&gt;).
|-
|南至南海，去昆侖三日程。
|It adjoins the '''Southern Ocean''' (南海; ie. South China Sea / Gulf of Thailand / Java Sea region) to the south, and it is three days' journey to '''Kūnlún''' (昆侖; ie. Eastern Indonesia circa the Moluccas&lt;ref&gt;There is a [https://books.google.com.vn/books?id=-AdJrE5RDvYC&amp;pg=PP2&amp;lpg=PP1&amp;focus=viewport&amp;hl=en#v=onepage&amp;q&amp;f=false discussion on p153+ of ''Between East and West: The Moluccas and the Traffic in Spices up to the Arrival of Europeans''] (2003) and [http://baike.baidu.com/view/7804007.htm here on Baidu Baike]. As evidence appears reasonable, I also [https://en.wikipedia.org/wiki/Kunlun#Ancient added this cited identification to Wikipedia].&lt;/ref&gt;).
|-
|中間又管模迦羅、幹泥、禮強子等族類五部落。
|In between lie '''Guǎnmójiāluó''' (管模迦羅&lt;ref&gt;Certainly a transliteration from a foreign language.&lt;/ref&gt;), '''Gànní''' (幹泥&lt;ref&gt;Certainly a transliteration from a foreign language.&lt;/ref&gt;), '''Lǐqiángzǐ''' (禮強子&lt;ref&gt;Certainly a transliteration from a foreign language.&lt;/ref&gt;) and another five kinds of tribes.
|-
|越禮城在永昌北，管長傍、藤彎。
|'''Yuè​lǐ City​''' (越禮城; lit. 'city of etiquette breaking') is located to the north of '''Yǒng​chāng​''' (永昌; ie. modern Baoshan), and is administratively responsible for '''Zhǎng​bàng​''' (長傍; lit. 'Near growth') and '''Téng​wān​''' (藤彎; lit. 'vine (or rattan) bend (or windy road?)').
|}

===镇西节度 （Zhènxī jié dù)===
[[File:Western_Nanzhao.png|thumb|373x373px|Map of Western Nanzhao and Northern Burma:]]
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 6: Part 12 — 镇西节度 （Zhènxī jié dù）
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|長傍城，三面高山，臨祿卑{曰鬥}江。
|'''Zhǎng​bàng​ City''' (長傍城)&lt;ref&gt;Likely modern day Chipwi (ချီဖွေ) in Myanmar.&lt;/ref&gt; is surrounded by high mountains on three sides and faces the  '''Lùbēi River''' (禄卑{曰鬥}江&lt;ref&gt;There appears to be no established reading of the character {曰鬥}, comprised of a 'speech' notion (曰/''yuē​'') and a 'fight' notion (鬥/''dòu''). Therefore I have translated it in a general semantic sense.​&lt;/ref&gt;).
|-
|藤灣城南至磨些樂城，西南有羅君尋城。
|South of '''Téng​wān City​''' (藤彎城)&lt;ref&gt;This is the previous name for Tengchong (腾冲) which carries the same name today. Despite the document being the first record of the name. It appears it was compiled over time and the sections on the cities were of older times. &lt;/ref&gt; one arrives at '''Mó​xiē​yuè​ City​''' (磨些樂城)&lt;ref&gt;This is Muse (မူဆယ်) of modern day Myanmar.&lt;/ref&gt;, southwest of which is  '''Luó​jūn​xún​ City''' (羅君尋城; lit. 'City of Gathered Gentleman').&lt;ref&gt;In the vicinity of Mangxingcun (芒杏村)&lt;/ref&gt;
|-
|又西至柯城，渡水郎陽川，直南過山至押西城。
|Further west lies '''Kē​chéng​'''&lt;ref&gt;This is likely Xinchengxiang (新城乡) on the northern river side of the Jiucheng, Yingjiang County (旧城镇).&lt;/ref&gt; (柯城; lit. 'City of Branches'&lt;ref&gt;Dictionaries suggest this may have a more general meaning, later meanings include axe-handles, such that rather than branches, branches/sticks/elongated wooden objects would perhaps be a more accurate assumption.&lt;/ref&gt;), from which one may cross the river to '''Láng​yáng​chuān​''' (郎陽川; lit. 'Sunny (East-facing) River-plain (Lands) of the Official'), directly south of which and across the mountains lies '''Yā​xī​chéng'''&lt;ref&gt;This was also an old name. Fang Guo Yu explains this, the page has to be found first to clarify. &lt;/ref&gt;​ (押西城; lit. 'City Protecting the West').
|-
|又南至首外川，又西至茫部落，又西至鹽井，又西至拔熬河。
|Further south again lies '''Shǒu​wài​chuān​''' (首外川), west of which are the '''Máng​bù​luò'''&lt;ref&gt;The current centre of the Dehong Dai and Jingpo Autonomous Prefecture. The city centre is known as 芒市. &lt;/ref&gt;​ (茫部落; lit. 'Mang&lt;ref&gt;Meaning vast, indistinct or mixed, though this is likely to be a phonetic import and as such the character choice potentially not so semantically loaded.&lt;/ref&gt; Tribe'), west of whom lies '''Yán​jǐng​''' (鹽井; lit. 'Salt Well'), west of which is the '''Bá​āo​hé​ River'''&lt;ref&gt;On conjecture, it appears to be the Mangshi or the Ruili River.&lt;/ref&gt; (拔熬河; lit. 'Boiling River'&lt;ref&gt;Suggesting a smaller river whose rough flow features many rapids. Larger, well established rivers tend to have less turbulence.&lt;/ref&gt;).
|-
|麗水城、尋傳大川城，在水東。
|'''Lí​shuǐ​ City'''&lt;ref&gt;The Eastern Bank of the City of Myitkhina (မြစ်ကြီးနား)&lt;/ref&gt; (麗水城; lit. 'City of (the River of?) Beautiful Waters') also known as '''Xún​zhuàn​dà​chuān​ City''' (尋傳大川城; lit. 'Search Relay-station Great River-plain City') are located east of the river.
|-
|從上郎坪北裏眉羅苴鹽井，又至安西城，直北至小婆羅門國。
|From '''Shàng​láng​píng​''' (上郎坪) northward is '''Méi​luó​jū'''&lt;ref&gt;It's in the broad vicinity of Akauktaung between the two rivers settled to the east of the river in the west.  &lt;/ref&gt;​ (眉羅苴; lit. 'Hillcrest Hemp Gathering')&lt;ref&gt;The identification of this place name is based upon a recurrence of the toponym two sentences below.&lt;/ref&gt; '''Yán​jǐng​''' (鹽井; lit. 'Salt Well'), one then arrives at '''Ān​xī City'''&lt;ref&gt;Located in present day Mogaung (မိုးကောင်း) in Myanmar.&lt;/ref&gt;​ (安西城; lit. 'City of the Peaceful West'), north of which lies the '''Little Brahman Country'''&lt;ref&gt;In the Hukawng Valley region likely strengthened with trade from the various river and rock passes. &lt;/ref&gt; (小婆羅門國; ie. Hukawng Valley&lt;ref&gt;See for example [http://baike.baidu.com/view/5446155.htm Baidu Baike entry].&lt;/ref&gt;).
|-
|東有寶山城，又西渡麗水至金寶城。
|The the east lies '''Bǎo​shān​ City'''&lt;ref&gt;Present day Xima (昔马镇) in Yunnan.&lt;/ref&gt; (寶山城). Crossing the '''Lí​shuǐ​''' (麗水; lit. '(River of) Beautiful Waters') and moving further westward one arrives at '''Jīn​bǎo​ City'''&lt;ref&gt;This is the west side of Myitkhina (မြစ်ကြီးနား).&lt;/ref&gt; (金寶城; lit. 'Golden Treasure City').
|-
|眉羅苴西南有金生城。
|Southwest of '''Méi​luó​jū​''' (眉羅苴; lit. 'Hillcrest Hemp Gathering') lies '''Jīn​shēng​ City'''&lt;ref&gt;Likely Sinbo (ဆင်ဘို) in Myanmar. &lt;/ref&gt; (金生城; lit. 'Gold-birth City').
|-
|從金寶城北牟郎城渡麗水，至金寶城。
|From '''Jīn​bǎo​ City''' (金寶城; lit. 'Golden Treasure City') northward one arrives at '''Móu​láng​chéng'''&lt;ref&gt;Around the vicinity of Maingnar district north of Myitkhina on the east bank. &lt;/ref&gt;​ (牟郎城) after crossing the '''Lí​shuǐ​''' (麗水; lit. '(River of) Beautiful Waters'), which flows toward '''Jīn​bǎo​ City''' (金寶城).
|-
|從金寶城西至道吉川，東北至門波城，西北至廣蕩城，接吐蕃界。
|Westward of '''Jīn​bǎo​ City''' (金寶城; lit. 'Golden Treasure City') one arrives at '''Dào​jí​chuān​''' (道吉川; lit. 'Daoji&lt;ref&gt;One of the 道 tribes of which four were mentioned in 新唐书 (道林，道双 ，道瓮，道勿 this tribe is unique for only being mentioned in this document. Since all 道 tribes were managed by Pyu and the little Brahmin kingdom is bordered by Pyu, it is very plausible this valley is under Pyu control. &lt;/ref&gt; River Plain'), northeast of which is '''Mén​bō​ City'''&lt;ref&gt;Modern day Sadon (ဆဒုံး) in Myanmar.&lt;/ref&gt; (門波城), northwest of which is '''Guǎng​dàng​ City'''&lt;ref&gt;Likely referring to Putao (ပူတာအို) in the north of the triangle region of Myanmar.&lt;/ref&gt; (廣蕩城), which borders '''Tubo Tibet''' (吐蕃).
|-
|北對雪山，所管部落與鎮西城同。
|The north faces snowy mountains, ... '''Zhèn​xī​ City'''&lt;ref&gt;The old name for Lishui according to Fang Guo Yu. &lt;/ref&gt; (鎮西城; lit. 'Town-west City').
|-
|鎮西城南至蒼望城，臨麗水，東北至彌城，西北至麗水渡。
|South of '''Zhèn​xī​ City''' (鎮西城; lit. 'Town-west City') one arrives at '''Cāng​wàng​ City'''&lt;ref&gt;Located in modern day Bhamo (ဗန်းမော်) in Myanmar.&lt;/ref&gt; (蒼望城; lit. 'Dark-Bluegreen Moon City'&lt;ref&gt;If indeed there is a semantic intention here, which is definitely in question as it is probably just a foreign language transliteration.&lt;/ref&gt;), overlooking the '''Lí​shuǐ​''' (麗水; lit. '(River of) Beautiful Waters'), northeast of which one arrives at '''Mí​ City'''&lt;ref&gt;Modern day Zhanxizhen (盏西镇) in Yunnan.&lt;/ref&gt; (彌城; lit. 'Full City'), further northwest of which one arrives at '''The Crossing of the Lí​shuǐ​''' (麗水渡; lit. '(River of) Beautiful Waters Crossing').
|-
|麗水渡而南至祁鮮山，山西有神龍河柵。
|South of '''The Crossing of the Lí​shuǐ​''' (麗水渡; lit. '(River of) Beautiful Waters Crossing') lies the '''Qí​xiǎn​ Mountains'''&lt;ref&gt;Modern day Gangaw Range jut west Katha (ကသာ) in Myanmar.&lt;/ref&gt; (祁鮮山; lit. 'Vast  Unwilting Mountains'), west of which is the '''Shenlong River Stockade'''&lt;ref&gt;Located Northwest of Tagaung on the Meza River. This was likely maintained through the cooperation of the Luoxing barbarians who according to the Dehua Stele submitted to Geluofeng willingly and cooperated with him. Otherwise, a valley establishment was rare for Nanzhao to commit to especially in lieu of malaria.&lt;/ref&gt; (神龍河柵&lt;ref&gt;Possibly implying some form of military garrison/political demarcation.&lt;/ref&gt;).
|-
|祁鮮已西，即裸形蠻也。
|West of the '''Qí​xiǎn​ (Mountains)''' (祁鮮(山); lit. 'Vast Unwilting (Mountains)') are the '''Luǒ​xíng​ Barbarians''' (裸形蠻; lit. 'Naked Barbarians').
|-
|管摩零都督城在山上，自尋傳、祁鮮已往，悉有瘴毒，地平如砥，冬草木不枯，日從草際沒。
|​'''Mó​líng​ Military Garrison City'''&lt;ref&gt;Within the area of Maingmu in Myanmar. &lt;/ref&gt; (管摩零都督城) is in the mountains, from '''Xún​zhuàn​''' (尋傳; lit. 'Search Relay-station') one enters the '''Qí​xiǎn​ (Mountains)''' (祁鮮(山)) which are full of malaria, the flat earth is slippery as a whetstone, the plants do not die back in any season, and the sun is drowned-out by foliage.
|-
|諸城鎮官懼瘴癘，或越在他處，不親視事。
|All of the town and city governors fear tropical disease, for if it invades their quarters, no family is spared.&lt;ref&gt;This last portion (&quot;no family is spared&quot;) is incorrect and translated as a gloss as I cannot understand the precise semantics.&lt;/ref&gt;
|-
|南詔特於摩零山上築城，置腹心，理尋傳、長傍、摩零、金、彌城等五道事雲。
|'''Nán​zhào​''' (南詔) has a unique fortification in the '''Mó​líng​ Mountains''' (摩零山) ...
|-
|凡管金齒、漆齒、繡腳、繡面、雕題、僧耆等十余部落。
|It controls some ten tribes including the '''Golden Tooth''' (金齒), '''Painted Tooth''' (漆齒), '''Tattoo-Foot''' (繡腳), '''Tattoo-Face''' (繡面), '''Diāo​tí​''' (雕題; lit. 'Carver'), '''Sēng​qí​''' (僧耆; lit. 'Monkly Elder') and others.
|}

{{BookCat}}</text>
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  </page>
  <page>
    <title>Manshu/Chapter 10</title>
    <ns>0</ns>
    <id>464547</id>
    <revision>
      <id>4636958</id>
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      <timestamp>2026-05-22T05:24:09Z</timestamp>
      <contributor>
        <username>Taitesena</username>
        <id>3485636</id>
      </contributor>
      <comment>/* The country of Biāo (驃國) */</comment>
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      <text bytes="41422" sha1="mx9q6yzzq2qfjsj507j9p2rdaaou2mo" xml:space="preserve">They {{incomplete translation}}
{{translation header
 | language = zh
 | original = 
 | title    = [[../]]
 | author   = Fan Chuo
 | override_editor   = Palace Museum Library
 | translator = Walter Stanish and Taitesena
 | section  = Chapter 10
 | previous = [[../Chapter 9/]]
 | next     =
 | notes    = '''Manshu''' (蠻書), written by [[Author:Fan Chuo|Fan Chuo]] in the 9th century, is a Chinese historical text regarding the geopolitics of southwest China, particularly Nanzhao. It is an important historical source for the period. This translation is based upon a digitized version of the recompiled 1774 movable type edition edited by the 武英 (Palace Museum Library).
}}

[[zh:蛮书/卷10]]

==Translator's note==
The translation of this section has begun but is incomplete. The sections are of my own creation.


Taitesena's Notes:

Will need to work with more reference materials and citations and get better at using QGIS for map work and wikimedia. The translation so far is sufficient and the Tubo Dynasty appendix will be translated later.

==Translation==
[[File:Western_Nanzhao.png|thumb|525x525px|Map of Western Nanzhao and Northern Burma:]]

===The countries of ''Mínuò'' (彌諾國) and ''Míchén'' (彌臣國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 1 {{mdash}} The countries of ''Mínuò'' (彌諾) and ''Míchén'' (彌臣)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|彌諾國、彌臣國，皆邊海國也。
|The countries of '''Mínuò''' (彌諾國) and '''Míchén''' (彌臣國) both lie on a lake.&lt;ref&gt;Many authors think '''Michen''' lies on the sea, but it said to border the Little Brahmin Kingdom situated north of Anxi. Indawgyi lake's location supports '''Michen'''&lt;nowiki/&gt;'s placement north where Persian traders and merchants record a similar sounding name. &lt;/ref&gt;
|-
|呼其君長為壽。
|They call their leaders shòu(MC: '''DzyuwH''').&lt;ref&gt;The Middle Chinese word '''dzyuwh''' has cognates in [[Mizo language]] and the [[Kadu lagnauge]]. Among the [[Zo people]] their name is listed by Luce phonetically in every dialect. [[Gordon Luce]] transcribes the phonetics of the Zo autonym as follows, Khongjai: ʒəu3, Tiddim: Zəu1, Lushai: Zo / Zou1, Hualngo: zau1, Kualsim: Zəu1, Haka: Zəu6, Asho: ăʃəu6 and Other: chou4. With Minuo Kingdom attested by scholars to be of the Chin people, this uncanny phonetic similarity and distirbution support this idea.  In Kadu, '''phūceū''' refers to chief as native word. In Mizo, other cognates such as '''thu''' means &quot;to rule&quot; and '''hotu''' means '''headman''' of a village.&lt;/ref&gt;&lt;ref&gt;Note that the character &quot;壽&quot; likely is a phonetic translation of a native title. This word is rarely used unless its for ceremonial purposes.&lt;/ref&gt;
|-
|彌諾面白而長，彌臣面黑而短，性恭謹，每與人語，向前一步一拜。
|The people of '''Mínuò''' (彌諾國) have white and long faces, (whereas) the people of '''Míchén''' (彌臣國) have dark and short faces; (both peoples) have a courteous and respesctful character, whomever they speak with, they step forward one pace and bow once.
|-
|國無城郭。
|The countries have no city walls.
|-
|彌諾王所居屋之中大柱，雕刻為文，飾以金銀。
|The '''King of Mínuò''' (彌諾王) at his residence in the centre has a large column-shaped object&lt;ref&gt;The most obvious translation is pillar, but I suggest that with tribal histories of the Zo people, it could also be ancestral pillars or structures and so something broader.&lt;/ref&gt;, engraved with patterns and decorated in gold and silver.
|-
|彌臣王以木柵居海際水中，以石獅子為屋四足，仍以板蓋，悉用香木。
|The '''King of Míchén''' (彌臣王) uses a wooden palisades as his dwelling in the lake's shore,&lt;ref&gt;Possibly referring to a stilted house.&lt;/ref&gt; which has a stone guardian lion&lt;ref&gt;Implying stone.&lt;/ref&gt; as four feets of the house. Yet they are concealed with planks completely using fragrant wood.&lt;ref&gt;Probably teak.&lt;/ref&gt;
|-
|百姓皆樓居，披婆羅籠，男女多好音樂。
|The common people all dwell in houses on stilts and wear (Brahmin) silkcotton cages [garments].&lt;ref&gt;The term Sha-la refers to a tree which the Michen and Minuo people cultivate to make clothes. Long means to veil or shroud closer to a verb than a noun. As a noun it means cages of bamboo. The first character apparently got corrupted. What originally would have been a Brahmin fabric with 婆罗笼 became 娑罗笼 due to textual corruption and this latter term is now the dominant term. It is still retained by the Tai tribe who wear the Mang Barbarian style of 5 colours in their skirts.

In Anxi, there is a large population of a tribe called 僧耆 '''Sēngqí''' (septenerian monks) which borders the little Brahmin Kingdom. This supports the view that '''Michen''' is likely on the Indawgyi lake than the ocean. &lt;/ref&gt; Men and women greatly like music.
|-
|樓兩頭置鼓，飲酒即擊鼓，男子攜手樓中舞蹈為樂。
|Drums are placed at both ends of the building. Upon drinking they beat drums. The men join hands in the centre of the building and dance for enjoyment.
|-
|在蠻永昌城西南六十日程。
|From the barbarian town of '''Yǒng​chāng​ City''' (永昌城) it is sixty days' journey to the southwest.&lt;ref&gt;Likely the Chindwin corridor of the Kale and Kabaw Valleys. '''Michen''' might stretch from Indawgyi lake to the Chindwin covergence with the Irrawaddy. This placing is consistent with the Xin Tang Shu arguing that it is West of Pyu. &lt;/ref&gt;
|-
|大和九年曾破其國，劫金銀，擄其族三二千人，配麗水淘金。
|In the ninth year of the ''Dahe/Taihe'' reign (2nd February 835) those countries were once defeated [by the Yunnan barbarians], gold and silver were plundered, and two to three thousand prisoners were taken to '''Lí​shuǐ​''' (麗水) to pan for gold.
|}
[[File:中国云南西双版纳1380傣历年_(253863837).jpeg|thumb|娑罗笼 (Suō luó lóng) dresses still retained by the Dai tribe of Yunnan.]]

===The country of ''Biāo'' (驃國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 2 {{mdash}} The country of ''Biāo'' (驃國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|驃國，在蠻永昌城南七十五日程，閣羅鳳所通也。
|The country of '''Biāo''' (驃國) is 75 days' journey south of the barbarian town of '''Yǒng​chāng​''' (永昌)&lt;ref&gt;Likely referencing the capital which at this time would have been ''Śrī Kṣetra'' based on this geography. This means that Minuo and Michen are both northwest of ''Śrī Kṣetra'' as they are 60 stages southwest to the 90 stages south of ''Śrī Kṣetra.'' &lt;/ref&gt;'''. '''
'''Gé​luó​fèng​''' (閣羅鳳) began communication with it.
|-
|其國用銀錢，以青磚為圓城，周行一日程。
|The country uses silver money, green-blue bricks for its circular city [walls], which takes one day stage to encircle by walking.
|-
|百姓盡在城內，有十二門。
|Ordinary citizens completely dwell inside the city, and there are twelve gates.
|-
|當國王所居門前有一大像，露坐高百余尺，白如霜雪。
|At the king's residence in front of the gate is a great statue, which is seated in the open. It is over 100 ''chǐ​'' (ie. 33 meters) in height, white as frost and snow.
|-
|俗尚廉恥，人性和善少言，重佛法，域中並無宰殺。
|Popular [traditional] customs are integrity and honour. The people are of a gentle nature and speak little. They attach importance to Buddhist law, and moreover, universally do not slaughter or butcher.
|-
|又多推步天文。
|They are furthermore skilled in calculating astrology.
|-
|若有兩相訴訟者，王即令焚香向大像，思惟其非，便各引退。
|If there is a case of a two-sided lawsuit, the king orders incense to burn in front of the statue. They reflect their faults as each withdraw [the case].
|-
|其或有災疫及不安穩之事，王亦焚香對大像，悔過自責。
|If there is calamity, plague, and unsteady events, the king also burns incense in front of the statue, repenting and blaming himself.
|-
|男子多衣白氈，婦人當頂為高髻，以金銀真珠為飾，著青婆羅裙，又披羅緞，行必持扇。
|Men mostly wear clothing of white felt. Married women undertake at the top of the head a high topknot. Gold, silver and pearls are used for decoration. They attach blue-gren (brahmin) silkcotton skirts, as well as drape gauze satin. Walking, they must hold fans.
|-
|貴家婦，皆三人五人在傍持扇。
|Elder family noblewomen always have three to five people at their side holding fans.
|-
|有移信使到蠻界河賧，則以江豬、白氈及琉璃、罌為貿易（案：「罌」原本作「盟」，「貿易」原本作「加」，今從《新唐書·驃國傳》改正）。
|There are couriers going to the barbarian border of '''Hé dàn (河賧)''', they bring porpoises, white felt and coloured stones &lt;ref&gt;Historically referring to a blue translucent stone thought to know be lapis lazuli.&lt;/ref&gt; in small-mouthed jars for trade.
&lt;span style=&quot;color:#f00&quot;&gt;（案：「罌」原本作「盟」，「貿易」原本作「加」，今從《新唐書·驃國傳》改正）。&lt;/span&gt;
|-
|與波斯及婆羅門鄰接，西去舍利城二十日程。
|It is adjacent with Persia and India.  It is 20 day stages westward to '''Sheli''' (舍利城; lit. 'city of post-cremation relics'; Vaisali, or the Arakanese Waithali of the same name&lt;ref&gt;Based on history and the location claimed, this appears to be Waithali, the adopted name of Vaishali, Vesali or Vaiśālī in the modern Arakan State. The original Vaishali is in Patna Bihar, a historically Buddhist stronghold. Fan Chuo likely equated this to Buddhist text not understanding the polity governing there held the same name. 

[http://www.world10k.com/blog/?p=1305 An external site discusses the toponym's appearance in a range of ancient Chinese texts], but fails to draw any conclusions. From a religious perspective it seems that Buddhism may have been responsible for the toponym's etymology, and this would strongly suggest a city in the Uttar Pradesh region. Given the specific reference to this single city it is likely a large city rather than a small town, which would tend to discount the place of the historical Buddha's death in favour of nearby large cities. The most likely contender seems to be Varanasi. Another option is Patna, however it does not seem to support the toponym's etymology.&lt;/ref&gt;).
|-
|據《佛經》：「舍利城，中天竺國也。近城有沙山，不生草木」。
|According to ''Buddhist Scripture'', &quot;'''Shelicheng''' (舍利城; lit. 'city of post-cremation relics') is in the middle of India. Near the city lies the '''Sand Mountains''' (沙山), upon which trees and grasses do not grow.&quot;
|-
|《恒河經》雲：「沙山中過」，然則驃國疑東天竺也。
|According to the ''Héng​ Hé​ Jīng​'' (恆河經; lit. 'Ganges River Scripture'), &quot;Crossing the Sandy Mountains&quot;. So thus '''Biào​ Guó''' (驃國; lit. 'The Country of the White Horse') is suspected to be east of India.&quot;
|-
|蠻賊大和六年劫掠驃國，虜其眾三幹余人，隸配柘東，令之自給。
|In the 6th year of the ''Dahe'' reign (ie. ~832), the barbarians bandits plundered '''Biào​ Guó''' (驃國; lit. 'The Country of the White Horse'), capturing their masses of 3000 people, subordinating them to join '''Tuodong''' (柘東; Kunming between the Panlong River and North Bank of Dianchi Lake) and ordered to be self-sufficient.
|-
|今子孫亦食魚蟲之類，是其種末也。
|To this day, their children and grandchildren [descendants] still consume fish, insects and alike. This is an offshoot of the same people.
|-
|鹹通四年正月六日寅時，有一胡僧裸形，手持一仗，束白絹，進退為步，在安南羅城南面。
|In the early daylight hours on the '''sixth day of the first month of the lunar year (28 January)''', in the '''4th year of the ''Xiantong'' reign (863 A.D)''', a naked monk from the western regions, holding in his hand a weapon and bound with white silk walked back and forth toward the city wall south of '''Ān​nán''' (安南; ie. Hanoi).
|-
|本使蔡襲當時以弓飛箭，當胸中此設法胡僧，眾蠻扶舁歸營幕。
|'''Comissioner Cài Xí (本使蔡襲)''', at once grabbed a bow and fired an arrow at the centre of the chest of this monk from the western regions seeking to do something. Masses of barbarians aided by carrying [him on their shoulder] back to the barracks tents. 
|-
|城內將士無不鼓噪。
|Inside the fortress, military officers invariably made commotion [by beating the drums of war while shouting loudly at the enemy]
|}

===The country of ''Kūnlún'' (昆侖國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 3 {{mdash}} The country of ''Kūnlún'' (昆侖國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|昆侖國，正北去蠻界西洱河八十一日程。
|The '''State of'''  '''Kūnlún (昆侖國)'''&lt;ref&gt;This location is disputed. It is either the Salween River Delta or further South to the port city of Thagara. I nominate the former. This entry in the '''[https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7222%E4%B8%8B#%E9%A9%83 New Book of Tang (新唐书)]''' states that the Kunlun Kingdom's rivers and plains are larger than Michen. If Michen is in the north by Indawgyi lake and stretches down to the Chindwin joining the Irrawaddy, then this placement makes sense for the Book of Tang to record the relative placement of kingdoms. &lt;/ref&gt; due north to the barbarian border of the '''Xīěr River (西洱河)''' is 81 day stages.
|-
|出青木香、檀香、紫檀香、檳榔、琉璃、水精、蠡坯等諸香藥、珍寶、犀牛等。
|It exports elephants, green fragrant wood, sandalwood, purple sandlewood, areca, glazed pearls, crystals, seashell cups and other gragrant medicine, jewels, rhinocerous horns, etc.
|-
|蠻賊曾將軍馬攻之，被昆侖國開路放進軍後，鑿其路通江，決水掩浸，進退無計。
|Barbarian bandits once led troops and cavalry to attack. The '''State of''' '''Kūnlún (昆侖國)''' opened the route allowing the army to move forward. They chiselled a river to connect to their road. The water's breach covered and submerged. They lacked a plan to advance or retreat.
|-
|餓死者萬余，不死者昆侖去其右腕放回。
|Ten thousand starved to death, the ones who didn't die die, the '''Kūnlún (昆侖)''' discarded their right forearm and allowed them to return.
|}

=== The Greater Qín Brahmin Country (大秦婆羅門國) ===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 4 {{mdash}} The Greater Qín Brahmin Country (大秦婆羅門國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|大秦婆羅門國，界永昌北，與彌諾國江西正東（案：此句疑有脫誤）安西城樓接界，東去蠻陽苴咩城四十日程。
|The '''Greater Qín Brahmin Country (大秦婆羅門國)'''&lt;ref&gt;'''NAME DISCUSSION:'''

The name 大秦 (colloquially meaning &quot;Roman&quot; or &quot;Byzantine&quot;) is used in the Nazhao Dehua Stele. The paragraph on the 寻传 mentions that west of them is 大秦. This probably meant this kingdom. The reason they use this name is likely due to the silk route &quot;ending&quot; at the Byzantine territory and so silk route affiliations carry this name. 

Zhao RuKuou's [https://storymaps.arcgis.com/stories/39bce63e4e0642d3abce6c24db470760 諸蕃志] mentions that the kings of India were elected by 大秦 likely meaning that they were chosen for the silk route where they could tax the merchants passing through. 大秦 is also mentioned as Byzantine.&lt;/ref&gt;&lt;ref&gt;'''STATE IDENTIFICATION''':

This is strongly suggested to be the eastern autonomous region of Kamarupa. Kamarupa was under the mlecchha dynasty during the 7-10th centuries. Lahiri in [https://www.scribd.com/document/905970705/Pre-Ahom-Assam-by-Nayanjot-Lahiri Pre-Ahom Assam] (p.78) mentions that the mlecchha dynasty was decentralized. The Tezpur Rock Inscription records a settling of waterway dispute. Sucitta a vassal king of Harjaravarman held his own army with judicial powers and levying rights of men and taxes. Below Sucitta was another subordinate office holder Silakuttakavaleya. This would explain why Jia Dan in his document [https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7043%E4%B8%8B &quot;Routes Leading Abroad from China&quot; in the &quot;New Book of Tang]&quot; states that it is another 300''li'' to enter Kamarupa from the Daqin Brahmin territory （西渡彌諾江水，千里至大秦婆羅門國。又西渡大嶺，三百里至東天竺北界箇沒盧國。）. The Mikir-Rengma hills divides Tezpur the Kamarupa capital from the eastern part of the country. This would evidently suggest that Daqin is an autonomous area of eastern Kamarupa.&lt;/ref&gt;  lies on the northern border of Yǒngchāng and west of the '''Mínuò Kingdom's''' River. Due east is the border of the '''Anxi (安西)''' Gatehouse/ Fortress. Going East to the Barbarian city of '''Yángjūmiē (陽苴咩)''' takes 40-day stages.
|-
|蠻王善之，街來其國（案：此八字文不相屬，疑有脫誤）。
|The Barbarian King is friendly to them, markets and fairs come to that country. (Editorial note: “These eight characters do not connect coherently in meaning, and the passage is suspected to contain omissions or textual corruption.”)&lt;ref&gt;The Omission is likely: 市 which would make it undoubted that its referring to commercials markets and fairs. &lt;/ref&gt;
|}

===The 'Lesser Brahman' Country (小婆羅門)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 5 {{mdash}} The 'Lesser Brahman' Country (小婆羅門)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|小婆羅門，與驃國及彌臣國接界，在永昌北七十四日程。
|The '''Lesser Brahmin Country (小婆羅門国)''' &lt;ref&gt;In earlier chapters we learn that this kingdom is north of Anxi in present day Mogaung. Hence, this kingdom is likely situated in the Hukawng Valley. &lt;/ref&gt; borders the State of '''Pyu''' '''(驃國)''' and '''Michen (彌臣國)'''. It is 74 day stages north of '''Yǒngchāng (昌北).'''&lt;ref&gt;I suspect an omission of 西，as the Hukawng valley is northwest of Yongchang (Baoshan)&lt;/ref&gt;
|-
|俗不食牛肉，預知身後事。
|As a custom, they do not consume cattle meat.&lt;ref&gt;This seems to indicate more orthodox Hindu traditions rather than Buddhist ones. This means that the 僧耆 (septenarian monks) in Anxi are likely Indian monks and hermits living in the Hukawng Valley area. They are also treated as a tribe and recruited for war as mentioned in the siege of Songping extracts. Likely an Indian tribe in the northwest with vague Hindu traditions and monks among them.&lt;/ref&gt; They have beforehand knowledge of what happens after life (belief in an afterlife).   
|-
|出見齒、&lt;蟲葛&gt;、越諾。
|They export cowry shells, ivory, white wax and '''Yuènuò (越諾).'''&lt;ref&gt;A type of cloth of fabric which comes from Persia and Afghanistan. This indicates that the kingdom was along the silk route at the time.The other products are also not locally produced in the Hukawng region suggesting that it grew as a trade outpost of the 大秦婆罗门 (Greater Qin Brahmin Kingdom) who managed the trade route. Jia Dan did not mention this kingdom at all in his routes suggesting that this outpost grew in the decades after his manuscript. Jia Dan's routes go straight from Anxi to Daqin.  &lt;/ref&gt;
|-
|其大耳國往來，蠻夷善之，信其國。
|They have relations with '''Big Ear Kingdom''' (大耳国)&lt;ref&gt;Gordon Luce believes this to be the Kadu who were known for large ear piercings which would stretch out their lobes. &lt;/ref&gt;, the barbarian king is friendly to them and communicates with that country.&lt;ref&gt;Can also be read as: The Barbarian king is friendly to them and places trust in that country. &lt;/ref&gt;
|}

===The 'Midnight' Country (夜半國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 6 {{mdash}} The 'Midnight' Country (夜半國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|夜半國，在蠻界蒼望城，東北隔麗水城。
|The State of Yeban lies northeast of the barbarian border city of '''Cāngwàng''' '''(蒼望)''' across the '''Lìshuǐ''' '''City's''' '''(麗水城)''' river plains.&lt;ref&gt;They are situated within Nanzhao's own territory. They are likely a hill tribe who are geographically fortified.&lt;/ref&gt;
|-
|其部落婦人唯與鬼通能知吉兇禍福本土君長崇信。
|That tribe's women are able to communicate/ connect with spirits to know auspicious and terrible fortunes and misfortunes. The local chieftains venerate them.&lt;ref&gt;Female fortune tellers and divination is a common practiced among the Kachin and Zo people. It was separated from the religious aspect of sacrifice and feasting but was important to identify spirits who caused sickness and illness in people. &lt;/ref&gt;
|-
|蠻夷往往以金購之，要知善惡。
|Barbarians often pay with gold, wanting to know good and evil (outcomes).
|-
|昆明、牂牁界接麗水，相近蠻賊曾攻不得，至今銜恨之。
|The '''Kūnmíng''' '''(昆明)''' and '''Zānggē''' '''(牂牁)''' are close to the border of '''Lìshuǐ (麗水)'''. Barbarian badits once attacked and failed. To this day, they bear resentment.
|-
|昆明、牂牁，本使臣蔡襲嘗奏請分布軍馬，從黔府路入（案：此條之首，當有脫文）。
|With regards to '''Kūnmíng''' '''(昆明)''' and '''Zānggē''' '''(牂牁), your servant, commissioner Cài Xí (本使臣蔡袭)''' attempted a formal request to distribute (soldiers) and war horses to enter into route from the ''Qián'' prefecture capital. 
|}

===The Country of the Queen (女王國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 7 {{mdash}} The Country of the Queen (女王國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|女王國，去蠻界鎮南節度三十余日程。
|The '''Queen's Kingdom''' '''(女王國)'''&lt;ref&gt;This is likely the Mon Kingdom of Haripuñjaya. It's founder was a legendary queen Jamadevi around 750AD. Haripuñjaya is situated in modern day '''Lamphun (เมืองลำพูน)''' and was largely a valley settlement which expanded to a significant territory of northwest Thailand. &lt;/ref&gt; to the barbarian border '''Jiédù (節度) of''' '''Zhènnán (鎮南)''' is over thirty day stages.
|-
|其國去驩州一十日程，往往與驩州百姓交易。
|That country to '''Huānzhōu (驩州)''' is ten day stages. Ordinary citizens regularly trade and make business.
|-
|蠻賊曾將二萬人伐其國，被女王藥箭射之，十不存一，蠻賊乃回。
|Barbarian bandits one led nearly twenty thousand people to defeat that country. The queen's poisoned arrows were shot at them and not even a tenth remained. The barbarian bandits thus returned.
|}

===The countries of ''Water Zhenla'' (水真蠟國) and ''Land Zhenla'' (陸真蠟國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 8 {{mdash}} The countries of ''Water Zhenla'' (水真蠟國) and ''Land Zhenla'' (陸真蠟國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|水真蠟國、陸真蠟國，與蠻鎮南相接，蠻賊曾領馬軍到海畔，見蒼波洶湧，悵然收軍卻回（案：此篇乃載南蠻接壤之國，自此以下，皆別說他事，蓋附錄之文，傳寫失其標目耳。
|'''Water Zhēnlà (水真蠟國)''' and '''Land Zhēnlà (陸真蠟國)''' join with '''Zhènnán (鎮南)'''. Barbarian bandits once led cavalry to the boundary of the water, seeing the turbulent, blue-green waves, the army despondently withdrew and retreated.
|-
|今各低一格，以別之）。
|Now each has been lowered by one rank in order to distinguish them.
|}

===''Nánzhào'' (南詔)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 9 {{mdash}} ''Nánzhào'' (南詔)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|鹹通四年六月六日，蠻賊四千余人，草賊朱道古下二千人，共棹小船數百只收郡州（案：《通鑒考異》引《唐實錄》以「郡州」為「交州」，《補國史》亦同。是「郡州」乃州名也），得安南都押衙張慶宗、杜存陵、武安州刺史陳行余（案：《新唐書·地理誌》武安州屬安南都護府），以航舶戰船十余只，築損蠻賊船三十來只沈溺。
|
|-
|臣九月二十一日，於膝州見安南虞候史孝慜，並得兵馬使徐崇雅信，蠻賊不解水，悉皆溺死。
|
|}

===The Tibetan Tubo Dynasty (吐蕃)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 10 {{mdash}} The Tibetan Tubo Dynasty (吐蕃)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|吐蕃鐵橋節度本屬吐蕃，貞元十年，蒙異牟尋攻破，今並屬蠻管（案：「吐蕃鐵橋」節度以下二十五字，文義與上文不相屬，是亦他處錯簡於此）。
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|異牟尋曾詐臣事吐蕃，吐蕃遂封異牟尋江。
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|西卑賤，（案：以下皆紀冊封南詔之事，此二十字文不用周，蓋所紀冊封一事，佚其前段，而此條佚其後段耳，今不可考，姑仍其舊）因遣曹長段南羅各同倫判官趙伽寬等九人，與南詔清平官尹輔酋及親信李羅劄將大馬二十匹迎，子弟羽儀六人沿路視事。
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|十五日至安南城。城使段伽諾出步軍二百隊，馬軍一百隊夾道排立，帶甲馬六十隊引前，步槍五百人隨後，去城五十裏迎候。
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|十九日到曲驛。
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|鎮使楊盛出馬軍一百三十隊、步軍一百七十隊，夾道排立，帶甲馬二百人引前，步槍三百人隨後，去驛一十裏迎接。
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|二十一日過吹舍川。
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|首領父老百余人，蠻夷百姓數千人，路傍羅列而拜，馬上送酒。
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|雲南節度將五十匹馬來迎。
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|二十三日到雲南城。
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|節度蒙酋物出馬軍一百隊，步軍三百人夾道排立，帶甲馬一十隊引前，步槍五百人隨後，去城十一裏迎候。
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|門前父老二百余人，吐蕃封王數人，在路迎拜。
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|是日，南詔使大軍將兼戶曹長王各苴來迎。
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|二十四日到白崖城。
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|城使尹瑳出馬軍一百隊，步軍二百隊夾路排立，引馬六十匹，步槍五百人，去城五裏迎候。
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|南詔遣大軍將李鳳嵐，將細馬一千匹並伎樂來迎。
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|渠斂道中路客館館前父老二百余人，蠻夷百姓五六十人，路迎馬前。
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|大軍將喻於念出馬步軍三百隊夾路排立，引馬六十匹，步槍三百人，去城五裏迎候。
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|南詔妹李波羅諾將細馬一十匹來迎。
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|入龍尾城客館。
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|南詔異牟尋叔父阿思將大馬二百匹來迎。
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|二十六日過大和城，南詔異牟尋從父兄蒙細羅勿（案：「羅勿」原本作「四勾」，今據《新唐書》改正）及清平官李異傍、大軍將李千傍等，將細馬六十匹來迎，皆金錟玉珂，拂髦振鐸（案：「振」原本作「根」，今據《新唐書》改正）。
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|夾路馬步軍排隊二十余裏。
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|南詔蒙異牟尋出陽苴咩城五裏迎。
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|先飾大象一十二頭引前，以次馬軍隊，以次伎樂隊，以次子弟持斧鉞。
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|南詔異牟尋衣金甲，披大蟲皮，執雙鐸。
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|男蒙閣勸在傍，步槍千余人隨後，馬上祗揖而退（原缺）「曰授冊」（原缺），貞元十年十月二十七日陽苴咩城具儀註設位，旌節當庭，東西特立。
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|南詔異牟尋及清平官已下，各具儀禮，面北序立，宣慰南詔使東向立，冊立南詔使南向立，宣敕書，讀冊文訖（案：此條「冊」字原本俱訛作「開」，今據文改正），相者引南詔蒙異牟尋離位受冊，次受貞元十年歷日。
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|南詔及清平官已下稽顙再拜，手舞足蹈。
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|慶退而言：「牟尋曾祖父開元中冊雲南王，祖父天寶中又蒙冊襲雲南王。
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|自隔大國，向五十年。
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|貞元中，皇帝聖明，念錄微效，今又賜禮命，復睹漢儀，對揚天休，實感心肺。」其日樓下大會，又坐上割牲，用銀平脫馬頭盤二面。
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|牟尋曰：「此是天寶初先人任鴻臚少卿宿衛時（案：「衛」上原脫「宿」字，今補入），開元皇帝所賜。比寶藏不敢用，得至今。」又伎樂中有老人吹笛，婦人唱歌，各年近七十余。
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|牟尋指之曰：「先人歸蕃來國，開元皇帝賜胡部及龜茲音聲各兩部。今死亡零落盡，只余此二人在國。」酒既行，牟尋自捧杯擎跽勸讓。
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|冊立使袁滋引杯釃酒曰：「南詔當深思祖宗緒業，堅守誠信，為西南藩屏，使後嗣有以傳繼也。」異牟尋噓嘻曰：「敢不承命！」其年十一月七日事畢，發陽苴咩城。
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|雲南王蒙異牟尋以清平官尹輔酋十七人奉表謝恩，進納吐蕃贊普鍾印一面（案：《通鑒》吐蕃謂弟為鍾，南詔服吐蕃時，封為贊普鍾日東王）並獻鐸鞘、浪川劍、生金、瑟瑟、牛黃、琥珀、白氈、紡絲、象牙、犀角、越賧馬、統備甲馬、並甲文金，皆方土所貴之物也。
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|仍令大軍將王各苴、柘東副使杜伽諾具牛羊，領鞍馬及丁夫三百人提荷食物。
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|其年十一月二十四日送至石門，從石門更十日程到茂州。
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|自後南蠻移心向化，遂與吐蕃仇隙。
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|伏緣數年之間，當州鎮厘革南詔入朝人數，縱有經過者，郵傳殘薄。
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|兼緣安南大中年（案：原本作「大中牟」，今據《唐書》及《通鑒》，宣宗大中十三年，杜棕為西川節度使，奏請節減南蠻習學子弟及入貢傔從人數，南詔怒，自是頗擾邊境，書中所說，當指此事。
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|「牟」字蓋「年」字之訛，謹改正）奏請隔絕南詔往來通好，謹按《尚書》雲：「撫我則後，虐我則仇」。
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|本使蔡襲去年正月十四日內，四度中矢石，家口並元隨七十余人，悉殞於賊所。
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|臣長男韜及奴婢一十四口，並陷蠻陬。
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|臣夙夜憂憶本使蔡襲，行坐痛心。
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|切以蠻賊尚據安南，今江源並諸州各自固守，其首領將吏，去年春夏頻請救兵。
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|自是海門（案：安南既陷，以海門鎮為行交州）不與發遣，並不給與戈甲弓弩，致令蠻賊侵掠州軍。
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|臣以南蠻從古及今，凡虜掠諸處百姓夷獠隸也處則貴。江源首領已下，知其配隸之事，固惜副卿必合戮力齊心，共禦蠻夷之殘暴（案：「臣」以下五十一字，文義未詳，且不相屬，當有脫誤）。
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|又黔、涇、巴、夏四邑苗眾，鹹通三年春三月八日，因入賊朱道古營柵，竟日與蠻賊將大羌楊阿觸、楊酋盛、柘東判官楊忠義話，得姓名，立邊城，自為一國之由。祖乃盤瓠之後，其蠻賊楊羌等雲綻盤古之後（案：「綻」字有訛）。
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|此時緣單車問罪，莫能若是（案：「若」字有訛）。
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|鹹通五年六月，左授夔州都督府長史，問蠻、夷、巴、夏四邑根源，悉以錄之，寄安南諸大首領。
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|詳錄於此，為《蠻誌》一十卷事，庶知南蠻首末之序（案：以下六條，又附錄中旁及之文，今再低一格以別之）。
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|謹按《後漢·南蠻傳》，昔高辛氏有戎寇吳將軍為患其侵暴，乃下敕曰：「有人得戎寇吳將軍頭者，賜金百鎰，封邑萬家，妻以少女。」時帝有犬名盤瓠，後遂之寇所，因嚙得吳將軍頭來，其寇遂平。
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|帝大喜，因以官爵賚賜，犬不起。
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|帝少女聞之，奏曰：「皇帝信不可失！深憂犬之為患。」帝曰：「當殺之。」女曰：「殺有功之犬，失天下之信矣！」帝曰：「善乎！」因請匹之。
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|帝不得已。
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|乃以配盤瓠。
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|盤瓠得女，負入南山，處於石室。
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|其處險阻，不通人跡。
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|後生十二子，六男六女，自相匹偶，緝草木皮以為衣服。
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|帝賜以南山，仍起高欄為居止之。
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|其後滋蔓，自為一國（案：此文與今《後漢書·南蠻傳》不同）。
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|按王通明《廣異記》雲：「高辛時，人家生一犬，初如小特，主怪之，棄於道下。七日不死，禽獸乳之，其形繼日而大，主人復收之。當初棄道下之時，以盤盛葉覆之，因以為瑞，遂獻於帝，以盤瓠為名也。後立功，嚙得戎寇吳將軍頭，帝妻以公主，封盤瓠為定邊侯。公主分娩七塊肉，割之，有七男，長大各認一姓，今巴東姓田、雷、再、向、蒙、旻、叔孫氏也。其後苗裔熾盛，從黔南逾昆、湘、高麗之地，自為一國。幽王為犬戎所殺，即其後也。盤瓠皮骨，今見在黔中，田、雷等家時祀之。」
|
|-
|巴中有大宗，廩君之後也。
|
|-
|《漢書》巴郡本有四姓，巴氏、繁氏、陳氏、鄭氏，皆出於武落鍾離山。
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|-
|其山黑、赤二穴，巴氏之子生於赤穴，繁、陳、鄭三姓生於黑穴。
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|-
|未有君長，俱事鬼。
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|乃其擲劍於石穴，約能中者，奉以為君。
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|巴氏子務相獨中之。
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|-
|又令乘土船下夷水到鹽陽，約能浮者為君。
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|-
|務相獨浮，因立務相為君也。
|
|-
|遂有神女謂廩君曰：「此地廣大，魚鹽所出，請為留之。」廩君不許。
|
|-
|神女暮來取宿，晨則化為飛蟲，群蔽日月，天地晦冥，積十余日。
|
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|廩君伺其便射之，天乃開朗。
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|廩君方定居於夷水，三姓皆臣事之。
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|廩君死，魂魄化為白虎，及惠王並巴蜀，以巴夷為蠻夷君，尚女。
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|其人有罪，得以爵除。
|
|-
|出賦二千一十六百萬錢，三歲一出義賦一千八百錢，人出幏布八丈二尺，雞羽三十鍭也（案：此文與今《後漢書·南郡蠻傳》稍有異同）。
|
|-
|巴氏祭其祀，擊鼓而祭，白虎之後也。
|
|-
|按《華陽國誌》，秦昭王時，白虎為害，多傷人。
|
|-
|乃購之曰：「有殺得白虎者，封邑千家，繼以金帛」。
|
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|於是朐忍夷、廖仲藥等，以竹弩射之，中而死。
|
|-
|秦遂刻石，為夷人立盟曰：「夷人頃田不租，十妻不算，傷人不論。秦犯夷，輸黃龍一只；夷犯秦，輸清酒一鐘。」夷人遂因號虎夷，一名弦頭，剛勇頗有先人之風（案：所引《華陽國誌》與今本文稍不同）。
|
|-
|按《秦紀》，「始皇十八年，巴郡出大人，長二十五丈，一夫兩妻，號曰左右也。」是故左思《蜀都賦》雲：「剛勇生其方，風謠尚其武。」
|
|-
|按《夔城圖經》雲：「夷事道，蠻事鬼。」初喪，鼙鼓以為道哀，其歌必號，其眾必跳，此乃盤瓠白虎之勇也。俗傳正月初夜，鳴鼓連腰以歌，為踏虎之戲。
|
|-
|五月十五日，招命騎健，畫楫圖舟，十船同角，千人齊聲唱鼓扣舷，沿江騰波而下。
|
|-
|俗三月八日為大節，以陳祠享，振鐸、擊鼓、師舞為敬也。
|
|-
|夷蜑居山谷（「蜑」即蠻之別名），巴夏居城郭。與中土風俗、禮樂不同。
|
|-
|雲南詔蒙異牟尋與中國誓文，臣今錄白進獻。
|
|-
|貞元十年，歲次甲戌，正月乙亥，五月己卯，雲南詔異牟尋及清平官、大軍將與劍南西川節度使崔佐時（案：崔佐時乃韋臯所遣西川節度巡官，不可直稱節度使，疑有脫文）謹詣玷蒼山北，上請天、地、水三官，五嶽、四瀆及管川谷諸神靈同請降臨，永為證據。念異牟尋乃祖乃父忠赤附漢。
|
|-
|去天寶九載，被姚川都督張乾拖等離間部落，因此與漢阻絕，經今四十三年。
|
|-
|與吐蕃洽和，為兄弟之國。
|
|-
|吐蕃贊普冊牟尋為日東王，亦無二心，亦無二誌。
|
|-
|去貞元四年，奉劍南節度使韋臯仆射書，具陳漢皇帝聖明，懷柔好生之德。
|
|-
|七年，又蒙遣使段忠義等招諭，兼送皇帝敕書。
|
|-
|遂與清平官、大軍將、大首領等密圖大計，誠矢天地，發於禎祥；所管部落，誓心如一。
|
|-
|去年四月十三日，差趙莫羅眉、揚大和眉等賫仆射來書，三路獻表，願歸清化，誓為漢臣。
|
|-
|啟告祖宗明神，鑒照忠款。
|
|-
|今再蒙皇帝蒙劍南西川節度使韋臯仆射遣巡官崔佐時傳語，牟尋等契誠，誓無遷變。
|
|-
|謹請西洱河、玷蒼山神祠監盟，牟尋與清平官洪驃利時、大軍將段盛等請全部落歸附漢朝，山河兩利，即願牟尋、清平官、大軍將等福祚無疆，子孫昌盛不絕，管諸賧首領永無離二。
|
|-
|興兵動眾，討伐吐蕃，無不克捷。
|
|-
|如會盟之後，發起二心，及與吐蕃私相會合，或輒窺侵漢界內田地，即願天地神祗其降災罰，宗祠殄滅，部落不安，災疾臻湊，人戶流散，稼穡產畜悉背減耗。
|
|-
|如蒙漢與通和之後，有起異心，窺圖牟尋所管疆土，侵害百姓，致使部落不安，及有患難不賜救恤，亦請準此誓文，神祗共罰。
|
|-
|如蒙大漢和通之後，更無異意，即願大漢國祚長久，福盛子孫，天下清平，永保無疆之祚。
|
|-
|漢使崔佐時至益州，不為牟尋陳說，及節度使不為奏聞牟尋赤心歸國之意，亦願神祗降之災。
|
|-
|今牟尋率眾官具牢醴，到西洱河，奏請山川土地靈祗。
|
|-
|請漢使計會，發動兵馬，同心戮力，共行討伐。
|
|-
|然吐蕃神川、昆侖、會同已來，不假天兵，牟尋盡收復鐵橋為界，歸漢舊疆宇。
|
|-
|謹率群官虔誠盟誓，共克金契，永為誓信。
|
|-
|其誓文一本請劍南節度隨表進獻，一本藏於神室，一本投西洱河，一本牟尋留詔城內府庫，貽誡子孫。
|
|-
|伏惟山川神祗，同鑒誠懇！
|
|-
|某年六月二十一日奏狀，今謹錄白獻進（案：後題貞元十年奏狀，而此闕其年，亦刊削不盡之文）
|
|-
|東蠻和使楊傳盛等，六月十八日到安南，賫蠻王蒙異牟尋與臣絹書一封，並金鏤合子一具。
|
|-
|合子有綿，有當歸，有朱砂，有金。
|
|-
|石東蠻國王是故雲南詔王閣羅鳳孫，姓蒙，名異牟尋。
|
|-
|遣前件使賫表詣闕，於今月十八日到，兼得其王牟尋與臣書，遠陳誠懇，並金鏤合子一枚。
|
|-
|其使昧言，送合子中有綿者，以表柔服，不敢更與為生梗；有當歸者，永願為內屬；有朱砂者，蓋獻丹心向闕；有金者，言歸義之意，如金之堅。
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|-
|又言：蠻王蒙異牟尋積代唐臣，遍沾皇化。
|
|-
|天寶年中，其祖閣羅鳳被邊將張乾拖讒構，部落驚懼，遂違聖化，北向歸投吐蕃贊普。
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|以贊普年少，信任讒佞，欲並其國。
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|-
|蒙尋遠懷聖化，北向請命。
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|-
|故遣和使，乞釋前罪，願與部落竭誠歸附。
|
|-
|緣道遐阻，伏恐和使不達，故三道遣：一道出石山，從戎州路入；一道出夷獠，從黔府路入；一道出夷獠，從安南路入。
|
|-
|其楊傳盛等，今年四月十九日從蠻王蒙異牟尋所理大和城發，六月十八日到安南府。
|
|-
|其和使楊傳盛年老，染瘴虐，未得進發。臣見醫療，候獲稍損，即差專使領赴闕廷。
|
|-
|其使雲：「異牟尋自祖父久背國恩，今者願棄豺狼之思，歸聖人之德。此皆陛下雨露之澤及外夷，故蠻僥遐荒，願為內屬。臣忝領蕃鎮，目睹升平，踴躍忻歡，倍萬常幸。」右蠻王與臣書及金鏤合子等，謹差十將李茂等隨表奉進，謹奏。
|
|-
|貞元十年六月二十一日，安南都護充管內節度觀察處置等使、檢校工部尚書、禦史大夫、臣「趙昌奏狀。」
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|-
|貞元十年，南詔蒙異牟尋請歸附聖唐，願充內屬，盟立誓言，永為西南藩屏。
|
|-
|臣今於安南郡州溪源首領耆老處借得故蠻王蒙異牟尋《誓文》一本，安南都護趙昌貞元十年《奏狀白》一本。
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|-
|伏以故南詔蒙異牟尋嗣孫惠龍不守祖父留訓，既違盟誓，自掇禍殃，尚未悛心，猶恣狂暴，全驅蟻聚之眾，攻劫邕、交之人。
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|五載興兵，三來虜掠。
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|顧生靈之何負，受塗炭之苦辛。
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|-
|臣去年正月二十九日，已錄蠻界程途及山川、城鎮、六詔始末、諸種名數、風俗條教、土宜物產、六名&lt;貝僉&gt;號、連接諸蕃，共纂錄成十卷，於安南郡州江口附襄州節度押衙張守忠進獻。
|
|-
|今臣謹錄故蠻王蒙異牟尋貞元十年《誓文》及趙昌《奏狀白》隨表奉進以上。
|
|}

{{BookCat}}</text>
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    </revision>
    <revision>
      <id>4636964</id>
      <parentid>4636958</parentid>
      <timestamp>2026-05-22T06:03:25Z</timestamp>
      <contributor>
        <username>Taitesena</username>
        <id>3485636</id>
      </contributor>
      <comment>/* The country of Biāo (驃國) */</comment>
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      <text bytes="42164" sha1="2wchom9oy1x3g6f4vc8q6wnpnlueuph" xml:space="preserve">They {{incomplete translation}}
{{translation header
 | language = zh
 | original = 
 | title    = [[../]]
 | author   = Fan Chuo
 | override_editor   = Palace Museum Library
 | translator = Walter Stanish and Taitesena
 | section  = Chapter 10
 | previous = [[../Chapter 9/]]
 | next     =
 | notes    = '''Manshu''' (蠻書), written by [[Author:Fan Chuo|Fan Chuo]] in the 9th century, is a Chinese historical text regarding the geopolitics of southwest China, particularly Nanzhao. It is an important historical source for the period. This translation is based upon a digitized version of the recompiled 1774 movable type edition edited by the 武英 (Palace Museum Library).
}}

[[zh:蛮书/卷10]]

==Translator's note==
The translation of this section has begun but is incomplete. The sections are of my own creation.


Taitesena's Notes:

Will need to work with more reference materials and citations and get better at using QGIS for map work and wikimedia. The translation so far is sufficient and the Tubo Dynasty appendix will be translated later.

==Translation==
[[File:Western_Nanzhao.png|thumb|525x525px|Map of Western Nanzhao and Northern Burma:]]

===The countries of ''Mínuò'' (彌諾國) and ''Míchén'' (彌臣國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 1 {{mdash}} The countries of ''Mínuò'' (彌諾) and ''Míchén'' (彌臣)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|彌諾國、彌臣國，皆邊海國也。
|The countries of '''Mínuò''' (彌諾國) and '''Míchén''' (彌臣國) both lie on a lake.&lt;ref&gt;Many authors think '''Michen''' lies on the sea, but it said to border the Little Brahmin Kingdom situated north of Anxi. Indawgyi lake's location supports '''Michen'''&lt;nowiki/&gt;'s placement north where Persian traders and merchants record a similar sounding name. &lt;/ref&gt;
|-
|呼其君長為壽。
|They call their leaders shòu(MC: '''DzyuwH''').&lt;ref&gt;The Middle Chinese word '''dzyuwh''' has cognates in [[Mizo language]] and the [[Kadu lagnauge]]. Among the [[Zo people]] their name is listed by Luce phonetically in every dialect. [[Gordon Luce]] transcribes the phonetics of the Zo autonym as follows, Khongjai: ʒəu3, Tiddim: Zəu1, Lushai: Zo / Zou1, Hualngo: zau1, Kualsim: Zəu1, Haka: Zəu6, Asho: ăʃəu6 and Other: chou4. With Minuo Kingdom attested by scholars to be of the Chin people, this uncanny phonetic similarity and distirbution support this idea.  In Kadu, '''phūceū''' refers to chief as native word. In Mizo, other cognates such as '''thu''' means &quot;to rule&quot; and '''hotu''' means '''headman''' of a village.&lt;/ref&gt;&lt;ref&gt;Note that the character &quot;壽&quot; likely is a phonetic translation of a native title. This word is rarely used unless its for ceremonial purposes.&lt;/ref&gt;
|-
|彌諾面白而長，彌臣面黑而短，性恭謹，每與人語，向前一步一拜。
|The people of '''Mínuò''' (彌諾國) have white and long faces, (whereas) the people of '''Míchén''' (彌臣國) have dark and short faces; (both peoples) have a courteous and respesctful character, whomever they speak with, they step forward one pace and bow once.
|-
|國無城郭。
|The countries have no city walls.
|-
|彌諾王所居屋之中大柱，雕刻為文，飾以金銀。
|The '''King of Mínuò''' (彌諾王) at his residence in the centre has a large column-shaped object&lt;ref&gt;The most obvious translation is pillar, but I suggest that with tribal histories of the Zo people, it could also be ancestral pillars or structures and so something broader.&lt;/ref&gt;, engraved with patterns and decorated in gold and silver.
|-
|彌臣王以木柵居海際水中，以石獅子為屋四足，仍以板蓋，悉用香木。
|The '''King of Míchén''' (彌臣王) uses a wooden palisades as his dwelling in the lake's shore,&lt;ref&gt;Possibly referring to a stilted house.&lt;/ref&gt; which has a stone guardian lion&lt;ref&gt;Implying stone.&lt;/ref&gt; as four feets of the house. Yet they are concealed with planks completely using fragrant wood.&lt;ref&gt;Probably teak.&lt;/ref&gt;
|-
|百姓皆樓居，披婆羅籠，男女多好音樂。
|The common people all dwell in houses on stilts and wear (Brahmin) silkcotton cages [garments].&lt;ref&gt;The term Sha-la refers to a tree which the Michen and Minuo people cultivate to make clothes. Long means to veil or shroud closer to a verb than a noun. As a noun it means cages of bamboo. The first character apparently got corrupted. What originally would have been a Brahmin fabric with 婆罗笼 became 娑罗笼 due to textual corruption and this latter term is now the dominant term. It is still retained by the Tai tribe who wear the Mang Barbarian style of 5 colours in their skirts.

In Anxi, there is a large population of a tribe called 僧耆 '''Sēngqí''' (septenerian monks) which borders the little Brahmin Kingdom. This supports the view that '''Michen''' is likely on the Indawgyi lake than the ocean. &lt;/ref&gt; Men and women greatly like music.
|-
|樓兩頭置鼓，飲酒即擊鼓，男子攜手樓中舞蹈為樂。
|Drums are placed at both ends of the building. Upon drinking they beat drums. The men join hands in the centre of the building and dance for enjoyment.
|-
|在蠻永昌城西南六十日程。
|From the barbarian town of '''Yǒng​chāng​ City''' (永昌城) it is sixty days' journey to the southwest.&lt;ref&gt;Likely the Chindwin corridor of the Kale and Kabaw Valleys. '''Michen''' might stretch from Indawgyi lake to the Chindwin covergence with the Irrawaddy. This placing is consistent with the Xin Tang Shu arguing that it is West of Pyu. &lt;/ref&gt;
|-
|大和九年曾破其國，劫金銀，擄其族三二千人，配麗水淘金。
|In the ninth year of the ''Dahe/Taihe'' reign (2nd February 835) those countries were once defeated [by the Yunnan barbarians], gold and silver were plundered, and two to three thousand prisoners were taken to '''Lí​shuǐ​''' (麗水) to pan for gold.
|}
[[File:中国云南西双版纳1380傣历年_(253863837).jpeg|thumb|娑罗笼 (Suō luó lóng) dresses still retained by the Dai tribe of Yunnan.]]

===The country of ''Biāo'' (驃國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 2 {{mdash}} The country of ''Biāo'' (驃國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|驃國，在蠻永昌城南七十五日程，閣羅鳳所通也。
|The country of '''Biāo''' (驃國) is 75 days' journey south of the barbarian town of '''Yǒng​chāng​''' (永昌)&lt;ref&gt;Likely referencing the capital which at this time would have been ''Śrī Kṣetra'' based on this geography. This means that Minuo and Michen are both northwest of ''Śrī Kṣetra'' as they are 60 stages southwest to the 90 stages south of ''Śrī Kṣetra.'' &lt;/ref&gt;'''. '''
'''Gé​luó​fèng​''' (閣羅鳳) began communication with it.
|-
|其國用銀錢，以青磚為圓城，周行一日程。
|The country uses silver money, green-blue bricks for its circular city [walls], which takes one day stage to encircle by walking.
|-
|百姓盡在城內，有十二門。
|Ordinary citizens completely dwell inside the city, and there are twelve gates.
|-
|當國王所居門前有一大像，露坐高百余尺，白如霜雪。
|At the king's residence in front of the gate is a great statue, which is seated in the open. It is over 100 ''chǐ​'' (ie. 33 meters) in height, white as frost and snow.
|-
|俗尚廉恥，人性和善少言，重佛法，域中並無宰殺。
|Popular [traditional] customs are integrity and honour. The people are of a gentle nature and speak little. They attach importance to Buddhist law, and moreover, universally do not slaughter or butcher.
|-
|又多推步天文。
|They are furthermore skilled in calculating astrology.
|-
|若有兩相訴訟者，王即令焚香向大像，思惟其非，便各引退。
|If there is a case of a two-sided lawsuit, the king orders incense to burn in front of the statue. They reflect their faults as each withdraw [the case].
|-
|其或有災疫及不安穩之事，王亦焚香對大像，悔過自責。
|If there is calamity, plague, and unsteady events, the king also burns incense in front of the statue, repenting and blaming himself.
|-
|男子多衣白氈，婦人當頂為高髻，以金銀真珠為飾，著青婆羅裙，又披羅緞，行必持扇。
|Men mostly wear clothing of white felt. Married women undertake at the top of the head a high topknot. Gold, silver and pearls are used for decoration. They attach blue-gren (brahmin) silkcotton skirts, as well as drape gauze satin. Walking, they must hold fans.
|-
|貴家婦，皆三人五人在傍持扇。
|Elder family noblewomen always have three to five people at their side holding fans.
|-
|有移信使到蠻界河賧，則以江豬、白氈及琉璃、罌為貿易（案：「罌」原本作「盟」，「貿易」原本作「加」，今從《新唐書·驃國傳》改正）。
|There are couriers going to the barbarian border of '''Hé dàn (河賧)''', they bring porpoises, white felt and coloured stones &lt;ref&gt;Historically referring to a blue translucent stone thought to know be lapis lazuli.&lt;/ref&gt; in small-mouthed jars for trade.
&lt;span style=&quot;color:#f00&quot;&gt;（案：「罌」原本作「盟」，「貿易」原本作「加」，今從《新唐書·驃國傳》改正）。&lt;/span&gt;
|-
|與波斯及婆羅門鄰接，西去舍利城二十日程。
|It borders Persia and India.&lt;ref&gt;There are Persian tribes in the south port cities of Myanmar and Thaton region according to this text. This suggests that they were sailor communities seen as an extension of the Persian Stat possibly. &lt;/ref&gt;  It is 20 day stages westward to '''Sheli''' (舍利城; lit. 'city of post-cremation relics'; Vaisali, or the Arakanese Waithali copying it.&lt;ref&gt;Based on history and the location claimed, this appears to be Waithali, the adopted name of Vaishali, Vesali or Vaiśālī in the modern Arakan State. The original Vaishali is in Patna Bihar, a historically Buddhist stronghold. Fan Chuo likely equated this to Buddhist text not understanding the polity governing there held the same name. Waithali was a coastal Rakhine Kingdom, highly indianized and west of Sri Ksetra, the Pyu Capital around 20 day stages. This puts into question of Minuo and Michen's locations. 

[http://www.world10k.com/blog/?p=1305 An external site discusses the toponym's appearance in a range of ancient Chinese texts], but fails to draw any conclusions. From a religious perspective it seems that Buddhism may have been responsible for the toponym's etymology, and this would strongly suggest a city in the Uttar Pradesh region. Given the specific reference to this single city it is likely a large city rather than a small town, which would tend to discount the place of the historical Buddha's death in favour of nearby large cities. The most likely contender seems to be Varanasi. Another option is Patna, however it does not seem to support the toponym's etymology.&lt;/ref&gt;).
|-
|據《佛經》：「舍利城，中天竺國也。近城有沙山，不生草木」。
|According to ''Buddhist Scripture'', &quot;'''Shelicheng''' (舍利城; lit. 'city of post-cremation relics') is in the middle of India.&lt;ref&gt;I believe Fan Chuo is mixing up the Arakanese Waithali with the Indian Vaisali. &lt;/ref&gt; Near the city lies the '''Sand Mountains''' (沙山), upon which trees and grasses do not grow.&quot;
|-
|《恒河經》雲：「沙山中過」，然則驃國疑東天竺也。
|According to the ''Héng​ Hé​ Jīng​'' (恆河經; lit. 'Ganges River Scripture'), &quot;Crossing the Sandy Mountains&quot;. So thus '''Biào​ Guó''' (驃國; lit. 'The Country of the White Horse') is suspected to be east of India.&quot;
|-
|蠻賊大和六年劫掠驃國，虜其眾三幹余人，隸配柘東，令之自給。
|In the 6th year of the ''Dahe'' reign (ie. ~832), the barbarians bandits plundered '''Biào​ Guó''' (驃國; lit. 'The Country of the White Horse'), capturing their masses of 3000 people, subordinating them to join '''Tuodong''' (柘東; Kunming between the Panlong River and North Bank of Dianchi Lake) and ordered to be self-sufficient.
|-
|今子孫亦食魚蟲之類，是其種末也。
|To this day, their children and grandchildren [descendants] still consume fish, insects and alike. This is an offshoot of the same people.
|-
|鹹通四年正月六日寅時，有一胡僧裸形，手持一仗，束白絹，進退為步，在安南羅城南面。
|In the early daylight hours on the '''sixth day of the first month of the lunar year (28 January)''', in the '''4th year of the ''Xiantong'' reign (863 A.D)''', a naked monk from the western regions, holding in his hand a weapon and bound with white silk&lt;ref&gt;This is likely an Indian Brahmin monk. 胡僧 is a term relating to a monk from the western regions, Buddhists from central asia, or Hindu-Buddhists from India. Indian Brahmins historically wore white robes so this suggests to me that this man was an Indian monk. &lt;/ref&gt; walked back and forth toward the city wall south of '''Ān​nán''' (安南; ie. Hanoi).
|-
|本使蔡襲當時以弓飛箭，當胸中此設法胡僧，眾蠻扶舁歸營幕。
|'''Comissioner Cài Xí (本使蔡襲)''', at once grabbed a bow and fired an arrow at the centre of the chest of this monk from the western regions seeking to do something. Masses of barbarians aided by carrying [him on their shoulder] back to the barracks tents. 
|-
|城內將士無不鼓噪。
|Inside the fortress, military officers invariably made commotion [by beating the drums of war while shouting loudly at the enemy]
|}

===The country of ''Kūnlún'' (昆侖國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 3 {{mdash}} The country of ''Kūnlún'' (昆侖國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|昆侖國，正北去蠻界西洱河八十一日程。
|The '''State of'''  '''Kūnlún (昆侖國)'''&lt;ref&gt;This location is disputed. It is either the Salween River Delta or further South to the port city of Thagara. I nominate the former. This entry in the '''[https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7222%E4%B8%8B#%E9%A9%83 New Book of Tang (新唐书)]''' states that the Kunlun Kingdom's rivers and plains are larger than Michen. If Michen is in the north by Indawgyi lake and stretches down to the Chindwin joining the Irrawaddy, then this placement makes sense for the Book of Tang to record the relative placement of kingdoms. &lt;/ref&gt; due north to the barbarian border of the '''Xīěr River (西洱河)''' is 81 day stages.
|-
|出青木香、檀香、紫檀香、檳榔、琉璃、水精、蠡坯等諸香藥、珍寶、犀牛等。
|It exports elephants, green fragrant wood, sandalwood, purple sandlewood, areca, glazed pearls, crystals, seashell cups and other gragrant medicine, jewels, rhinocerous horns, etc.
|-
|蠻賊曾將軍馬攻之，被昆侖國開路放進軍後，鑿其路通江，決水掩浸，進退無計。
|Barbarian bandits once led troops and cavalry to attack. The '''State of''' '''Kūnlún (昆侖國)''' opened the route allowing the army to move forward. They chiselled a river to connect to their road. The water's breach covered and submerged. They lacked a plan to advance or retreat.
|-
|餓死者萬余，不死者昆侖去其右腕放回。
|Ten thousand starved to death, the ones who didn't die die, the '''Kūnlún (昆侖)''' discarded their right forearm and allowed them to return.
|}

=== The Greater Qín Brahmin Country (大秦婆羅門國) ===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 4 {{mdash}} The Greater Qín Brahmin Country (大秦婆羅門國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|大秦婆羅門國，界永昌北，與彌諾國江西正東（案：此句疑有脫誤）安西城樓接界，東去蠻陽苴咩城四十日程。
|The '''Greater Qín Brahmin Country (大秦婆羅門國)'''&lt;ref&gt;'''NAME DISCUSSION:'''

The name 大秦 (colloquially meaning &quot;Roman&quot; or &quot;Byzantine&quot;) is used in the Nazhao Dehua Stele. The paragraph on the 寻传 mentions that west of them is 大秦. This probably meant this kingdom. The reason they use this name is likely due to the silk route &quot;ending&quot; at the Byzantine territory and so silk route affiliations carry this name. 

Zhao RuKuou's [https://storymaps.arcgis.com/stories/39bce63e4e0642d3abce6c24db470760 諸蕃志] mentions that the kings of India were elected by 大秦 likely meaning that they were chosen for the silk route where they could tax the merchants passing through. 大秦 is also mentioned as Byzantine.&lt;/ref&gt;&lt;ref&gt;'''STATE IDENTIFICATION''':

This is strongly suggested to be the eastern autonomous region of Kamarupa. Kamarupa was under the mlecchha dynasty during the 7-10th centuries. Lahiri in [https://www.scribd.com/document/905970705/Pre-Ahom-Assam-by-Nayanjot-Lahiri Pre-Ahom Assam] (p.78) mentions that the mlecchha dynasty was decentralized. The Tezpur Rock Inscription records a settling of waterway dispute. Sucitta a vassal king of Harjaravarman held his own army with judicial powers and levying rights of men and taxes. Below Sucitta was another subordinate office holder Silakuttakavaleya. This would explain why Jia Dan in his document [https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7043%E4%B8%8B &quot;Routes Leading Abroad from China&quot; in the &quot;New Book of Tang]&quot; states that it is another 300''li'' to enter Kamarupa from the Daqin Brahmin territory （西渡彌諾江水，千里至大秦婆羅門國。又西渡大嶺，三百里至東天竺北界箇沒盧國。）. The Mikir-Rengma hills divides Tezpur the Kamarupa capital from the eastern part of the country. This would evidently suggest that Daqin is an autonomous area of eastern Kamarupa.&lt;/ref&gt;  lies on the northern border of Yǒngchāng and west of the '''Mínuò Kingdom's''' River. Due east is the border of the '''Anxi (安西)''' Gatehouse/ Fortress. Going East to the Barbarian city of '''Yángjūmiē (陽苴咩)''' takes 40-day stages.
|-
|蠻王善之，街來其國（案：此八字文不相屬，疑有脫誤）。
|The Barbarian King is friendly to them, markets and fairs come to that country. (Editorial note: “These eight characters do not connect coherently in meaning, and the passage is suspected to contain omissions or textual corruption.”)&lt;ref&gt;The Omission is likely: 市 which would make it undoubted that its referring to commercials markets and fairs. &lt;/ref&gt;
|}

===The 'Lesser Brahman' Country (小婆羅門)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 5 {{mdash}} The 'Lesser Brahman' Country (小婆羅門)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|小婆羅門，與驃國及彌臣國接界，在永昌北七十四日程。
|The '''Lesser Brahmin Country (小婆羅門国)''' &lt;ref&gt;In earlier chapters we learn that this kingdom is north of Anxi in present day Mogaung. Hence, this kingdom is likely situated in the Hukawng Valley. &lt;/ref&gt; borders the State of '''Pyu''' '''(驃國)''' and '''Michen (彌臣國)'''. It is 74 day stages north of '''Yǒngchāng (昌北).'''&lt;ref&gt;I suspect an omission of 西，as the Hukawng valley is northwest of Yongchang (Baoshan)&lt;/ref&gt;
|-
|俗不食牛肉，預知身後事。
|As a custom, they do not consume cattle meat.&lt;ref&gt;This seems to indicate more orthodox Hindu traditions rather than Buddhist ones. This means that the 僧耆 (septenarian monks) in Anxi are likely Indian monks and hermits living in the Hukawng Valley area. They are also treated as a tribe and recruited for war as mentioned in the siege of Songping extracts. Likely an Indian tribe in the northwest with vague Hindu traditions and monks among them.&lt;/ref&gt; They have beforehand knowledge of what happens after life (belief in an afterlife).   
|-
|出見齒、&lt;蟲葛&gt;、越諾。
|They export cowry shells, ivory, white wax and '''Yuènuò (越諾).'''&lt;ref&gt;A type of cloth of fabric which comes from Persia and Afghanistan. This indicates that the kingdom was along the silk route at the time.The other products are also not locally produced in the Hukawng region suggesting that it grew as a trade outpost of the 大秦婆罗门 (Greater Qin Brahmin Kingdom) who managed the trade route. Jia Dan did not mention this kingdom at all in his routes suggesting that this outpost grew in the decades after his manuscript. Jia Dan's routes go straight from Anxi to Daqin.  &lt;/ref&gt;
|-
|其大耳國往來，蠻夷善之，信其國。
|They have relations with '''Big Ear Kingdom''' (大耳国)&lt;ref&gt;Gordon Luce believes this to be the Kadu who were known for large ear piercings which would stretch out their lobes. &lt;/ref&gt;, the barbarian king is friendly to them and communicates with that country.&lt;ref&gt;Can also be read as: The Barbarian king is friendly to them and places trust in that country. &lt;/ref&gt;
|}

===The 'Midnight' Country (夜半國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 6 {{mdash}} The 'Midnight' Country (夜半國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|夜半國，在蠻界蒼望城，東北隔麗水城。
|The State of Yeban lies northeast of the barbarian border city of '''Cāngwàng''' '''(蒼望)''' across the '''Lìshuǐ''' '''City's''' '''(麗水城)''' river plains.&lt;ref&gt;They are situated within Nanzhao's own territory. They are likely a hill tribe who are geographically fortified.&lt;/ref&gt;
|-
|其部落婦人唯與鬼通能知吉兇禍福本土君長崇信。
|That tribe's women are able to communicate/ connect with spirits to know auspicious and terrible fortunes and misfortunes. The local chieftains venerate them.&lt;ref&gt;Female fortune tellers and divination is a common practiced among the Kachin and Zo people. It was separated from the religious aspect of sacrifice and feasting but was important to identify spirits who caused sickness and illness in people. &lt;/ref&gt;
|-
|蠻夷往往以金購之，要知善惡。
|Barbarians often pay with gold, wanting to know good and evil (outcomes).
|-
|昆明、牂牁界接麗水，相近蠻賊曾攻不得，至今銜恨之。
|The '''Kūnmíng''' '''(昆明)''' and '''Zānggē''' '''(牂牁)''' are close to the border of '''Lìshuǐ (麗水)'''. Barbarian badits once attacked and failed. To this day, they bear resentment.
|-
|昆明、牂牁，本使臣蔡襲嘗奏請分布軍馬，從黔府路入（案：此條之首，當有脫文）。
|With regards to '''Kūnmíng''' '''(昆明)''' and '''Zānggē''' '''(牂牁), your servant, commissioner Cài Xí (本使臣蔡袭)''' attempted a formal request to distribute (soldiers) and war horses to enter into route from the ''Qián'' prefecture capital. 
|}

===The Country of the Queen (女王國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 7 {{mdash}} The Country of the Queen (女王國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|女王國，去蠻界鎮南節度三十余日程。
|The '''Queen's Kingdom''' '''(女王國)'''&lt;ref&gt;This is likely the Mon Kingdom of Haripuñjaya. It's founder was a legendary queen Jamadevi around 750AD. Haripuñjaya is situated in modern day '''Lamphun (เมืองลำพูน)''' and was largely a valley settlement which expanded to a significant territory of northwest Thailand. &lt;/ref&gt; to the barbarian border '''Jiédù (節度) of''' '''Zhènnán (鎮南)''' is over thirty day stages.
|-
|其國去驩州一十日程，往往與驩州百姓交易。
|That country to '''Huānzhōu (驩州)''' is ten day stages. Ordinary citizens regularly trade and make business.
|-
|蠻賊曾將二萬人伐其國，被女王藥箭射之，十不存一，蠻賊乃回。
|Barbarian bandits one led nearly twenty thousand people to defeat that country. The queen's poisoned arrows were shot at them and not even a tenth remained. The barbarian bandits thus returned.
|}

===The countries of ''Water Zhenla'' (水真蠟國) and ''Land Zhenla'' (陸真蠟國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 8 {{mdash}} The countries of ''Water Zhenla'' (水真蠟國) and ''Land Zhenla'' (陸真蠟國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|水真蠟國、陸真蠟國，與蠻鎮南相接，蠻賊曾領馬軍到海畔，見蒼波洶湧，悵然收軍卻回（案：此篇乃載南蠻接壤之國，自此以下，皆別說他事，蓋附錄之文，傳寫失其標目耳。
|'''Water Zhēnlà (水真蠟國)''' and '''Land Zhēnlà (陸真蠟國)''' join with '''Zhènnán (鎮南)'''. Barbarian bandits once led cavalry to the boundary of the water, seeing the turbulent, blue-green waves, the army despondently withdrew and retreated.
|-
|今各低一格，以別之）。
|Now each has been lowered by one rank in order to distinguish them.
|}

===''Nánzhào'' (南詔)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 9 {{mdash}} ''Nánzhào'' (南詔)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|鹹通四年六月六日，蠻賊四千余人，草賊朱道古下二千人，共棹小船數百只收郡州（案：《通鑒考異》引《唐實錄》以「郡州」為「交州」，《補國史》亦同。是「郡州」乃州名也），得安南都押衙張慶宗、杜存陵、武安州刺史陳行余（案：《新唐書·地理誌》武安州屬安南都護府），以航舶戰船十余只，築損蠻賊船三十來只沈溺。
|
|-
|臣九月二十一日，於膝州見安南虞候史孝慜，並得兵馬使徐崇雅信，蠻賊不解水，悉皆溺死。
|
|}

===The Tibetan Tubo Dynasty (吐蕃)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 10 {{mdash}} The Tibetan Tubo Dynasty (吐蕃)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|吐蕃鐵橋節度本屬吐蕃，貞元十年，蒙異牟尋攻破，今並屬蠻管（案：「吐蕃鐵橋」節度以下二十五字，文義與上文不相屬，是亦他處錯簡於此）。
|
|-
|異牟尋曾詐臣事吐蕃，吐蕃遂封異牟尋江。
|
|-
|西卑賤，（案：以下皆紀冊封南詔之事，此二十字文不用周，蓋所紀冊封一事，佚其前段，而此條佚其後段耳，今不可考，姑仍其舊）因遣曹長段南羅各同倫判官趙伽寬等九人，與南詔清平官尹輔酋及親信李羅劄將大馬二十匹迎，子弟羽儀六人沿路視事。
|
|-
|十五日至安南城。城使段伽諾出步軍二百隊，馬軍一百隊夾道排立，帶甲馬六十隊引前，步槍五百人隨後，去城五十裏迎候。
|
|-
|十九日到曲驛。
|
|-
|鎮使楊盛出馬軍一百三十隊、步軍一百七十隊，夾道排立，帶甲馬二百人引前，步槍三百人隨後，去驛一十裏迎接。
|
|-
|二十一日過吹舍川。
|
|-
|首領父老百余人，蠻夷百姓數千人，路傍羅列而拜，馬上送酒。
|
|-
|雲南節度將五十匹馬來迎。
|
|-
|二十三日到雲南城。
|
|-
|節度蒙酋物出馬軍一百隊，步軍三百人夾道排立，帶甲馬一十隊引前，步槍五百人隨後，去城十一裏迎候。
|
|-
|門前父老二百余人，吐蕃封王數人，在路迎拜。
|
|-
|是日，南詔使大軍將兼戶曹長王各苴來迎。
|
|-
|二十四日到白崖城。
|
|-
|城使尹瑳出馬軍一百隊，步軍二百隊夾路排立，引馬六十匹，步槍五百人，去城五裏迎候。
|
|-
|南詔遣大軍將李鳳嵐，將細馬一千匹並伎樂來迎。
|
|-
|渠斂道中路客館館前父老二百余人，蠻夷百姓五六十人，路迎馬前。
|
|-
|大軍將喻於念出馬步軍三百隊夾路排立，引馬六十匹，步槍三百人，去城五裏迎候。
|
|-
|南詔妹李波羅諾將細馬一十匹來迎。
|
|-
|入龍尾城客館。
|
|-
|南詔異牟尋叔父阿思將大馬二百匹來迎。
|
|-
|二十六日過大和城，南詔異牟尋從父兄蒙細羅勿（案：「羅勿」原本作「四勾」，今據《新唐書》改正）及清平官李異傍、大軍將李千傍等，將細馬六十匹來迎，皆金錟玉珂，拂髦振鐸（案：「振」原本作「根」，今據《新唐書》改正）。
|
|-
|夾路馬步軍排隊二十余裏。
|
|-
|南詔蒙異牟尋出陽苴咩城五裏迎。
|
|-
|先飾大象一十二頭引前，以次馬軍隊，以次伎樂隊，以次子弟持斧鉞。
|
|-
|南詔異牟尋衣金甲，披大蟲皮，執雙鐸。
|
|-
|男蒙閣勸在傍，步槍千余人隨後，馬上祗揖而退（原缺）「曰授冊」（原缺），貞元十年十月二十七日陽苴咩城具儀註設位，旌節當庭，東西特立。
|
|-
|南詔異牟尋及清平官已下，各具儀禮，面北序立，宣慰南詔使東向立，冊立南詔使南向立，宣敕書，讀冊文訖（案：此條「冊」字原本俱訛作「開」，今據文改正），相者引南詔蒙異牟尋離位受冊，次受貞元十年歷日。
|
|-
|南詔及清平官已下稽顙再拜，手舞足蹈。
|
|-
|慶退而言：「牟尋曾祖父開元中冊雲南王，祖父天寶中又蒙冊襲雲南王。
|
|-
|自隔大國，向五十年。
|
|-
|貞元中，皇帝聖明，念錄微效，今又賜禮命，復睹漢儀，對揚天休，實感心肺。」其日樓下大會，又坐上割牲，用銀平脫馬頭盤二面。
|
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|牟尋曰：「此是天寶初先人任鴻臚少卿宿衛時（案：「衛」上原脫「宿」字，今補入），開元皇帝所賜。比寶藏不敢用，得至今。」又伎樂中有老人吹笛，婦人唱歌，各年近七十余。
|
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|牟尋指之曰：「先人歸蕃來國，開元皇帝賜胡部及龜茲音聲各兩部。今死亡零落盡，只余此二人在國。」酒既行，牟尋自捧杯擎跽勸讓。
|
|-
|冊立使袁滋引杯釃酒曰：「南詔當深思祖宗緒業，堅守誠信，為西南藩屏，使後嗣有以傳繼也。」異牟尋噓嘻曰：「敢不承命！」其年十一月七日事畢，發陽苴咩城。
|
|-
|雲南王蒙異牟尋以清平官尹輔酋十七人奉表謝恩，進納吐蕃贊普鍾印一面（案：《通鑒》吐蕃謂弟為鍾，南詔服吐蕃時，封為贊普鍾日東王）並獻鐸鞘、浪川劍、生金、瑟瑟、牛黃、琥珀、白氈、紡絲、象牙、犀角、越賧馬、統備甲馬、並甲文金，皆方土所貴之物也。
|
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|仍令大軍將王各苴、柘東副使杜伽諾具牛羊，領鞍馬及丁夫三百人提荷食物。
|
|-
|其年十一月二十四日送至石門，從石門更十日程到茂州。
|
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|自後南蠻移心向化，遂與吐蕃仇隙。
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|-
|伏緣數年之間，當州鎮厘革南詔入朝人數，縱有經過者，郵傳殘薄。
|
|-
|兼緣安南大中年（案：原本作「大中牟」，今據《唐書》及《通鑒》，宣宗大中十三年，杜棕為西川節度使，奏請節減南蠻習學子弟及入貢傔從人數，南詔怒，自是頗擾邊境，書中所說，當指此事。
|
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|「牟」字蓋「年」字之訛，謹改正）奏請隔絕南詔往來通好，謹按《尚書》雲：「撫我則後，虐我則仇」。
|
|-
|本使蔡襲去年正月十四日內，四度中矢石，家口並元隨七十余人，悉殞於賊所。
|
|-
|臣長男韜及奴婢一十四口，並陷蠻陬。
|
|-
|臣夙夜憂憶本使蔡襲，行坐痛心。
|
|-
|切以蠻賊尚據安南，今江源並諸州各自固守，其首領將吏，去年春夏頻請救兵。
|
|-
|自是海門（案：安南既陷，以海門鎮為行交州）不與發遣，並不給與戈甲弓弩，致令蠻賊侵掠州軍。
|
|-
|臣以南蠻從古及今，凡虜掠諸處百姓夷獠隸也處則貴。江源首領已下，知其配隸之事，固惜副卿必合戮力齊心，共禦蠻夷之殘暴（案：「臣」以下五十一字，文義未詳，且不相屬，當有脫誤）。
|
|-
|又黔、涇、巴、夏四邑苗眾，鹹通三年春三月八日，因入賊朱道古營柵，竟日與蠻賊將大羌楊阿觸、楊酋盛、柘東判官楊忠義話，得姓名，立邊城，自為一國之由。祖乃盤瓠之後，其蠻賊楊羌等雲綻盤古之後（案：「綻」字有訛）。
|
|-
|此時緣單車問罪，莫能若是（案：「若」字有訛）。
|
|-
|鹹通五年六月，左授夔州都督府長史，問蠻、夷、巴、夏四邑根源，悉以錄之，寄安南諸大首領。
|
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|詳錄於此，為《蠻誌》一十卷事，庶知南蠻首末之序（案：以下六條，又附錄中旁及之文，今再低一格以別之）。
|
|-
|謹按《後漢·南蠻傳》，昔高辛氏有戎寇吳將軍為患其侵暴，乃下敕曰：「有人得戎寇吳將軍頭者，賜金百鎰，封邑萬家，妻以少女。」時帝有犬名盤瓠，後遂之寇所，因嚙得吳將軍頭來，其寇遂平。
|
|-
|帝大喜，因以官爵賚賜，犬不起。
|
|-
|帝少女聞之，奏曰：「皇帝信不可失！深憂犬之為患。」帝曰：「當殺之。」女曰：「殺有功之犬，失天下之信矣！」帝曰：「善乎！」因請匹之。
|
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|帝不得已。
|
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|乃以配盤瓠。
|
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|盤瓠得女，負入南山，處於石室。
|
|-
|其處險阻，不通人跡。
|
|-
|後生十二子，六男六女，自相匹偶，緝草木皮以為衣服。
|
|-
|帝賜以南山，仍起高欄為居止之。
|
|-
|其後滋蔓，自為一國（案：此文與今《後漢書·南蠻傳》不同）。
|
|-
|按王通明《廣異記》雲：「高辛時，人家生一犬，初如小特，主怪之，棄於道下。七日不死，禽獸乳之，其形繼日而大，主人復收之。當初棄道下之時，以盤盛葉覆之，因以為瑞，遂獻於帝，以盤瓠為名也。後立功，嚙得戎寇吳將軍頭，帝妻以公主，封盤瓠為定邊侯。公主分娩七塊肉，割之，有七男，長大各認一姓，今巴東姓田、雷、再、向、蒙、旻、叔孫氏也。其後苗裔熾盛，從黔南逾昆、湘、高麗之地，自為一國。幽王為犬戎所殺，即其後也。盤瓠皮骨，今見在黔中，田、雷等家時祀之。」
|
|-
|巴中有大宗，廩君之後也。
|
|-
|《漢書》巴郡本有四姓，巴氏、繁氏、陳氏、鄭氏，皆出於武落鍾離山。
|
|-
|其山黑、赤二穴，巴氏之子生於赤穴，繁、陳、鄭三姓生於黑穴。
|
|-
|未有君長，俱事鬼。
|
|-
|乃其擲劍於石穴，約能中者，奉以為君。
|
|-
|巴氏子務相獨中之。
|
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|又令乘土船下夷水到鹽陽，約能浮者為君。
|
|-
|務相獨浮，因立務相為君也。
|
|-
|遂有神女謂廩君曰：「此地廣大，魚鹽所出，請為留之。」廩君不許。
|
|-
|神女暮來取宿，晨則化為飛蟲，群蔽日月，天地晦冥，積十余日。
|
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|廩君伺其便射之，天乃開朗。
|
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|廩君方定居於夷水，三姓皆臣事之。
|
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|廩君死，魂魄化為白虎，及惠王並巴蜀，以巴夷為蠻夷君，尚女。
|
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|其人有罪，得以爵除。
|
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|出賦二千一十六百萬錢，三歲一出義賦一千八百錢，人出幏布八丈二尺，雞羽三十鍭也（案：此文與今《後漢書·南郡蠻傳》稍有異同）。
|
|-
|巴氏祭其祀，擊鼓而祭，白虎之後也。
|
|-
|按《華陽國誌》，秦昭王時，白虎為害，多傷人。
|
|-
|乃購之曰：「有殺得白虎者，封邑千家，繼以金帛」。
|
|-
|於是朐忍夷、廖仲藥等，以竹弩射之，中而死。
|
|-
|秦遂刻石，為夷人立盟曰：「夷人頃田不租，十妻不算，傷人不論。秦犯夷，輸黃龍一只；夷犯秦，輸清酒一鐘。」夷人遂因號虎夷，一名弦頭，剛勇頗有先人之風（案：所引《華陽國誌》與今本文稍不同）。
|
|-
|按《秦紀》，「始皇十八年，巴郡出大人，長二十五丈，一夫兩妻，號曰左右也。」是故左思《蜀都賦》雲：「剛勇生其方，風謠尚其武。」
|
|-
|按《夔城圖經》雲：「夷事道，蠻事鬼。」初喪，鼙鼓以為道哀，其歌必號，其眾必跳，此乃盤瓠白虎之勇也。俗傳正月初夜，鳴鼓連腰以歌，為踏虎之戲。
|
|-
|五月十五日，招命騎健，畫楫圖舟，十船同角，千人齊聲唱鼓扣舷，沿江騰波而下。
|
|-
|俗三月八日為大節，以陳祠享，振鐸、擊鼓、師舞為敬也。
|
|-
|夷蜑居山谷（「蜑」即蠻之別名），巴夏居城郭。與中土風俗、禮樂不同。
|
|-
|雲南詔蒙異牟尋與中國誓文，臣今錄白進獻。
|
|-
|貞元十年，歲次甲戌，正月乙亥，五月己卯，雲南詔異牟尋及清平官、大軍將與劍南西川節度使崔佐時（案：崔佐時乃韋臯所遣西川節度巡官，不可直稱節度使，疑有脫文）謹詣玷蒼山北，上請天、地、水三官，五嶽、四瀆及管川谷諸神靈同請降臨，永為證據。念異牟尋乃祖乃父忠赤附漢。
|
|-
|去天寶九載，被姚川都督張乾拖等離間部落，因此與漢阻絕，經今四十三年。
|
|-
|與吐蕃洽和，為兄弟之國。
|
|-
|吐蕃贊普冊牟尋為日東王，亦無二心，亦無二誌。
|
|-
|去貞元四年，奉劍南節度使韋臯仆射書，具陳漢皇帝聖明，懷柔好生之德。
|
|-
|七年，又蒙遣使段忠義等招諭，兼送皇帝敕書。
|
|-
|遂與清平官、大軍將、大首領等密圖大計，誠矢天地，發於禎祥；所管部落，誓心如一。
|
|-
|去年四月十三日，差趙莫羅眉、揚大和眉等賫仆射來書，三路獻表，願歸清化，誓為漢臣。
|
|-
|啟告祖宗明神，鑒照忠款。
|
|-
|今再蒙皇帝蒙劍南西川節度使韋臯仆射遣巡官崔佐時傳語，牟尋等契誠，誓無遷變。
|
|-
|謹請西洱河、玷蒼山神祠監盟，牟尋與清平官洪驃利時、大軍將段盛等請全部落歸附漢朝，山河兩利，即願牟尋、清平官、大軍將等福祚無疆，子孫昌盛不絕，管諸賧首領永無離二。
|
|-
|興兵動眾，討伐吐蕃，無不克捷。
|
|-
|如會盟之後，發起二心，及與吐蕃私相會合，或輒窺侵漢界內田地，即願天地神祗其降災罰，宗祠殄滅，部落不安，災疾臻湊，人戶流散，稼穡產畜悉背減耗。
|
|-
|如蒙漢與通和之後，有起異心，窺圖牟尋所管疆土，侵害百姓，致使部落不安，及有患難不賜救恤，亦請準此誓文，神祗共罰。
|
|-
|如蒙大漢和通之後，更無異意，即願大漢國祚長久，福盛子孫，天下清平，永保無疆之祚。
|
|-
|漢使崔佐時至益州，不為牟尋陳說，及節度使不為奏聞牟尋赤心歸國之意，亦願神祗降之災。
|
|-
|今牟尋率眾官具牢醴，到西洱河，奏請山川土地靈祗。
|
|-
|請漢使計會，發動兵馬，同心戮力，共行討伐。
|
|-
|然吐蕃神川、昆侖、會同已來，不假天兵，牟尋盡收復鐵橋為界，歸漢舊疆宇。
|
|-
|謹率群官虔誠盟誓，共克金契，永為誓信。
|
|-
|其誓文一本請劍南節度隨表進獻，一本藏於神室，一本投西洱河，一本牟尋留詔城內府庫，貽誡子孫。
|
|-
|伏惟山川神祗，同鑒誠懇！
|
|-
|某年六月二十一日奏狀，今謹錄白獻進（案：後題貞元十年奏狀，而此闕其年，亦刊削不盡之文）
|
|-
|東蠻和使楊傳盛等，六月十八日到安南，賫蠻王蒙異牟尋與臣絹書一封，並金鏤合子一具。
|
|-
|合子有綿，有當歸，有朱砂，有金。
|
|-
|石東蠻國王是故雲南詔王閣羅鳳孫，姓蒙，名異牟尋。
|
|-
|遣前件使賫表詣闕，於今月十八日到，兼得其王牟尋與臣書，遠陳誠懇，並金鏤合子一枚。
|
|-
|其使昧言，送合子中有綿者，以表柔服，不敢更與為生梗；有當歸者，永願為內屬；有朱砂者，蓋獻丹心向闕；有金者，言歸義之意，如金之堅。
|
|-
|又言：蠻王蒙異牟尋積代唐臣，遍沾皇化。
|
|-
|天寶年中，其祖閣羅鳳被邊將張乾拖讒構，部落驚懼，遂違聖化，北向歸投吐蕃贊普。
|
|-
|以贊普年少，信任讒佞，欲並其國。
|
|-
|蒙尋遠懷聖化，北向請命。
|
|-
|故遣和使，乞釋前罪，願與部落竭誠歸附。
|
|-
|緣道遐阻，伏恐和使不達，故三道遣：一道出石山，從戎州路入；一道出夷獠，從黔府路入；一道出夷獠，從安南路入。
|
|-
|其楊傳盛等，今年四月十九日從蠻王蒙異牟尋所理大和城發，六月十八日到安南府。
|
|-
|其和使楊傳盛年老，染瘴虐，未得進發。臣見醫療，候獲稍損，即差專使領赴闕廷。
|
|-
|其使雲：「異牟尋自祖父久背國恩，今者願棄豺狼之思，歸聖人之德。此皆陛下雨露之澤及外夷，故蠻僥遐荒，願為內屬。臣忝領蕃鎮，目睹升平，踴躍忻歡，倍萬常幸。」右蠻王與臣書及金鏤合子等，謹差十將李茂等隨表奉進，謹奏。
|
|-
|貞元十年六月二十一日，安南都護充管內節度觀察處置等使、檢校工部尚書、禦史大夫、臣「趙昌奏狀。」
|
|-
|貞元十年，南詔蒙異牟尋請歸附聖唐，願充內屬，盟立誓言，永為西南藩屏。
|
|-
|臣今於安南郡州溪源首領耆老處借得故蠻王蒙異牟尋《誓文》一本，安南都護趙昌貞元十年《奏狀白》一本。
|
|-
|伏以故南詔蒙異牟尋嗣孫惠龍不守祖父留訓，既違盟誓，自掇禍殃，尚未悛心，猶恣狂暴，全驅蟻聚之眾，攻劫邕、交之人。
|
|-
|五載興兵，三來虜掠。
|
|-
|顧生靈之何負，受塗炭之苦辛。
|
|-
|臣去年正月二十九日，已錄蠻界程途及山川、城鎮、六詔始末、諸種名數、風俗條教、土宜物產、六名&lt;貝僉&gt;號、連接諸蕃，共纂錄成十卷，於安南郡州江口附襄州節度押衙張守忠進獻。
|
|-
|今臣謹錄故蠻王蒙異牟尋貞元十年《誓文》及趙昌《奏狀白》隨表奉進以上。
|
|}

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 | language = zh
 | original = 
 | title    = [[../]]
 | author   = Fan Chuo
 | override_editor   = Palace Museum Library
 | translator = Walter Stanish and Taitesena
 | section  = Chapter 10
 | previous = [[../Chapter 9/]]
 | next     =
 | notes    = '''Manshu''' (蠻書), written by [[Author:Fan Chuo|Fan Chuo]] in the 9th century, is a Chinese historical text regarding the geopolitics of southwest China, particularly Nanzhao. It is an important historical source for the period. This translation is based upon a digitized version of the recompiled 1774 movable type edition edited by the 武英 (Palace Museum Library).
}}

[[zh:蛮书/卷10]]

==Translator's note==
The translation of this section has begun but is incomplete. The sections are of my own creation.


Taitesena's Notes:

Will need to work with more reference materials and citations and get better at using QGIS for map work and wikimedia. The translation so far is sufficient and the Tubo Dynasty appendix will be translated later.

==Translation==
[[File:Western_Nanzhao.png|thumb|525x525px|Map of Western Nanzhao and Northern Burma:]]

===The countries of ''Mínuò'' (彌諾國) and ''Míchén'' (彌臣國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 1 {{mdash}} The countries of ''Mínuò'' (彌諾) and ''Míchén'' (彌臣)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|彌諾國、彌臣國，皆邊海國也。
|The countries of '''Mínuò''' (彌諾國)&lt;ref&gt;Minuo is named after the river. It was used in Jia Dan's work at the start of the 9th century decades before Fan Chuo. The kingdom wasn't mentioned until this document. This suggests that nak for 诺 meaning deep in old Bai language is a descriptor for the river. 弥 is also a common used word among nanzhao place names whose meaning is not recorded. On the surface, Minuo means &quot;overflowing&quot; and &quot;deep&quot; which makes sense superficially. 

Luce associates this with the Chins as by the 11th century we begin to see Pagan inscriptions of the Khyan in the west and the naming of the Chindwin (Khyengweng). Minuo was likely a tribal confederation led by a supratribal chief in the Kale-Kabaw Valleys whose descendants were pushed into Manipur and the Chin Hills. There were historically significant Luish speakers in Manipur suggesting that the Sak were the dominant power of the Chindwin. However it is likely that the Michen (Sak) simply bounded the Chins from north to east. This explains why Minuo doesn't border the Hukawng Brahmin Kingdom but Michen does along with Pyu (Daoji Valley likely). It is also possible that Nanzhao invasions encouraged Sak speakers to migrate into Manipur rather than them staying autochthonous to the Chindwin-Kabaw Valleys.&lt;/ref&gt; and '''Míchén''' (彌臣國)&lt;ref&gt;弥臣 means Mi Vassal. This makes sense as it was a tributary to the Tang and had its heir enoffed by the Tang emperor in 803AD. Another explanation is it might be an adapation for a proto-luish term for village/kingdom administration through the word *thiŋ. The reconstruction argues it to mean village, but from a chieftainship point of view, this could mean &quot;kingdom&quot; of a chief. 

The Proto-Luish autonym for the Luish speaking groups is *Cak which I will use for convenience explaining this. The *Cak are likely the inhabitants of Michen. Michen stretches from the tip of Hukawng to the west of the Chindwin near the Arakan Mountains where Burmese Chronicles record many wars and conflicts with the *Cak. This contributed to the disapora that resides in Arakan and some who moved west into the Chittagong Hill Tracts. 

[https://opal.latrobe.edu.au/ndownloader/files/38770497 A Grammar of the Kadu] lists the native term for chief as '''phūceū''', the ceū syllable can be argued to be derivation of the original title for their chiefs and leaders &quot;壽&quot; [DzyuwH]. The term for king has been overwritten with Burmese borrowing and influence and so chief is the only title which retains a legacy of this supposed title. &lt;/ref&gt; both lie on a lake.&lt;ref&gt;Many authors think '''Michen''' lies on the sea, but it said to border the Little Brahmin Kingdom situated north of Anxi. Indawgyi lake's location supports '''Michen'''&lt;nowiki/&gt;'s placement north where Persian traders and merchants record a similar sounding name.

[[iarchive:hudud-al-alam-minorsky-1970/page/242/mode/2up|Minorsky's translation of the Hudud al Alam]] states Persian trades use the term Muja with alternative spelling hinting at a mu-cha/mo-cha sound. This likely is just adopting the autonym of the Proto-Luish *cak. They are known for exporting musk, which is procured near the Himalayas near Hukawng Valley rather than the coast according to [https://archive.org/details/historicalencycl00masrich/page/394/mode/2up?q=musk meadows of gold and mines of gems]. Musha is also part of the route to Yunnan from India along with ''Mank'' as discussed in [https://archive.org/details/in.ernet.dli.2015.80976/page/n157/mode/2up?q=Musha Sharaf Al-Zaman Tahir]. &lt;/ref&gt;
|-
|呼其君長為壽。
|They call their leaders shòu(MC: '''DzyuwH''').&lt;ref&gt;The Middle Chinese word '''dzyuwh''' has cognates in [[Mizo language]] and the [[Kadu lagnauge]]. Among the [[Zo people]] their name is listed by Luce phonetically in every dialect. [[Gordon Luce]] transcribes the phonetics of the Zo autonym as follows, Khongjai: ʒəu3, Tiddim: Zəu1, Lushai: Zo / Zou1, Hualngo: zau1, Kualsim: Zəu1, Haka: Zəu6, Asho: ăʃəu6 and Other: chou4. With Minuo Kingdom attested by scholars to be of the Chin people, this uncanny phonetic similarity and distirbution support this idea.  In Kadu, '''phūceū''' refers to chief as native word. In Mizo, other cognates such as '''thu''' means &quot;to rule&quot; and '''hotu''' means '''headman''' of a village.&lt;/ref&gt;&lt;ref&gt;Note that the character &quot;壽&quot; likely is a phonetic translation of a native title. This word is rarely used unless its for ceremonial purposes.&lt;/ref&gt;
|-
|彌諾面白而長，彌臣面黑而短，性恭謹，每與人語，向前一步一拜。
|The people of '''Mínuò''' (彌諾國) have white and long faces, (whereas) the people of '''Míchén''' (彌臣國) have dark and short faces; (both peoples) have a courteous and respesctful character, whomever they speak with, they step forward one pace and bow once.
|-
|國無城郭。
|The countries have no city walls.
|-
|彌諾王所居屋之中大柱，雕刻為文，飾以金銀。
|The '''King of Mínuò''' (彌諾王) at his residence in the centre has a large column-shaped object&lt;ref&gt;The most obvious translation is pillar, but I suggest that with tribal histories of the Zo people, it could also be ancestral pillars or structures and so something broader.&lt;/ref&gt;, engraved with patterns and decorated in gold and silver.
|-
|彌臣王以木柵居海際水中，以石獅子為屋四足，仍以板蓋，悉用香木。
|The '''King of Míchén''' (彌臣王) uses a wooden palisades as his dwelling in the lake's shore,&lt;ref&gt;Possibly referring to a stilted house.&lt;/ref&gt; which has a stone guardian lion&lt;ref&gt;Implying stone.&lt;/ref&gt; as four feets of the house. Yet they are concealed with planks completely using fragrant wood.&lt;ref&gt;Probably teak.&lt;/ref&gt;
|-
|百姓皆樓居，披婆羅籠，男女多好音樂。
|The common people all dwell in houses on stilts and wear (Brahmin) silkcotton cages [garments].&lt;ref&gt;The term Sha-la refers to a tree which the Michen and Minuo people cultivate to make clothes. Long means to veil or shroud closer to a verb than a noun. As a noun it means cages of bamboo. The first character apparently got corrupted. What originally would have been a Brahmin fabric with 婆罗笼 became 娑罗笼 due to textual corruption and this latter term is now the dominant term. It is still retained by the Tai tribe who wear the Mang Barbarian style of 5 colours in their skirts.

In Anxi, there is a large population of a tribe called 僧耆 '''Sēngqí''' (septenerian monks) which borders the little Brahmin Kingdom. This supports the view that '''Michen''' is likely on the Indawgyi lake than the ocean. &lt;/ref&gt; Men and women greatly like music.
|-
|樓兩頭置鼓，飲酒即擊鼓，男子攜手樓中舞蹈為樂。
|Drums are placed at both ends of the building. Upon drinking they beat drums. The men join hands in the centre of the building and dance for enjoyment.
|-
|在蠻永昌城西南六十日程。
|From the barbarian town of '''Yǒng​chāng​ City''' (永昌城) it is sixty days' journey to the southwest.&lt;ref&gt;Likely the Chindwin corridor of the Kale and Kabaw Valleys. '''Michen''' might stretch from Indawgyi lake to the Chindwin covergence with the Irrawaddy. This placing is consistent with the Xin Tang Shu arguing that it is West of Pyu. &lt;/ref&gt;
|-
|大和九年曾破其國，劫金銀，擄其族三二千人，配麗水淘金。
|In the ninth year of the ''Dahe/Taihe'' reign (2nd February 835) those countries were once defeated [by the Yunnan barbarians], gold and silver were plundered, and two to three thousand prisoners were taken to '''Lí​shuǐ​''' (麗水) to pan for gold.
|}
[[File:中国云南西双版纳1380傣历年_(253863837).jpeg|thumb|娑罗笼 (Suō luó lóng) dresses still retained by the Dai tribe of Yunnan.]]

===The country of ''Biāo'' (驃國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 2 {{mdash}} The country of ''Biāo'' (驃國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|驃國，在蠻永昌城南七十五日程，閣羅鳳所通也。
|The country of '''Biāo''' (驃國) is 75 days' journey south of the barbarian town of '''Yǒng​chāng​''' (永昌)&lt;ref&gt;Likely referencing the capital which at this time would have been ''Śrī Kṣetra'' based on this geography. This means that Minuo and Michen are both northwest of ''Śrī Kṣetra'' as they are 60 stages southwest to the 90 stages south of ''Śrī Kṣetra.'' &lt;/ref&gt;'''. '''
'''Gé​luó​fèng​''' (閣羅鳳) began communication with it.
|-
|其國用銀錢，以青磚為圓城，周行一日程。
|The country uses silver money, green-blue bricks for its circular city [walls], which takes one day stage to encircle by walking.
|-
|百姓盡在城內，有十二門。
|Ordinary citizens completely dwell inside the city, and there are twelve gates.
|-
|當國王所居門前有一大像，露坐高百余尺，白如霜雪。
|At the king's residence in front of the gate is a great statue, which is seated in the open. It is over 100 ''chǐ​'' (ie. 33 meters) in height, white as frost and snow.
|-
|俗尚廉恥，人性和善少言，重佛法，域中並無宰殺。
|Popular [traditional] customs are integrity and honour. The people are of a gentle nature and speak little. They attach importance to Buddhist law, and moreover, universally do not slaughter or butcher.
|-
|又多推步天文。
|They are furthermore skilled in calculating astrology.
|-
|若有兩相訴訟者，王即令焚香向大像，思惟其非，便各引退。
|If there is a case of a two-sided lawsuit, the king orders incense to burn in front of the statue. They reflect their faults as each withdraw [the case].
|-
|其或有災疫及不安穩之事，王亦焚香對大像，悔過自責。
|If there is calamity, plague, and unsteady events, the king also burns incense in front of the statue, repenting and blaming himself.
|-
|男子多衣白氈，婦人當頂為高髻，以金銀真珠為飾，著青婆羅裙，又披羅緞，行必持扇。
|Men mostly wear clothing of white felt. Married women undertake at the top of the head a high topknot. Gold, silver and pearls are used for decoration. They attach blue-gren (brahmin) silkcotton skirts, as well as drape gauze satin. Walking, they must hold fans.
|-
|貴家婦，皆三人五人在傍持扇。
|Elder family noblewomen always have three to five people at their side holding fans.
|-
|有移信使到蠻界河賧，則以江豬、白氈及琉璃、罌為貿易（案：「罌」原本作「盟」，「貿易」原本作「加」，今從《新唐書·驃國傳》改正）。
|There are couriers going to the barbarian border of '''Hé dàn (河賧)''', they bring porpoises, white felt and coloured stones &lt;ref&gt;Historically referring to a blue translucent stone thought to know be lapis lazuli.&lt;/ref&gt; in small-mouthed jars for trade.
&lt;span style=&quot;color:#f00&quot;&gt;（案：「罌」原本作「盟」，「貿易」原本作「加」，今從《新唐書·驃國傳》改正）。&lt;/span&gt;
|-
|與波斯及婆羅門鄰接，西去舍利城二十日程。
|It borders Persia and India.&lt;ref&gt;There are Persian tribes in the south port cities of Myanmar and Thaton region according to this text. This suggests that they were sailor communities seen as an extension of the Persian Stat possibly. &lt;/ref&gt;  It is 20 day stages westward to '''Sheli''' (舍利城; lit. 'city of post-cremation relics'; Vaisali, or the Arakanese Waithali copying it.&lt;ref&gt;Based on history and the location claimed, this appears to be Waithali, the adopted name of Vaishali, Vesali or Vaiśālī in the modern Arakan State. The original Vaishali is in Patna Bihar, a historically Buddhist stronghold. Fan Chuo likely equated this to Buddhist text not understanding the polity governing there held the same name. Waithali was a coastal Rakhine Kingdom, highly indianized and west of Sri Ksetra, the Pyu Capital around 20 day stages. This puts into question of Minuo and Michen's locations. 

[http://www.world10k.com/blog/?p=1305 An external site discusses the toponym's appearance in a range of ancient Chinese texts], but fails to draw any conclusions. From a religious perspective it seems that Buddhism may have been responsible for the toponym's etymology, and this would strongly suggest a city in the Uttar Pradesh region. Given the specific reference to this single city it is likely a large city rather than a small town, which would tend to discount the place of the historical Buddha's death in favour of nearby large cities. The most likely contender seems to be Varanasi. Another option is Patna, however it does not seem to support the toponym's etymology.&lt;/ref&gt;).
|-
|據《佛經》：「舍利城，中天竺國也。近城有沙山，不生草木」。
|According to ''Buddhist Scripture'', &quot;'''Shelicheng''' (舍利城; lit. 'city of post-cremation relics') is in the middle of India.&lt;ref&gt;I believe Fan Chuo is mixing up the Arakanese Waithali with the Indian Vaisali. &lt;/ref&gt; Near the city lies the '''Sand Mountains''' (沙山), upon which trees and grasses do not grow.&quot;
|-
|《恒河經》雲：「沙山中過」，然則驃國疑東天竺也。
|According to the ''Héng​ Hé​ Jīng​'' (恆河經; lit. 'Ganges River Scripture'), &quot;Crossing the Sandy Mountains&quot;. So thus '''Biào​ Guó''' (驃國; lit. 'The Country of the White Horse') is suspected to be east of India.&quot;
|-
|蠻賊大和六年劫掠驃國，虜其眾三幹余人，隸配柘東，令之自給。
|In the 6th year of the ''Dahe'' reign (ie. ~832), the barbarians bandits plundered '''Biào​ Guó''' (驃國; lit. 'The Country of the White Horse'), capturing their masses of 3000 people, subordinating them to join '''Tuodong''' (柘東; Kunming between the Panlong River and North Bank of Dianchi Lake) and ordered to be self-sufficient.
|-
|今子孫亦食魚蟲之類，是其種末也。
|To this day, their children and grandchildren [descendants] still consume fish, insects and alike. This is an offshoot of the same people.
|-
|鹹通四年正月六日寅時，有一胡僧裸形，手持一仗，束白絹，進退為步，在安南羅城南面。
|In the early daylight hours on the '''sixth day of the first month of the lunar year (28 January)''', in the '''4th year of the ''Xiantong'' reign (863 A.D)''', a naked monk from the western regions, holding in his hand a weapon and bound with white silk&lt;ref&gt;This is likely an Indian Brahmin monk. 胡僧 is a term relating to a monk from the western regions, Buddhists from central asia, or Hindu-Buddhists from India. Indian Brahmins historically wore white robes so this suggests to me that this man was an Indian monk. &lt;/ref&gt; walked back and forth toward the city wall south of '''Ān​nán''' (安南; ie. Hanoi).
|-
|本使蔡襲當時以弓飛箭，當胸中此設法胡僧，眾蠻扶舁歸營幕。
|'''Comissioner Cài Xí (本使蔡襲)''', at once grabbed a bow and fired an arrow at the centre of the chest of this monk from the western regions seeking to do something. Masses of barbarians aided by carrying [him on their shoulder] back to the barracks tents. 
|-
|城內將士無不鼓噪。
|Inside the fortress, military officers invariably made commotion [by beating the drums of war while shouting loudly at the enemy]
|}

===The country of ''Kūnlún'' (昆侖國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 3 {{mdash}} The country of ''Kūnlún'' (昆侖國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|昆侖國，正北去蠻界西洱河八十一日程。
|The '''State of'''  '''Kūnlún (昆侖國)'''&lt;ref&gt;This location is disputed. It is either the Salween River Delta or further South to the port city of Thagara. I nominate the former. This entry in the '''[https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7222%E4%B8%8B#%E9%A9%83 New Book of Tang (新唐书)]''' states that the Kunlun Kingdom's rivers and plains are larger than Michen. If Michen is in the north by Indawgyi lake and stretches down to the Chindwin joining the Irrawaddy, then this placement makes sense for the Book of Tang to record the relative placement of kingdoms. &lt;/ref&gt; due north to the barbarian border of the '''Xīěr River (西洱河)''' is 81 day stages.
|-
|出青木香、檀香、紫檀香、檳榔、琉璃、水精、蠡坯等諸香藥、珍寶、犀牛等。
|It exports elephants, green fragrant wood, sandalwood, purple sandlewood, areca, glazed pearls, crystals, seashell cups and other gragrant medicine, jewels, rhinocerous horns, etc.
|-
|蠻賊曾將軍馬攻之，被昆侖國開路放進軍後，鑿其路通江，決水掩浸，進退無計。
|Barbarian bandits once led troops and cavalry to attack. The '''State of''' '''Kūnlún (昆侖國)''' opened the route allowing the army to move forward. They chiselled a river to connect to their road. The water's breach covered and submerged. They lacked a plan to advance or retreat.
|-
|餓死者萬余，不死者昆侖去其右腕放回。
|Ten thousand starved to death, the ones who didn't die die, the '''Kūnlún (昆侖)''' discarded their right forearm and allowed them to return.
|}

=== The Greater Qín Brahmin Country (大秦婆羅門國) ===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 4 {{mdash}} The Greater Qín Brahmin Country (大秦婆羅門國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|大秦婆羅門國，界永昌北，與彌諾國江西正東（案：此句疑有脫誤）安西城樓接界，東去蠻陽苴咩城四十日程。
|The '''Greater Qín Brahmin Country (大秦婆羅門國)'''&lt;ref&gt;'''NAME DISCUSSION:'''

The name 大秦 (colloquially meaning &quot;Roman&quot; or &quot;Byzantine&quot;) is used in the Nazhao Dehua Stele. The paragraph on the 寻传 mentions that west of them is 大秦. This probably meant this kingdom. The reason they use this name is likely due to the silk route &quot;ending&quot; at the Byzantine territory and so silk route affiliations carry this name. 

Zhao RuKuou's [https://storymaps.arcgis.com/stories/39bce63e4e0642d3abce6c24db470760 諸蕃志] mentions that the kings of India were elected by 大秦 likely meaning that they were chosen for the silk route where they could tax the merchants passing through. 大秦 is also mentioned as Byzantine.&lt;/ref&gt;&lt;ref&gt;'''STATE IDENTIFICATION''':

This is strongly suggested to be the eastern autonomous region of Kamarupa. Kamarupa was under the mlecchha dynasty during the 7-10th centuries. Lahiri in [https://www.scribd.com/document/905970705/Pre-Ahom-Assam-by-Nayanjot-Lahiri Pre-Ahom Assam] (p.78) mentions that the mlecchha dynasty was decentralized. The Tezpur Rock Inscription records a settling of waterway dispute. Sucitta a vassal king of Harjaravarman held his own army with judicial powers and levying rights of men and taxes. Below Sucitta was another subordinate office holder Silakuttakavaleya. This would explain why Jia Dan in his document [https://zh.wikisource.org/wiki/%E6%96%B0%E5%94%90%E6%9B%B8/%E5%8D%B7043%E4%B8%8B &quot;Routes Leading Abroad from China&quot; in the &quot;New Book of Tang]&quot; states that it is another 300''li'' to enter Kamarupa from the Daqin Brahmin territory （西渡彌諾江水，千里至大秦婆羅門國。又西渡大嶺，三百里至東天竺北界箇沒盧國。）. The Mikir-Rengma hills divides Tezpur the Kamarupa capital from the eastern part of the country. This would evidently suggest that Daqin is an autonomous area of eastern Kamarupa.&lt;/ref&gt;  lies on the northern border of Yǒngchāng and west of the '''Mínuò Kingdom's''' River. Due east is the border of the '''Anxi (安西)''' Gatehouse/ Fortress. Going East to the Barbarian city of '''Yángjūmiē (陽苴咩)''' takes 40-day stages.
|-
|蠻王善之，街來其國（案：此八字文不相屬，疑有脫誤）。
|The Barbarian King is friendly to them, markets and fairs come to that country. (Editorial note: “These eight characters do not connect coherently in meaning, and the passage is suspected to contain omissions or textual corruption.”)&lt;ref&gt;The Omission is likely: 市 which would make it undoubted that its referring to commercials markets and fairs. &lt;/ref&gt;
|}

===The 'Lesser Brahman' Country (小婆羅門)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 5 {{mdash}} The 'Lesser Brahman' Country (小婆羅門)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|小婆羅門，與驃國及彌臣國接界，在永昌北七十四日程。
|The '''Lesser Brahmin Country (小婆羅門国)''' &lt;ref&gt;In earlier chapters we learn that this kingdom is north of Anxi in present day Mogaung. Hence, this kingdom is likely situated in the Hukawng Valley. &lt;/ref&gt; borders the State of '''Pyu''' '''(驃國)''' and '''Michen (彌臣國)'''. It is 74 day stages north of '''Yǒngchāng (昌北).'''&lt;ref&gt;I suspect an omission of 西，as the Hukawng valley is northwest of Yongchang (Baoshan)&lt;/ref&gt;
|-
|俗不食牛肉，預知身後事。
|As a custom, they do not consume cattle meat.&lt;ref&gt;This seems to indicate more orthodox Hindu traditions rather than Buddhist ones. This means that the 僧耆 (septenarian monks) in Anxi are likely Indian monks and hermits living in the Hukawng Valley area. They are also treated as a tribe and recruited for war as mentioned in the siege of Songping extracts. Likely an Indian tribe in the northwest with vague Hindu traditions and monks among them.&lt;/ref&gt; They have beforehand knowledge of what happens after life (belief in an afterlife).   
|-
|出見齒、&lt;蟲葛&gt;、越諾。
|They export cowry shells, ivory, white wax and '''Yuènuò (越諾).'''&lt;ref&gt;A type of cloth of fabric which comes from Persia and Afghanistan. This indicates that the kingdom was along the silk route at the time.The other products are also not locally produced in the Hukawng region suggesting that it grew as a trade outpost of the 大秦婆罗门 (Greater Qin Brahmin Kingdom) who managed the trade route. Jia Dan did not mention this kingdom at all in his routes suggesting that this outpost grew in the decades after his manuscript. Jia Dan's routes go straight from Anxi to Daqin.  &lt;/ref&gt;
|-
|其大耳國往來，蠻夷善之，信其國。
|They have relations with '''Big Ear Kingdom''' (大耳国)&lt;ref&gt;Gordon Luce believes this to be the Kadu who were known for large ear piercings which would stretch out their lobes. &lt;/ref&gt;, the barbarian king is friendly to them and communicates with that country.&lt;ref&gt;Can also be read as: The Barbarian king is friendly to them and places trust in that country. &lt;/ref&gt;
|}

===The 'Midnight' Country (夜半國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 6 {{mdash}} The 'Midnight' Country (夜半國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|夜半國，在蠻界蒼望城，東北隔麗水城。
|The State of Yeban lies northeast of the barbarian border city of '''Cāngwàng''' '''(蒼望)''' across the '''Lìshuǐ''' '''City's''' '''(麗水城)''' river plains.&lt;ref&gt;They are situated within Nanzhao's own territory. They are likely a hill tribe who are geographically fortified.&lt;/ref&gt;
|-
|其部落婦人唯與鬼通能知吉兇禍福本土君長崇信。
|That tribe's women are able to communicate/ connect with spirits to know auspicious and terrible fortunes and misfortunes. The local chieftains venerate them.&lt;ref&gt;Female fortune tellers and divination is a common practiced among the Kachin and Zo people. It was separated from the religious aspect of sacrifice and feasting but was important to identify spirits who caused sickness and illness in people. &lt;/ref&gt;
|-
|蠻夷往往以金購之，要知善惡。
|Barbarians often pay with gold, wanting to know good and evil (outcomes).
|-
|昆明、牂牁界接麗水，相近蠻賊曾攻不得，至今銜恨之。
|The '''Kūnmíng''' '''(昆明)''' and '''Zānggē''' '''(牂牁)''' are close to the border of '''Lìshuǐ (麗水)'''. Barbarian badits once attacked and failed. To this day, they bear resentment.
|-
|昆明、牂牁，本使臣蔡襲嘗奏請分布軍馬，從黔府路入（案：此條之首，當有脫文）。
|With regards to '''Kūnmíng''' '''(昆明)''' and '''Zānggē''' '''(牂牁), your servant, commissioner Cài Xí (本使臣蔡袭)''' attempted a formal request to distribute (soldiers) and war horses to enter into route from the ''Qián'' prefecture capital. 
|}

===The Country of the Queen (女王國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 7 {{mdash}} The Country of the Queen (女王國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|女王國，去蠻界鎮南節度三十余日程。
|The '''Queen's Kingdom''' '''(女王國)'''&lt;ref&gt;This is likely the Mon Kingdom of Haripuñjaya. It's founder was a legendary queen Jamadevi around 750AD. Haripuñjaya is situated in modern day '''Lamphun (เมืองลำพูน)''' and was largely a valley settlement which expanded to a significant territory of northwest Thailand. &lt;/ref&gt; to the barbarian border '''Jiédù (節度) of''' '''Zhènnán (鎮南)''' is over thirty day stages.
|-
|其國去驩州一十日程，往往與驩州百姓交易。
|That country to '''Huānzhōu (驩州)''' is ten day stages. Ordinary citizens regularly trade and make business.
|-
|蠻賊曾將二萬人伐其國，被女王藥箭射之，十不存一，蠻賊乃回。
|Barbarian bandits one led nearly twenty thousand people to defeat that country. The queen's poisoned arrows were shot at them and not even a tenth remained. The barbarian bandits thus returned.
|}

===The countries of ''Water Zhenla'' (水真蠟國) and ''Land Zhenla'' (陸真蠟國)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 8 {{mdash}} The countries of ''Water Zhenla'' (水真蠟國) and ''Land Zhenla'' (陸真蠟國)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|水真蠟國、陸真蠟國，與蠻鎮南相接，蠻賊曾領馬軍到海畔，見蒼波洶湧，悵然收軍卻回（案：此篇乃載南蠻接壤之國，自此以下，皆別說他事，蓋附錄之文，傳寫失其標目耳。
|'''Water Zhēnlà (水真蠟國)''' and '''Land Zhēnlà (陸真蠟國)''' join with '''Zhènnán (鎮南)'''. Barbarian bandits once led cavalry to the boundary of the water, seeing the turbulent, blue-green waves, the army despondently withdrew and retreated.
|-
|今各低一格，以別之）。
|Now each has been lowered by one rank in order to distinguish them.
|}

===''Nánzhào'' (南詔)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 9 {{mdash}} ''Nánzhào'' (南詔)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|鹹通四年六月六日，蠻賊四千余人，草賊朱道古下二千人，共棹小船數百只收郡州（案：《通鑒考異》引《唐實錄》以「郡州」為「交州」，《補國史》亦同。是「郡州」乃州名也），得安南都押衙張慶宗、杜存陵、武安州刺史陳行余（案：《新唐書·地理誌》武安州屬安南都護府），以航舶戰船十余只，築損蠻賊船三十來只沈溺。
|
|-
|臣九月二十一日，於膝州見安南虞候史孝慜，並得兵馬使徐崇雅信，蠻賊不解水，悉皆溺死。
|
|}

===The Tibetan Tubo Dynasty (吐蕃)===
{| class=&quot;wikitable&quot; style=&quot;text-align:center; width:80%;&quot;
|+ Chapter 10: Part 10 {{mdash}} The Tibetan Tubo Dynasty (吐蕃)
|-
! scope=&quot;col&quot; | Original
! scope=&quot;col&quot; | Translation
|-
|吐蕃鐵橋節度本屬吐蕃，貞元十年，蒙異牟尋攻破，今並屬蠻管（案：「吐蕃鐵橋」節度以下二十五字，文義與上文不相屬，是亦他處錯簡於此）。
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|異牟尋曾詐臣事吐蕃，吐蕃遂封異牟尋江。
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|西卑賤，（案：以下皆紀冊封南詔之事，此二十字文不用周，蓋所紀冊封一事，佚其前段，而此條佚其後段耳，今不可考，姑仍其舊）因遣曹長段南羅各同倫判官趙伽寬等九人，與南詔清平官尹輔酋及親信李羅劄將大馬二十匹迎，子弟羽儀六人沿路視事。
|
|-
|十五日至安南城。城使段伽諾出步軍二百隊，馬軍一百隊夾道排立，帶甲馬六十隊引前，步槍五百人隨後，去城五十裏迎候。
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|十九日到曲驛。
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|鎮使楊盛出馬軍一百三十隊、步軍一百七十隊，夾道排立，帶甲馬二百人引前，步槍三百人隨後，去驛一十裏迎接。
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|二十一日過吹舍川。
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|首領父老百余人，蠻夷百姓數千人，路傍羅列而拜，馬上送酒。
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|雲南節度將五十匹馬來迎。
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|二十三日到雲南城。
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|節度蒙酋物出馬軍一百隊，步軍三百人夾道排立，帶甲馬一十隊引前，步槍五百人隨後，去城十一裏迎候。
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|門前父老二百余人，吐蕃封王數人，在路迎拜。
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|是日，南詔使大軍將兼戶曹長王各苴來迎。
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|二十四日到白崖城。
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|城使尹瑳出馬軍一百隊，步軍二百隊夾路排立，引馬六十匹，步槍五百人，去城五裏迎候。
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|南詔遣大軍將李鳳嵐，將細馬一千匹並伎樂來迎。
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|渠斂道中路客館館前父老二百余人，蠻夷百姓五六十人，路迎馬前。
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|大軍將喻於念出馬步軍三百隊夾路排立，引馬六十匹，步槍三百人，去城五裏迎候。
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|南詔妹李波羅諾將細馬一十匹來迎。
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|入龍尾城客館。
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|南詔異牟尋叔父阿思將大馬二百匹來迎。
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|二十六日過大和城，南詔異牟尋從父兄蒙細羅勿（案：「羅勿」原本作「四勾」，今據《新唐書》改正）及清平官李異傍、大軍將李千傍等，將細馬六十匹來迎，皆金錟玉珂，拂髦振鐸（案：「振」原本作「根」，今據《新唐書》改正）。
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|夾路馬步軍排隊二十余裏。
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|南詔蒙異牟尋出陽苴咩城五裏迎。
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|先飾大象一十二頭引前，以次馬軍隊，以次伎樂隊，以次子弟持斧鉞。
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|南詔異牟尋衣金甲，披大蟲皮，執雙鐸。
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|男蒙閣勸在傍，步槍千余人隨後，馬上祗揖而退（原缺）「曰授冊」（原缺），貞元十年十月二十七日陽苴咩城具儀註設位，旌節當庭，東西特立。
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|南詔異牟尋及清平官已下，各具儀禮，面北序立，宣慰南詔使東向立，冊立南詔使南向立，宣敕書，讀冊文訖（案：此條「冊」字原本俱訛作「開」，今據文改正），相者引南詔蒙異牟尋離位受冊，次受貞元十年歷日。
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|南詔及清平官已下稽顙再拜，手舞足蹈。
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|慶退而言：「牟尋曾祖父開元中冊雲南王，祖父天寶中又蒙冊襲雲南王。
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|自隔大國，向五十年。
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|貞元中，皇帝聖明，念錄微效，今又賜禮命，復睹漢儀，對揚天休，實感心肺。」其日樓下大會，又坐上割牲，用銀平脫馬頭盤二面。
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|牟尋曰：「此是天寶初先人任鴻臚少卿宿衛時（案：「衛」上原脫「宿」字，今補入），開元皇帝所賜。比寶藏不敢用，得至今。」又伎樂中有老人吹笛，婦人唱歌，各年近七十余。
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|牟尋指之曰：「先人歸蕃來國，開元皇帝賜胡部及龜茲音聲各兩部。今死亡零落盡，只余此二人在國。」酒既行，牟尋自捧杯擎跽勸讓。
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|冊立使袁滋引杯釃酒曰：「南詔當深思祖宗緒業，堅守誠信，為西南藩屏，使後嗣有以傳繼也。」異牟尋噓嘻曰：「敢不承命！」其年十一月七日事畢，發陽苴咩城。
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|雲南王蒙異牟尋以清平官尹輔酋十七人奉表謝恩，進納吐蕃贊普鍾印一面（案：《通鑒》吐蕃謂弟為鍾，南詔服吐蕃時，封為贊普鍾日東王）並獻鐸鞘、浪川劍、生金、瑟瑟、牛黃、琥珀、白氈、紡絲、象牙、犀角、越賧馬、統備甲馬、並甲文金，皆方土所貴之物也。
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|仍令大軍將王各苴、柘東副使杜伽諾具牛羊，領鞍馬及丁夫三百人提荷食物。
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|其年十一月二十四日送至石門，從石門更十日程到茂州。
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|自後南蠻移心向化，遂與吐蕃仇隙。
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|伏緣數年之間，當州鎮厘革南詔入朝人數，縱有經過者，郵傳殘薄。
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|兼緣安南大中年（案：原本作「大中牟」，今據《唐書》及《通鑒》，宣宗大中十三年，杜棕為西川節度使，奏請節減南蠻習學子弟及入貢傔從人數，南詔怒，自是頗擾邊境，書中所說，當指此事。
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|「牟」字蓋「年」字之訛，謹改正）奏請隔絕南詔往來通好，謹按《尚書》雲：「撫我則後，虐我則仇」。
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|本使蔡襲去年正月十四日內，四度中矢石，家口並元隨七十余人，悉殞於賊所。
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|臣長男韜及奴婢一十四口，並陷蠻陬。
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|臣夙夜憂憶本使蔡襲，行坐痛心。
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|切以蠻賊尚據安南，今江源並諸州各自固守，其首領將吏，去年春夏頻請救兵。
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|自是海門（案：安南既陷，以海門鎮為行交州）不與發遣，並不給與戈甲弓弩，致令蠻賊侵掠州軍。
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|臣以南蠻從古及今，凡虜掠諸處百姓夷獠隸也處則貴。江源首領已下，知其配隸之事，固惜副卿必合戮力齊心，共禦蠻夷之殘暴（案：「臣」以下五十一字，文義未詳，且不相屬，當有脫誤）。
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|又黔、涇、巴、夏四邑苗眾，鹹通三年春三月八日，因入賊朱道古營柵，竟日與蠻賊將大羌楊阿觸、楊酋盛、柘東判官楊忠義話，得姓名，立邊城，自為一國之由。祖乃盤瓠之後，其蠻賊楊羌等雲綻盤古之後（案：「綻」字有訛）。
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|此時緣單車問罪，莫能若是（案：「若」字有訛）。
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|鹹通五年六月，左授夔州都督府長史，問蠻、夷、巴、夏四邑根源，悉以錄之，寄安南諸大首領。
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|詳錄於此，為《蠻誌》一十卷事，庶知南蠻首末之序（案：以下六條，又附錄中旁及之文，今再低一格以別之）。
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|謹按《後漢·南蠻傳》，昔高辛氏有戎寇吳將軍為患其侵暴，乃下敕曰：「有人得戎寇吳將軍頭者，賜金百鎰，封邑萬家，妻以少女。」時帝有犬名盤瓠，後遂之寇所，因嚙得吳將軍頭來，其寇遂平。
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|帝大喜，因以官爵賚賜，犬不起。
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|帝少女聞之，奏曰：「皇帝信不可失！深憂犬之為患。」帝曰：「當殺之。」女曰：「殺有功之犬，失天下之信矣！」帝曰：「善乎！」因請匹之。
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|帝不得已。
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|乃以配盤瓠。
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|盤瓠得女，負入南山，處於石室。
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|其處險阻，不通人跡。
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|後生十二子，六男六女，自相匹偶，緝草木皮以為衣服。
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|帝賜以南山，仍起高欄為居止之。
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|其後滋蔓，自為一國（案：此文與今《後漢書·南蠻傳》不同）。
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|按王通明《廣異記》雲：「高辛時，人家生一犬，初如小特，主怪之，棄於道下。七日不死，禽獸乳之，其形繼日而大，主人復收之。當初棄道下之時，以盤盛葉覆之，因以為瑞，遂獻於帝，以盤瓠為名也。後立功，嚙得戎寇吳將軍頭，帝妻以公主，封盤瓠為定邊侯。公主分娩七塊肉，割之，有七男，長大各認一姓，今巴東姓田、雷、再、向、蒙、旻、叔孫氏也。其後苗裔熾盛，從黔南逾昆、湘、高麗之地，自為一國。幽王為犬戎所殺，即其後也。盤瓠皮骨，今見在黔中，田、雷等家時祀之。」
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|巴中有大宗，廩君之後也。
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|《漢書》巴郡本有四姓，巴氏、繁氏、陳氏、鄭氏，皆出於武落鍾離山。
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|其山黑、赤二穴，巴氏之子生於赤穴，繁、陳、鄭三姓生於黑穴。
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|未有君長，俱事鬼。
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|乃其擲劍於石穴，約能中者，奉以為君。
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|巴氏子務相獨中之。
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|又令乘土船下夷水到鹽陽，約能浮者為君。
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|務相獨浮，因立務相為君也。
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|遂有神女謂廩君曰：「此地廣大，魚鹽所出，請為留之。」廩君不許。
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|神女暮來取宿，晨則化為飛蟲，群蔽日月，天地晦冥，積十余日。
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|廩君伺其便射之，天乃開朗。
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|廩君方定居於夷水，三姓皆臣事之。
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|廩君死，魂魄化為白虎，及惠王並巴蜀，以巴夷為蠻夷君，尚女。
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|其人有罪，得以爵除。
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|出賦二千一十六百萬錢，三歲一出義賦一千八百錢，人出幏布八丈二尺，雞羽三十鍭也（案：此文與今《後漢書·南郡蠻傳》稍有異同）。
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|巴氏祭其祀，擊鼓而祭，白虎之後也。
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|按《華陽國誌》，秦昭王時，白虎為害，多傷人。
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|乃購之曰：「有殺得白虎者，封邑千家，繼以金帛」。
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|於是朐忍夷、廖仲藥等，以竹弩射之，中而死。
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|秦遂刻石，為夷人立盟曰：「夷人頃田不租，十妻不算，傷人不論。秦犯夷，輸黃龍一只；夷犯秦，輸清酒一鐘。」夷人遂因號虎夷，一名弦頭，剛勇頗有先人之風（案：所引《華陽國誌》與今本文稍不同）。
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|按《秦紀》，「始皇十八年，巴郡出大人，長二十五丈，一夫兩妻，號曰左右也。」是故左思《蜀都賦》雲：「剛勇生其方，風謠尚其武。」
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|按《夔城圖經》雲：「夷事道，蠻事鬼。」初喪，鼙鼓以為道哀，其歌必號，其眾必跳，此乃盤瓠白虎之勇也。俗傳正月初夜，鳴鼓連腰以歌，為踏虎之戲。
|
|-
|五月十五日，招命騎健，畫楫圖舟，十船同角，千人齊聲唱鼓扣舷，沿江騰波而下。
|
|-
|俗三月八日為大節，以陳祠享，振鐸、擊鼓、師舞為敬也。
|
|-
|夷蜑居山谷（「蜑」即蠻之別名），巴夏居城郭。與中土風俗、禮樂不同。
|
|-
|雲南詔蒙異牟尋與中國誓文，臣今錄白進獻。
|
|-
|貞元十年，歲次甲戌，正月乙亥，五月己卯，雲南詔異牟尋及清平官、大軍將與劍南西川節度使崔佐時（案：崔佐時乃韋臯所遣西川節度巡官，不可直稱節度使，疑有脫文）謹詣玷蒼山北，上請天、地、水三官，五嶽、四瀆及管川谷諸神靈同請降臨，永為證據。念異牟尋乃祖乃父忠赤附漢。
|
|-
|去天寶九載，被姚川都督張乾拖等離間部落，因此與漢阻絕，經今四十三年。
|
|-
|與吐蕃洽和，為兄弟之國。
|
|-
|吐蕃贊普冊牟尋為日東王，亦無二心，亦無二誌。
|
|-
|去貞元四年，奉劍南節度使韋臯仆射書，具陳漢皇帝聖明，懷柔好生之德。
|
|-
|七年，又蒙遣使段忠義等招諭，兼送皇帝敕書。
|
|-
|遂與清平官、大軍將、大首領等密圖大計，誠矢天地，發於禎祥；所管部落，誓心如一。
|
|-
|去年四月十三日，差趙莫羅眉、揚大和眉等賫仆射來書，三路獻表，願歸清化，誓為漢臣。
|
|-
|啟告祖宗明神，鑒照忠款。
|
|-
|今再蒙皇帝蒙劍南西川節度使韋臯仆射遣巡官崔佐時傳語，牟尋等契誠，誓無遷變。
|
|-
|謹請西洱河、玷蒼山神祠監盟，牟尋與清平官洪驃利時、大軍將段盛等請全部落歸附漢朝，山河兩利，即願牟尋、清平官、大軍將等福祚無疆，子孫昌盛不絕，管諸賧首領永無離二。
|
|-
|興兵動眾，討伐吐蕃，無不克捷。
|
|-
|如會盟之後，發起二心，及與吐蕃私相會合，或輒窺侵漢界內田地，即願天地神祗其降災罰，宗祠殄滅，部落不安，災疾臻湊，人戶流散，稼穡產畜悉背減耗。
|
|-
|如蒙漢與通和之後，有起異心，窺圖牟尋所管疆土，侵害百姓，致使部落不安，及有患難不賜救恤，亦請準此誓文，神祗共罰。
|
|-
|如蒙大漢和通之後，更無異意，即願大漢國祚長久，福盛子孫，天下清平，永保無疆之祚。
|
|-
|漢使崔佐時至益州，不為牟尋陳說，及節度使不為奏聞牟尋赤心歸國之意，亦願神祗降之災。
|
|-
|今牟尋率眾官具牢醴，到西洱河，奏請山川土地靈祗。
|
|-
|請漢使計會，發動兵馬，同心戮力，共行討伐。
|
|-
|然吐蕃神川、昆侖、會同已來，不假天兵，牟尋盡收復鐵橋為界，歸漢舊疆宇。
|
|-
|謹率群官虔誠盟誓，共克金契，永為誓信。
|
|-
|其誓文一本請劍南節度隨表進獻，一本藏於神室，一本投西洱河，一本牟尋留詔城內府庫，貽誡子孫。
|
|-
|伏惟山川神祗，同鑒誠懇！
|
|-
|某年六月二十一日奏狀，今謹錄白獻進（案：後題貞元十年奏狀，而此闕其年，亦刊削不盡之文）
|
|-
|東蠻和使楊傳盛等，六月十八日到安南，賫蠻王蒙異牟尋與臣絹書一封，並金鏤合子一具。
|
|-
|合子有綿，有當歸，有朱砂，有金。
|
|-
|石東蠻國王是故雲南詔王閣羅鳳孫，姓蒙，名異牟尋。
|
|-
|遣前件使賫表詣闕，於今月十八日到，兼得其王牟尋與臣書，遠陳誠懇，並金鏤合子一枚。
|
|-
|其使昧言，送合子中有綿者，以表柔服，不敢更與為生梗；有當歸者，永願為內屬；有朱砂者，蓋獻丹心向闕；有金者，言歸義之意，如金之堅。
|
|-
|又言：蠻王蒙異牟尋積代唐臣，遍沾皇化。
|
|-
|天寶年中，其祖閣羅鳳被邊將張乾拖讒構，部落驚懼，遂違聖化，北向歸投吐蕃贊普。
|
|-
|以贊普年少，信任讒佞，欲並其國。
|
|-
|蒙尋遠懷聖化，北向請命。
|
|-
|故遣和使，乞釋前罪，願與部落竭誠歸附。
|
|-
|緣道遐阻，伏恐和使不達，故三道遣：一道出石山，從戎州路入；一道出夷獠，從黔府路入；一道出夷獠，從安南路入。
|
|-
|其楊傳盛等，今年四月十九日從蠻王蒙異牟尋所理大和城發，六月十八日到安南府。
|
|-
|其和使楊傳盛年老，染瘴虐，未得進發。臣見醫療，候獲稍損，即差專使領赴闕廷。
|
|-
|其使雲：「異牟尋自祖父久背國恩，今者願棄豺狼之思，歸聖人之德。此皆陛下雨露之澤及外夷，故蠻僥遐荒，願為內屬。臣忝領蕃鎮，目睹升平，踴躍忻歡，倍萬常幸。」右蠻王與臣書及金鏤合子等，謹差十將李茂等隨表奉進，謹奏。
|
|-
|貞元十年六月二十一日，安南都護充管內節度觀察處置等使、檢校工部尚書、禦史大夫、臣「趙昌奏狀。」
|
|-
|貞元十年，南詔蒙異牟尋請歸附聖唐，願充內屬，盟立誓言，永為西南藩屏。
|
|-
|臣今於安南郡州溪源首領耆老處借得故蠻王蒙異牟尋《誓文》一本，安南都護趙昌貞元十年《奏狀白》一本。
|
|-
|伏以故南詔蒙異牟尋嗣孫惠龍不守祖父留訓，既違盟誓，自掇禍殃，尚未悛心，猶恣狂暴，全驅蟻聚之眾，攻劫邕、交之人。
|
|-
|五載興兵，三來虜掠。
|
|-
|顧生靈之何負，受塗炭之苦辛。
|
|-
|臣去年正月二十九日，已錄蠻界程途及山川、城鎮、六詔始末、諸種名數、風俗條教、土宜物產、六名&lt;貝僉&gt;號、連接諸蕃，共纂錄成十卷，於安南郡州江口附襄州節度押衙張守忠進獻。
|
|-
|今臣謹錄故蠻王蒙異牟尋貞元十年《誓文》及趙昌《奏狀白》隨表奉進以上。
|
|}

{{BookCat}}</text>
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  </page>
  <page>
    <title>Death Stranding</title>
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    <id>466430</id>
    <revision>
      <id>4636898</id>
      <parentid>4636824</parentid>
      <timestamp>2026-05-21T15:57:55Z</timestamp>
      <contributor>
        <username>Xania</username>
        <id>40302</id>
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      <text bytes="17322" sha1="obwcn8xfppb38nd5s7dz4co0gtkp2ck" xml:space="preserve">This video game is not a game, but a piece of extraordinary art.
In Death Stranding, you assume the role of a delivery man after a cataclysmic event that forced mankind to retreat into bunkers and small tight knit communities called “knots.” 
There are occasional combats, but the primary mode is to remain undetected (“stealth game”).
This Wikibook can serve as your guide.

== Briefing ==
This section contains circumstances you wish you had known ''before'' playing the game.
It does not contain any spoilers.

=== Non‐Technical ===
; Slow Narration&amp;#58; Death Stranding Can be a ''Looooooong'' Game
: Depending on how you would like to play the game, expect anything between 40 hours at the ''Very Easy'' setting focusing just on the main story missions to over 800 hours at the ''Very Hard'' game difficulty setting completing everything to perfection on your own (= offline, ''without'' connecting to the internet).
; Watch Your Mental Health
: Death is an ever‐present topic in this video game. If you play the game over the course of multiple years, consider the chance that you may witness death in your social sphere, too. ''The combination'' of death in real life and (the topic of) death in virtuality may become too much to cope with. To get a good night’s sleep avoid playing Death Stranding right before going to bed.
; Eastern Region is Tutorial
: It is not advertised as such, but consider the first map ''one long tutorial''. Avoid spending ''excessively more'' time or resources than necessary. At the end of this stage you will transfer to another map where you spend by far the most time. Later you gain the ability to “teleport” should you want to revisit the first map.

=== Technical ===
* You can export your saved game from ''Death Stranding'' to ''Death Stranding Director’s Cut''.
* The best way to play Death Stranding on Steam Deck ''while using the FSR optimization'' seems to be:
** No TDP cap
** 40 {{abbr|FPS|frames per second}} lock (40 Hz)
** Default graphic settings
** FSR set to quality
* Before the game begins you need to enter your birthday and month. Choose a day you like playing on, e. g. a holiday during the cold “indoor” season.

== Answers ==
To avoid unnecessary confusion, this section explains some aspects of the game the in‐game help explains poorly or not at all.
It contains “spoilers” insofar as you ''may'' ask questions, but those questions ''only'' arise if you ''are'' playing the game.

=== Cargo ===
* Although there is “lost” cargo scattered all over the map, you ''will not lose'' any cargo. You can ''deliberately'' let go of cargo by entering the ''Cargo'' menu. In close combat or should you fall very hard, cargo may detach but you will notice that right away as a cargo tag pops up floating above it.

=== Condition ===
* Vehicles remain operational even if damaged 100%. You do not ''have'' to get them repaired.
* Gear does not show wear. Unlike in real life, you do not have to replace anything just because it has been used.

=== Fight ===
* In many video games you can ''find'' ammunition and fill up magazines ''instantly''. In {{abbr|DS|Death Stranding}} there are no ammo packs. Instead, if you carry weapons as you enter your private room, those weapons get a refill. You do not have to destroy and (re‑)fabricate weapons to refill them.

== Tips and Tricks ==
Part of the game is finding things out on your own.
This section contains tips and tricks ''not'' pointed out by the game itself.

=== Game mechanics ===
* Lost cargo and Chiral crystals are spawned at random locations across the world. Should you spot precious cargo or large crystal, head for them ''right away''; it may be gone as soon as you turn around (''literally'' as soon as the object is not in your [third‐person camera’s] view).
* Lost cargo appears at the same spots over and over again, the locations changing a bit with each episode. After you have picked up something at one location, it takes a while before a new item appears in that same spot.
* If lost cargo is undesirable, leave it and go away. After approaching the same location again, some ''random'' lost cargo is generated which may be more to your taste.

=== Objectives ===
* In some missions you deliver materials. Frequently the recipient rewards you by fully or partially sharing the materials you just delivered, i. e. it becomes available for you to use. To maximize profits consider claiming materials from the destination facility right ''before'' delivery so a full reward does not exceed the facility’s resource limits.

=== Navigation ===
* The routes you take ''while'' fulfilling a mission ''stay'' on the map. You cannot erase them. The routes you take while roaming around – gathering resources, collecting lost cargo, and so on – eventually ''disappear'' from the map, even if taken repeatedly. The routes you take form trails – especially rocky or snowy ground is hard to traverse, so a beattrack is a blessing. Therefore, consider exploring the area ''before'' accepting an order so you take a route where you would like a trail to appear ''and stay'' for the remainder of the game. Otherwise you may end up with a trail that is unfavorable.
* Sometimes you can use other porters – non‐playable characters that also deliver cargo – as guides to get through unknown areas. Scan their cargo to find out where they are heading next. Porters do not enter dangerous areas and take routes that ''can'' be traversed without tools (say, ladders).

=== Gear ===
* You can repair and recharge vehicles by giving them a paintjob. Park the vehicle on the elevator and select ''Garage'' from the delivery terminal menu. It is not necessary to rest in your private room.

=== Structures ===
* Upgrading a structure also fully repairs it. You may withhold upgrades until a structure is significantly deteriorated.

== Guide ==
In this section you will ''learn about plot points'' as far as it can prevent loading a saved game or just having a frustrating experience.
For example, the guide may point out an ambush making you lose all your precious belongings, therefore you want to travel light.

=== Eastern Region ===
==== Prologue: Porter ====
When the prologue video ends, recover your dropped items.
Walk a straight line until a cave.&lt;ref name='prologue'/&gt;
Press up to wear sunglasses.
Once the movie ends, go down the cliff from right cross the river and keep pushing toward the city.
There is a force field.
Go right to cross the river.
When you get more items you must maneuver and balance the cargo weight when taking turn or else they fall.

==== 1&lt;sup&gt;st&lt;/sup&gt; Episode: Bridget ====
Getting to the incinerator there are not any enemies.
There is a cutscene then some {{abbr|BT|Beached Thing}}s appear and you get past them holding {{key press|left alt}}&lt;sup&gt;PC&lt;/sup&gt;/{{key press|Rb}}&lt;sup&gt;XBox&lt;/sup&gt;/{{key press|R1}}&lt;sup&gt;{{abbr|PS|PlayStation}}&lt;/sup&gt;.
If they surround you try and get away by hitting {{key press|F}}/{{key press|🗙}}&lt;sup&gt;XBox&lt;/sup&gt;/{{key press|▢}}&lt;sup&gt;{{abbr|PS|PlayStation}}&lt;/sup&gt;.

==== 2&lt;sup&gt;nd&lt;/sup&gt; Episode: Amelie ====
===== 14&lt;sup&gt;th&lt;/sup&gt; Order: Connect Port Knot City =====
While delivering aid package, you can both avoid or fight {{abbr|BT|Beached Thing}} whale with grenades.
If you have the bike park it halfway at the distribution center.&lt;ref name='egp3'/&gt;

=== Central Region ===
==== 3&lt;sup&gt;rd&lt;/sup&gt; Episode: Fragile ====
Withhold building any roads until the [[#25th Order: Road Reconstruction|25&lt;sup&gt;th&lt;/sup&gt; order]], although you may already add materials to ''any but the first'' road segment.

===== 25&lt;sup&gt;th&lt;/sup&gt; Order: Road Reconstruction =====
As you probably already have found out, the Central Region features roads you can build by supplying tons and tons of materials.
The way highways take cannot be influenced, so some sections pass through enemy territories whether you like it or not.
Rest assured, while driving on four short sections of the roads you get close enough to trigger {{abbr|BT|Beached Thing}} warnings, yet you are ''not in danger''.

The 25&lt;sup&gt;th&lt;/sup&gt; order is not be available if you have already completed a highway section on your own accord.&lt;ref name='ns25'/&gt;

==== 6&lt;sup&gt;th&lt;/sup&gt; Episode: Deadman ====
===== 53&lt;sup&gt;th&lt;/sup&gt; Order: Stone Fragment Delivery =====
The [[#54th Order: Escape the Battlefield|next order]] entails combat:
some equipment can be found at the battle field, but you may want to consider gearing up for combat e. g. with armor plates and high‐tech (lethal) weapons.

As soon as you make delivery to the spiritualist, there is a thunderstorm.
The thunder can be heard (almost) all over the map and is extremely annoying (because it sounds cheap: there is no difference between distant and close thunder).

You do not want to take a vehicle to the cabin because you will wake up in {{abbr|MKC|Mountain Knot City}} but your vehicle is parked all the way up in the mountains.

==== 7&lt;sup&gt;th&lt;/sup&gt; Episode: Clifford ====
===== 54&lt;sup&gt;th&lt;/sup&gt; Order: Escape the Battlefield =====
A memory chip can be found in the debris of the cabin that got destroyed at the end of the 53&lt;sup&gt;rd&lt;/sup&gt; order.

=== Western Region ===
{{empty section}}

== References ==
This section contains data that can be accessed from within the game, but the game does not provide an overview as presented here.

=== Resource capacities ===
To plan ahead of your trip, you may want to consult this table to determine how much materials you want to carry to a facility.
These maxima do not apply private lockers; they can store an infinite amount of stuff.
{| class='wikitable sortable' style='margin: auto; text-align: right;'
|+ Maximum resource capacities at maximum connection level
! facility                                                                !! crystals !! resins !! metals !! ceramics !! chemicals !! alloys
|-
! {{abbr|LKC|Lake Knot City}}                                             
|                                                                               1,699 ||  5,238 ||  8,367 ||    5,216 ||     1,912 ||  8,826
|-
! engineer                                                                
|                                                                               1,366 ||  4,092 ||  5,291 ||    3,332 ||     1,668 ||  6,908
|-
! elder                                                                   
|                                                                               1,288 ||  2,897 ||  4,353 ||    2,056 ||     1,584 ||  6,288
|-
! craftsman                                                               
|                                                                               1,414 ||  4,353 ||  5,456 ||    3,332 ||     1,668 ||  7,112
|-
! film                                                                    
|                                                                               1,324 ||  3,311 ||  4,838 ||    2,472 ||     1,848 ||  6,288
|-
! {{abbr|DC|Distribution Center}}{{abbr|S|south of}}LKC                   
|                                                                               1,696 ||  5,720 ||  9,777 ||    6,604 ||     1,984 ||  9,066
|-
! collector                                                               
|                                                                               1,288 ||  2,897 ||  4,353 ||    1,880 ||     1,848 ||  6,288
|-
! junk                                                                    
|                                                                               1,414 ||  4,316 ||  5,396 ||    3,332 ||     1,668 ||  7,112
|-
! weather                                                                 
|                                                                               1,560 ||  4,890 ||  6,947 ||    3,684 ||     1,668 ||  7,028
|-
! timefall                                                                
|                                                                               1,414 ||  4,530 ||  5,476 ||    3,332 ||     1,668 ||  6,848
|-
! {{abbr|SKC|South Knot City}}                                            
|                                                                               1,696 ||  6,614 ||  9,999 ||    6,724 ||     1,984 ||  9,762
|-
! mama                                                                    
|                                                                                     ||        ||        ||          ||           ||       
|-
! cosplayer                                                               
|                                                                               1,288 ||  3,001 ||  4,353 ||    1,880 ||     1,584 ||  6,288
|-
! studio                                                                  
|                                                                               2,662 ||  3,319 ||  4,773 ||    2,472 ||     1,608 ||  6,288
|-
! {{abbr|wayst.|waystation}} {{abbr|N|north of}}MKC                       
|                                                                               1,560 ||  5,090 ||  8,432 ||    3,332 ||     1,668 ||  7,136
|-
! MKCDC                                                                   
|                                                                               1,696 ||  6,994 ||  9,999 ||    6,844 ||     2,008 ||  9,570
|-
! novelist’s                                                              
|                                                                               1,288 ||  2,897 ||  4,353 ||    2,056 ||     1,584 ||  6,288
|-
! roboticist                                                              
|                                                                               1,414 ||  5,478 ||  5,691 ||    5,092 ||     1,668 ||  7,502
|-
! {{abbr|MKC|Mountain Knot City}}                                         
|                                                                               1,696 ||  7,778 ||  9,999 ||    7,896 ||     2,344 ||  9,676
|-
! doctor                                                                  
|                                                                               1,288 ||  4,301 ||  4,353 ||    3,420 ||     1,584 ||  6,570
|-
! mountaineer                                                             
|                                                                               1,324 ||  4,651 ||  4,838 ||    4,108 ||     1,608 ||  6,618
|-
! photographer                                                            
|                                                                                     ||        ||        ||          ||           ||       
|-
! spiritualist                                                            
|                                                                                     ||        ||        ||          ||           ||       
|}
Access the map to find out how much resources are currently stored at a facility.

=== Structure requirements ===
{| class='wikitable sortable' style='margin: auto; text-align: right;'
|+ Resource requirements for structures
! structure                                                               !! crystals !! resins !! metals !! ceramics !! chemicals !! alloys
|-
! zip‐line {{abbr|lv.|level}} 1                                           
|                                                                                     ||        ||        ||          ||           ||       
|-
! zip‐line {{abbr|lv.|level}} 2                                           
|                                                                               0,000 ||  0,000 ||  0,000 ||    0,000 ||     0,240 ||  0,480
|-
! zip‐line {{abbr|lv.|level}} 3                                           
|                                                                                     ||        ||        ||          ||           ||       
|}

== Sources ==
&lt;references&gt;
&lt;ref name='egp3'&gt;{{cite web
| title                = Death Stranding - Episode 2 missions list: How to complete Orders 4 to 16 to bring Port Knot City into the Chiral Network
| date                 = 2019-11-29
| url                  = https://www.eurogamer.net/death-stranding-walkthrough-guide-6027?page=3
| work                 = Eurogamer.net
| access-date          = 2024-05-04
| df                   = mdy-all
}}&lt;/ref&gt;
&lt;ref name='prologue'&gt;{{cite web
| title                = Death Stranding Walkthrough Guide: Prologue Tips - GameSpot
| date                 = 2021-09-24
| url                  = https://www.gamespot.com/gallery/death-stranding-walkthrough-guide-prologue-tips/2900-3162/
| work                 = Gamespot
| access-date          = 2024-04-12
| df                   = mdy-all
}}&lt;/ref&gt;
&lt;ref name='ns25'&gt;{{cite web
| title                = [Order No. 25] Road Reconstruction: How to use the Auto Paver Walkthrough
| author               = Vinheim
| date                 = 2019-11-25
| url                  = https://www.neoseeker.com/death-stranding/walkthrough/Order_No._25
| access-date          = 2025-06-28
| quote                = This order '''WILL NOT''' appear if you've completed a road.
| df                   = mdy-all
}}&lt;/ref&gt;
&lt;/references&gt;

{{small book}}
{{alphabetical}}
{{shelves|Electronic games}}</text>
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      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
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      <comment>Updating Luna preferences</comment>
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        <id>3441010</id>
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      <comment>Updating Luna preferences</comment>
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  <page>
    <title>Chess Opening Theory/1. d4/1...e5/2. dxe5/2...f6/3. exf6</title>
    <ns>0</ns>
    <id>473586</id>
    <revision>
      <id>4636928</id>
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      <timestamp>2026-05-21T20:20:18Z</timestamp>
      <contributor>
        <username>~2026-30389-26</username>
        <id>3591637</id>
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      <comment>/* Soller Gambit Accepted */</comment>
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      <text bytes="389" sha1="a5fozx9k9xdgbbslflb5rvcwezzlcwu" xml:space="preserve">= Soller Gambit Accepted =
White continues to grab free pawns. However this is the end of this cycle, and black will take pawn back with knight.

{{BookCat}}king from white side will move f3 blacks bishop will move c5 white will move there bishop to g5 then black will move there night to e4 sacrificing the queen to the bishop then black capture the f2 pwn with the night making chekcmate</text>
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  <page>
    <title>Minecraft/Llama</title>
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    <revision>
      <id>4636902</id>
      <parentid>4490441</parentid>
      <timestamp>2026-05-21T17:40:02Z</timestamp>
      <contributor>
        <username>Nautekul</username>
        <id>3577226</id>
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      <comment>Wrote a lot about the llama</comment>
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      <text bytes="896" sha1="6xzfiz7e7h97c9avvrt6rwx2hwmn42n" xml:space="preserve">== About the Llama ==
Llamas are neutral mobs found that can be tamed. When tamed, llamas can be equipped with a chest for more storage, and can wear carpets. When killed, llamas can drop leather, which is an easy way to get leather. Llamas can spawn with wandering traders, or in the savannah plateau, windswept gravelly hills, and windswept forest biomes. When attacked, llamas will spit at you, dealing 1 damage in normal and easy mode.

== Taming ==
Llamas can be tamed by repeatedly riding them until hearts appear. You can also speed up the taming process by feeding llamas wheat. Llamas will not accept saddles, so you cannot ride llamas even when tamed. When tamed, llamas can carry chests. Each llamas has a strength level from 1 to 5, and the amount of chest spaces each llamas can carry is three times that amount. Also, you can place carpets on your llamas as decoration.

{{BookCat}}</text>
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  <page>
    <title>Minecraft/First Day</title>
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    <id>474525</id>
    <revision>
      <id>4636903</id>
      <parentid>4631576</parentid>
      <timestamp>2026-05-21T17:42:22Z</timestamp>
      <contributor>
        <username>Nautekul</username>
        <id>3577226</id>
      </contributor>
      <minor />
      <comment>Capitilization</comment>
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      <text bytes="1750" sha1="3vgwajwj7r4r9vslm0ukvsuvc23hhus" xml:space="preserve">Sweet, playing survival Minecraft? Good luck!

==Things To Do First==
Collect as many logs from any tree—the closer, the better. Then, turn it into planks using your inventory crafting table, then turn your planks into a crafting table. Use the crafting table to create weapons and tools. 

==Tools and Shelter==
Create a small base, or dig a hole into the ground. Then, make tools. The main tools to create are swords, axes, pickaxes, shovels, and hoes (I recommend making 2 swords, axes, and pickaxes first!). Swords will be used to attack things (On Java, axes are better than swords for killing animals), axes made chopping down trees faster, pickaxes let you mine most things faster, shovels let you mine dirt and sand faster, and hoes will let you farm. Use your pickaxes to dig up stone for cobblestone to create stone tools, which have higher durability and mining speed. 

==What About Food?==
Use the swords and kill pigs, cows, and chickens for meat. It’s best if you mainly kill sheep for wool for now to make a [[Minecraft/Bed|bed]], unless you find a village while exploring (If you do, take food from there). Craft a furnace with 8 cobblestone, because you will need to cook the meat for more hunger points (You can eat meat raw, but it has a chance of giving you hunger, which drains your hunger bar faster). There are many fuel sources you can use to cook your food, like collecting leaf litter on the ground, or mining for coal.

==Recommendations==
A Minecraft day lasts for 20 minutes, so best if you collect 20 to 40 logs (quite a lot!) and build a 9×9×3 house for safety. If you’re in hard mode, zombies can break wooden doors and kill you, but only if you were being chased and was seen entering the abode.  {{BookCat}}</text>
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    </revision>
    <revision>
      <id>4636904</id>
      <parentid>4636903</parentid>
      <timestamp>2026-05-21T17:45:25Z</timestamp>
      <contributor>
        <username>Nautekul</username>
        <id>3577226</id>
      </contributor>
      <comment>Added surviving the night</comment>
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      <text bytes="1854" sha1="tcpfpzji1g8m59pe1vtunmcouvy5i7i" xml:space="preserve">Sweet, playing survival Minecraft? Good luck!

==Things To Do First==
Collect as many logs from any tree—the closer, the better. Then, turn it into planks using your inventory crafting table, then turn your planks into a crafting table. Use the crafting table to create weapons and tools. 

==Tools and Shelter==
Create a small base, or dig a hole into the ground. Then, make tools. The main tools to create are swords, axes, pickaxes, shovels, and hoes (I recommend making 2 swords, axes, and pickaxes first!). Swords will be used to attack things (On Java, axes are better than swords for killing animals), axes made chopping down trees faster, pickaxes let you mine most things faster, shovels let you mine dirt and sand faster, and hoes will let you farm. Use your pickaxes to dig up stone for cobblestone to create stone tools, which have higher durability and mining speed. 

==What About Food?==
Use the swords and kill pigs, cows, and chickens for meat. It’s best if you mainly kill sheep for wool for now to make a [[Minecraft/Bed|bed]], unless you find a village while exploring (If you do, take food from there). Craft a furnace with 8 cobblestone, because you will need to cook the meat for more hunger points (You can eat meat raw, but it has a chance of giving you hunger, which drains your hunger bar faster). There are many fuel sources you can use to cook your food, like collecting leaf litter on the ground, or mining for coal.

==Surviving the Night==
A Minecraft day lasts for 20 minutes, so best if you collect 20 to 40 logs (quite a lot!) and build a 9×9×3 house for safety. If you’re in hard mode, zombies can break wooden doors and kill you, but only if you were being chased and was seen entering the abode. If you don’t have enough time to build a house, go mining underground while waiting for daytime.   {{BookCat}}</text>
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  <page>
    <title>Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nf6/3. Nxe5/3...Nc6/4. Nxc6/4...dxc6/5. f3</title>
    <ns>0</ns>
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    <revision>
      <id>4636978</id>
      <parentid>4519494</parentid>
      <timestamp>2026-05-22T08:12:52Z</timestamp>
      <contributor>
        <username>JCrue</username>
        <id>2226064</id>
      </contributor>
      <comment>/* 5. f3 */ Clarified black's move</comment>
      <origin>4636978</origin>
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      <text bytes="2928" sha1="2a6cyu8588b4hrri5r8xwps68fpjygt" xml:space="preserve">{{Chess Opening Theory/Position
|Stafford gambit
|eco=[[Chess/ECOC|C42]]
|parent=[[../|Stafford gambit]]
}}
== 5. f3 ==

'''5. f3''' defends e4 and prevents Black's knight from coming to g4. White therefore achieves their first two priorities in refuting the Stafford gambit in one move. 

5. f3 looks very unnatural because conventional wisdom is that moves like f3 or f6 weaken the kingside. However in this situation it is surprisingly sound, and a straight-forward way to refute the Stafford gambit.

If Black plays '''5...Bc5?!''', the usual Stafford move, White delays developing pieces still further and continues with 6. c3 O-O 7. d4 Bb6. White gets a huge centre and plenty of safe space to develop which Black, having removed their pawns from the centre, cannot contest. 8. a4 threatens to trap the bishop. 

Black, knowing that the f-pawn is usually a poor defender of the e-pawn, may assume this 5. f3 is the [[Chess Opening Theory/1. e4/1...e5/2. Nf3/2...f6|Damiano defence]] with colours-reversed, and snap of the e-pawn with '''5...Nxe4?'''. 

However, because Black has no e-pawn, this does not work out: 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2 and Qxh1 isn't possible because Black's queen is pinned to their king. 9...Qxe2+ 9. Bxe2 and White gets an endgame where they are up a minor piece for a pawn. 
{{clear}}{{Chess/board|moves=1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 5. f3 Nxe4 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2|caption=Position after '''5...Nxe4? 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2'''. Black's queen is pinned.|float=right|frame=1}}

Thus the engine recommendation for Black is '''5...Be6''': interposing on the e file to prevent the eventual pin and reinvigorating the threat of ...Nxe4. 6. Qe2 is White's strongest reply: defending the e pawn but keeping the idea of c3 and d4 possible.

'''5...Nh5''' is Black's trickiest reply. The idea is to support the threat of Qh4: after (e.g.) 6. Nc3? Qh4+! 7. g3 the knight can take on g3. 7...Nxg3 8. hxg3 Qxh1{{Chess/not|---}}. The most straightforward way to defuse this threat is 6. g3, preventing the queen from coming to the h4 square in the first place.

== Theory table ==
{{ChessTable}}

{{Chess/theory table |links=0
|name1=Stafford gambit with 5. f3
|line1=5...Be6 6. Qe2 Bc5 7. c3 Bb6 8. d4 O-O 9. Be3
|eval1={{Chess/not|++}}
|line2=5...Bc5 6. c3 O-O 7. d4 Bb6 8. a4 a5 9. Be3 Re8 
|eval2={{Chess/not|++}}
|line3=5...Nh5 6. g3 f5 7. Qe2 f4 8. g4 Qh4+ 9. Qf2 Qxf2+ 10. Kxf2 
|eval3={{Chess/not|++}}
|line4=5. ... ... 6. Nc3? Qh4+ 7. g3? Nxg3 8. hxg3 Qxh1 
|eval4={{Chess/not|--}}
|line5=5. ... ... 6. ... ... 7. Ke2 Ng3+ 8. hxg3 Qxh1 
|eval5={{Chess/not|-}}
|line6=5...Nxe4? 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2 Qxe2+ 9. Bxe2
|eval6={{Chess/not|+++}}
}}

{{ChessMid}}

== References ==
{{reflist}}

=== See also ===

*Youtube: [https://www.youtube.com/watch?v=-thzKkxiuCo Refuting unsound Gambits | Stafford Gambit - Andras Toth]

{{Chess Opening Theory/Footer}}</text>
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    </revision>
    <revision>
      <id>4636981</id>
      <parentid>4636978</parentid>
      <timestamp>2026-05-22T08:24:20Z</timestamp>
      <contributor>
        <username>JCrue</username>
        <id>2226064</id>
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      <comment>/* 5. f3 */</comment>
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      <text bytes="2931" sha1="pfoqyp0737rtw69d9ds5b10dibpuh7s" xml:space="preserve">{{Chess Opening Theory/Position
|Stafford gambit
|eco=[[Chess/ECOC|C42]]
|parent=[[../|Stafford gambit]]
}}
== 5. f3 ==

'''5. f3''' defends e4 and prevents Black's knight from coming to g4. White therefore achieves their first two priorities in refuting the Stafford gambit in one move. 

5. f3 looks very unnatural because conventional wisdom is that moves like f3 or f6 weaken the kingside. However in this situation it is surprisingly sound, and a straight-forward way to refute the Stafford gambit.

If Black plays '''5...Bc5?!''', the usual Stafford move, White delays developing pieces still further and continues with 6. c3 O-O 7. d4 Bb6. White gets a huge centre and plenty of safe space to develop which Black, having removed their pawns from the centre, cannot contest. 8. a4 threatens to trap the bishop. 

Black, knowing that the f-pawn is usually a poor defender of the e-pawn, may assume this 5. f3 is the [[Chess Opening Theory/1. e4/1...e5/2. Nf3/2...f6|Damiano defence]] with colours-reversed, and snap of the e-pawn with '''5...Nxe4?'''. 

However, because Black has no e-pawn, this does not work out: 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2 and ...Qxh1 isn't possible because Black's queen is pinned to their king. 9...Qxe2+ 9. Bxe2 and White gets an endgame where they are up a minor piece for a pawn. 
{{clear}}{{Chess/board|moves=1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 5. f3 Nxe4 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2|caption=Position after '''5...Nxe4? 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2'''. Black's queen is pinned.|float=right|frame=1}}

Thus the engine recommendation for Black is '''5...Be6''': interposing on the e file to prevent the eventual pin and reinvigorating the threat of ...Nxe4. 6. Qe2 is White's strongest reply: defending the e pawn but keeping the idea of c3 and d4 possible.

'''5...Nh5''' is Black's trickiest reply. The idea is to support the threat of Qh4: after (e.g.) 6. Nc3? Qh4+! 7. g3 the knight can take on g3. 7...Nxg3 8. hxg3 Qxh1{{Chess/not|---}}. The most straightforward way to defuse this threat is 6. g3, preventing the queen from coming to the h4 square in the first place.

== Theory table ==
{{ChessTable}}

{{Chess/theory table |links=0
|name1=Stafford gambit with 5. f3
|line1=5...Be6 6. Qe2 Bc5 7. c3 Bb6 8. d4 O-O 9. Be3
|eval1={{Chess/not|++}}
|line2=5...Bc5 6. c3 O-O 7. d4 Bb6 8. a4 a5 9. Be3 Re8 
|eval2={{Chess/not|++}}
|line3=5...Nh5 6. g3 f5 7. Qe2 f4 8. g4 Qh4+ 9. Qf2 Qxf2+ 10. Kxf2 
|eval3={{Chess/not|++}}
|line4=5. ... ... 6. Nc3? Qh4+ 7. g3? Nxg3 8. hxg3 Qxh1 
|eval4={{Chess/not|--}}
|line5=5. ... ... 6. ... ... 7. Ke2 Ng3+ 8. hxg3 Qxh1 
|eval5={{Chess/not|-}}
|line6=5...Nxe4? 6. fxe4 Qh4+ 7. g3 Qxe4+ 8. Qe2 Qxe2+ 9. Bxe2
|eval6={{Chess/not|+++}}
}}

{{ChessMid}}

== References ==
{{reflist}}

=== See also ===

*Youtube: [https://www.youtube.com/watch?v=-thzKkxiuCo Refuting unsound Gambits | Stafford Gambit - Andras Toth]

{{Chess Opening Theory/Footer}}</text>
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This template displays the text that users see when they do not have permission to edit a page. This template was created to encourage reuse of code in the MediaWiki messages that display said errors.

For convenience, there are five subtemplates already filled out with the settings for semi-protection, full protection, cascade protection, user JSON page protection, and user script protection: {{tl|Protected page text/semi}}, {{tl|Protected page text/full}}, {{tl|Protected page text/cascade}}, {{tl|Protected page text/user-json}} and {{tl|Protected page text/interface}}. It is recommended that you use these subtemplates, as this will allow you to benefit from future updates to the templates.
__TOC__

== Syntax ==

=== Pre-defined settings ===

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* {{para|suggestions}} – If this parameter is set with any text, the template shows the &quot;Why is the page protected?&quot; and &quot;What can I do?&quot; headings with a list of suggestions on what actions editors can take upon discovering that they can't edit the page. This parameter can be used with the [[mw:Help:Extension:ParserFunctions##ifexist|#ifexist parser function]] to display the suggestions only on existing pages (i.e. to disable them on create-protected pages).
* {{para|protection-reason}} – The general reasons why pages of a given protection level might be protected. This is the first bullet point under the &quot;Why is the page protected?&quot; heading. This parameter is required.
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* {{para|template-links}} – If this parameter is set with any text, and the current page is in the [[Help:Templates|template namespace]], the template will display links to the documentation and the template sandbox if they exist.
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    <title>FORTRAN program for calculating representative parameters and operating conditions of AC overhead transmission lines</title>
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Software is currently used to study the operation of electric power transmission lines. As an example, this article presents a program developed in the late 1970s to analyze the electrical behaviour of power lines.

The program was used for about a decade in the second half of the 20th century by the European electric utility Iberduero, based in Bilbao (Basque Country). Written by the author of this article, who was also its only user, it ceased to be used when he left the transmission power line department during a company restructuring. Several years after his retirement, he was the only person aware of its existence, capabilities, and accuracy.

Although the program is now obsolete, it can still be used to calculate line parameters, the electric and magnetic fields produced by the line, and the voltage and current imbalances generated under different operating conditions. It can also be used to study overvoltages caused by ferroresonance when one circuit of a double-circuit line is de-energized while connected to a shunt reactor at one end. The resulting overvoltages are not calculated with high accuracy, but the program allows identification of the reactance values for which they may occur.

The program is written in the FORTRAN programming language, which was commonly used for technical calculations at the time. Although minor modifications have been made to allow it to run on more recent computers and compilers, the source code largely retains the structure of the original version

Initially, the software consisted of two separate programs: EREMU, mainly intended to calculate the electric and magnetic fields produced by AC overhead power lines, and PARLI, used to calculate their principal parameters and representative operating conditions. 

These programs were later merged into a single program in a way that preserved compatibility with the previously used input data files. This origin is still evident in the source code.

The electric and magnetic field calculations are performed in accordance with the methods described in ''Transmission Line Reference Book: 345 kV and Above'' (TLRB)&lt;ref name=&quot;TLRB345kV&quot;&gt;{{cite book|last1=Chaston|first1=A.N.|last2=LaForest|first2=J.J.|last3=Ramirez|first3=A.R.|last4=and|first4=others|url=https://books.google.es/books/about/Transmission_line_reference_book_345_KV.html?id=17MsAQAAIAAJ&amp;redir_esc=y |title=Transmission Line Reference Book 345 kV and Above|year=1975|edition=1st|pages=393}}&lt;/ref&gt;, published by the Electric Power Research Institute in 1975, and ''L’Effet de Couronne en Tension Alternative'' (ECTA)&lt;ref name=&quot;ECTA-EDF&quot;&gt;{{cite book|last1=Gary|first1=Claude|last2=Moreau|first2=Marcel|title=L’Effet de Couronne en Tension Alternative|edition=1st|year=1977|url=https://www.eyrolles.com/BTP/Livre/l-effet-de-couronne-en-tension-alternative-9782212015539/ |publisher=Eyrolles|pages=464}}&lt;/ref&gt;, published by Eyrolles in 1976 as part of the ''Collection de la Direction des Études et Recherches d’Électricité de France''.

Calculations of other line parameters, including series impedances, shunt admittances, ABCD parameters, noise profiles, and imbalances under operating conditions, are also carried out following the procedures described in the TLRB.

The analysis of resonant overvoltages is performed by means of successive imbalance calculations with different shunt reactors connected at one end, the other end, or both ends of the line.

The complete program is provided so that interested users can copy it and run it using a free FORTRAN compiler.

One suitable compiler is available from the Silverfrost website, which provides a free version for private use. Using the FTN95 Personal Edition compiler, the program can be compiled and executed without modification.


== Input data for running the program ==

As was common in files of that period, the input data are written in lines with a maximum length of 80 characters.

Although minor changes have been made to improve the documentation of the program, it is still not fully documented and no detailed instructions for its use are available. In addition, the method of entering input data may not be entirely clear.

To assist anyone wishing to run the program, this section provides the data used to generate the results presented in this Wikibook. To run the program initially, copy this data into a file.

Some of the input data may appear unusual, but they were chosen to illustrate how the data are entered rather than to represent realistic cases. 

The first two cases are intended to illustrate how the results of the program for the electric and magnetic fields should be interpreted at any location near a power line.

The third case presents some of the line parameters used in the calculation of the electric and magnetic fields and shows that the values of the potential gradients (electric fields) at the conductor surface, as calculated by the program for single-circuit lines, are consistent with those given in Figure 3.2.8 of the TLRB.

The fourth and fifth cases show that the values of the potential gradients (electric fields) at the conductor surface, as calculated by the program for double-circuit lines, are consistent with those given in Figures 3.2.24 and 3.2.25 of the TLRB. In these cases, in addition to the conductor surface gradients used for comparison with the aforementioned figures, the electric and magnetic fields at other locations near the lines are also calculated. This makes it possible to observe the significant influence of the phase arrangement of the second circuit relative to that of the first circuit on the electric and magnetic fields in the surrounding space.

The sixth case compares the acoustic noise profile calculated by the program with the values presented in Chapter 6 of the TLRB.

&lt;div style=&quot;font-size:60%&quot;&gt;
&lt;source lang=&quot;text&quot;&gt;
 ESPLA-N FITXATEGIEN HASIERAN SARTUTAKO HIRU AZALPEN-LERROEN EREDUA.              2026-02-08 The program does not read the comments on the right.
LERRO HAUEK FITXATEGIEN EDUKIA IDENTIFIKATZEKO ERABILTEN DIRA,                   They are only useful for showing how to enter data.
PROGRAMA LAGUNTZAILEAK ERABILIZ.  (DATA FOR TESTING THE LIPARE PROGRAM)
 496890862    0    0    2 371935712                                              Default language in column 25 (1=&gt;Basque or 2=&gt;English)
***EREMU                                                                         ***EREMU =&gt; calculate fields
800.EPRI Tansmission line ref.book 345kV &amp; above,pag.47,52  80001320002026.03.08
  5       0.   0.00 0 0 0 0 0  -10.002.00 22  0.002.00  0                        5 conductors, (0. 0. not used im EREMU), 1 0 1 1 0 output (SEE PROGRAM)
 1.2300 1.5000 4  .4572 0 -14.00  18.50  18.50   0.200  1.00-120.0  800.0-120.0  cm  cm  kop  m  zerden1  m  m  m  ohm/km  zerden2  /  kA  gr  kV  gr
 1.2300 1.5000 4  .4572 0    .00  18.50  18.50   0.200  1.00    .0  800.0   0.0  zerden1 0=&gt;previous value dist.between cond.1=&gt;prev.val.bundle diameter
  12300  15000 4   4572 0  14000  18500  18500   0.200  1.00 12000 800000 12000  IN THIS LINE other way to insert similar data to data en previous lines
 0.6000 0.8000 1        0 -11.05  30.70  30.70   0.500                           ohm/m and zerden2 are not necesary in EREMU
   6000   8000 1        0  11050  30700  30700   0.500                           IN THIS LINE other way to insert data that allows more accurate figures.
***PARLI
765.TWO CIRCUIT E62SB LINE, ABC ABC Super Bundle, 1-456456  62100765202014-06-27
 0 2 2 1    50.                                                                  0. def.lang., 2 tasks, 2 circuits, MERGE CIRCUITS ,Frecuency
1  80003   300.  75. 0000   -7.621.27 22  0.003.81   71HA CX-XXX
  13700  17590 4   4572    -7750  25240  25240 0.200 4  4000-12000 765000-12000  zirkuituak paraleloan jartzen dira
  13700  17590 4   4572   -12750  20240  20240 0.200 5  4000   000 765000   000  eta zirkuitu konposatuari dagozkion
  13700  17590 4   4572    -7750  15240  15240 0.200 6  4000 12000 765000 12000  aldaezin generalizatuak kalkulatzen dira
  13700  17590 4   4572     7750  25240  25240 0.200 4  4000-12000 765000-12000
  13700  17590 4   4572    12750  20240  20240 0.200 5  4000   000 765000   000  BAINA
  13700  17590 4   4572     7750  15240  15240 0.200 6  4000 12000 765000 12000
  06000  08000 1          -10000  35000  35000 0.500
  06000  08000 1           10000  35000  35000 0.500
0
 1 750.-120.    750. 120.    750.   0.    200.  .2 3   200.  .2 3   200.  .2 3   Zirkuitu konposatuaren aldaezinak lortu eta gero
 2 750.-120.    750. 120.    750.   0.    200.  .2 3   200.  .2 3   200.  .2 3   ezin dira aztertu linearen egoerak
                                                                      These two final lines are required if the final calculation is of type &quot;***PARLI&quot;.
 
&lt;/source&gt;&lt;/div&gt;


== Electric and magnetic fields ==
=== Calculations ===
==== Electric field on the surface of conductors ====
The electric field on the surface of conductors is calculated as señaled on  pages 7 to 15 of ECTA&lt;ref name=&quot;ECTA-EDF&quot;/&gt; and 109 to 111 of TLRF&lt;ref name=&quot;TLRB345kV&quot;/&gt;.

Taking into acount that the ground surface can be considered an equipotential surface at zero potential, if the ground surface is represented as a plane (flat surface) at zero potential, the potential at any point above that surface created by the electric charges in &lt;math&gt;n&lt;/math&gt; conductors is calculated considering these &lt;math&gt;n&lt;/math&gt; charges and other &lt;math&gt;n&lt;/math&gt; opposite charges situadeted simetricaly to the original ones with respect to the ground plane; as shown in the figure F1.

With that disposition the potential of an uncharged condutor &lt;math&gt;j &lt;/math&gt; dew to the charge of the conductor &lt;math&gt;i&lt;/math&gt; would be:

&lt;math&gt;V_{ji} = {-\frac{q_i}{2\pi\epsilon_0}}\ln{D_{ji}} - {\frac{-q_i}{2\pi\epsilon_0}}\ln{D'_{ji}} = {\frac{q_i}{2\pi\epsilon_0}}\ln\frac{D'_{ji}}{D_{ji}}&lt;/math&gt;

At the surface of the &lt;math&gt;i&lt;/math&gt; conductor of radius &lt;math&gt;r_i&lt;/math&gt; and placed at an height &lt;math&gt;h_i&lt;/math&gt; above the gound, taking into account that &lt;math&gt;2h_i &gt;&gt; r_i&lt;/math&gt;, would be:

 &lt;math&gt;V_{ii} = {\frac{q_i}{2\pi\epsilon_0}}\ln\frac{2h_i}{r_i}&lt;/math&gt;

where:

&lt;math&gt;q_i&lt;/math&gt; = uniform linear charge density of &lt;math&gt;i&lt;/math&gt; conductor.

&lt;math&gt;h_i&lt;/math&gt; = &lt;math&gt;i&lt;/math&gt; conductor height.

&lt;math&gt;r_i &lt;/math&gt; = &lt;math&gt;i&lt;/math&gt; conductor radius.

&lt;math&gt;D'_{ji}&lt;/math&gt; = direct distance from conductor &lt;math&gt;j&lt;/math&gt; to image conductor &lt;math&gt;i&lt;/math&gt;.

&lt;math&gt;D_{ji}&lt;/math&gt; = direct distance from conductor &lt;math&gt;j&lt;/math&gt; to conductor &lt;math&gt;i&lt;/math&gt;

&lt;math&gt;\epsilon&lt;/math&gt; = dielectric constant = &lt;math&gt;\frac {1}{36\pi}10^{-9}&lt;/math&gt; farads/meter for air.


So

Considering the &lt;math&gt;n&lt;/math&gt; conductors:

&lt;math&gt;V_1 = P_{11}q_1 + .. + P_{1i}q_i + .. + P_{1n}q_n&lt;/math&gt;

..............................................................

&lt;math&gt;V_i= P_{i1}q_1 + .. + P_{ii}q_i + .. + P_{in}q_n&lt;/math&gt;

..............................................................

&lt;math&gt;V_n = P_{n1}q_1 + .. + P_{ni}q_i + .. + P_{nn}q_n&lt;/math&gt;

in matrix notation

&lt;math&gt;
\begin{Bmatrix}
V_1\\
..\\
V_i\\
..\\
V_n\\
\end{Bmatrix}
=\begin{bmatrix}
P_{11} &amp; .. &amp; P_{1i}&amp; .. &amp; P_{1n} \\
.. &amp; .. &amp; .. &amp; .. &amp; .. \\
P_{i1} &amp; .. &amp; P_{ii}&amp; .. &amp; P_{in} \\
.. &amp; .. &amp; .. &amp; .. &amp; .. \\
P_{n1} &amp; .. &amp; P_{ni} &amp; .. &amp; P_{nn} \\
\end{bmatrix}
\begin{Bmatrix}
q_1\\
..\\
q_i\\
..\\
q_n\\
\end{Bmatrix}
&lt;/math&gt;

and more succinctly for a system of &lt;math&gt;m+n&lt;/math&gt; conductors

&lt;math&gt;
\begin{Bmatrix}
V_{m+n}\\
\end{Bmatrix}
=\begin{bmatrix}
P_{m+n,m+n} \\
\end{bmatrix}
\begin{Bmatrix}
q_{m+n}\\
\end{Bmatrix}
&lt;/math&gt;

Where &lt;math&gt;\begin{Bmatrix}
V_{m+n}\\
\end{Bmatrix}&lt;/math&gt; is the column vector of electric potentials of the &lt;math&gt;m+n&lt;/math&gt; conductors, and &lt;math&gt;
\begin{Bmatrix}
q_{m+n}\\
\end{Bmatrix}&lt;/math&gt; is the column vector of charge per unit length of these conductors. The &lt;math&gt;(m+n).(m+n)&lt;/math&gt; square matrix &lt;math&gt;\begin{bmatrix}
P_{m+n,m+n} \\
\end{bmatrix}&lt;/math&gt; is known as the matrix of Maxwell potential coefficients of the system.

Thus, if the Maxwell potential coefficients of an electric line are known, the conductor potentials can be expressed as a function of their linear charge densities. However, in practical applications, the conductor potentials are typically known, whereas the quantities required to compute the resulting electric fields are the linear charge densities.

To obtain these, both sides of the previous equation are premultiplied by the inverse of the Maxwell potential coefficient matrix.

This yields:

&lt;math&gt;
\begin{bmatrix}
P_{m+n,m+n} \\
\end{bmatrix}^{-1}.
\begin{Bmatrix}
V_{m+n}\\
\end{Bmatrix}
=\begin{bmatrix}
C_{m+n,m+n} \\
\end{bmatrix}.
\begin{Bmatrix}
V_{m+n}\\
\end{Bmatrix}
=\begin{bmatrix}
P_{m+n,m+n} \\
\end{bmatrix}^{-1}.\begin{bmatrix}
P_{m+n,m+n} \\
\end{bmatrix}.
\begin{Bmatrix}
q_{m+n}\\
\end{Bmatrix}
=\begin{bmatrix}
I_{m+n} \\
\end{bmatrix}.
\begin{Bmatrix}
q_{m+n}\\
\end{Bmatrix}
=\begin{Bmatrix}
q_{m+n}\\
\end{Bmatrix}
&lt;/math&gt;

where &lt;math&gt; \begin{bmatrix}
I_{m+n} \\
\end{bmatrix}&lt;/math&gt; is the &lt;math&gt;(m+n)\times (m+n) &lt;/math&gt; identity matrix, and &lt;math&gt;\begin{bmatrix}
C_{m+n,m+n} \\
\end{bmatrix}&lt;/math&gt;, which is the inverse of the Maxwell potential coefficient matrix, is called the capacitance matrix of the conductor system. In this matrix, &lt;math&gt;C_{ii}&lt;/math&gt;​ represents the self-capacitance of conductor &lt;math&gt;i&lt;/math&gt;, while &lt;math&gt;C_{ij}&lt;/math&gt; represents the mutual capacitance between conductors &lt;math&gt;i&lt;/math&gt; and &lt;math&gt;j&lt;/math&gt;.

Once the matrix &lt;math&gt;\begin{bmatrix}
C_{m+n,m+n} \\
\end{bmatrix}&lt;/math&gt; is known, the conductor charges can be calculated as a function of the conductor potentials. From these charges, the electric potential and the electric field at any point can also be determined.

==== Electric and magnetic fields above ground ====

Auxiliary formulas to be inserted later into a figure.

( provisional while the figures are being prepared )

&lt;math&gt;V_{pi} = {-\frac{q_i}{2\pi\epsilon_0}}\ln{D_{pi}} - {\frac{-q_i}{2\pi\epsilon_0}}\ln{D'_{pi}} = {\frac{q_i}{2\pi\epsilon_0}}\ln\frac{D'_{pi}}{D_{pi}}&lt;/math&gt;

&lt;math&gt;V_p = \sum_{i=1}^{n}{\frac{q_i}{2\pi\epsilon_0}}\ln\frac{D'_{pi}}{D_{pi}}&lt;/math&gt;

=== Program results for that data ===

[[File:AC overhead power line electromagnetic fields en.gif|thumb|Electric and magnetic fields at a single point below a 750 kV AC overhead power line.]]

This section shows how the program presents the calculated electric and magnetic fields, how the data provided for these fields at locations other than the conductor surface should be interpreted, and the influence of phase arrangement in double-circuit lines on the resulting fields.

The adjacent figure illustrates the meaning of the data presented by the program on pages three and four for the electric and magnetic fields at a point located 12 m from the line centre and 4 m above ground level.

The most relevant values are those shown in the last four columns of these pages, and they are presented in static form in the figure. The program is not designed to calculate directly the time-varying values also shown in the figure. To obtain these values without modifying the program, it is necessary to repeat the calculations 36 times, each time changing the phase angles of the input voltages and currents by 10 degrees.

Theoretically, the three phases A, B, and C of an AC three-phase system can be assigned to the conductors of a single-circuit transmission line in six different ways: ABC, BCA, CAB, ACB, CBA, and BAC. In practice, however, the first three configurations are equivalent, since under steady-state conditions the voltages and currents in the conductors behave identically in each case. The same equivalence applies to the last three configurations.

Output for the lines L01 and L02 of the shown input data file:

&lt;div style=&quot;font-size:60%&quot;&gt;
&lt;source lang=&quot;text&quot;&gt;
1     ENPRESELEK,E.A.                                                                                       PAGE                 1
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L01 H32 CX-DIPPER for Wikibooks figure                 EXPEDIENT   7500132.01
 
 
        ***************************  INPUT DATA, LINE CHARACTERISTICS  ***************************
 
        CON.NUM.  FNCY     RHO          PC AN CE CM PL             XA    XG   NX     YA    YG   NY
          5         0.     0.00          0  0  1  1  0          -14.00  1.00   4    4.00  2.00   0
 
        EROA  BGE  ERR  ZEN SOR.D ZER      X       Y1      Y2      INT KA  FAS G    TEN KV  PHAS G
 
          1  1.37 1.76   4  45.72  0    -15.00   15.00   15.00      1.00 -140.00    750.00 -120.00
          2  1.37 1.76   4  45.72  0      0.00   15.00   15.00      1.00  -20.00    750.00    0.00
          3  1.37 1.76   4  45.72  0     15.00   15.00   15.00      1.00  100.00    750.00  120.00
          4  0.60 0.80   1   0.00  0    -10.00   24.00   24.00      0.00    0.00      0.00    0.00
          5  0.60 0.80   1   0.00  0     10.00   24.00   24.00      0.00    0.00      0.00    0.00
1     ENPRESELEK,E.A.                                                                                       PAGE                 2
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L01 H32 CX-DIPPER for Wikibooks figure                 EXPEDIENT   7500132.01
 
 
                                                 ORIGINAL CONFIGURATION
 
                                             ELECTRIC FIELD ON THE CONDUCTORS
 
 
                           CONDUC.    CHARGE Q/M         GR.MV KV/CM        GRMAX KV/CM
 
                             1      0.56294989E-05       14.40179E+00       16.75257E+00
 
                             2      0.59636313E-05       15.25659E+00       17.74690E+00
 
                             3      0.56294989E-05       14.40179E+00       16.75257E+00
 
                             4      0.47318039E-06       10.64656E+00       10.64656E+00
 
                             5      0.47318034E-06       10.64656E+00       10.64656E+00
1     ENPRESELEK,E.A.                                                                                       PAGE                 3
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L01 H32 CX-DIPPER for Wikibooks figure                 EXPEDIENT   7500132.01
 
                                                   ORIGINAL CONFIGURATION
 
                                            ELECTRIC FIELD  4.00 M ABOVE GROUND
 
 
  DIST.   HORIZONTAL FIELD    VERTICAL FIELD      MAXIMUM FIELD      MINIMUM FIELD      PRESENT FIELD    FIELD 90 G LATER
           MOD.KV/M  ARG.G    MOD.KV/M  ARG.G   MAG.KV/M   DIR.G   MAG.KV/M   DIR.G   MAG.KV/M   DIR.G   MAG.KV/M   DIR.G
 
  -14.00  2.207E+00 -154.86  9.612E+00   75.18  1.375E+01  -81.35  2.366E+00    8.65  4.481E+00  129.10  1.321E+01  -84.24
  -13.00  2.774E+00 -149.91  9.147E+00   78.23  1.321E+01  -77.99  2.861E+00   12.01  4.299E+00  142.13  1.282E+01  -81.17
  -12.00  3.289E+00 -146.97  8.564E+00   82.26  1.252E+01  -74.77  3.408E+00   15.23  4.227E+00  157.31  1.227E+01  -78.07
  -11.00  3.722E+00 -145.11  7.918E+00   87.56  1.171E+01  -71.90  4.003E+00   18.10  4.344E+00  173.70  1.159E+01  -74.94
  -10.00  4.055E+00 -143.83  7.278E+00   94.41  1.083E+01  -69.81  4.632E+00   20.19  4.696E+00 -170.30  1.081E+01  -71.75
1     ENPRESELEK,E.A.                                                                                       PAGE                 4
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L01 H32 CX-DIPPER for Wikibooks figure                 EXPEDIENT   7500132.01
 
                                                   ORIGINAL CONFIGURATION
 
                                            MAGNETIC INDUCTION  4.00 M ABOVE GROUND
 
 
   DIST.  INDUC.HORIZONTAL    INDUC.VERTICAL      MAXIM.INDUC.       MINIM.INDUC.      PRESENT INDUC.    INDUC. 90 G LAT.
         MOD.TESLA   ARG.G  MOD.TESLA   ARG.G  MAG.TESLA   DIR.G  MAG.TESLA   DIR.G  MAG.TESLA   DIR.G  MAG.TESLA   DIR.G
 
  -14.00  1.401E-05   56.72  9.384E-06   24.98  2.308E-05   32.08  5.992E-06  -57.92  1.622E-05   47.89  1.749E-05 -161.31
  -13.00  1.336E-05   59.52  1.104E-05   27.39  2.359E-05   38.60  6.650E-06  -51.40  1.685E-05   55.34  1.780E-05 -156.21
  -12.00  1.250E-05   63.32  1.253E-05   29.22  2.393E-05   45.10  7.341E-06  -44.90  1.739E-05   62.84  1.801E-05 -151.29
  -11.00  1.152E-05   68.42  1.382E-05   30.73  2.413E-05   51.51  8.067E-06  -38.49  1.784E-05   70.37  1.815E-05 -146.61
  -10.00  1.054E-05   75.15  1.486E-05   32.12  2.420E-05   57.80  8.830E-06  -32.20  1.820E-05   77.89  1.823E-05 -142.20
1     ENPRESELEK,E.A.                                                                                       PAGE                 5
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L02 H32 CX-DIPPER for Wfigure, two phases interchanged EXPEDIENT   7500132.02
 
 
        ***************************  INPUT DATA, LINE CHARACTERISTICS  ***************************
 
        CON.NUM.  FNCY     RHO          PC AN CE CM PL             XA    XG   NX     YA    YG   NY
          5         0.     0.00          0  0  1  1  0          -14.00  1.00   4    4.00  2.00   0
 
        EROA  BGE  ERR  ZEN SOR.D ZER      X       Y1      Y2      INT KA  FAS G    TEN KV  PHAS G
 
          1  1.37 1.76   4  45.72  0    -15.00   15.00   15.00      1.00  100.00    750.00  120.00
          2  1.37 1.76   4  45.72  0      0.00   15.00   15.00      1.00  -20.00    750.00    0.00
          3  1.37 1.76   4  45.72  0     15.00   15.00   15.00      1.00 -140.00    750.00 -120.00
          4  0.60 0.80   1   0.00  0    -10.00   24.00   24.00      0.00    0.00      0.00    0.00
          5  0.60 0.80   1   0.00  0     10.00   24.00   24.00      0.00    0.00      0.00    0.00
1     ENPRESELEK,E.A.                                                                                       PAGE                 6
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L02 H32 CX-DIPPER for Wfigure, two phases interchanged EXPEDIENT   7500132.02
 
 
                                                 ORIGINAL CONFIGURATION
 
                                             ELECTRIC FIELD ON THE CONDUCTORS
 
 
                           CONDUC.    CHARGE Q/M         GR.MV KV/CM        GRMAX KV/CM
 
                             1      0.56294989E-05       14.40179E+00       16.75257E+00
 
                             2      0.59636313E-05       15.25659E+00       17.74690E+00
 
                             3      0.56294989E-05       14.40179E+00       16.75257E+00
 
                             4      0.47318039E-06       10.64656E+00       10.64656E+00
 
                             5      0.47318034E-06       10.64656E+00       10.64656E+00
1     ENPRESELEK,E.A.                                                                                       PAGE                 7
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L02 H32 CX-DIPPER for Wfigure, two phases interchanged EXPEDIENT   7500132.02
 
                                                   ORIGINAL CONFIGURATION
 
                                            ELECTRIC FIELD  4.00 M ABOVE GROUND
 
 
  DIST.   HORIZONTAL FIELD    VERTICAL FIELD      MAXIMUM FIELD      MINIMUM FIELD      PRESENT FIELD    FIELD 90 G LATER
           MOD.KV/M  ARG.G    MOD.KV/M  ARG.G   MAG.KV/M   DIR.G   MAG.KV/M   DIR.G   MAG.KV/M   DIR.G   MAG.KV/M   DIR.G
 
  -14.00  2.207E+00  154.86  9.612E+00  -75.18  1.375E+01  -81.35  2.366E+00    8.65  4.481E+00  129.10  1.321E+01   95.76
  -13.00  2.774E+00  149.91  9.147E+00  -78.23  1.321E+01  -77.99  2.861E+00   12.01  4.299E+00  142.13  1.282E+01   98.83
  -12.00  3.289E+00  146.97  8.564E+00  -82.26  1.252E+01  -74.77  3.408E+00   15.23  4.227E+00  157.31  1.227E+01  101.93
  -11.00  3.722E+00  145.11  7.918E+00  -87.56  1.171E+01  -71.90  4.003E+00   18.10  4.344E+00  173.70  1.159E+01  105.06
  -10.00  4.055E+00  143.83  7.278E+00  -94.41  1.083E+01  -69.81  4.632E+00   20.19  4.696E+00 -170.30  1.081E+01  108.25
1     ENPRESELEK,E.A.                                                                                       PAGE                 8
      LINES DIVISION                                                                                        DATE        2026-02-19
                       TRANSMISSION LINE OF  750. KV L02 H32 CX-DIPPER for Wfigure, two phases interchanged EXPEDIENT   7500132.02
 
                                                   ORIGINAL CONFIGURATION
 
                                            MAGNETIC INDUCTION  4.00 M ABOVE GROUND
 
 
   DIST.  INDUC.HORIZONTAL    INDUC.VERTICAL      MAXIM.INDUC.       MINIM.INDUC.      PRESENT INDUC.    INDUC. 90 G LAT.
         MOD.TESLA   ARG.G  MOD.TESLA   ARG.G  MAG.TESLA   DIR.G  MAG.TESLA   DIR.G  MAG.TESLA   DIR.G  MAG.TESLA   DIR.G
 
  -14.00  1.401E-05  -96.72  9.384E-06  -64.98  2.308E-05   32.08  5.992E-06  -57.92  6.072E-06  112.43  2.306E-05   31.43
  -13.00  1.336E-05  -99.52  1.104E-05  -67.39  2.359E-05   38.60  6.650E-06  -51.40  6.766E-06  117.52  2.355E-05   37.71
  -12.00  1.250E-05 -103.32  1.253E-05  -69.22  2.393E-05   45.10  7.341E-06  -44.90  7.494E-06  122.92  2.389E-05   43.93
  -11.00  1.152E-05 -108.42  1.382E-05  -70.73  2.413E-05   51.51  8.067E-06  -38.49  8.253E-06  128.59  2.407E-05   50.04
  -10.00  1.054E-05 -115.15  1.486E-05  -72.12  2.420E-05   57.80  8.830E-06  -32.20  9.041E-06  134.47  2.412E-05   56.00

&lt;/source&gt;&lt;/div&gt;


An analysis of the results shown on pages 1 to 8 of the program output for lines L01 and L02 indicates that the electric and magnetic fields generated by these two phase configurations are identical. The only difference is that the direction of rotation of the fields outside the conductors is reversed.

_ The voltage gradients (electric fields) at the conductor surfaces do not rotate and are identical in both cases.

_ The maximum and minimum values of the electric and magnetic fields at all points outside the conductors are also identical in both cases.

_ At all locations where the minimum field value is nonzero, the direction of field rotation is opposite in the two configurations.

To interpret these results, it is necessary to consider that the absolute difference in angular position of the fields over a 5 ms interval must be less than 180°. Accordingly, defining FAP1 and FAP2 as the angular positions of the fields at instants 1 and 2, respectively, the rotation over 5 ms is given by:
    • FAP2 − FAP1, if |FAP2 − FAP1| &lt; 180° 
    • FAP2 − FAP1 + 360°, if |FAP2 − FAP1| ≥ 180° and FAP2 − FAP1 &lt; 0 
    • FAP2 − FAP1 − 360°, if |FAP2 − FAP1| ≥ 180° and FAP2 − FAP1 &gt; 0 

Note:
In the analyzed cases, the angular velocities of the rotating fields may appear to differ. However, this is due to the fact that the angular velocity is not constant: it is higher when the field magnitude is lower and lower when the field magnitude is higher. Additionally, the initial field values (corresponding to the instantaneous voltage and current conditions specified in the input data) are different in each case. 

[[File:AC_Overhead_power_line_e-field_at_ground_level-en.png|500px|thumb|Maximun electric field at conductor surfaces and ground level for two phase arrangements of a double-circut 800 kV AC transmission line.]]

Conversely, in transmission lines with more than one circuit, the phase arrangement of the additional circuits relative to that of the first circuit has a significant impact on the electric field values, as illustrated in Figure 3. This figure shows the maximum electric field at conductor surfaces and ground level for two of the six possible phase arrangements of the second circuit in a double-circuit 800 kV AC transmission line.


=== Audible noise profiles ===
=== Power line parameters ===
=== Resonance evaluations ===
=== Operating conditions ===
On pages 51, 52, 58, and 61 of transmission lines L10, L11, and L12 are illustrated the effects of using shunt reactors connected to an end of a long transmission line or a weak system to prevent overvoltages under light-load conditions, and series capacitors to compensate for the inductive reactance of loaded transmission lines,  as described in the [[w:en:Voltage control and reactive power management|Voltage control and reactive power management]] Wikipedia article. 

The output of the program for those lines and two operating conditions (moderate inductive load and no load) is the following:

&lt;div style=&quot;font-size:60%&quot;&gt;
&lt;source lang=&quot;text&quot;&gt;
1     ENPRESELEK,E.A.                                                                                       PAGE                44
      LINES DIVISION                                                                                        DATE        2013-10-24
                       TRANSMISSION LINE OF  765. KV L09 SINGLE CIRCUIT H32 1x1 sections                    EXPEDIENT  75013211.00
0     SECTION  1       TRANSMISSION LINE BUILT WITH 71HA STRUCTURES AND CX-XXX CONDUCTORS
0                       INPUT DATA
0                       LINE LONG.   1*300.00= 300.00 KM
                        GROUND RESISTIVITY      75.00 OHM.M
                        FREQUENCY               50.00 HZ
0                       ***************************  CONDUCTORS� FEATURES  ***************************
                           ..   GMR(CM)   RAD(CM)     IN   D(M)  ID      DX(M)   DY(M)      R(OHM:KM)
 
                            1   1.37000   1.75900      4   0.46   0     -15.24   15.24      0.2000000
                            2   1.37000   1.75900      4   0.46   0       0.00   15.24      0.2000000
                            3   1.37000   1.75900      4   0.46   0      15.24   15.24      0.2000000
                            4   0.60000   0.80000      1   0.00   0     -10.00   24.00      0.5000000
                            5   0.60000   0.80000      1   0.00   0      10.00   24.00      0.5000000
1     ENPRESELEK,E.A.                                                                                       PAGE                45
      LINES DIVISION                                                                                        DATE        2013-10-24
                       TRANSMISSION LINE OF  765. KV L09 SINGLE CIRCUIT H32 1x1 sections                    EXPEDIENT  75013211.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      746.450        0.585      188.145     -167.872        750.000        0.471      200.000       40.000     42.393   0 0
  1   2      741.212        0.637      204.246     -180.220        750.000        0.471      200.000       40.000     39.758   0 0
  1   3      733.405        0.640      219.038     -159.847        750.000        0.471      200.000       40.000     45.890   0 0
0 1                                    611.429     -507.939                                  600.000      120.000
 
 
0 0                                    611.429     -507.939                                  600.000      120.000
 
 
1     ENPRESELEK,E.A.                                                                                       PAGE                46
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L10 SINGLE CIRCUIT H32 1x6 sections                    EXPEDIENT  75013216.00
0     SECTION  1       TRANSMISSION LINE BUILT WITH 71HA STRUCTURES AND CX-XXX CONDUCTORS
0                       INPUT DATA
0                       LINE LONG.   6* 50.00= 300.00 KM
                        GROUND RESISTIVITY      75.00 OHM.M
                        FREQUENCY               50.00 HZ
0                       ***************************  CONDUCTORS� FEATURES  ***************************
                           ..   GMR(CM)   RAD(CM)     IN   D(M)  ID      DX(M)   DY(M)      R(OHM:KM)
 
                            1   1.37000   1.75900      4   0.46   0     -15.24   15.24      0.2000000
                            2   1.37000   1.75900      4   0.46   0       0.00   15.24      0.2000000
                            3   1.37000   1.75900      4   0.46   0      15.24   15.24      0.2000000
                            4   0.60000   0.80000      1   0.00   0     -10.00   24.00      0.5000000
                            5   0.60000   0.80000      1   0.00   0      10.00   24.00      0.5000000
1     ENPRESELEK,E.A.                                                                                       PAGE                47
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L10 SINGLE CIRCUIT H32 1x6 sections                    EXPEDIENT  75013216.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      745.885        0.589      188.280     -169.966        750.000        0.471      200.000       40.000     41.764   0 0
  1   2      740.790        0.640      204.507     -182.246        750.000        0.471      200.000       40.000     39.212   0 0
  1   3      733.096        0.644      219.417     -161.946        750.000        0.471      200.000       40.000     45.204   0 0
0 1                                    612.204     -514.158                                  600.000      120.000
 
 
0 0                                    612.204     -514.158                                  600.000      120.000
 
 
1     ENPRESELEK,E.A.                                                                                       PAGE                48
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L10 SINGLE CIRCUIT H32 1x6 sections                    EXPEDIENT  75013216.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      750.000        0.549      -16.272     -236.953        792.853        0.000        0.000        0.000     25.210   1 0
  1   2      750.000        0.579        1.646     -250.835        788.678        0.000        0.000        0.000     22.729   2 0
  1   3      750.000        0.548       19.506     -236.479        791.493        0.000        0.000        0.000     24.332   3 0
0 1                                      4.880     -724.267                                    0.000        0.000
 
 
0 0                                      4.880     -724.267                                    0.000        0.000
 
 
1     ENPRESELEK,E.A.                                                                                       PAGE                49
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L11 1C H32 1x6 sections + receiving end shunt reactor  EXPEDIENT  75013216.00
0       SECTI  1                                    SHUNT ADMITANCES (MHO)
 
                   1                2                3
 
        1    0.0000000E+00    0.0000000E+00    0.0000000E+00
            -0.4000000E-03    0.0000000E+00    0.0000000E+00
 
        2    0.0000000E+00    0.0000000E+00    0.0000000E+00
             0.0000000E+00   -0.4000000E-03    0.0000000E+00
 
        3    0.0000000E+00    0.0000000E+00    0.0000000E+00
             0.0000000E+00    0.0000000E+00   -0.4000000E-03
 
1     ENPRESELEK,E.A.                                                                                       PAGE                50
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L11 1C H32 1x6 sections + receiving end shunt reactor  EXPEDIENT  75013216.00
0     SECTION  2       TRANSMISSION LINE BUILT WITH 71HA STRUCTURES AND CX-XXX CONDUCTORS
0                       INPUT DATA
0                       LINE LONG.   6* 50.00= 300.00 KM
                        GROUND RESISTIVITY      75.00 OHM.M
                        FREQUENCY               50.00 HZ
0                       ***************************  CONDUCTORS� FEATURES  ***************************
                           ..   GMR(CM)   RAD(CM)     IN   D(M)  ID      DX(M)   DY(M)      R(OHM:KM)
 
                            1   1.37000   1.75900      4   0.46   0     -15.24   15.24      0.2000000
                            2   1.37000   1.75900      4   0.46   0       0.00   15.24      0.2000000
                            3   1.37000   1.75900      4   0.46   0      15.24   15.24      0.2000000
                            4   0.60000   0.80000      1   0.00   0     -10.00   24.00      0.5000000
                            5   0.60000   0.80000      1   0.00   0      10.00   24.00      0.5000000
1     ENPRESELEK,E.A.                                                                                       PAGE                51
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L11 1C H32 1x6 sections + receiving end shunt reactor  EXPEDIENT  75013216.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      770.663        0.482      187.027     -105.234        750.000        0.471      200.000       40.000     38.759   0 0
  1   2      763.706        0.534      204.028     -117.360        750.000        0.471      200.000       40.000     36.518   0 0
  1   3      758.906        0.549      219.753      -97.347        750.000        0.471      200.000       40.000     42.684   0 0
0 1                                    610.808     -319.941                                  600.000      120.000
 
 
0 0                                    610.808     -319.941                                  600.000      120.000
 
 
1     ENPRESELEK,E.A.                                                                                       PAGE                52
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L11 1C H32 1x6 sections + receiving end shunt reactor  EXPEDIENT  75013216.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      750.000        0.363      -17.257     -156.154        765.313        0.000        0.000        0.000      8.846   1 0
  1   2      750.000        0.394        0.569     -170.438        763.694        0.000        0.000        0.000      8.023   2 0
  1   3      750.000        0.363       18.297     -155.914        763.484        0.000        0.000        0.000      8.337   3 0
0 1                                      1.608     -482.506                                    0.000        0.000
 
 
0 0                                      1.608     -482.506                                    0.000        0.000
 
 
1     ENPRESELEK,E.A.                                                                                       PAGE                53
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L12 1C H32 1x6 sections + receiving end series capacit EXPEDIENT  75013216.00
0       SECTI  1                                    SERIES IMPEDANCES (OHM)
 
                   1                2                3
 
        1    0.0000000E+00    0.0000000E+00    0.0000000E+00
            -0.4000000E+03    0.0000000E+00    0.0000000E+00
 
        2    0.0000000E+00    0.0000000E+00    0.0000000E+00
             0.0000000E+00   -0.4000000E+03    0.0000000E+00
 
        3    0.0000000E+00    0.0000000E+00    0.0000000E+00
             0.0000000E+00    0.0000000E+00   -0.4000000E+03
 
1     ENPRESELEK,E.A.                                                                                       PAGE                54
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L12 1C H32 1x6 sections + receiving end series capacit EXPEDIENT  75013216.00
0     SECTION  2       TRANSMISSION LINE BUILT WITH 71HA STRUCTURES AND CX-XXX CONDUCTORS
0                       INPUT DATA
0                       LINE LONG.   6* 50.00= 300.00 KM
                        GROUND RESISTIVITY      75.00 OHM.M
                        FREQUENCY               50.00 HZ
0                       ***************************  CONDUCTORS� FEATURES  ***************************
                           ..   GMR(CM)   RAD(CM)     IN   D(M)  ID      DX(M)   DY(M)      R(OHM:KM)
 
                            1   1.37000   1.75900      4   0.46   0     -15.24   15.24      0.2000000
                            2   1.37000   1.75900      4   0.46   0       0.00   15.24      0.2000000
                            3   1.37000   1.75900      4   0.46   0      15.24   15.24      0.2000000
                            4   0.60000   0.80000      1   0.00   0     -10.00   24.00      0.5000000
                            5   0.60000   0.80000      1   0.00   0      10.00   24.00      0.5000000
1     ENPRESELEK,E.A.                                                                                       PAGE                55
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L12 1C H32 1x6 sections + receiving end series capacit EXPEDIENT  75013216.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      723.186        0.744      191.235     -244.626        750.000        0.471      200.000       40.000    138.759   0 0
  1   2      720.314        0.794      206.213     -257.834        750.000        0.471      200.000       40.000    143.290   0 0
  1   3      709.199        0.788      219.800     -236.299        750.000        0.471      200.000       40.000    139.391   0 0
0 1                                    617.249     -738.760                                  600.000      120.000
 
 
0 0                                    617.249     -738.760                                  600.000      120.000
 
 
1     ENPRESELEK,E.A.                                                                                       PAGE                56
      LINES DIVISION                                                                                        DATE        2014-06-27
                       TRANSMISSION LINE OF  765. KV L12 1C H32 1x6 sections + receiving end series capacit EXPEDIENT  75013216.00
0         ***************      SENDING END     **************   *****************  RECEIVING END   ****************
 *** ***   EQUIV. LINE       LINE       ACTIVE      REACTIVE     EQUIV. LINE       LINE       ACTIVE      REACTIVE   VOLTAGE   ***
 CIR PHA     VOLTAGE      INTENSITY      POWER        POWER        VOLTAGE      INTENSITY      POWER        POWER      DROP    E I
 *** ***       (KV)         (KA)         (MW)        (MVAR)          (KV)         (KA)         (MW)        (MVAR)      (KV)    ***
 
 
  1   1      750.000        0.549      -16.272     -236.953        792.853        0.000        0.000        0.000     25.210   1 0
  1   2      750.000        0.579        1.646     -250.835        788.678        0.000        0.000        0.000     22.729   2 0
  1   3      750.000        0.548       19.506     -236.479        791.493        0.000        0.000        0.000     24.332   3 0
0 1                                      4.880     -724.267                                    0.000        0.000
 
 
0 0                                      4.880     -724.267                                    0.000        0.000
 
 
&lt;/source&gt;&lt;/div&gt;

== Source file ==

&lt;source lang=&quot;fortran&quot;&gt;
C  Lineen parametro elektromagnetikoak eta egoerak kalkulatzeko eta
C  ferroerresonantzia azterketak egiteko PARLI programa eta
C  aireko linea elektrikoek sortzen dituzten eremu elektromagnetikoak
C  kalkulatzeko EREMU programa batuta.
C  Programak Jon Peli Oleaga Olabarriak garatu zituen
C  1970eko hamarkadaren amaieran.
C  1980ko hamarkadaren amaieran batu ziren eta, geroago, konpilatzaile
C  berriagorekin erabili ahal izateko beharrezko aldaketak egin zaizkie.
C  Sarrerako datuak oraindino 80 zutabetan sartzen dira, 
C  behinolako fitxetan legez.
C  Bigarren hizkuntza modu naif eta ez sistematikoan sartu da.
C  Letra xehez idatzitako lerroak programaren dokumentazioa
C  apur bat hobetzeko sartu dira geroago.
C  Programa Creative Commons-en
C  Attribution-ShareAlike 4.0 lizentziapean partekatzen da
C  http://creativecommons.org/licenses/by-sa/4.0/
C
C  The original PARLI program to calculate electromagnetic parameters
C  and operating conditions of AC overhead transmission lines
C  (it can also be used to conduct ferroresonance studies)
C  and the EREMU program to calculate electromagnetic fields
C  created by AC overhead transmission lines
C  were created by Jon Peli Oleaga Olabarria
C  at the end of the 1970s.
C  They were merged in the last 1980s, and later 
C  they have been changed just to compile them with newer compilers
C  and to add a second language; changing only the strictly necessary.
C  Input data still are inserted in 80 columns as with the old cards.
C  The incorporation of a second language has been done 
C  in a rather naif and unsystematic way.
C  The lines in lowercase were added later 
C  to slightly improve the program documentation.
C  The work is licensed under the Creative Commons 
C  Attribution-ShareAlike 4.0 License.
C  http://creativecommons.org/licenses/by-sa/4.0/

C
      PROGRAM LIPARE
      CHARACTER FITX*14,FILE*40,CHK*4
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      DOUBLE PRECISION EXPE
      COMMON /IZENBN/ IZK,EXPE,NOZ,N,KT,TL,MOZ,NFL
      IZK0=1
      IRT=5
      IRF=4
      IDT=6
      IDF=7
      IDU=9
      FITX='LIPARE.DAT'
      CHK=' '
      NOZ=0
      MOZ=0
      NFL=0
      CALL HIZKUN
      OPEN(UNIT=IDF,FILE='LIPARE.RES',STATUS='UNKNOWN')
      OPEN(UNIT=IDU,FILE='LIPARE.RPU',STATUS='UNKNOWN')
    1 IF(CHK.NE.' ')GOTO 12
      PRINT *,'SAR ERABILIKO DEN DATU-FITXATEGIAREN IZENA:'
      PRINT *,'&lt;RETURN&gt; SAKATUZ GERO, FITXATEGIA = '//FITX
      PRINT *,'(  AMAITZEKO SAKA *&lt;RETURN&gt; BAKARRIK  )'
      PRINT *,' '
      PRINT *,'Enter the name of the input data file:'
      PRINT *,'&lt;RETURN&gt; implies default file name, = '//FITX
      PRINT *,'( To exit the program enter *&lt;RETURN&gt; )'
      READ(IRT,'(A)')FILE
      IF(FILE.EQ.'*')GOTO 9999
      IF(FILE.EQ.' ')FILE=FITX
C-VAX      OPEN(UNIT=IRF,STATUS='OLD',FILE=FILE,READONLY)
C-PC      OPEN(UNIT=IRF,STATUS='OLD',FILE=FILE,MODE='READ')
C-PC-F95-C20041023
      OPEN(UNIT=IRF,STATUS='OLD',FILE=FILE,ACTION='READ')
      READ(IRF,'(//)')
C --- ZAINDU SUBRUTINEA, PROGRAMEA ERABILTEKO BAIMENA AZTERTUTEKO
C     CALL ZAINDU(2,IRF) !&quot;1993-02-03 eta 2003-10-06&quot;ko &quot;parli4.for&quot;ean
      CALL ZAINDU(0,IRF,IZK0)
      IF(IZK0.LT.1 .OR. IZK0.GT.2) IZK0=1  ! 20140626 oraingoz hizkuntza bi bakarrik
      READ(IRF,'(A)')CHK
                              BACKSPACE IRF
   12 IZK=IZK0
      IF    (CHK.EQ.'***E'.OR.CHK.EQ.'***e')THEN
        CHK=' '
        CALL EREPRO(CHK)
      ELSEIF(CHK.EQ.'***P'.OR.CHK.EQ.'***p')THEN
        CHK=' '
        CALL LINPAR(CHK,IZK0) !2026-03-31 gehitu IZK0
      ELSE
        PRINT'(A)',' ',
     +' Lehengo PARLI eta EREMU programak LIPARE barri honetan'//
     +' batu ziranetik,',' datu fitxategietan euretatik'//
     +' zein erabili gura dan esan behar da,',
     +' datu fitxategiaren bostgarren lerroaren lehenengo tokietan',
     +' ***EREMU ala ***PARLI iminiz.',' ',
     +' Aldatu egizuz lehengo fitxategiak.',' '
        GOTO 9999
      ENDIF
      GOTO 1
 9999 END
CJFO      PROGRAM LINPAR
C     Aireko linea elektrikoen parametro esanguratsuenak
C     eta haien funtzionatzeko moduak kalkulatzeko programa
      SUBROUTINE LINPAR(CHK,IZK0) !2026-03-31 gehitu IZK0
      PARAMETER (ND1=10,ND2=12)
C-20131026AN ND1 8TIK 10ERA ALDATUTA ZIRKUITU 2 4 LUR KABLEREKIN ONARTZEKO
      COMPLEX AD(ND2,ND2),BC(ND2,ND2),RI(ND2,ND2),RF(ND2,ND2)
     &amp;,Z(ND1,ND1),Y(ND1,ND1),W(ND1,ND1)
      COMPLEX ER(ND2),ES(ND2),PR,PS,PRT,PST,PTR,PTS,ERO
      REAL DX(ND1),DY(ND1),R(ND1),G(ND1),RMG(ND1),RAD(ND1),D(ND1)
      INTEGER IN(ND1),ID(ND1),KR(ND1),LOC(ND2)
      CHARACTER EGUNA*10,IZENA*56,TT1*27,TT2*27,SII*44,SAK*44,SI*29
     &amp;,SA*29,KG*24,OS*18,ZAT*5,EUSK*5,EROA*15,AZALP*5,CHK*4
      DOUBLE PRECISION EXPE
      COMMON /IZENBN/ IZK,EXPE,NOZ,N,KT,TL,MOZ,NFL
      COMMON /IZENBC/ EGUNA,IZENA,EUSK,EROA
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      PBAS=100.
    2 CALL HIRUAT(IRF,CHK,*9999,*6,*9998)
    6 READ(IRF,5011,END=9998)TL,IZENA,EXPE,EGUNA
 5011 FORMAT(F4.0,A56,F10.2,A10)
      READ(IRF,5012)IZK2,NT,NC,KP,FNY
      IZK=IZK0  !2026-03-31
      IF (IZK2.NE.0) IZK=IZK2
      IF (IZK.LT.1 .OR. IZK.GT.2) IZK=1
C-20131027 5012 FORMAT(4I5,F10.5)
 5012 FORMAT(4I2,F7.3)
                print *,'LINPAR  ',izena
C     IZK = ERABILIKO DEN HIZKUNTZA
C     NT  = LINEAN AZTERTUKO DIREN ZATI GEHI EGOEREN KOPURUA
C     NC  = LINEAREN ZIRKUITU KOPURUA
C     KP  = 1=&gt; EROALE BATZUK BESTE BATZUEKIN PARALELOAN JARTZEN DIRELA
C           EROALE BAKOTZAREN 54. ZUTABEAN JARRI ZEIN BESTE EROALEREKIN.
C           ( PARALELOAN JARRI ETA GERO EZIN DIRA AZTERTU EGOERAK,
C             BAKARRIk ATARA AHAL DIRA ALDAEZIN OROKORRAK )
C     FNY = LINEAREN FREKUENTZIA
      IF(IZK-1)11,10,11
   10 ZAT='ZATI   '
      OS='OSAGAI SIMETRIKOAK'
      KG='   ALDAEZIN  OROKORRAK  '
      TT1='  (EGIAZKO KONFIGURAZIOA)  '
      TT2=' (KONFIGURAZIO BALIOKIDEA) '
      SI='  SERIE INPEDANTZEAK (OHM)   '
      SA='   SHUNT ADMITANTZEAK (MHO)  '
      SII=' SERIE INPEDANTZE INDUKTIBOAK (OHM:KM)  '
      SAK=' SHUNT ADMITANTZE KAPAZITIBOAK (MHO:KM) '
      GO TO 12
   11 ZAT='SECTION'						!7
      OS=' SIMETRICAL COMP. '			!18
      KG='A,B,C,D  TRANSFER MATRIX'		!24 EPRI's TLRB345(1975)pag.116
      TT1=' ( ACTUAL CONFIGURATION )'	!27
      TT2='(EQUIVALENT CONFIGURATION)'	!27
      SI='   SERIES IMPEDANCES (OHM)   '	!29
      SA='   SHUNT ADMITANCES (MHO)    '	!29
      SII='  SERIES INDUCTIVE IMPEDANCES (OHM:KM)  '	!40
      SAK='  SHUNT CAPACITIVE ADMITANCES (MHO:KM)  '	!40

   12 CONTINUE
      N3=NC*3
      N2=N3*2
      DO 20 I=1,N2
      DO 20 J=1,N2
      RF(I,J)=(0.,0.)
      IF(I.EQ.J)RF(I,I)=(1.,0.)
   20 CONTINUE
      XLUZ=0.
      DO 1000 N=1,NT
C-20131027      READ(IRF,5021)KT,K1,K2,K3,NCO,NST,ELT,RHO,EUSK,EROA
      READ(IRF,5021)KT,NCO,K1,K2,K3,NST,ELT,RHO,EUSK,EROA
C-20131027 5021 FORMAT(6I5,2F10.5,A5,A15)
 5021 FORMAT(I1,I3,4I1,F7.3,F5.2,33X,A5,A15)
C     KT =0 =&gt; TENTSIO ETA INTENTSITATEEN AZTERKETA,
C        =1 =&gt; LINEAREN SERIE INPEDANTZE ETA SHUNT ADMITANTZEEN KALKULUA
C        =2 =&gt; KONEKTATUTAKO SERIE INPEDANTZEEN DATUAK
C        =3 =&gt; KONEKTATUTAKO SHUNT ADMITANTZEEN DATUAK
C        =4 =&gt; LINEAREN ERRESONANTZIA FERROMAGNETIKOA AZTERTUKO DA
C     K1 &lt;1 =&gt; EZ DIRA ATARATZEN SERIE INPEDANTZEAK ETA SHUNT ADMITANTZEAK
C        =1 =&gt; KONFIGURAZIO BALIOKIDEAREN SI ETA SA-AK IDAZTEN DIRA
C        &gt;1 =&gt; KONFIGURAZIO ORIGINAL ETA BALIOKIDEAREN SI ETA SA-AK IDAZTEN DIRA
C        (KT=4)2=&gt; ERREAKTAN.ALBO BATEAN, 2=&gt;ER.BESTE ALBOAN, 3=&gt;ER.ALBO BIETAN
C     K2 &lt;1 =&gt; EZ DIRA ATARATZEN ALDAEZIN OROKORTUAK
C        &gt;0 =&gt; ALDAEZIN OROKORTUAK ATARATZEN DIRA (ZATIARENAK)
C        (KT=4)0=&gt;, 1=&gt;
C     K3 &lt;1 =&gt; EZ DIRA ATARATZEN ALDAEZIN OROKORTUAK
C        =1 =&gt; FASEEN ALDAEZIN OROKORTUAK ATARATZEN DIRA (ZATI GUZTIENAK)
C        &gt;1 =&gt; FASEEN ETA KONPOSATU SIMETRIKOEN ALDAEZIN OROKORTUAK ATARATZEN DIRA
C        (KT=4)0=&gt;IRTEERA GRAFIKO LOGARITMIKOAN, 1=&gt;IRTEERA GRAFIKO LINEALEAN
C     NCO = EROALEEN KOPURUA, EDO KT=4 BADA PUNTU KOPURUA GRAFIKOAN
C     NST = AZPITARTEEN KOPURUA (KALKULUAK ZEHAZTASUN HANDIAGOZ EGITEKO)
C     ELT = TARTEAREN LUZERA KM-TAN
C     RHO = LINEA TARTE HONETAKO LURRAREN ERRESISTIBITATEA OHM-M-TAN
C     EUSK = ERABILITAKO EUSKARRIEN IZENA (IRTEERAN IDAZTEKO BAKARRIK)
C     EROA = ERABILITAKO EROALEEN IZENA (IRTEERAN IDAZTEKO BAKARRIK)
      IF(KT.LE.0)GO TO 300
      IF(KT.GE.2)GO TO 200
C
C --- LINE BATEN SERIE INPEDANTZE ETA SHUNT ADMITANTZEEN KALKULUA
      IF(K1.LT.0)K1=0     !C-20131026
      IF(K2.LT.0)K2=0     !C-20131026
      IF(K3.LT.0)K3=0     !C-20131026
      XLUZ=XLUZ+ELT
      ELT=ELT/NST
      DO 100 I=1,NCO
      READ(IRF,5100)RMG(I),RAD(I),IN(I),D(I),ID(I),DX(I),DY(I)
     +,R(I),KR(I)
 5100 FORMAT(2F7.4,I2,F7.4,I2,2F7.3,7X,F7.5,I2)
C     RMG = EROALEAREN &quot;BATEZBESTEKO ERRADIO GEOMETRIKOA&quot; CM-TAN
C     RAD = EROALEAREN ERRADIOA CM-TAN
C     IN  = EROALE SORTAREN AZPIEROALE KOPURUA
C     D   = AZPIEROALEEN ARTEKO DISTANTZIA EDO EROALE SORTAREN DIAMETROA M-TAN
C     ID  =0=&gt; AURREKO DATUA AZPIEROALEN ARTEKO DISTANTZIA DA
C         =1=&gt; AURREKO DATUA EROALE SORTAREN DIAMETROA DA
C     DX  = EROALEAREN X KOORDENATUA M-TAN
C     DY  = EROALEAREN y KOORDENATUA M-TAN
C     R   = EROALEEN ERRESISTENTZIA OHM/KM-TAN
C     KR  =
      IF(R(I).GT.0.)GO TO 100
      J=I-1
      RMG(I)=RMG(J)
      RAD(I)=RAD(J)
      IN(I)=IN(J)
      ID(I)=ID(J)
      D(I)=D(J)
      R(I)=R(J)
  100 CONTINUE
C
C --- SARRERAKO DATUAK ATARATZEN DIRA
      CALL IZENBU
      IF(N.EQ.1)LOZ=NOZ
      IF(IZK-1)102,101,102
  101 WRITE(IDF,6101)NST,ELT,NST*ELT,RHO,FNY
 6101 FORMAT(1H0,23X,'SARRERAKO DATUAK'/1H0,23X,'LINE-LUZERA',I3,'*',
     1F6.2,'=',F7.2,' KM'/1H ,23X,'LUR-ERRESISTIBITATEA',F9.2,' OHM.M'/
     21H ,23X,'MAIZTASUNA', 8X,F11.2,' HZ'/ 1H0,23X,28('*'),
     3' EROALEEN EZAUGARRIAK '          ,29('*') )
      GO TO 103
  102 WRITE(IDF,6102)NST,ELT,NST*ELT,RHO,FNY
 6102 FORMAT(1H0,23X,'INPUT DATA'/1H0,23X,'LINE LONG. ',I3,'*',
     1F6.2,'=',F7.2,' KM'/1H ,23X,'GROUND RESISTIVITY',F11.2,' OHM.M'/
     21H ,23X,'FREQUENCY ', 8X,F11.2,' HZ'/ 1H0,23X,27('*'),
     3'  CONDUCTORS´ FEATURES  ',27('*') )
  103 WRITE(IDF,6103)(I,RMG(I),RAD(I),IN(I),D(I),ID(I),DX(I),DY(I),R(I),
     1I=1,NCO)
 6103 FORMAT(1H ,26X,'..   GMR(CM)   RAD(CM)     IN   D(M)  ID      DX(M
     1)   DY(M)      R(OHM:KM)'//(1H ,26X,I2,2F10.5,I7,F7.2,I4,3X,2F8.2,
     24X,F11.7))
      CALL ZY(ND1,NCO,FNY,RHO,Z,Y,DX,DY,RAD,RMG,IN,D,ID,R,G,KR,W,KP)
      IF(K1.LE.1)GO TO 112
C
C --- BENETAKO EROALE GUZTIEI JAGOKEZAN BALIOAK ATARATZEN DIRA URTEERAN
      CALL IZENBU
      WRITE(IDF,6111)SII,TT1
 6111 FORMAT(1H0,39X,A40,/,46X,A27 )
      CALL ATARAC(Z,NCO,ND1)
      IF(NCO.GT.6)CALL IZENBU
      WRITE(IDF,6111)SAK,TT1
      CALL ATARAC(Y,NCO,ND1)
C
C --- BENETAKO EROALEEN BALIOKIDEEI JAGOKEZAN BALIOAK ATARATZEN DIRA
  112 CALL LABURT(Z,NCO,N3,ND1,KR,KP,ID)
      N2=N3*2
      IF(K1.LT.1)GO TO 113
      CALL IZENBU
      WRITE(IDF,6111)SII,TT2
      CALL ATARAC(Z,N3,ND1)
      IF(N3.GT.6)CALL IZENBU
      WRITE(IDF,6111)SAK,TT2
      CALL ATARAC(W,N3,ND1)
C
C --- LINEKO ZATI AU BENETAKO LINE BAT DA
  113 CONTINUE
      DO 115 I=1,N3
      DO 115 J=1,N3
      Z(I,J)=ELT*Z(I,J)
  115 Y(I,J)=ELT*W(I,J)
      GO TO 211   ! Linearen zati honen azpizatien inp. eta adm.
C
C --- LINEKO ZATI AU SERIE INPEDANTZE ALA SHUNT ADMITANTZE BAT DA
  200 DO 201 I=1,N3
      DO 201 J=1,N3
  201 Z(I,J)=CMPLX(0.,0.)
      IF(KT.LT.4)GO TO 205
C
C --- ERRESONANTZE KASU BAT AZTERTZEN DA
      ELT=ELT*FNY*6.2831853
      RHO=RHO*FNY*6.2831853
      CALL RES(ND2,NC,K1,K2,K3,ELT,RHO,NCO,RF,RI,BC,AD,ES,ER,LOC)
      GO TO 1000
C
C     ******************************************************************
C     ASTERISKOZ OSATUTAKO LERROEN ARTEAN PROGRAMA EZ DAGO PRESTATUTA
C     SARTZEKO FASE ARTEKO SERIE ELKAR INPEDANTZEAK EDO ADMITANTZEAK.
C     HORRETARAKO PROGRAMAREN ZATI HAU ALDATU BEHAR DA
  205 READ(IRF,5205)(Z(I,I),I=1,N3)
 5205 FORMAT(12F6.3)! 2026-03-28 lehen 12F6.3 (datuak S eta ohm-etan) 
      IF(KT.EQ.3)THEN
      DO 206 I=1,N3    ! inpedanziak eta admitantziak sartu ordez
  206 Z(I,I)= 1/Z(I,I) ! beti erreaktoreen inpedantziak sartzeko 
      ENDIF            ! Ohiko erreaktoreakaz datu zehatzagoak sartzeko 
C     ******************************************************************
      IF(K1.LE.0)GO TO 211
      CALL IZENBU
      IF(N.EQ.1)LOZ=NOZ
      IF(KT.EQ.2)WRITE(IDF,6210)ZAT,N,SI
      IF(KT.EQ.3)WRITE(IDF,6210)ZAT,N,SA
 6210 FORMAT(1H0, 5X,A7,I3,33X,A29   )
      CALL ATARAC(Z,N3,ND1)
C
C --- ZATIAREN ALDAEZIN GENERALIZATUAK KALKULATZEKO DO 220
  211 DO 220 I1=1,N3
      DO 220 J1=1,N3
      I2=I1+N3
      J2=J1+N3
      AD(I1,J1)=(0.,0.)
      AD(I2,J2)=(0.,0.)
      IF(I1.NE.J1)GO TO 219
      AD(I1,J1)=(1.,0.)
      AD(I2,J2)=(1.,0.)
  219 AD(I1,J2)=(0.,0.)
      IF(KT.EQ.2)AD(I1,J2)=Z(I1,J1)
      AD(I2,J1)=(0.,0.)
      IF(KT.EQ.3)AD(I2,J1)=Z(I1,J1)
      IF(KT.NE.1)GO TO 220
      AD(I2,J1)=Y(I1,J1)/2.
      BC(I1,J1)=AD(I1,J1)
      BC(I2,J2)=AD(I2,J2)
      BC(I1,J2)=Z(I1,J1)
      BC(I2,J1)=AD(I1,J2)
  220 CONTINUE   !zatiaren azpizati honen ABCD matrizea OOJP-20260312
C
      IF(KT.GT.1)GO TO 244
      IF(K2.LE.0)GO TO 225
      CALL IZENBU
      WRITE(IDF,6224)KG
 6224 FORMAT(1H0,49X,A24   )
  225 CALL BITRIC(BC,N2,N2,AD,N2,N2,RI,ND2)   
      CALL BITRIC(AD,N2,N2,RI,N2,N2,BC,ND2)                
      DO 230 I=1,N2
      DO 230 J=1,N2
      RI(I,J)=(0.,0.)
  230 IF(I.EQ.J)RI(I,J)=(1.,0.)
      KRL=0
      DO 240 I=1,NST !DO honetan barneko azpizatiak batzen dira OOJP
      IF(KRL.GT.0)GO TO 239
      CALL BITRIC(BC,N2,N2,RI,N2,N2,AD,ND2)
      KRL=1
      GO TO 240
  239 CALL BITRIC(BC,N2,N2,AD,N2,N2,RI,ND2)
      KRL=0
  240 CONTINUE
      IF(KRL.GT.0)GO TO 243
      IF(K2.GE.1)CALL ATARAC(RI,N2,ND2)
      CALL BITRIC(RI,N2,N2,RF,N2,N2,BC,ND2)
      !=&gt;hasi sartzen zatiak hartzaile muturretik OOJP-20260315
      GO TO 245
  243 IF(K2.GE.1)CALL ATARAC(AD,N2,ND2)
  244 CALL BITRIC(AD,N2,N2,RF,N2,N2,BC,ND2)
      !=&gt;hasi sartzen zatiak hartzaile muturretik OOJP-20260315
  245 DO 250 I=1,N2
      DO 250 J=1,N2
  250 RF(I,J)=BC(I,J)
      IF(K3.EQ.0)GO TO 1000
      KT=3
      CALL IZENBU
      WRITE(IDF,6224)KG
      CALL ATARAC(RF,N2,ND2)
      IF(K3.LT.2)GO TO 1000
C
C --- LINEKO ALDAEZIN GENERALIZATUEN OSAGAI SIMETRIKOAK ATARATZEN DIRA
      CALL IZENBU
      WRITE(IDF,6224)KG
      WRITE(IDF,6255)OS
 6255 FORMAT(1H ,51X,1H(,A18,1H) )
      CALL OSASYM(2,NC,ND2,RF,RI,AD,BC)
      CALL ATARAC(RI,N2,ND2)
      IF(K3.LT.2) GOTO 1000
C
C --- BESTE FITXATEGI BAT EMOITZA LABURTUAKAZ IDAZTEN DA
      IF(MOD(NFL,60).EQ.0)THEN
       MOZ=MOZ+1
       IF(IZK.EQ.2)WRITE(IDU,6260)PBAS,MOZ
 6260 FORMAT(1H1,'POWER BASE =',F5.0,' MVA',103X,'PAGE',I3/
     1 1X,49('-'),'LINE CHARACTERISTICS IN P.U.     ',50('-')/
     3 1X,17('-'),'-LINE',18('-'),'   LONG.',7X,'  SERIES IMPEDANCE ',
     4 11X,'   SHUNT ADMITANCE    ',4X,'COMENT.',1X,' PAGES   BASE'/
     5 43X,'(KM)',2(6X,'DIRECT C.',5X,'HOMOPOLAR C.',1X),16X,'(KV)')
       IF(IZK.NE.2)WRITE(IDU,6261)PBAS,MOZ
 6261 FORMAT(1H1,'POTENTZIA BASE =',F5.0,' MVA',95X,'ORRIALDE',I3/
     1 1X,52('-'),'LINEEN EZAUGARRIAK  P.U.TAN',53('-')/
     3 1X,17('-'),'LINEA',18('-'),'  LUZER.',7X,' SERIE  INPEDANTZEA',
     4 11X,'   SHUNT  ADMITANTZEA ',4X,'ARGIBI.',1X,'ORRIAL.  BASE'/
     5 43X,'(KM)',2(6X,'O.ZUZENAK',6X,'O.HOMOPOLAR',1X),16X,'(KV)')
       NFL=5
      ENDIF
      AZALP='     '
      IF(NC.GT.1)THEN
       AZALP='CIR.1'
       IF(KP.EQ.1)AZALP='CIR.P'
      ENDIF
      TBAS=1200.
      IF(TL.LT.899.)TBAS=700.
      IF(TL.LT.499.)TBAS=400.
      IF(TL.LT.299.)TBAS=230.
      IF(TL.LT.199.)TBAS=132.
      IF(TL.LT.99.)TBAS=66.
      IF(TL.LT.55.)TBAS=45.
      IF(TL.LT.37.)TBAS=30.
      IF(TL.LT.25.)TBAS=20.
      IF(TL.LT.17.)TBAS=15.
      IF(TL.LT.14.)TBAS=13.2
      IF(TL.LT.8.)TBAS=5.
      BASE=TBAS**2/PBAS
      IF(MOD(NFL,5).EQ.0)THEN
       WRITE(IDU,'(1X)')
       NFL=NFL+1
      ENDIF
      WRITE(IDU,6265)IZENA,XLUZ
     1,RI(1,N3+1)/BASE,RI(3,N3+3)/BASE,RI(N3+1,1)*BASE,RI(N3+3,3)*BASE
     2,AZALP,LOZ,NOZ,TBAS
 6265 FORMAT(1X,A40,F8.2,8F8.4,1X,A5,1X,I3,'-',I3,F6.1)
      NFL=NFL+1
      GO TO 1000
C
C --- LINEKO TENTSIO ETA INTENTSITATEEN AZTERKETA
  300 CALL IRAKUR(NC,ER,LOC,ND2)
      DO 310 I=1,N2
      DO 310 J=1,N2
  310 RI(I,J)=RF(I,J)
      CALL EXCHAN(RI,N2,LOC,ND2,*1000,2)
      CALL BITRIC(RI,N2,N2,ER,N2,1,ES,ND2)
      CALL IZENBU
      DO 320 I=1,N2
      IF(LOC(I).EQ.0)GO TO 320
      ERO=ER(I)
      ER(I)=ES(LOC(I))
      ES(LOC(I))=ERO
  320 CONTINUE
      PTR=(0.,0.)
      PTS=(0.,0.)
      DO 330 I=1,NC
      I1=3*(I-1)
      PRT=(0.,0.)
      PST=(0.,0.)
      DO 325 J=1,3
      I1=I1+1
      I2=I1+N3
      PR=ER(I1)*CONJG(ER(I2))
      PS=ES(I1)*CONJG(ES(I2))
      TJ=CABS(ES(I1)-ER(I1))
      PRT=PRT+PR
      PST=PST+PS
  325 WRITE(IDF,6325)I,J,CABS(ES(I1))*SQRT(3.),CABS(ES(I2)),PS,
     1CABS(ER(I1))*SQRT(3.),CABS(ER(I2)),PR,TJ,LOC(I1),LOC(I2)
 6325 FORMAT(1H ,I2,I4,2(4F13.3,2X),F9.3,I4,I2)
      PTR=PTR+PRT
      PTS=PTS+PST
  330 WRITE(IDF,6330)I,PST,PRT
 6330 FORMAT(1H0,I2,4X,2(26X,2F13.3,2X)//)
      WRITE(IDF,6330)0,PTS,PTR
 1000 CONTINUE
      GOTO 2
 9998 CLOSE(UNIT=IRF)
      CHK=' '
 9999 RETURN
      END
C---------------------------------
      SUBROUTINE ATARAC(ZC,NEU,ND)
      COMPLEX ZC(ND,ND)
      CHARACTER AX*20,AY*45
      INTEGER ASI,BUK,ZEN
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      LZ=1
      ASI=1
      BUK=6
   11 IF(NEU.LE.BUK)GO TO 21
      WRITE(IDF,911)(K,K=ASI,BUK)
  911 FORMAT(1H / 3X,6(15X,I2))
      WRITE(IDF,912)(K,(REAL(ZC(K,I)),I=ASI,BUK),(AIMAG(ZC(K,I))
     1,I=ASI,BUK),K=LZ,NEU)
  912 FORMAT(1H /(7X,I2,6(3X,E14.7),/,9X,6(3X,E14.7)/))
      ASI=ASI+6
      BUK=BUK+6
      GO TO 11
   21 ZEN=NEU-ASI+1
      WRITE(AX,921)ZEN
  921 FORMAT(9H(1H / 3X,,I1,9H(15X,I2)))
      WRITE(IDF,AX)(K,K=ASI,NEU)
      WRITE(AY,922)ZEN,ZEN
  922 FORMAT('(1H /(7X,I2,',I1,'(3X,E14.7)/9X,',I1,'(3X,E14.7)/))')
      WRITE(IDF,AY)(K,(REAL(ZC(K,I)),I=ASI,NEU),(AIMAG(ZC(K,I))
     1,I=ASI,NEU),K=LZ,NEU)
      RETURN
      END
      SUBROUTINE BITRIC(A,NFA,NCA,B,NFB,NCB,C,ND)
C     A ETA B MATRIZEAK BIDERKATZEKO AZPIERRUTINA
C-20041122      COMPLEX A(ND, 1),B(ND, 1),C(ND, 1)
      COMPLEX A(ND, *),B(ND, *),C(ND, *)  !C-20041122
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      IF(NCA.NE.NFB)GO TO 88
       DO 200 J=1,NCB
        DO 200 I=1,NFA
        C(I,J)=CMPLX(0.,0.)
         DO 200 K=1,NCA
  200    C(I,J)=C(I,J)+A(I,K)*B(K,J)
   99 RETURN
   88 WRITE(IDF,888)
  888 FORMAT(6X/ 6X,'SR. BITRIC - MULTZOEN DIMENTSIOAK EZ DIRA EGOKIAK')
      GO TO 99
      END
      SUBROUTINE EXCHAN(A,KA,LOC,ND,*,KON)
C     VS = A x VR ekuazioetan VS eta VR bektoreetako bi balio
C     bata bestearen tokian jartzeko azpierrutina.
C     Egingo diren bikote aldaketak LOC(K)-z definitzen dira.
C     LOC(K) guztiak =K badira EXCHAN eta INTRIX antzekoak dira.
C     (ez guztiz berdinak)
C20041023      COMPLEX A(ND, 1),DIV,FAC
      COMPLEX A(ND, ND),DIV,FAC
      INTEGER LOC(ND)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      XL=1.E-20
      IF(KON-1)3,1,2
    1 DO 100 I=1,KA
  100 LOC(I)=I
    2 DO 200 K=1,KA
      IF(LOC(K).EQ.0)GO TO 200
      DIV=-A(LOC(K),K)
      IF(CABS(DIV).LT.XL)GO TO 1001
      A(LOC(K),K)=(1.,0.)
      DO 210 J=1,KA
  210 A(LOC(K),J)=A(LOC(K),J)/DIV
      DO 220 I=1,KA
      IF(I.EQ.LOC(K))GO TO 220
      FAC=A(I,K)
      A(I,K)=(0.,0.)
      DO 221 J=1,KA
  221 A(I,J)=A(I,J)+FAC*A(LOC(K),J)
  220 CONTINUE
      DO 230 I=1,KA
  230 A(I,K)=-A(I,K)
  200 CONTINUE
    3 RETURN
 1001 WRITE(IDF,999)LOC(K),K
  999 FORMAT(1H //11X,1H(,I2,1H,,I2,22H) ARDATZA TXIKIEGIA DA)
      RETURN 1
      END
      SUBROUTINE LABURT(A,NI,NF,ND,KS,KQ,KR)
C20131023      COMPLEX A(ND, 1)
      COMPLEX A(ND,*)
      INTEGER KR(ND),KS(ND)
      NF=NI
      DO 1100 I=1,NI
 1100 KR(I)=KS(I)
      IF(KQ.EQ.0)GO TO 1
      DO 1300 I=1,NI
      IF(KR(I).LE.I.OR.KR(I).GT.NI)GO TO 1300
      K=KR(I)
      DO 310 J=1,NI
  310 A(I,J)=A(I,J)-A(K,J)
      DO 320 J=1,NI
  320 A(J,I)=A(J,I)-A(J,K)
      KR(I)=0
 1300 CONTINUE
    1 DO 1600 L=1,NI
      M=NI-L+1
      IF(KR(M).GT.0)GO TO 1600
      DO 630 I=1,NF
      DO 630 J=1,NF
      IF(I.EQ.M.OR.J.EQ.M)GO TO 630
      A(I,J)=A(I,J)-A(I,M)/A(M,M)*A(M,J)
  630 CONTINUE
      IF(M.EQ.NF)GO TO 601
      DO 610 I=M,NF-1
      DO 610 J=1,NF
  610 A(J,I)=A(J,I+1)
      DO 620 I=M,NF-1
      DO 620 J=1,NF-1
  620 A(I,J)=A(I+1,J)
  601 NF=NF-1
 1600 CONTINUE
      RETURN
      END
      SUBROUTINE IRAKUR(NC,ER,LOC,ND)
      COMPLEX ER(ND)
      REAL VM(3),VF(3),AM(3),AF(3)
      INTEGER IV(3),NCV(3),NFV(3),IA(3),NCA(3),NFA(3),LOC(ND)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      DO 2100 I=1,NC
      READ(IRF,106)NCT,(VM(J),VF(J),IV(J),NCV(J),NFV(J),J=1,3)
     +                ,(AM(J),AF(J),IA(J),NCA(J),NFA(J),J=1,3)
  106 FORMAT(I2,6(2F5.1,3I1))        !OOJP-20260219
C     NCT = ZIRKUITUA
C     VM  = TENTSIOAREN (INTENTSITATEAREN) MODULUA
C     VF  = TENTSIOAREN (INTENTSITATEAREN) FASEA
C     IV  =0=&gt;MUTUR ELIKATUAREN TENTSIOA
C         =1=&gt;MUTUR ELIKATZILEAREN TENTSIOA
C         =2=&gt;MUTUR ELIKATZAILEAREN INTENTSITATEA
C     NCV = ZIRKUITUA
C     NFV = FASEA
C     AM  = INTENTSITATEAREN (TENTSIOAREN) MODULUA
C     AF  = INTENTSITATEAREN (TENTSIOAREN) FASEA
C     IA  =0=&gt;MUTUR ELIKATUAREN INTENTSITATEA
C         =1=&gt;MUTUR ELIKATZAILEAREN TENTSIOA
C         =2=&gt;MUTUR ELIKATZAILEAREN INTENTSITATEA
C         =3=&gt;POTENTZIA MUTUR ELIKATUAN (EZ BETI)
C     NCA = ZIRKUITUA
C     NFA = FASEA
      DO 2110 J=1,3
      I1=3*(NCT-1)+J
      I2=I1+NC*3
      LOC(I1)=0
      IF(IV(J).EQ.1)LOC(I1)=3*(NCV(J)-1)+NFV(J)
      IF(IV(J).EQ.2)LOC(I1)=3*(NCV(J)-1)+NFV(J)+NC*3
      LOC(I2)=0
      IF(IA(J).EQ.1)LOC(I2)=3*(NCA(J)-1)+NFA(J)
      IF(IA(J).EQ.2)LOC(I2)=3*(NCA(J)-1)+NFA(J)+NC*3
      VF(J)=VF(J)/57.295779
      IF(IV(J).NE.2)VM(J)=VM(J)/SQRT(3.)
      ER(I1)=CMPLX(VM(J)*COS(VF(J)),VM(J)*SIN(VF(J)))
      IF(IA(J).EQ.3)GO TO 2111
      AF(J)=AF(J)/57.295779
      IF(IA(J).EQ.1)AM(J)=AM(J)/SQRT(3.)
      GO TO 2110
 2111 AM(J)=AM(J)/VM(J)/COS(ATAN(AF(J)))
      AF(J)=VF(J)-ATAN(AF(J))
 2110 ER(I2)=CMPLX(AM(J)*COS(AF(J)),AM(J)*SIN(AF(J)))
 2100 CONTINUE
      RETURN
      END
      SUBROUTINE OSASYM(NB,NC,ND,Z123,ZDIH,SD,SI)
      COMPLEX A0,A1,A2,Z123(ND,ND),ZDIH(ND,ND),SD(ND,ND),SI(ND,ND)
      NTT=3*NB*NC
      A0=(1.,0.)
      A1=(-0.5, 0.8660254)
      A2=(-0.5,-0.8660254)
      DO 100 I=1,NTT
      DO 100 J=1,NTT
  100 SD(I,J)=(0.,0.)
      DO 200 I=1,NTT-2,3
      SD(I  ,I  )=A0
      SD(I  ,I+1)=A0
      SD(I  ,I+2)=A0
      SD(I+1,I  )=A2
      SD(I+1,I+1)=A1
      SD(I+1,I+2)=A0
      SD(I+2,I  )=A1
      SD(I+2,I+1)=A2
  200 SD(I+2,I+2)=A0
      N=ND
      CALL BITRIC(Z123,NTT,NTT,SD,NTT,NTT,SI,N)
      DO 300 I=1,NTT-2,3
      SD(I  ,I  )=A0/3.
      SD(I  ,I+1)=A1/3.
      SD(I  ,I+2)=A2/3.
      SD(I+1,I  )=A0/3.
      SD(I+1,I+1)=A2/3.
      SD(I+1,I+2)=A1/3.
      SD(I+2,I  )=A0/3.
      SD(I+2,I+1)=A0/3.
  300 SD(I+2,I+2)=A0/3.
      CALL BITRIC(SD,NTT,NTT,SI,NTT,NTT,ZDIH,N)
      RETURN
      END
      SUBROUTINE REGRA(Y,NG,XG,X ,K3)
C20131024      REAL Y( 6,1)
      REAL Y( 6,236)
C20041023      CHARACTER*1 CL(121),PUN/'.'/,ZUR/' '/
C20041023      CHARACTER*1 E1/'1'/,E2/'2'/,E3/'3'/,E4/'4'/,E5/'5'/,E6/'6'/
      CHARACTER*1 CL(121),PUN,ZUR
      CHARACTER*1 E1,E2,E3,E4,E5,E6
      CHARACTER MEZUA1(4)*38,MEZUA2(4)*35,MEZUA3(4)*5
      DOUBLE PRECISION EXPE
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      COMMON /IZENBN/ IZK,EXPE,NOZ,N,KT,TL,MOZ,NFL
      MEZUA1(1)='FASEEN ETA NEUTROAREN ARTEKO TENTSIOAK'
      MEZUA1(2)='PHASE NEUTRAL VOLTAGES                '
      MEZUA2(1)='FASEKO TENTSIOEN BALIORIK HANDIENA:'
      MEZUA2(2)='      PHASE VOLTAGE, MAXIMUM VALUE:'
      MEZUA3(1)=' FASE'
      MEZUA3(2)='PHASE'
      PUN='.'
      ZUR=' '
      E1='1'
      E2='2'
      E3='3'
      E4='4'
      E5='5'
      E6='6'
      IF(K3.GT.0)GO TO 100
      WRITE(IDF,105)MEZUA1(IZK)
  105 FORMAT(1H1,10X,A38,77X,'V:VMAX',/1H0
     1,2X,'XL(OHM)',1X,3('1',11X,'2',6X,'3    4   5  6  7 8 9 '),'1')
      WRITE(IDF,103)
  103 FORMAT(11X,121('.'))
      GO TO 200
  100 WRITE(IDF,205)MEZUA1(IZK)
  205 FORMAT(1H1,10X,A38,77X,'V:VMAX',/ 1H0,2X,'XL(OHM)',1X,
     1'0.00',25X,'0.25',26X,'0.50',26X,'0.75',24X,'1.00')
      WRITE(IDF,103)
  200 YMAX=ABS(Y(1,1))
      DO 1 I=1,6
      DO 1 IJ=1,NG
    1 IF(YMAX.LT.ABS(Y(I,IJ))) YMAX=ABS(Y(I,IJ))
      DO 10 I=1,121
   10 CL(I)=ZUR
      DO 20 I=1,NG
      X=X+XG
      CL(1)=PUN
      IF(K3.GT.0)GO TO 21
      CL(41)=PUN
      CL(81)=PUN
      CL(121)=PUN
      J1=40.*ALOG10(Y(1,I)/YMAX)+121.5
      J2=40.*ALOG10(Y(2,I)/YMAX)+121.5
      J3=40.*ALOG10(Y(3,I)/YMAX)+121.5
      J4=40.*ALOG10(Y(4,I)/YMAX)+121.5
      J5=40.*ALOG10(Y(5,I)/YMAX)+121.5
      J6=40.*ALOG10(Y(6,I)/YMAX)+121.5
      IF(J1.GE.1)CL(J1)=E1
      IF(J2.GE.1)CL(J2)=E2
      IF(J3.GE.1)CL(J3)=E3
      IF(J4.GE.1)CL(J4)=E4
      IF(J5.GE.1)CL(J5)=E5
      IF(J6.GE.1)CL(J6)=E6
      WRITE(IDF,104)X,(CL(J),J=1,121)
  104 FORMAT(1H , F9.3,1X,121A1)
      GO TO 22
   21 CL(61)=PUN
      CL(31)=PUN
      CL(91)=PUN
      CL(121)=PUN
      J1=120.*Y(1,I)/YMAX+1.5
      J2=120.*Y(2,I)/YMAX+1.5
      J3=120.*Y(3,I)/YMAX+1.5
      J4=120.*Y(4,I)/YMAX+1.5
      J5=120.*Y(5,I)/YMAX+1.5
      J6=120.*Y(6,I)/YMAX+1.5
      CL(J1)=E1
      CL(J2)=E2
      CL(J3)=E3
      CL(J4)=E4
      CL(J5)=E5
      CL(J6)=E6
      WRITE(IDF,104)X,(CL(J),J=1,121)
C  204 FORMAT(1H ,F10.3,4X,121A1)
   22 IF (J1.GT.0) CL(J1)=ZUR
      IF (J2.GT.0) CL(J2)=ZUR
      IF (J3.GT.0) CL(J3)=ZUR
      IF (J4.GT.0) CL(J4)=ZUR
      IF (J5.GT.0) CL(J5)=ZUR
      IF (J6.GT.0) CL(J6)=ZUR
   20 CONTINUE
      IF(K3.EQ.0)WRITE(IDF,103)
      IF(K3.GT.0)WRITE(IDF,103)
      WRITE(IDF,108)(MEZUA3(IZK),I=1,3),MEZUA2(IZK),YMAX
C 108 FORMAT(1H // 15X,'1144 FASE 1',5X,'2255 FASE 2',5X,'3366 FASE 3',
C    1 7X,'FASEKO TENTSIOEN BALIORIK HANDIENA:',F13.3,' KV')
  108 FORMAT(1H // 15X,'1144 ',A5,' 1',5X,'2255 ',A5,' 2',5X,'3366 ',A5
     1,' 3',7X,A35,F13.3,' KV')
      RETURN
      END
      SUBROUTINE RES(ND,NC,N1,N2,N3,XA,XG,NG,RF,RI,BC,AD,ES,ER,LOC)
      COMPLEX RF(ND,ND),RI(ND,ND),BC(ND,ND),AD(ND,ND),ES(ND),ER(ND)
      REAL VOLT(6,236)
      INTEGER LOC(ND)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      NT=ND
      N6=NC*6
      N5=NC*3-3
      N4=N6-3
      IF(NG.GT.236)NG=236
      CALL IRAKUR(NC,ER,LOC,NT)
      WRITE(IDF,199)(J,J=1,N6)
  199 FORMAT(1H1// 3X,7HXL(OHM),3X,12(3X,2HES,I2,3X)// )
      XA=XA-XG
      XH=XA
      DO 1000 I=1,NG
      XA=XA+XG
      DO 1100 I1=1,NC*3
      DO 1100 J1=1,NC*3
      I2=I1+NC*3
      J2=J1+NC*3
      BC(I1,J1)=(0.,0.)
      BC(I2,J2)=(0.,0.)
      BC(I1,J2)=(0.,0.)
      BC(I2,J1)=(0.,0.)
      IF(I1.NE.J1) GO TO 1100
      BC(I1,J1)=(1.,0.)
      BC(I2,J2)=(1.,0.)
      IF(N2.EQ.0.OR.J1.GT.N5)BC(I2,J1)=CMPLX(0.,-1./XA)
 1100 CONTINUE
C     N1 ESATEN DU ERREAKTANTZIAK NON DAUDEN KOKATUTA
      IF(N1.GE.3)CALL BITRIC(RF,N6,N6,BC,N6,N6,RI,NT)
      IF(N1.EQ.2)CALL BITRIC(BC,N6,N6,RF,N6,N6,RI,NT)
      IF(N1.NE.4)GO TO 1001
      CALL BITRIC(BC,N6,N6,RI,N6,N6,AD,NT)
      DO 1200 I1=1,N6
      DO 1200 J1=1,N6
 1200 RI(I1,J1)=AD(I1,J1)
 1001 CALL EXCHAN(RI,N6,LOC,NT,*999,2)
      CALL BITRIC(RI,N6,N6,ER,N6,1,ES,NT)
      WRITE(IDF,198)XA,(CABS(ES(J)),J=1,N6)
  198 FORMAT(1H ,F10.3,1X,12(1PE10.2))
      DO 1300 I1=1,3
      VOLT(I1,I)=CABS(ES(I1+N5))
 1300 VOLT(I1+3,I)=CABS(ES(I1+N4))
 1000 CONTINUE
C     N3 ESATEN DU IRTEERA GRAFIKOA NOLAKOA DEN
      CALL REGRA(VOLT,NG,XG,XH,N3)
  999 RETURN
      END
      SUBROUTINE ZY(L,N,FNCY,RHO,Z,Y,DX,DY,RAD,RMG,IN,D,ID,R,G,KR,W,KW)
C***** SUBROUTINE ONEN BIDEZ LINE BATEN (R+JX) INPEDANTZEAK ETA   ******
C***** (G+JB) ADMITANTZEAK KALKULATZEN DIRA                       ******
C***** &quot;Transmission Line Reference Book 345 kV and Above&quot;        ******
C***** liburuaren 95. orrialdean esandakoaren arabera             ******
C***** Electric Power Research Institute, Palo Alto CA94304, 1975 ******
      REAL FNCY,DX(L),DY(L),RAD(L),RMG(L),D(L),R(L),G(L),K,MUCY
      INTEGER IN(L),ID(L),KR(L)
      COMPLEX Z(L,L),Y(L,L),W(L,L)
      FK(A,F,RLOC)=2.80E-3*A*SQRT(F/RLOC)
      FP(K,T,P)=P/8.-K*COS(T)/3./SQRT(2.)+K**2 *(COS(2.*T)*(0.6728+ALOG(
     12./K))+T*SIN(2.*T))/16.+K**3 *COS(3.*T)/45./SQRT(2.)-P*K**4 *COS(4
     2.*T)/1536.
      FQ(K,T,P)=ALOG(2./K)/2.-0.0386+K*COS(T)/3./SQRT(2.)-P*K**2 *COS(2.
     1*T)/64.+K**3 *COS(3.*T)/45./SQRT(2.)-K**4 *(T*SIN(4.*T)+COS(4.*T)*
     2(ALOG(2./K)+1.0895))/384.
      PI=3.1415926
      C=3.E8
      OMEG=2.*PI*FNCY
      MUCY=2.E-4*OMEG
C *** MUCY=MU ZATI (BI BIDER PI) BIDER OMEGA (MU=4*PI*E-7, MUCY=MU*FNCY)
C *** MUCY=MU ENTRE DOS PI POR OMEGA         (MU=4*PI*E-7, MUCY=MU*FNCY)
      EPCY=2.E-10*C**2/OMEG
C *** EPCY=BAT ZATI (BI BIDER PI EPSILON OMEGA)(EPS=1/MU/C**2=E-9/36/PI)
C *** EPCY=UNO ENTRE DOS PI EPSILON OMEGA      (EPS=1/MU/C**2=E-9/36/PI)
        DO 1 I=1,N
          G(I)=0.  !C-20041122
        R(I)=R(I)/IN(I)
        RMG(I)=RMG(I)/100.
        RAD(I)=RAD(I)/100.
        RG=GMR(IN(I),RMG(I),D(I),ID(I))
        RR=GMR(IN(I),RAD(I),D(I),ID(I))
        DPMM=2.*DY(I)
        TETA=0.
        K=FK(DPMM,FNCY,RHO)
        P=FP(K,TETA,PI)*2.*MUCY
        Q=FQ(K,TETA,PI)*2.*MUCY
        X=ALOG(DPMM/RG)*MUCY
        Z(I,I)=CMPLX(R(I)+P,X+Q)
        X=ALOG(DPMM/RR)*EPCY
        Y(I,I)=CMPLX(0.,-X)
        W(I,I)=Y(I,I)
        J1=I+1
        IF(N-J1)1,15,15
   15     DO 16 J=J1,N
          DPMN=DY(I)+DY(J)
          DMN =DY(I)-DY(J)
          HMN =DX(I)-DX(J)
          DPMN=SQRT(DPMN**2+HMN**2)
          DMN =SQRT(DMN **2+HMN**2)
          TETA=ASIN(HMN/DPMN)
          K=FK(DPMN,FNCY,RHO)
          P=FP(K,TETA,PI)*2.*MUCY
          Q=FQ(K,TETA,PI)*2.*MUCY
          X=ALOG(DPMN/DMN)*MUCY
          Z(I,J)=CMPLX(P,X+Q)
          Z(J,I)=Z(I,J)
          X=ALOG(DPMN/DMN)*EPCY
          Y(I,J)=CMPLX(0.,-X)
          W(I,J)=Y(I,J)
          W(J,I)=W(I,J)
   16     Y(J,I)=Y(I,J)
    1   CONTINUE
      M=L
      CALL LABURT(W,N,N3,M,KR,KW,ID)
      CALL EXCHAN(Y,N,ID,M,*99,1)
      CALL EXCHAN(W,N3,ID,M,*99,1)
        DO 2 I=1,N
        W(I,I)=CMPLX(G(I),0.)+W(I,I)
    2   Y(I,I)=CMPLX(G(I),0.)+Y(I,I)
   99 RETURN
      END
C --- *** --- *** --- *** --- *** --- *** --- *** --- *** --- *** ---
      SUBROUTINE EREPRO(CHK)
C     AIREKO LINEA ELEKTRIKOEK SORTUTAKO
C     EREMU ELEKTROMAGNETIKOAK KALKULATZEKO PROGRAMA.
C     PARALELOAN JARRITAKO 10 LINEA ARTE KONTUAN HARTU AHAL DITU.
C$      FORTY   MAP,XREF,FDS                                             EREMU
CEREMU
      PARAMETER (N1=32)
      DIMENSION V(N1),PHI(N1),RA(N1),RMG(N1),D(N1),IDL(N1),IN(N1),X(N1),
     &amp;Y1(N1),Y2(N1),PC(N1,N1),VR(N1),VI(N1),XR(N1),XI(N1),FI(N1),JCK(N1)
      REAL FNCY
      INTEGER POPT
      CHARACTER  IZENA*56,EGUNA*10,  EUSK*5,EROA*15,  CHK*4
      DOUBLE PRECISION EXPE
      EQUIVALENCE(RMG(1),PC(1,N1))
      COMMON/BI/PC,VR,VI,RA,D,IN,IDL
      COMMON/IRU/XA,XG,NX,YA,YG,NY,X,Y1
      COMMON /IZENBN/ IZK,EXPE,NOZ,NNN,KTKTKT,TL,MOZ,NFL
      COMMON /IZENBC/ EGUNA,IZENA,EUSK,EROA
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      CHARACTER     IZBR21(2)*7, IZBR22(2)*28,IZBR23(2)*15,IZBR24(2)*33
     4,IZBR31(2)*22,IZBR32(2)*18,IZBR33(2)*54,IZBR34(2)*16,IZBR35(2)*8
     5,IZBR36(2)*54,IZBR37(2)*16
      COMMON /HZENBU/IZBR21,IZBR22,IZBR23,IZBR24
     4       ,IZBR31,IZBR32,IZBR33,IZBR34,IZBR35,IZBR36,IZBR37
      CHARACTER IZBE21(2)*90,IZBE22(2)*46
      COMMON /HZEPRO/IZBE21,IZBE22
   99 CALL HIRUAT(IRF,CHK,*98,*9999,*9998)
   98 READ(IRF,'(F4.0,A56,F10.2,A10)',END=9998)TL,IZENA,EXPE,EGUNA
      READ(IRF,599)L2,FNCY,RHO,POPT,NA,IE,IM,L,XA,XG,NX,YA,YG,NY
  599 FORMAT(I3,F9.0,F7.2,5I2,2X,2(F6.2,F4.2,I3))
                         print *,'EREMU   ',izena
C     L2   = EROALEEN KOPURUA
C     FNCY = LINEAREN FREKUENTZIA
C     RHO  = LINE TARTE HONEN LURRAREN ERRESISTIBITATEA
C     POPT &lt;1 =&gt; KONF. ORIGINALAREN MAXWELL-EN POTENTZIAL KOEF. ATARATZEN DIRA
C          =1 =&gt; KONF. ORIGINALAREN MAXWELL-EN POTENTZIAL KOEF. ATARATZEN DIRA
C          =2 =&gt; KONF. BALIOKIDEAREN M-EN POT. KOEF. ATARATZEN DIRA
C          &gt;2 =&gt; BI KONFIGURAZIOEN M-EN POT. KOEFIZIENTEAK ATARATZEN DIRA
C     NA   =1 =&gt; ZARATA AKUSTIKOARI BURUZKO DATUAK ATARATZEN DIRA
C     IE   &gt;0 =&gt; EREMU ELEKTRIKOAREN EMAITZAK ATARATZEN DIRA
C     IM   &gt;0 =&gt; EREMU MAGNETIKOAREN EMAITZAK ATARATZEN DIRA
C     L    =
C     XA   = EREMUAK KALKULATZEKO HASIERAKO X KOORDENADA (M-TAN)
C     XG   = EREMUAK KALKULATZEKO X KOORDENADARENTZAKO GEHIGARRIA (M-TAN)
C     NX   = ZENBAT BIDER GEHITUKO DEN XG ( &lt;101 )
C     YA   = EREMUAK KALKULATZEKO HASIERAKO Y KOORDENADA (M-TAN)
C     YG   = EREMUAK KALKULATZEKO Y KOORDENADARENTZAKO GEHIGARRIA (M-TAN)
C     NY   = ZENBAT BIDER GEHITUKO DEN YG ( &lt;11 )
      READ(IRF,598)(RMG(I),RA(I),IN(I),D(I),IDL(I),X(I),Y1(I),Y2(I)
     &amp;,XI(I),FI(I),V(I),PHI(I),I=1,L2)
  598 FORMAT(2F7.4,I2,F7.4,I2,3F7.3,9X,F5.3,F6.2,F7.3,F6.2)
C     RMG = EROALEAREN &quot;BATEZBESTEKO ERRADIO GEOMETRIKOA&quot; CM-TAN
C     RA  = EROALEAREN ERRADIOA CM-TAN
C     IN  = EROALE SORTAREN AZPIEROALE KOPURUA
C     D   = AZPIEROALEEN ARTEKO DISTANTZIA EDO EROALE SORTAREN DIAMETROA M-TAN
C     IDL =0 =&gt; AURREKO DATUA AZPIEROALEN ARTEKO DISTANTZIA DA
C         =1 =&gt; AURREKO DATUA EROALE SORTAREN DIAMETROA DA
C     X   = EROALEAREN X KOORDENATUA M-TAN
C     Y1  = EROALEAREN Y KOORDENATUA M-TAN EUSKARRIEN ONDOAN
C     Y2  = EROALEAREN Y KOORDENATUA M-TAN EUSKARRIEN ARTEKO TARTEAREN ERDIAN
C     XI  = INTENTSITATEAREN BALIOA KA-TAN
C     FI  = INTENTSITATEAREN FASEA GRADUTAN
C     V   = TENTSIOAREN BALIOA KV-TAN
C     PHI = TENTSIOAREN FASEA GRADUTAN
                  KTKTKT=20
      CALL IZENBU
C     IZBE21='SARRERAKO DATUAK, AZTERTUTAKO LINEAREN EZAUGARRIAK'
      WRITE(IDF,696)IZBE21(IZK),IZBE22(IZK)
     1,L2,FNCY,RHO,POPT,NA,IE,IM,L,XA,XG,NX,YA,YG,NY
  696 FORMAT(//8X,A//8X,A,13X,'XA    XG   NX     YA    YG   NY'/
     &amp; 9X,I2,F11.0,F9.2,8X,5I3, 8X,2(F8.2,F6.2,I4))

      WRITE(IDF,697)(I,RMG(I),RA(I),IN(I),100.*D(I),IDL(I),X(I),Y1(I),
     1Y2(I),XI(I),FI(I),V(I),PHI(I),I=1,L2)
C 697 FORMAT(1H /8X,'COND  GMR  RAD  ZEN BUN D ZER      X       Y1     '
C    1,' Y2      INT KA  FAS G    TEN KV  PHAS G'//
C    2,(9X,I2,F6.2,F5.2,I4,F7.2,I3,2X,3F8.2,2(F10.2,F8.2)))
  697 FORMAT(1H /8X,'EROA  BGE  ERR  ZEN SOR.D ZER      X       Y1     '
     1,' Y2      INT KA  FAS G    TEN KV  PHAS G'//
     2,(9X,I2,F6.2,F5.2,I4,F7.2,I3,2X,3F8.2,2(F10.2,F8.2)))
      IF(RHO)95,95,97
   97 IF(FNCY)95,95,96
   96 DK=660.*SQRT(RHO/FNCY)
      GO TO 94
   95 DK=800.
   94 CONTINUE
          DO 1 I=1,L2
    1     Y1(I)=Y1(I)+(Y2(I)-Y1(I))*2./3.
        DO 2 I=1,L2
        PHI(I)=PHI(I)*0.017453293
        V(I)=1000.*V(I)/1.7320508
        VR(I)=V(I)*COS(PHI(I))
        VI(I)=V(I)*SIN(PHI(I))
        FI(I)=FI(I)*0.017453293
        XI(I)=1000.*XI(I)
        XR(I)=XI(I)*COS(FI(I))
        XI(I)=XI(I)*SIN(FI(I))
        RA (I)=RA (I)/100.
    2   CONTINUE
      KOPT=0
      IF(POPT.LT.0)POPT=0     !C-20131026
      IF(POPT.GT.3)POPT=3     !C-20131026
      POPT=POPT+1
  100 CALL PMAXW(L2,X,Y1,IN,RA,D,IDL,PC)
      GO TO(203,202,201,200),POPT
  200 IF(KOPT)202,202,201
  201 CALL GITRIX(PC,L2,V,L4)
      KOPT=1                 !C-20131026
      L2=L4
  202 CALL IDATZM(PC,L2,KOPT,1,IZK)
  203 CALL INTRIX(PC,L2,JCK,N1,*99)
      IF(POPT-1)204,205,204
  204 CALL IDATZM(PC,L2,KOPT,2,IZK)
  205 CALL IDATZG(L2,KOPT,IZK)
      IF(IE.GT.0.OR.IM.GT.0.OR.L.GT.0)
     &amp;CALL EREMU(L2,KOPT,XR,XI,DK,IE,IM,L)
      IF(NA.GT.0)CALL ANOISE(L2,KOPT,V,PHI,RA,IN,NA,IZK)
      IF(KOPT) 99,208, 99
  208 KOPT=1
      IF(POPT-3)99,99,100
 9998 CLOSE(UNIT=IRF)
      CHK=' '
 9999 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             ANOISE
      SUBROUTINE ANOISE(N,KOPT,V,PHI,RA,IN,AN,IZK)
C  *********************************************************************
C  *  SUBRUTINA HONETAN LINEEK SORTUTAKO PRESIO AKUSTIKOAREN ZEHARKAKO *
C  *  PROFILA KALKULATZEN DA,   ''E.P.R.I.''K 1975EAN ARGITARATUTAKO   *
C  *  '' TRANSMISSION  LINE  REFERENCE  BOOK  345  KV  AND  ABOVE ''   *
C  *  LIBURUAREN 6. KAPITULUAN (AUDIBLE NOISE) ESANDAKOAREN ARABERA    *
C  *********************************************************************
      PARAMETER (N1=32)
      REAL V(N1),RA(N1),PHI(N1),X(N1),Y(N1),GRS(N1),Z(N1),GRM(N1)
      INTEGER AN,IN(N1)
      COMPLEX P
      REAL LONG,JHR,JWC,NM2HR,NM2WC,NM2PT,LANDA,LANDA1,LANDA2
      CHARACTER ANOI11(2)*4, ANOI12(2)*72,ANOI21(2)*47,ANOI22(2)*54
     1,ANOI23(2)*72,ANOI24(2)*26,ANOI25(2)*25,ANOI26(2)*23
      COMMON /HZOISE/ ANOI11,ANOI12,ANOI21,ANOI22,ANOI23,ANOI24,ANOI25
     1,ANOI26
      EQUIVALENCE(GRM(1),Z(1))
      COMMON/BAT/A1(N1),A2(N1)
      COMMON/IRU/XA,XG,NX,YA,YG,NY,X,Y
      COMMON/LAU/GRM
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      CHARACTER*25 KONFOR(2),KONFBA(2),POTGR1(2)*32,POTGR2(2)*60
     1,MAXP1(2)*35,MAXP2(2)*19,KAP1(2)*27,KAP2(2)*19
      COMMON /HZDATZ/ KONFOR,KONFBA,POTGR1,POTGR2,MAXP1,MAXP2,KAP1,KAP2
      DB(XNM2)=20.*ALOG10(XNM2/2.E-5)
      AB(AX)=10.**(AX/10.)
      IF(AN.EQ.0) GO TO 99
      ATE=-0.0075
      ATE=-0.0075
      LANDA=3.43
      DC=20.5
      XK1=0.
      XK2=1.
      LONG=5000.
      L1=100
      L2=10
      XM=0.01
C     YM=0.01
      ZM=10.
      KONTR=0
      PI=3.14159265
      IF(NX.GT.L1.OR.NY.GT.L2.OR.XG.LT.XM.OR.YG.LT.XM)GO TO 98
        DO 100 I=1,N
        IF(IN(I)-2)101,102,103
  101   XKN=5.6
        GO TO 104
  102   XKN=1.8
        GO TO 104
  103   XKN=1.0
  104   A1(I)=46.4-665.0/GRM(I)
        A1(I)=AB(A1(I))
        A1(I)=IN(I)**2*(200.*RA(I)/3.8)**4.4*A1(I)*XKN
        A2(I)=53.5-505.5/GRM(I)
        C1=10.6-0.41/(2.*RA(I))
        A2(I)=A2(I)+C1
        C1=47.4-1000./(IN(I)+15)
        C2=24.1-390.0/(IN(I)+10)
        C=(C2-C1)/2.28
        C=C1+C*(200.*RA(I)-2.35)
        A2(I)=A2(I)+C
        A2(I)=AB(A2(I))
        GRS(I)=(12.5*200.*RA(I)-4.57)/(200.*RA(I)-1.07)
        IF(IN(I)-4)106,106,105
  105   GRS(I)=GRS(I)/(1.+0.027*(IN(I)-4))
  106   GRS(I)=GRM(I)/GRS(I)
        U=10.*(GRS(I)-0.8)
        Z(I)=(63.4*U**2+1.87*U**3-1.15*U**4)/1000.
  100   CONTINUE
      Y2=YA-YG
        DO 200 K=1,NY+1
        CALL IZENBU
        Y2=Y2+YG
        IF(Y2)200,201,201
  201   IF(KOPT)202,202,203
C 997 FORMAT(1H /51X,22HKONFIGURAZIO ORIGINALA)
  202   WRITE(IDF,'(1H /51X,A)')KONFOR(IZK)
        GO TO 204
C 996 FORMAT(1H /51X,23HKONFIGURAZIO BALIOKIDEA)
  203   WRITE(IDF,'(1H /51X,A)')KONFBA(IZK)
  204     DO 300 I=1,N
          IF(ABS(V(I))-ZM)301,301,300
  301     R=RA(I)*100.
          G=GRS(I)
          IF(R.GE.1.0.AND.R.LE.3.0.AND.G.LE.1.4.AND.G.GE.0.8)GO TO 300
C 998 FORMAT(/I3,' EROALEA (LUR KABLEA) EZ DA KONTUAN HARTZEN'
C    1,' EROALE HEZEKO KASUAN ')
          WRITE(IDF,'(/A,I3,A)')TRIM(ANOI11(IZK)),I,TRIM(ANOI12(IZK))
  300     CONTINUE

C 995 FORMAT(/16X,'PRESIO AKUSTIKOAREN ZEHARKAKO PROFILA, LURRETIK',F6.2
C    1,' M-RA N/M2 ETA 20 MICRON/M2-REN GAINEKO DB-TAN' // 2X,5HDIST.,8X
C    2,'*******  BANDA ZABALEKO ZARATA ALEATORIOAREN MAILA  *******',12X
C    3,'100 HZ-EKO ZARATAREN MAILA' / 15X,'** EURITE GOGORRAK ***',14X,
C    4'**** EROALE HEZEAK ****', 13X,'**** EURITE GOGORRAK ****' /
C    5 18X,'N/M2',9X,5HDB(A),18X,4HN/M2,9X,5HDB(A),19X,4HN/M2,9X,2HDB)
        WRITE(IDF,995)ANOI21(IZK),Y2,ANOI22(IZK),ANOI23(IZK),ANOI24(IZK)
     1, ANOI25(IZK),ANOI26(IZK),ANOI25(IZK)
  995 FORMAT(/16X,A,F6.2,A//2X,A,12X,A/15X,A,11X,A,13X,A/
     5 19X,'N/M2',9X,5HDB(A),18X,4HN/M2,9X,5HDB(A),19X,4HN/M2,10X,2HDB)

        ILK=0     !Datuekin idatzitako lerro kopurua
        X2=XA-XG
         DO 400 J=1,NX+1
         JHR=0.
         JWC=0.
         P=(0.,0.)
         X2=X2+XG
         IF(MOD(ILK,6).EQ.0)THEN
          WRITE(IDF,'(1X)')
          ILK=ILK+1
         ENDIF
         ILK=ILK+1   !Idatzitako lerroen kopurua
          DO 500 I=1,N
          XD=X2-X(I)
          YH1=Y2-Y(I)
          YH2=Y2+Y(I)
          IF(ABS(XD)-XM)501,502,502
  501     IF(ABS(YH1)-XM)403,502,502
  502     R=RA(I)*100.
          G=GRS(I)
          R1=SQRT(XD*XD+YH1*YH1)
          R2=SQRT(XD*XD+YH2*YH2)
          IF(LONG-1000.)505,505,506
  505     HM1=(ATAN2(LONG,2.*R1)*EXP(ATE*R1)/R1 + XK1*ATAN2(LONG,2.*R2)*
     1    EXP(ATE*R2)/R2)/(2.*PI)
          GO TO 507
  506     HM1=(EXP(ATE*R1)/R1+XK1*EXP(ATE*R2)/R2)/4.
  507     JHR=JHR+A1(I)*HM1
          COEF=DC*A2(I)/SQRT(2.)/PI
          LANDA1=0.-PHI(I)-2.*PI*R1/LANDA
          LANDA2=0.-PHI(I)-2.*PI*R2/LANDA
          P1=COEF*(COS(LANDA1)/R1+XK2*COS(LANDA2)/R2)
          P2=COEF*(SIN(LANDA1)/R1+XK2*SIN(LANDA2)/R2)
          P=P+CMPLX(P1,P2)
          IF(R.GE.1..AND.R.LE.3..AND.G.LE.1.4.AND.G.GE..8) GO TO 504
          IF(ABS(V(I))-ZM)500,500,503
  503     KONTR=1
  504     JWC=JWC+A1(I)*HM1*Z(I)
  500     CONTINUE
         NM2HR=DC*SQRT(JHR)*1.E-3
         NM2WC=DC*SQRT(JWC)*1.E-3
         NM2PT=CABS(P)*1.E-3
         DBAHR=DB(NM2HR)
         DBAWC=DB(NM2WC)
         DBAPT=DB(NM2PT)
         IF(KONTR)402,401,402
  401 WRITE(IDF,994)X2,NM2HR,DBAHR,NM2WC,DBAWC,NM2PT,DBAPT
  994 FORMAT(1H , F7.2,8X,1PE9.2,0PF12.2,15X,1PE9.2,0PF12.2,16X,1PE9.2
     1,0PF12.2,1X)
         GO TO 400
  402 WRITE(IDF,993)X2,NM2HR,DBAHR,NM2PT,DBAPT
C 993 FORMAT(1H / F7.2,8X,1PE9.2,0PF12.2,10X,
C    1'NOT ENOUGH STATISTICAL DATA',13X,1PE9.2,0PF12.2 )
  993 FORMAT(1H , F7.2,8X,1PE9.2,0PF12.2,10X,
     1'DATU ESTATISTIKO GUTXIEGI',15X,1PE9.2,0PF12.2 )
         GO TO 400
  403    WRITE(IDF,992)X2,X2,Y2
C 992 FORMAT(1H / F7.2,25X,' RESULTS FOR X=',F6.2,' E Y=',F6.2,'
C    1 ARE NOT SIGNIFICANT')
  992 FORMAT(1H , F7.2,25X,' X=',F6.2,' ETA Y=',F6.2,
     1' TOKIRAKO EMAITZAK EZ DIRA ESANGURATSUAK')
  400    CONTINUE
  200   CONTINUE
      GO TO 99
   98 WRITE(IDF,999)
  999 FORMAT(1H1///10HANOISE-N, ,'MUGAEI JAGOKEZAN (DAGOKIEZAN, DAGOZKIE
     1N) BALDINTZAK EZ DIRA BETETZEN')
   99 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             ATARA
      SUBROUTINE ATARA (MULTZO,NEURRI)
      PARAMETER (N1=32)
      REAL MULTZO(N1,N1)
      CHARACTER *20 AX
      CHARACTER *25 AY
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      INTEGER ASIERA,AMAIA
      ASIERA=1
      AMAIA=6
   33 IF(NEURRI-AMAIA)1,1,2
    2 WRITE(IDF,999)(K,K=ASIERA,AMAIA)
  999 FORMAT(1H //3X,6(15X,I2))
      WRITE(IDF,997)(K,(MULTZO(K,I),I=ASIERA,AMAIA),K=1,NEURRI)
  997 FORMAT(1H /(7X,I2,6(3X,E14.7)))
      ASIERA=ASIERA+6
      AMAIA=AMAIA+6
      GO TO 33
    1 NBARRI=NEURRI-ASIERA+1
      WRITE(AX,998)NBARRI
  998 FORMAT(9H(1H //3X,,I1,9H(15X,I2)))
      WRITE(IDF,AX)(K,K=ASIERA,NEURRI)
      WRITE(AY,996)NBARRI
  996 FORMAT(12H(1H /(7X,I2,,I1,12H(3X,E14.7))))
      WRITE(IDF,AY)(K,(MULTZO(K,I),I=ASIERA,NEURRI),K=1,NEURRI)
      RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             BITRIX
      SUBROUTINE BITRIX(A,NFA,NCA,B,NFB,NCB,P)
      PARAMETER (N1=32)
      DIMENSION A(N1,N1),B(N1,1),P(N1,1)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
  888 FORMAT(1H ,5X,'MULTZO ONEIK EZIN DIRA BIDERTU')
      IF(NCA-NFB)3,1,3
    1 CONTINUE
        DO 2 J=1,NCB
          DO 21 I=1,NFA
          P(I,J)=0.
            DO 211 K=1,NCA
  211       P(I,J)=P(I,J)+A(I,K)*B(K,J)
   21     CONTINUE
    2   CONTINUE
      RETURN
    3 WRITE(IDT,888)
      STOP 1002
      END
C$      FORTY   MAP,XREF,FDS                                             EREMU
      SUBROUTINE EREMU(N,KOPT,XIR,XII,DEK,IELEC,IMAG,L)
C *** ******************************************************************
C     SUBRUTINA HONETAN LINEA BATEK SORTUTAKO EREMU ELEKTRIKO ETA
C     MAGNETIKOA KALKULATZEN DIRA,   D.W. DENO-REN 'TRANSMISSION
C     LINE FIELDS' (IEEE TRANSACTIONS VOL.PAS-95 NO.5 SEP/OCT 1976) 
C     ARTIKULUAREN ETA WG 36-01(EFFECTS OF CORONA AND FIELD) LAN TALDEAK
C     SC 36(INTERFERENCE) KOMITEAREN IZENEAN AURKEZTUTAKO
C     36-07(CIGRE 1978) TXOSTENAREN ARABERA
C *** ******************************************************************
      PARAMETER (N1=32)
      DOUBLE PRECISION EXPE
      COMMON/BAT/QR,QI
      COMMON/IRU/XASI,XGEI,NXG,YASI,YGEI,NYG,X,Y
      COMMON /IZENBN/ IZK,EXPE,NOZ,NNNN,KT,TL,MOZ,NFL
      REAL X(N1),Y(N1),QR(N1),QI(N1),XIR(N1),XII(N1)
      REAL MUPI
      COMPLEX POTEN
C     COMMON /HIZKON/ KONFOR,KONFBA   OOJP-20260208
      CHARACTER*25 KONFOR(2),KONFBA(2),POTGR1(2)*32,POTGR2(2)*60
     1,MAXP1(2)*35,MAXP2(2)*19,KAP1(2)*27,KAP2(2)*19
      COMMON /HZDATZ/ KONFOR,KONFBA,POTGR1,POTGR2,MAXP1,MAXP2,KAP1,KAP2
      CHARACTER*25  POTEL1(2)*48,POTEL2(2)*50
     1,ERMAG1(2)*28,ERMAG2(2)*15,ERMAG3(2)*122,ERMAG4(2)*19,ERMAG5(2)*19
     2,ERELE1(2)*25,ERELE2(2)*15,ERELE3(2)*121,ERELE4(2)*19,ERELE5(2)*19
     3,MEZU21(2)*15,MEZU22(2)*7, MEZU23(2)*36, MEZU24(2)*74
      COMMON /HZREMU/ POTEL1,POTEL2
     1       ,ERMAG1,ERMAG2,ERMAG3,ERMAG4,ERMAG5
     2       ,ERELE1,ERELE2,ERELE3,ERELE4,ERELE5
     3       ,MEZU21,MEZU22,MEZU23,MEZU24
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      FUNK(R,S,T,U,A)=SQRT((R*SIN(A)+S*COS(A))**2 +(T*SIN(A)+U*COS(A))**
     12 )
      BAT(A,B)=A/(A*A+B*B)

      LIM1=100
      LIM2=10
      XMUGA=0.01
      YMUGA=0.01
C20041023      ZMG=1.E-38
      ZMG=1.E-37
      RD=57.295779
      EPPI=18.E6
C     EPPI=BAT ZATI (BI BIDER PI BIDER EPSILON)
C     =1./(2.*PI*EPS)=18.E9(S.I.) C=3.E8 BADA
      MUPI=2.E-7
C     MUPI=MU ZATI (BI BIDER PI)=MU/(2.*PI)=2.E-7(S.I.)
      IF(IELEC)11,11,12
   11 IF(IMAG)99,99,12
   12 IF(NXG-LIM1)14,14,13
   13 WRITE(IDF,613)
  613 FORMAT(1H1///10X,'BIDEA ZABALEGIA DA, NXG 100 BAINO AUNDIAGOA DA')
      GO TO 99
   14 IF(NYG-LIM2)16,16,15
   15 WRITE(IDF,615)
  615 FORMAT(1H1///10X,'BIDEA GARAIEGIA DA, NYG 10 BAINO AUNDIAGOA DA')
      GO TO 99
   16 IF(XGEI-0.01)17,18,18
   17 WRITE(IDF,617)
  617 FORMAT(1H1///10X,'XGEI 0.01 BAINO TXIKIAGOA DA')
      GO TO 99
   18 IF(YGEI-0.01)19,20,20
   19 WRITE(IDF,619)
  619 FORMAT(1H1///10X,'YGEI 0.01 BAINO TXIKIAGOA DA')
      GO TO 99
   20 CONTINUE
       DO 100 KB=1,2
       IF(KB-1)101,101,102
  101  IF(IELEC)103,103,102
  102  YA=YASI-YGEI
C*200   DO 200 EREMU ELEKTRIKO EDO INDUKZIO MAGNETIKOAREN KALKULUA
C       AZTERTU GURA DIREN SESTRA GUZTIETAN
        DO 200 K=1,NYG+1
        CALL IZENBU
        ILK=0     !Datuekin idatzitako lerroen kopurua
        IF(KOPT)201,201,203
  201   WRITE(IDF,995)KONFOR(IZK)     !Konfigurazio originala
  995 FORMAT(1H /51X,A)
        GO TO 204
  203   WRITE(IDF,995)KONFBA(IZK)     !Konfigurazio baliokidea
  204   YA=YA+YGEI
        IF(KB-1)208,208,206
  206   WRITE(IDF,988)TRIM(ERMAG1(IZK)),YA,ERMAG2(IZK)
     1  ,ERMAG3(IZK),(ERMAG4(IZK),I=1,2),(ERMAG5(IZK),I=1,4)
  988   FORMAT(1H /44X,A,F6.2,A///3X,A/8X,2(A),4(A))
        GO TO 210
  208   WRITE(IDF,989)TRIM(ERELE1(IZK)),YA,ERELE2(IZK)
     1  ,ERELE3(IZK),(ERELE4(IZK),I=1,2),(ERELE5(IZK),I=1,4)
  989   FORMAT(1H /44X,A,F6.2,A///2X,A/1H ,8X,2(A),4(A))
  210   XA=XASI-XGEI
C*500    DO 500 E.ELEK. EDO I.MAG.-AREN KALKULUA SESTRA BAKOITZEAN
         DO 500 I=1,NXG+1
         GXR=0.
         GXI=0.
         GYR=0.
         GYI=0.
         XA=XA+XGEI
C*600     DO 600 E.ELEK. EDO I.MAG.-AREN KALKULUA
C         SESTRA BATEKO PUNTUETAN
          DO 600 J=1,N
          XD=XA-X(J)
          YH1=YA-Y(J)
          IF(KB-1)602,602,601
  601     YH2=YA+DEK
          GO TO 603
  602     YH2=YA+Y(J)
  603     CONTINUE
          IF(ABS(XD).GE.XMUGA)GO TO 606
          IF(ABS(YH1).LT.XMUGA.OR.ABS(YH2).LT.XMUGA)GO TO 504
  606     S11=BAT(XD,YH1)
          S12=BAT(XD,YH2)
          S21=BAT(YH1,XD)
          S22=BAT(YH2,XD)
          IF(KB-1)608,608,607
  607     XM=(S21-S22)*MUPI
          YM=(S12-S11)*MUPI
          GXR=GXR+XIR(J)*XM
          GXI=GXI+XII(J)*XM
          GYR=GYR+XIR(J)*YM
          GYI=GYI+XII(J)*YM
          GO TO 600
  608     XM=(S11-S12)*EPPI
          YM=(S21-S22)*EPPI
          GXR=GXR+QR(J)*XM
          GXI=GXI+QI(J)*XM
          GYR=GYR+QR(J)*YM
          GYI=GYI+QI(J)*YM
  600     CONTINUE
C        ELIPSE BAKOITZAREN ARDATZ NAGUSIEN KALKULUA
         IF(ABS(YA).LE.YMUGA.AND.KB.EQ.1)GO TO 591
         ECUA=GYR*GXR+GYI*GXI
         IF(ABS(ECUA).LE.ZMG)GO TO 599
         ECUB=GXI*GXI-GYI*GYI+GXR*GXR-GYR*GYR
         ECUC=-ECUA
         TANA1=(-ECUB+SQRT(ECUB**2 -4.*ECUA*ECUC))/(2.*ECUA)
         TANA2=(-ECUB-SQRT(ECUB**2 -4.*ECUA*ECUC))/(2.*ECUA)
         A1=ATAN(TANA1)
         A2=ATAN(TANA2)
  592    FA1=FUNK(GYI,GXI,GYR,GXR,A1)
         FA2=FUNK(GYI,GXI,GYR,GXR,A2)
         A11=A1*57.295779
         A22=A2*57.295779
         IF(FA1-FA2)502,501,501
  501    F1=FA1*SQRT(2.)
         F2=FA2*SQRT(2.)
         A1=A11
         A2=A22
         GO TO 503
  502    F1=FA2*SQRT(2.)
         F2=FA1*SQRT(2.)
         A1=A22
         A2=A11
C        ALDIUNEKO BALIOEN KALKULUA
  503    GXR2=-GXI
         GYR2=-GYI
         G1M=SQRT(GXR *GXR +GYR *GYR )*SQRT(2.)
         G2M=SQRT(GXR2*GXR2+GYR2*GYR2)*SQRT(2.)
         G1D=0.
         IF(ABS(GYR ).GE.ZMG.OR.ABS(GXR ).GE.ZMG)G1D=ATAN2(GYR ,GXR )*RD
         G2D=0.
         IF(ABS(GYR2).GE.ZMG.OR.ABS(GXR2).GE.ZMG)G2D=ATAN2(GYR2,GXR2)*RD
         GXABS=SQRT(GXR*GXR+GXI*GXI)
         GYABS=SQRT(GYR*GYR+GYI*GYI)
         GXFAS=0.
         IF(ABS(GXR).GE.ZMG.OR.ABS(GXI).GE.ZMG)GXFAS=ATAN2(GXI,GXR)*RD
         GYFAS=ATAN2(GYI,GYR)*57.295779
         IF(MOD(ILK,6).EQ.0)THEN
           WRITE(IDF,'(1X)')
          ILK=ILK+1
         ENDIF
         ILK=ILK+1   !Idatzitako lerroen kopurua
         WRITE(IDF,987)XA,GXABS,GXFAS,GYABS,GYFAS,F1,A1,F2,A2,G1M,G1D,
     1   G2M,G2D
  987 FORMAT(1H ,F7.2,6(2X,1PE9.3,0PF8.2)) !OOJP-20260216 lehen 1PE9.2
         GO TO 500
C MEZU23='-RAKO EMAITZAK EZ DIRA ESANGURATSUAK'
  504    WRITE(IDF,985)XA,TRIM(MEZU21(IZK)),XA,TRIM(MEZU22(IZK)),YA,
     1   MEZU23(IZK)
  985 FORMAT(1H ,F7.2,2X,A,F6.2,A,F6.2,A)
         ILK=ILK+1
         GO TO 500
C MEZU24='BEGIRATU IA EROALEEN TENTSIOAK EDO INTENTSITATEAK SARTU DIREN'
  599    WRITE(IDF,984)MEZU24(IZK)
  984 FORMAT(1H ///10X,A///)

         IF(KB-1)103,103,99
  591    GXR=0.
         GXI=0.
         A1=90./57.295779
         A2= 0.
         GO TO 592
  500    CONTINUE
  200   CONTINUE
  103  IF(IMAG)99,99,100
  100  CONTINUE
   99 IF(L.LT.1.OR.NYG.GT.LIM1.OR.NXG.GT.LIM2)GO TO 98
      XA=XASI-XGEI
      DO 700 K=1,NXG+1
      IF(KOPT.GT.0)GO TO 701
      WRITE(IDF,995)KONFOR(IZK)     !Konf. originala
      GO TO 702
  701 WRITE(IDF,995)KONFBA(IZK)     !Konf. baliokidea
  702 XA=XA+XGEI
      WRITE(IDF,983)XA
C 983 FORMAT(1H /34X,'POTENCIAL ELECTRICO A DIFERENTES ALTURAS PARA X=',
C    &amp;F6.2,' M'///36X,'ALTURA    VA.EF.POT.     A.FAS.POT.     VA.AC.POT
C    &amp;.'/37X,'(M)',9X,'(KV)',11X,'(GS)',11X,'(KV)')
  983 FORMAT(1H /34X,'POTENTZIAL ELEKTRIKOAK GARIAERA EZBERDINETAN (X=',
     &amp;F6.2,' M)'
     &amp;///36X,'GOIERA    POT.BA.EF.     POT.FAS.A.     POT.UN.BA.'
     &amp;/37X,'(M)',9X,'(KV)',11X,'(GS)',11X,'(KV)')
      YA=YASI-YGEI
      DO 700 I=1,NYG+1
      YA=YA+YGEI
      IF(YA.LT.0.)GO TO 700
      POTEN=(0.,0.)
      DO 800 J=1,N
      XD=XA-X(J)
      YH1=YA-Y(J)
      YH2=YA+Y(J)
      IF(ABS(XD).LT.XMUGA.AND.ABS(YH1).LT.XMUGA)GO TO 703
      YH1=SQRT(XD*XD+YH1*YH1)
      YH2=SQRT(XD*XD+YH2*YH2)
      XD=EPPI*QR(J)*ALOG(YH2/YH1)
      YH1=EPPI*QI(J)*ALOG(YH2/YH1)
  800 POTEN=POTEN+CMPLX(XD,YH1)
      XD=CABS(POTEN)
C     HURRENGO AGINDUA 1999.07.14.AN GEHITU ZEN, EMOITZAK EGOKITZEKO
      XD=XD*1000.
      IF(XD.LT.ZMG)GO TO 700
      YH1=ATAN2(AIMAG(POTEN),REAL(POTEN))
      YH2=XD*COS(YH1)*SQRT(2.)
      YH1=YH1*57.295779
      WRITE(IDF,982)YA,XD,YH1,YH2
  982 FORMAT(1H /35X,F6.2,3(6X,1PE9.2))
      GO TO 700
  703 WRITE(IDF,985)YA,XA,YA
  700 CONTINUE
   98 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             GITRIX
      SUBROUTINE GITRIX(Z,L2,V,L4)
      PARAMETER (N1=32)
      DIMENSION Z(N1,N1),V(N1)
      L3=L2+1
      L4=L2
        DO 1 L=1,L2
        L1=L3-L
        IF(V(L1)-10.E-6)2,2,4
    2   L4=L1-1
          DO 11 I=1,L4
            DO 111 K=1,L4
  111       Z(I,K)=Z(I,K)-Z(I,L1)/Z(L1,L1)*Z(L1,K)
   11     CONTINUE
    1   CONTINUE
    4 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             GMR
      FUNCTION GMR(IN,RA,D,IDL)
C     GMR = EROALE SORTA BATEN BATEZBESTEKO GEOMETRIKOKO ERRADIOA
C     IN = EROALE KOPURUA
C     RA = EROALE BATEN ERRADIOA
C     D = SORTAREN DIAMETROA EDO EROALEN ARTEKO DISTANTZIA
C     IDL = &quot;D&quot; ZER DEN ADIERAZTEKO ALDAGAIA
      IF(IN-2)1,22,2
    2 IF(IDL)21,21,22
   21 A=D/(2.*SIN(3.1415926/IN))
      GO TO 3
   22 A=D/2.
    3 GMR=(IN*RA*A**(IN-1))**(1./IN)
      GO TO 4
    1 GMR=RA
    4 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             IDATZG
      SUBROUTINE IDATZG(N,KOPT,IZK)
C     EROALEETAKO BATEZ BESTEKO POTENTZIAL GRADIENTEAK ETA
C     POTENTZIAL GRADIENTE HANDIENAK IDAZTEKO SUBRUTINA
      PARAMETER (N1=32)
      COMMON/BAT/QR,QI/BI/MULTZO,VR,VI,RA,D,IN,IDL
      COMMON/LAU/XGM(N1)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      CHARACTER*25 KONFOR(2),KONFBA(2),POTGR1(2)*32,POTGR2(2)*60
     1,MAXP1(2)*35,MAXP2(2)*19,KAP1(2)*27,KAP2(2)*19
      COMMON /HZDATZ/ KONFOR,KONFBA,POTGR1,POTGR2,MAXP1,MAXP2,KAP1,KAP2
      REAL MULTZO(N1,N1),VR(N1),VI(N1),QR(N1),QI(N1),RA(N1),D(N1)
      INTEGER IN(N1),IDL(N1)
      M=N
      CALL BITRIX(MULTZO,M,M,VR,M,1,QR)
      CALL BITRIX(MULTZO,M,M,VI,M,1,QI)
      CALL IZENBU
      IF(KOPT)1,1,2
    1 WRITE(IDF,601)KONFOR(IZK)
  601 FORMAT(1H ///49X,A)
      GO TO 3
    2 WRITE(IDF,602)KONFBA(IZK)
  602 FORMAT(1H ///49X,A)
C     POTGR1='POTENTZIAL GRADIENTEA EROALEETAN'
    3 WRITE(IDF,603)POTGR1(IZK),POTGR2(IZK)
  603 FORMAT(1H /45X,A32///27X,A60)
        DO 4 I=1,N
        Q=QR(I)*QR(I)+QI(I)*QI(I)
        Q=SQRT(Q)
        XGR=18.E4*Q/(RA(I)*IN(I))
        IF(IN(I)-1)2001,45,44
   45   XGRM=XGR
        GO TO 43
   44   IF(IDL(I))2001,41,42
   41   XGRM=XGR*(1+(IN(I)-1)*RA(I)*2./D(I)*SIN(3.1415927/IN(I)))
        GO TO 43
   42   XGRM=XGR*(1+(IN(I)-1)*RA(I)*2./D(I))
   43   XGM(I)=XGRM
        WRITE(IDF,643)I,Q,XGR,XGRM
  643 FORMAT(1H /(28X,I2,5X,E15.8,4X,2(2PE15.6,4X)))
    4   CONTINUE
 2001 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             IDATZM
      SUBROUTINE IDATZM(PC,L2,KOPT,K,IZK)
      PARAMETER (N1=32)
      DIMENSION PC(N1,N1)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      CHARACTER*25 KONFOR(2),KONFBA(2),POTGR1(2)*32,POTGR2(2)*60
     1,MAXP1(2)*35,MAXP2(2)*19,KAP1(2)*27,KAP2(2)*19
      COMMON /HZDATZ/ KONFOR,KONFBA,POTGR1,POTGR2,MAXP1,MAXP2,KAP1,KAP2
      IF(KOPT)1,1,2
    1 WRITE(IDF,601)KONFOR(IZK)
  601 FORMAT(1H ///30X,A)
      GO TO 3
    2 WRITE(IDF,602)KONFBA(IZK)
  602 FORMAT(1H ///30X,A)
    3 IF(K-1)7,4,5 
C   4 WRITE(IDF,604)
C 604 FORMAT(1H /25X,36HMAXWELL-EN POTENTZIAL KOEFIZIENTEAK, /
C    &amp;32X,19H( METRO FARADIOKO ))
    4 WRITE(IDF,604)MAXP1(IZK),MAXP2(IZK)
  604 FORMAT(1H /25X,A,/32X,A)
      GO TO 6
C    5 WRITE(IDF,605)
C 605 FORMAT(1H /36X,12HKAPAZITATEAK,/32X,19H( FARADIO METROKO ))
    5 WRITE(IDF,605)KAP1(IZK),KAP2(IZK)
  605 FORMAT(1H /29X,A,/32X,A)
    6 L3=L2
      CALL ATARA(PC,L3)
    7 RETURN
      END
C$      FORTY   MAP,XREF,FDS                                             INTRIX
      SUBROUTINE INTRIX(A,KA,LCK,ND,*)
C     A MATRIZEA ALDERANTZIKATZEKO AZPIERRUTINA
C20041023      DIMENSION A(ND, 1),LCK(ND)
      DIMENSION A(ND, ND),LCK(ND)
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
        DO 1 I=1,KA
    1   LCK(I)=0
        DO 2 I=1,KA
        AMAX=0.
          DO 21 K=1,KA
          IF(AMAX-ABS(A(K,K)))211,21,21
  211     IF(LCK(K))212,212,21
  212     L=K
          AMAX=ABS(A(K,K))
   21     CONTINUE
        IF(ABS(AMAX)-10.E-6)1001,1001,22
   22   LCK(L)=1
        DIV=A(L,L)
        A(L,L)=1.
          DO 23 J=1,KA
   23     A(L,J)=A(L,J)/DIV
          DO 24 J=1,KA
          IF(L-J)241,24,241
  241     EAJ=A(J,L)
          A(J,L)=0.
            DO 242 K=1,KA
  242       A(J,K)=A(J,K)-A(L,K)*EAJ
   24     CONTINUE
    2   CONTINUE
      RETURN
 1001 WRITE(IDT,999)I,L,L
  999 FORMAT(1H /9X,'INTRIX,',I3,1H(,I2,1H,,I2,') ARDATZA TXIKIEGIA DA')
      RETURN 1
      END
C$      FORTY   MAP,XREF,FDS                                             PMAXW
      SUBROUTINE PMAXW(L2,X,Y,IN,RA,D,IDL,P)
C     MAXWELL-EN &quot;P&quot; POTENTZIAL KOEFIZIENTEAK KALKULATZEKO SUBRUTINA
      PARAMETER (N1=32)
      DIMENSION X(N1),Y(N1),IN(N1),RA(N1),D(N1),IDL(N1),P(N1,N1)
        DO 1 I=1,L2
        X1=2.*Y(I)
        X3=GMR(IN(I),RA(I),D(I),IDL(I))
        P(I,I)=18.E9*ALOG(X1/X3)
        J1=I+1
        IF(L2-J1)1,3,3
    3     DO 2 J=J1,L2
          X1=X(I)-X(J)
          X1=X1*X1
          X2=Y(I)+Y(J)
          X3=Y(I)-Y(J)
          X2=SQRT(X1+X2*X2)
          X3=SQRT(X1+X3*X3)
          P(I,J)=18.E9*ALOG(X2/X3)
          P(J,I)=P(I,J)
    2     CONTINUE
    1   CONTINUE
      RETURN
      END
      SUBROUTINE IZENBU
      CHARACTER EGUNA*10,IZENA*56,EUSK*5,EROA*15
      DOUBLE PRECISION EXPE
      CHARACTER     IZBR21(2)*7, IZBR22(2)*28,IZBR23(2)*15,IZBR24(2)*33
     4,IZBR31(2)*22,IZBR32(2)*18,IZBR33(2)*54,IZBR34(2)*16,IZBR35(2)*8
     5,IZBR36(2)*54,IZBR37(2)*16
      COMMON /HZENBU/IZBR21,IZBR22,IZBR23,IZBR24
     4       ,IZBR31,IZBR32,IZBR33,IZBR34,IZBR35,IZBR36,IZBR37
      COMMON /IZENBN/ IZK,EXPE,NOZ,N,KT,TL,MOZ,NFL
      COMMON /IZENBC/ EGUNA,IZENA,EUSK,EROA
      COMMON /IRKIDT/ IRT,IDT,IRF,IDF,IDU
      NOZ=NOZ+1
      IF(IZK-1)30,20,30
   20 WRITE(IDF,620) NOZ,EGUNA,IZENA,TL,EXPE
  620 FORMAT(1H1,5X,'ENPRESELEK,E.A.',87X,'ORRIALDE',I14/
     1           6X,'LINETAKO SAILA',88X,'DATA ',7X,A10/
     2 23X,A56,F5.0,'KV-EKO LINE ELEKTRIKOA',2X,'ESPEDIENTE',F12.2 )
      GO TO 40
   30 WRITE(IDF,630) NOZ,EGUNA,TL,IZENA,EXPE
  630 FORMAT(1H1,5X,'ENPRESELEK,E.A.',87X,'PAGE',I18/
     1           6X,'LINES DIVISION',88X,'DATE',8X,A10/
     223X,'TRANSMISSION LINE OF ',F5.0,' KV ',A54 ,1X,'EXPEDIENT',F13.2)

C     IZBR23=' EUSKARRIZ ETA ',IZBR24=' EROALEZ EGINDAKO LINE ELEKTRIKOA'
   40 IF(KT.EQ.1)WRITE(IDF,621)TRIM(IZBR21(IZK)),N
     1,TRIM(IZBR22(IZK))//' '//TRIM(EUSK)//TRIM(IZBR23(IZK))//
     2' '//TRIM(EROA)//TRIM(IZBR24(IZK))
  621 FORMAT(1H0, 5X,A,I3,T24,A)

C     IZBR31='  MUTUR ELIKATZAILEA  ', IZBR32='  MUTUR ELIKATUA  '
      IF(KT.EQ.0)WRITE(IDF,622)IZBR31(IZK),IZBR32(IZK)
     1,            (IZBR33(IZK),I=1,2),IZBR34(IZK)
     2,IZBR35(IZK),(IZBR36(IZK),I=1,2),IZBR37(IZK)
  622 FORMAT(1H0, 9X,15('*'),A22,14('*'),3X,17('*'),A18,16('*')/
     1  2(' ***'),2(A54),1X,A/ A,2(A54),1X,A/
     2 2(' ***'),2(7X,'(KV)', 9X,'(KA)', 9X,'(MW)', 8X,'(MVAR)',3X)
     3,3X,'(KV)',4X,'***'  ///)
      RETURN
      END

      SUBROUTINE HIRUAT(IR,CAUX,*,*,*)
      CHARACTER CAUX*4
CJF
      READ (IR,'(A)',END=3) CAUX
      IF (CAUX.EQ.'***E'.OR.CAUX.EQ.'***e') RETURN1
      IF (CAUX.EQ.'***P'.OR.CAUX.EQ.'***P') RETURN2
      BACKSPACE IR
      RETURN
    3 RETURN3
      END
C--+------------------------------------------------------
      SUBROUTINE ZAINDU(ERA,IRF,IZK0)
C  Behinolako programaren erabilera-baimenak kontrolatzeko azpierrutinea
C  gaur egun kasu batzutan erabiliko den hizkuntza zein den jakiteko
C  baino ez da erabiltzen bertsio laburrean
      INTEGER ERA
      READ(IRF,'(20X,I5)') IZK0
      RETURN
      END
C--+------------------------------------------------
      SUBROUTINE HIZKUN
C     Hizkuntzen araberako kateak definitzeko;
C     bi hizkuntzatarako dimentsionatuta
      CHARACTER CHL*132
      CHARACTER*25 KONFOR(2),KONFBA(2),POTGR1(2)*32,POTGR2(2)*60
     1,MAXP1(2)*35,MAXP2(2)*19,KAP1(2)*27,KAP2(2)*19
      COMMON /HZDATZ/ KONFOR,KONFBA,POTGR1,POTGR2,MAXP1,MAXP2,KAP1,KAP2
      CHARACTER     POTEL1(2)*48,POTEL2(2)*50
     1,ERMAG1(2)*28,ERMAG2(2)*15,ERMAG3(2)*122,ERMAG4(2)*19,ERMAG5(2)*19
     2,ERELE1(2)*25,ERELE2(2)*15,ERELE3(2)*121,ERELE4(2)*19,ERELE5(2)*19
     3,MEZU21(2)*15,MEZU22(2)*7, MEZU23(2)*36, MEZU24(2)*74
      COMMON /HZREMU/ POTEL1,POTEL2
     1       ,ERMAG1,ERMAG2,ERMAG3,ERMAG4,ERMAG5
     2       ,ERELE1,ERELE2,ERELE3,ERELE4,ERELE5
     3       ,MEZU21,MEZU22,MEZU23,MEZU24
      CHARACTER     IZBR21(2)*7, IZBR22(2)*28,IZBR23(2)*15,IZBR24(2)*33
     1,IZBR31(2)*22,IZBR32(2)*18,IZBR33(2)*54,IZBR34(2)*16,IZBR35(2)*8
     2,IZBR36(2)*54,IZBR37(2)*16
      COMMON /HZENBU/IZBR21,IZBR22,IZBR23,IZBR24
     1       ,IZBR31,IZBR32,IZBR33,IZBR34,IZBR35,IZBR36,IZBR37
      CHARACTER IZBE21(2)*90,IZBE22(2)*46
      COMMON /HZEPRO/IZBE21,IZBE22
      CHARACTER ANOI11(2)*4, ANOI12(2)*72,ANOI21(2)*47,ANOI22(2)*54
     1,ANOI23(2)*72,ANOI24(2)*26,ANOI25(2)*25,ANOI26(2)*23
      COMMON /HZOISE/ ANOI11,ANOI12,ANOI21,ANOI22,ANOI23,ANOI24,ANOI25
     1,ANOI26
      KONFOR(1)='KONFIGURAZIO ORIGINALA'
      KONFOR(2)='ORIGINAL CONFIGURATION'
      KONFBA(1)='KONFIGURAZIO BALIOKIDEA'
      KONFBA(2)='EQUIVALENT CONFIGURATION'
      POTGR1(1)='POTENTZIAL GRADIENTEA EROALEETAN'
      POTGR1(2)='ELECTRIC FIELD ON THE CONDUCTORS'
      CHL='EROALE     KARGA Q/M          BB-GR KV/CM'
      POTGR2(1)=TRIM(CHL)//'        GRMAX KV/CM'
      CHL='CONDUC.    CHARGE Q/M         GR.MV KV/CM'
      POTGR2(2)=TRIM(CHL)//'        GRMAX KV/CM'
      MAXP1(1)='MAXWELL-EN POTENTZIAL KOEFIZIENTEAK'
      MAXP1(2)=&quot; MAXWELL'S POTENTIAL COEFFICIENTS &quot; 
      MAXP2(1)='( METRO FARADEKO )'
      MAXP2(2)='( METRE PER FARAD )'
      KAP1(1)='KAPAZITANTZIA-KOEFIZIENTEAK'
      KAP1(2)='CAPACITANCE COEFFICIENTS' !EPRI'S TLRB345kV(1975) pag.94
      KAP2(1)=' ( FARAD METROKO )'
      KAP2(2)='( FARAD PER METRE )'
      
      ERMAG1(1)='INDUKZIO MAGNETIKOA LURRETIK'
      ERMAG1(2)='MAGNETIC INDUCTION'
      ERMAG2(1)=' M-RA'
      ERMAG2(2)=' M ABOVE GROUND'
      CHL='DIST.  INDUK.HORIZONTALA   INDUK.BERTIKALA'
      CHL=TRIM(CHL)//'     INDUK.MAXIMOA      INDUK.MINIMOA'
      CHL=TRIM(CHL)//'      UNEKO INDUK.   INDUK. 90 G GEROAGO'
      ERMAG3(1)=TRIM(CHL)
      CHL='DIST.  INDUC.HORIZONTAL    INDUC.VERTICAL'
      CHL=TRIM(CHL)//'      MAXIM.INDUC.       MINIM.INDUC.'
      CHL=TRIM(CHL)//'      PRESENT INDUC.    INDUC. 90 G LAT.'
      ERMAG3(2)=TRIM(CHL)
      ERMAG4(1)=' MOD.TESLA   ARG.G '
      ERMAG4(2)=' MOD.TESLA   ARG.G '
      ERMAG5(1)=' MAG.TESLA   DIR.G '
      ERMAG5(2)=' MAG.TESLA   DIR.G '
      ERELE1(1)='EREMU ELEKTRIKOA LURRETIK'
      ERELE1(2)='ELECTRIC FIELD'
      ERELE2(1)=' M-RA'
      ERELE2(2)=' M ABOVE GROUND'
      CHL='DIST.   EREMU HORIZONTALA   EREMU BERTIKALA'
      CHL=TRIM(CHL)//'     EREMU MAXIMOA      EREMU MINIMOA'
      CHL=TRIM(CHL)//'      UNEKO EREMUA    EREMUA 90 G GEROAGO'
      ERELE3(1)=TRIM(CHL)
      CHL='DIST.   HORIZONTAL FIELD    VERTICAL FIELD'
      CHL=TRIM(CHL)//'      MAXIMUM FIELD      MINIMUM FIELD'
      CHL=TRIM(CHL)//'      PRESENT FIELD    FIELD 90 G LATER'
      ERELE3(2)=TRIM(CHL)
      ERELE4(1)='  MOD.KV/M  ARG.G  '
      ERELE4(2)='  MOD.KV/M  ARG.G  '
      ERELE5(1)=' MAG.KV/M   DIR.G  '
      ERELE5(2)=' MAG.KV/M   DIR.G  '

      MEZU21(1)=' X='
      MEZU21(2)=' RESULTS FOR X='
      MEZU22(1)=' ETA Y='
      MEZU22(2)=' AND Y='
      MEZU23(1)='-RAKO EMAITZAK EZ DIRA ESANGURATSUAK'
      MEZU23(2)=' ARE NOT SIGNIFICATIV'
      CHL='BEGIRATU IA EROALEEN TENTSIOAK EDO INTENTSITATEAK SARTU'
      MEZU24(1)=TRIM(CHL)//' DIREN'
      CHL='CHECK IF THE VOLTAGES AND CURRENTS OF ALL THE CONDUCTORS'
      MEZU24(2)=TRIM(CHL)//' HAVE BEEN DEFINED'

      POTEL1(1)='POTENTZIAL ELEKTRIKOAK GARIAERA EZBERDINETAN (X='
      POTEL1(2)='ELECTRICAL POTENTIAL AT DIFFERENT HEIGHTS (X='
      POTEL2(1)='GOIERA    POT.BA.EF.     POT.FAS.A.     POT.UN.BA.'
      POTEL2(2)='HEIGHT    POT.VA.EF.     POT.PHA.A.     POT.UN.BA.'
      IZBR21(1)='ZATI'
      IZBR21(2)='SECTION'
      IZBR22(1)=' '
      IZBR22(2)='TRANSMISSION LINE BUILT WITH'
      IZBR23(1)=' EUSKARRIZ ETA'
      IZBR23(2)=' STRUCTURES AND'
      IZBR24(1)=' EROALEZ EGINDAKO LINE ELEKTRIKOA'
      IZBR24(2)=' CONDUCTORS'
      IZBR31(1)='  MUTUR ELIKATZAILEA  '
      IZBR31(2)='      SENDING END     '
      IZBR32(1)='  MUTUR ELIKATUA  '
      IZBR32(2)='  RECEIVING END   '
      IZBR33(1)='     TENTSIO      LINETAKO    POTENTZIA    POTENTZIA '
      IZBR33(2)='   EQUIV. LINE       LINE       ACTIVE      REACTIVE '
      IZBR34(1)='TENTSIO-  ***'
      IZBR34(2)='VOLTAGE   ***'
      IZBR35(1)=' ZIR FAS'
      IZBR35(2)=' CIR PHA'
      IZBR36(1)='  KONPOSATU B. INTENTSITATEA  ERAGINKOR. BERRERAGINK.'
      IZBR36(2)='     VOLTAGE      INTENSITY      POWER        POWER  '
      IZBR37(1)='JAUSKERA  E I'
      IZBR37(2)='  DROP    E I'
      CHL='******************  SARRERAKO DATUAK, AZTERTUTAKO LI'
      IZBE21(1)=TRIM(CHL)//'NEAREN EZAUGARRIAK  ******************'
      CHL='***************************  INPUT DATA, LINE CHARAC'
      IZBE21(2)=TRIM(CHL)//'TERISTICS  ***************************'
      IZBE22(1)='ER.KOP.   FNCY     RHO          PC AN CE CM PL'
      IZBE22(2)='CON.NUM.  FNCY     RHO          PC AN CE CM PL'

      ANOI11(1)=' '
      ANOI11(2)=' THE'
      CHL=' EROALEA (LUR KABLEA) EZ DA KONTUAN HARTZEN'
      ANOI12(1)=TRIM(CHL)//' EROALE HEZEKO KASUAN '
      CHL=' CONDUCTOR  (GROUND WIRE) NOT CONSIDERED'
      ANOI12(2)=TRIM(CHL)//' FOR THE WET CONDUCTOR CONDITION'
      ANOI21(1)='PRESIO AKUSTIKOAREN ZEHARKAKO PROFILA, LURRETIK'
      ANOI21(2)='SOUND PRESSURE, LATERAL PROFILE'
      ANOI22(1)=' M-RA N/M2 ETA 20 MICRON/M2-REN GAINEKO DB-TAN'
      ANOI22(2)=' M ABOVE THE GROUND, IN N/M2 AND DB ABOVE 20 MICRON/M2'
      CHL=' DIST.       *******  BANDA ZABALEKO ZARATA ALEATORIOAREN'
      ANOI23(1)=TRIM(CHL)//' MAILA  *******'
      CHL=' DIST.       **************  BROADBAND RANDOM NOISE LEVEL'
      ANOI23(2)=TRIM(CHL)//'  *************'
      ANOI24(1)='100 HZ-EKO ZARATAREN MAILA'
      ANOI24(2)=' 100 HZ HUM  NOISE LEVEL  '
      ANOI25(1)='**** EURITE GOGORRAK ****'
      ANOI25(2)='****** HEAVY RAIN *****'
      ANOI26(1)='**** EROALE HEZEAK ****'
      ANOI26(2)='**** WET CONDUCTOR ****'

      RETURN
      END
&lt;/source&gt;


{{shelves|Electrical engineering}}</text>
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  <page>
    <title>Maxima/Getting Started Using Maxima</title>
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    <revision>
      <id>4636854</id>
      <parentid>4636750</parentid>
      <timestamp>2026-05-21T12:03:57Z</timestamp>
      <contributor>
        <username>Idavidmiller</username>
        <id>3577687</id>
      </contributor>
      <comment>Work in progress. Saving Changes.</comment>
      <origin>4636854</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="21183" sha1="ndruqixq78rr4wcjv16pgego8q63eko" xml:space="preserve">== Getting Started Using Maxima - Some Essentials ==
This section is intended for those that are new to Maxima. It may or may not be of value or interest to those having prior experience.

=== The Maxima Way of doing Mathematics ===
Imagine that you want to create a computer application to perform some general mathematical tasks - not merely numerical calculations or &quot;number crunching&quot; as it is sometimes referred to somewhat pejoratively. It seems likely that it would be realized early on that, unlike humans that can interpret concepts and notation using context, computers and programming software generally are intolerant of any sort of ambiguity. Progress is being made in providing programming software with the ability to interpret based on context, but not here in Maxima. The Maxima expression syntax was created to be logical as well as unambiguous and precise in meaning and intention.

Another realization likely would be that mathematical expressions are the essential object on which mathematical concepts hinge, and that these concepts are conveyed using a conventional (if not entirely standard) system of notation. So, the means to compose mathematical expressions using some syntax for interpreting mathematical notation that your program could read and process as input would be essential. So Maxima is not a programming language in the conventional sense.

With the foregoing in mind, before starting to see examples of Maxima in action, keep the following in mind while learning and using Maxima:

* Expressions of various types (especially mathematical expressions) are the input to Maxima
* Every expression returns a value which is displayed as output unless the display is suppressed by some means
* Expressions as input are entered using an expression syntax that Maxima can read and process

==== Maxima expressions are of three types: ====

# Mathematical expressions
# Object expressions
# Programming expressions

==== Maxima expressions are comprised of two &quot;ingredients&quot; so to speak: ====

# Atoms
# Operators

==== Atoms: ====
These are one type of the built-in basic expression ingredients of Maxima. They are:

# Identifiers - names used alone or to identify other expressions by name
# Literal numerals for numbers - integer, fraction, and floating point literals
# Strings - quoted strings of one or more characters

==== Operators: ====
These are the second type of the built-in expression ingredients of Maxima. Including:

# Mathematical operators such as + , - , * ,  /, ^ , ! for addition, subtraction, negation, multiplication, division, exponentiation, factorial and the like. Internally to Maxima these are short-hand symbols for operators. Maxima operators also include &quot;functions&quot; such as sin(x), log(x), etc.
# Operators that are used to accomplish something other than for mathematical purposes 


'''Note:''' It is important to point out that there is a difference between operators, functions as used in the context of programming, and the mathematical concept of functions. In this book all Maxima functions in the programming sense of the word that are built-in to Maxima (that is &quot;out-of-the-box&quot; so to speak) will be referred to as operators, including those from loaded packages that are included with the Maxima distribution. Maxima functions in the programming sense of the word created by the user will be referred to as functions. The context should make it clear when the mathematical concept of a function is being referred to. It is unfortunately the case that the Maxima documentation refers to operators as functions. Like so much else, the word &quot;function&quot; has become overloaded.

=== A Brief Introduction to Expressions - Atoms, Identifiers and Operators ===
Below follows a brief introduction to Maxima expressions. All Maxima expressions are composed of '''''atoms''''' (including identifiers) and '''''operators''''', and every expression has a value.

With the foregoing information in mind, Maxima can be used to provide some examples of these various aspects of working with Maxima. This will be accomplished in the spirit of providing some insight and clarity for how to interact with Maxima, and how to compose expressions for input and how to interpret the values of expressions as output.

=== &lt;u&gt;Atoms&lt;/u&gt; ===
There are three types of atoms used as &quot;ingredients&quot; for composing Maxima expressions for input:

# Identifiers
# Numerical literals for representing numbers
# Strings

An elaboration of the technical details of each of these three types will follow in subsequent sections. In this section is a brief introduction, and examples of each of these types presented to gain a basic level of familiarity with each type of atom.

==== &lt;u&gt;Identifiers&lt;/u&gt; ====
Identifiers are one type of what are termed '''''atoms''''' as used in the context of Maxima expressions, but they are unique in that they are the only type of atom that can be assigned an expression other than their literal value.

Identifiers as atoms are used in Maxima expressions for two main purposes:

# To be unassigned an expression, and serve as a named variable
# To name an expression by way of an assignment operator

Try the following using Python:

&lt;code&gt;m + n&lt;/code&gt;&lt;syntaxhighlight lang=&quot;python3&quot;&gt;

&gt;&gt;&gt; m + n
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
NameError: name 'm' is not defined
&gt;&gt;&gt; 

&lt;/syntaxhighlight&gt;or using R:&lt;syntaxhighlight lang=&quot;r&quot;&gt;

&gt; m + n
Error: object 'm' not found
&gt;
&lt;/syntaxhighlight&gt;or using Octave:&lt;syntaxhighlight lang=&quot;octave&quot;&gt;

octave:1&gt; m + n
error: 'm' undefined near line 1, column 1
octave:2&gt; 

&lt;/syntaxhighlight&gt;Now, try this using Maxima:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
Maxima 5.49.0 https://maxima.sourceforge.io
using Lisp SBCL 2.0.1.debian
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) m + n;    
(%o1)                                n + m
&lt;/syntaxhighlight&gt;Take it on faith that the identifiers &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; are in the Maxima namespace as a consequence of this expression, and that each has a value assigned by Maxima merely as a consequence of being used in the &lt;code&gt;m + n&lt;/code&gt;  input expression – &lt;code&gt;m&lt;/code&gt; is &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; is &lt;code&gt;n&lt;/code&gt; in this case.&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i2)	m;
(%o2)	m

(%i3)	n;
(%o3)	n


&lt;/syntaxhighlight&gt;A value for any identifier (other than itself) may never be assigned while using Maxima no matter how many times it is referenced. That is perfectly okay. Maxima doesn't care.

But sometimes a value is assigned to an identifier – either the first time it is referenced or after it is first referenced:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i4)	m : n;
(m)	n

(%i5)	m;
(%o5)	n

(%i6)	remvalue(m);
(%o6)	[m]

(%i7)	m;
(%o7)	m


&lt;/syntaxhighlight&gt;In the above expressions, the identifier &lt;code&gt;m&lt;/code&gt; is assigned, using the &lt;code&gt;:&lt;/code&gt; assignment operator, the value of identifier &lt;code&gt;n&lt;/code&gt; (which is in this case &lt;code&gt;n&lt;/code&gt;), and then the value of &lt;code&gt;m&lt;/code&gt; is removed using the &lt;code&gt;remvalue()&lt;/code&gt; operator. Thus, the value of &lt;code&gt;m&lt;/code&gt; reverts to itself – &lt;code&gt;m&lt;/code&gt;.

These expressions, while trivial in a sense, provide some insight into an important way Maxima behaves. When identifiers are first referenced as input, they have a value – either a value through some sort of assignment, or merely the identifier name itself. Identifiers can be assigned values by different means as part of expressions as input.

Below follows some examples of Maxima identifiers as a very brief introduction:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;(%i1)	x; /* An unassigned identifier x */
(%o1)	x

(%i2)	mass; /* An unassigned identifier name of mass */
(%o2)	mass

(%i3)	f(x); /* An identifier f(x) for unassigned Maxima user-defined function */
(%o3)	f(x)

(%i4)	is(x = X); /* Identifiers are case-sensitive - x is not X */
(%o4)	false

(%i6)	y = x^2; /* Identifiers x and y used in an expression */
(%o6)	y=x^2

(%i7)	x : sqrt(2); /* Idenifier x assigned a value */
(x)	sqrt(2)

/* An identifier w(x,y,z) for a Maxima user-defined function */
(%i8)	w(x,w,z) := a*x^2 + b*y^2 + c*z^2;
(%o8)	w(x,w,z):=a*x^2+b*y^2+c*z^2&lt;/syntaxhighlight&gt;Maxima identifiers serve to name expressions as a value by means on some type of assignment, or they can be simply a name with a value of the name itself, in which case these unassigned identifiers may be considered to be variables. The technical details of Identifiers, assignment types, and expressions are elaborated upon in other book sections for each of these topics. 

==== &lt;u&gt;Numerical literals for representing numbers&lt;/u&gt; ====
There are four types of numerical literal atoms used to compose Maxima expressions:

# Integers
# Fractions (for rational numbers)
# Floating Point
# Bigfloat  (variable-precision floating point)

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i8)	1234; /* This is an integer type. */
(%o8)	1234

(%i9)	5/9; /* This is a fraction for a rational number type. */
(%o9)	5/9

(%i10)	3.14159; /* This is a floating point type. */
(%o10)	3.14159

(%i11)	5.532051841609784b-1; /* This is a bigfloat type. */
(%o11)	5.532051841609784b-1


&lt;/syntaxhighlight&gt;

==== &lt;u&gt;Strings&lt;/u&gt; ====
Strings are simply a quoted sequence of characters:

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i12)	&quot;a string atom&quot;;  /* This is a string atom. */
(%o12)	&quot;a string atom&quot;

(%i13)	&quot;Hello World!&quot;;  /* This is another string atom. */
(%o13)	&quot;Hello World!&quot;

(%i14)	&quot;Supercalifagilisticexpialidocious&quot;;  /* This is a longer string atom. */
(%o14)	&quot;Supercalifagilisticexpialidocious&quot;

(%i15)	&quot;C&quot;;  /* There is no Maxima character type. */
(%o15)	&quot;C&quot;
&lt;/syntaxhighlight&gt;

=== &lt;u&gt;Operators&lt;/u&gt; ===
Along with atoms, Maxima operators are the second ingredient used to form expressions used as input. There are many Maxima operators. Some are used frequently as a consequence of their utility for forming mathematical expressions. Many others are used infrequently as these operators are used for specialized purposes.   
{| class=&quot;wikitable&quot;
|+Operators
!Operator 
!Operation
!Notes
!Type
|-
|&lt;u&gt;'''Arithmetic'''&lt;/u&gt;
|
|
|
|-
| '''+'''
|addition
|also unary addition prefix
|n-ary
infix
commutative
|-
| '''-'''
|subtaction
|also unary negation prefix
|binary
infix
noncommutative
|-
|'''*'''
|multiplication
|
|n-ary infix
commutative
|-
|'''/'''
|division
|or fraction
|binary infix
noncommutative
|-
|'''^'''
|exponentiation
|
|binary postfix 
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Relational'''&lt;/u&gt;
|
|
|
|-
|'''&lt;'''
|less than
|
|binary infix
|-
|'''&lt;='''
|less than or equal
|
|binary infix
|-
|'''&gt;'''
|greater than
|
|binary infix
|-
|'''&gt;='''
|greater thanor equal
|
|binary infix
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Logical'''&lt;/u&gt;
|
|
|
|-
|'''and'''
|and
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
|'''not'''
|not
|Operand is a Boolean expression
Result is a Boolean value
|unary prefix
|-
|'''or'''
|or
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Equations'''&lt;/u&gt;
|
|
|
|-
|'''='''
|equality
|Unevaluated equation
| Syntactically equal
|-
|'''#'''
|negation of syntactic equality =
|Unevaluated negation of an equation
|Syntactically not equal
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Assignment'''&lt;/u&gt;
|
|
|
|-
|''':'''
|assignment to left hand side
|evaluates right hand side
|
|-
|'''::'''
|assignment to left hand side
|evaluates both sides
|
|-
|''':='''
|function definition
|does not evaluate right hand side
|
|-
|'''::='''
|macro function definition 
|
|
|-
|'''define''' ()
|function definition
|does evaluate right hand side
|
|}
{| class=&quot;wikitable&quot;
|+Mathematical Operators (Functions)
!Operators (Functions)
or
Option Variables
!Description
!Notes
!
|-
|'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''abs''' (''z'')
|mathematical absolute value
|works for both numerical and symbolic values
|
|-
|'''ceiling''' (x)
|returns the least integer that is greater than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''entier''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer less than or equal to &lt;var&gt;x&lt;/var&gt; where &lt;var&gt;x&lt;/var&gt; is numeric
|
|
|-
|'''floor''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer that is less than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''fix''' &lt;var&gt;(x)&lt;/var&gt; 
|a synonym for entier (x)
|
|
|-
|'''hstep''' &lt;var&gt;(x)&lt;/var&gt;
|the Heaviside unit step function
|
|
|-
|'''lmax''' &lt;var&gt;(L)&lt;/var&gt;
|when &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('max, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''lmin''' &lt;var&gt;(L)&lt;/var&gt;
|When &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('m&lt;/code&gt;&lt;code&gt;in, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''max''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt; 
|returns a simplified value for the numerical maximum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;
|
|
|-
|'''min''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt;
|returns a simplified value for the numerical minimum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;.
|
|
|-
|'''round''' &lt;var&gt;(x)&lt;/var&gt;
|when &lt;var&gt;x&lt;/var&gt; is a real number, returns the closest integer to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''signum''' &lt;var&gt;(x)&lt;/var&gt;
|for either real or complex numbers &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns 0 if &lt;var&gt;x&lt;/var&gt; is zero; for a nonzero numeric input &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns &lt;code&gt;x/abs(x)&lt;/code&gt;
|
|
|-
|'''truncate''' &lt;var&gt;(x)&lt;/var&gt;
|when x is a real number, return the closest integer to x not greater in absolute value than ''x''
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Complex&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''cabs''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the absolute value of an expression representing a complex number
|
|
|-
|'''carg''' &lt;var&gt;(z)&lt;/var&gt;
|returns the complex argument of ''z''
|
|
|-
|'''conjugate''' &lt;var&gt;(x)&lt;/var&gt;
|returns the complex conjugate of ''x''
|
|
|-
|'''imagpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the imaginary part of the expression ''expr''
|
|
|-
|'''polarform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;r %e^(%i theta)&lt;/code&gt; equivalent to ''expr'', such that ''r'' and ''theta'' are purely real
|
|
|-
|'''realpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the real part of &lt;var&gt;expr&lt;/var&gt;
|
|
|-
|'''rectform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;a + b %i&lt;/code&gt; equivalent to &lt;var&gt;expr&lt;/var&gt;, such that &lt;var&gt;a&lt;/var&gt; and &lt;var&gt;b&lt;/var&gt; are purely real
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Combinatorial&lt;/u&gt;'''
|
|
|
|-
|'''!!'''
|the double factorial operator
|
|
|-
|'''binomial''' &lt;var&gt;(x, y)&lt;/var&gt;
|returns the binomial coefficient &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!/(&lt;var&gt;y&lt;/var&gt;! (&lt;var&gt;x&lt;/var&gt; - &lt;var&gt;y&lt;/var&gt;)!)&lt;/code&gt;.
|
|
|-
|'''factcomb''' &lt;var&gt;(expr)&lt;/var&gt;
|tries to combine the coefficients of factorials in &lt;var&gt;expr&lt;/var&gt; with the factorials themselves
| by converting for example, &lt;code&gt;(n + 1)*n!&lt;/code&gt; into &lt;code&gt;(n + 1)!&lt;/code&gt;.
|
|-
|'''factorial''' ''(x)''

'''!'''
|returns the factorial of ''x''
|&lt;code&gt;factorial (&lt;var&gt;x&lt;/var&gt;)&lt;/code&gt; the same as &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!&lt;/code&gt;
|
|-
|'''factlim'''
|specifies the highest factorial which is automatically expanded
|option variable
default: 100000
|
|-
|'''factorial_expand'''
|controls the simplification of expressions like &lt;code&gt;(x+n)!&lt;/code&gt;, where &lt;code&gt;n&lt;/code&gt; is an integer
|option variable
default: false
|
|-
|'''genfact''' &lt;var&gt;(x, y, z)&lt;/var&gt;
|returns the generalized factorial, defined as &lt;code&gt;x (x-z) (x - 2 z) ... (x - (y - 1) z)&lt;/code&gt;
|when &lt;var&gt;x&lt;/var&gt; is an integer, &lt;code&gt;genfact (x, x, 1) = x!&lt;/code&gt; and &lt;code&gt;genfact (x, x/2, 2) = x!!&lt;/code&gt;
|
|-
|'''minfactorial''' &lt;var&gt;(expr)&lt;/var&gt;
|examines &lt;var&gt;expr&lt;/var&gt; for occurrences of two factorials which differ by an integer
|&lt;code&gt;minfactorial&lt;/code&gt;then turns one into a polynomial times the other
|
|-
|'''sumsplitfact'''
|when &lt;code&gt;sumsplitfact&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;, &lt;code&gt;minfactorial&lt;/code&gt; is applied after a &lt;code&gt;factcomb&lt;/code&gt;
|option variable
default: true
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Root&lt;/u&gt;'''
'''&lt;u&gt;Exponential&lt;/u&gt;'''
'''&lt;u&gt;Logarithmic&lt;/u&gt;'''
|
|
|
|-
|'''%e_to_numlog'''
|when &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;r&lt;/code&gt; some rational number, and &lt;code&gt;x&lt;/code&gt; some expression, &lt;code&gt;%e^(r*log(x))&lt;/code&gt; will be simplified into &lt;code&gt;x^r&lt;/code&gt;
|option variable
default: false
|
|-
|'''%emode'''
|when &lt;code&gt;%emode&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e^(%pi %i x)&lt;/code&gt; is simplified
|option variable
default: true
|
|-
|'''%enumer'''
|when &lt;code&gt;%enumer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e&lt;/code&gt; is replaced by its numeric value 2.718… whenever &lt;code&gt;numer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;.
|option variable
default: false
|
|-
|'''exp''' &lt;var&gt;(x)&lt;/var&gt;
|represents the exponential function
|
|
|-
|'''li''' &lt;var&gt;[s] (z)&lt;/var&gt;
|represents the polylogarithm function of order &lt;var&gt;s&lt;/var&gt; and argument &lt;var&gt;z&lt;/var&gt;, defined by an infinite series 
|
|
|-
|'''log''' &lt;var&gt;(x)&lt;/var&gt;
|represents the natural (base ) logarithm of &lt;var&gt;x&lt;/var&gt;.
|Maxima does not have a built-in function for the base 10 logarithm or other bases
|
|-
|'''logabs'''
|when doing indefinite integration where logs are generated, e.g. &lt;code&gt;integrate(1/x,x)&lt;/code&gt;, the answer is given in terms of &lt;code&gt;log(abs(...))&lt;/code&gt; if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, but in terms of &lt;code&gt;log(...)&lt;/code&gt;if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;
for definite integration, the &lt;code&gt;logabs:true&lt;/code&gt; setting is used, because here &quot;evaluation&quot; of the indefinite integral at the endpoints is often needed
|option variable
default: false
|
|-
|'''logarc''' &lt;var&gt;(expr)&lt;/var&gt;
|carries out the replacement of inverse circular and hyperbolic functions with equivalent logarithmic functions for an expression &lt;var&gt;expr&lt;/var&gt; without setting the global variable &lt;code&gt;logarc&lt;/code&gt;
|
|
|-
| '''logarc'''
|when the global variable &lt;code&gt;logarc&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, inverse circular and hyperbolic functions are replaced by equivalent logarithmic functions.
|option variable
default: false
|
|-
|'''logconcoeffp'''
|controls which coefficients are contracted when using &lt;code&gt;logcontract&lt;/code&gt;
|option variable
default: false
|
|-
|'''logcontract''' &lt;var&gt;(expr)&lt;/var&gt;
|recursively scans the expression &lt;var&gt;expr&lt;/var&gt;, transforming subexpressions of the form &lt;code&gt;a1*log(b1) + a2*log(b2) + c&lt;/code&gt; into &lt;code&gt;log(ratsimp(b1^a1 * b2^a2)) + c&lt;/code&gt;
|
|
|-
|'''logexpand'''
|if &lt;code&gt;true&lt;/code&gt;, that is the default value, causes &lt;code&gt;log(a^b)&lt;/code&gt; to become &lt;code&gt;b*log(a)&lt;/code&gt; 
If it is set to &lt;code&gt;all&lt;/code&gt;, &lt;code&gt;log(a*b)&lt;/code&gt; will also simplify to &lt;code&gt;log(a)+log(b)&lt;/code&gt;
If it is set to &lt;code&gt;super&lt;/code&gt;, then &lt;code&gt;log(a/b)&lt;/code&gt;will also simplify to &lt;code&gt;log(a)-log(b)&lt;/code&gt; for rational numbers &lt;code&gt;a/b&lt;/code&gt;, &lt;code&gt;a#1&lt;/code&gt;(&lt;code&gt;log(1/b)&lt;/code&gt;, for integer &lt;code&gt;b&lt;/code&gt;, always simplifies.) 

if it is set to &lt;code&gt;false&lt;/code&gt;, all of these simplifications will be turned off
|option variable
default: true
|
|-
|'''lognegint'''
|implements the rule &lt;code&gt;log(-n) -&gt; log(n)+%i*%pi&lt;/code&gt; for &lt;code&gt;n&lt;/code&gt; a positive integer if &lt;code&gt;true&lt;/code&gt; 
|option variable
default: false
|
|-
|'''logsimp'''
|if &lt;code&gt;false&lt;/code&gt; then no simplification of &lt;code&gt;%e&lt;/code&gt; to a power containing &lt;code&gt;log&lt;/code&gt; is done
|option variable
default: true
|
|-
| '''plog''' &lt;var&gt;(x)&lt;/var&gt;
|represents the principal branch of the complex-valued natural logarithm with &lt;code&gt;-%pi &lt; carg(&lt;var&gt;x&lt;/var&gt;) &lt;= +%pi&lt;/code&gt; 
|
|
|-
|'''sqrt''' &lt;var&gt;(x)&lt;/var&gt; 
|the square root of &lt;var&gt;x&lt;/var&gt;. It is represented internally by &lt;code&gt;&lt;var&gt;x&lt;/var&gt;^(1/2)&lt;/code&gt;
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Trigonometric&lt;/u&gt;'''
'''&lt;u&gt;Hyperbolic&lt;/u&gt;'''
|
|
|
|-
|'''acos''' &lt;var&gt;(x)&lt;/var&gt;
|arc cosine
|
|
|-
|'''acosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosine
|
|
|-
|'''acot''' &lt;var&gt;(x)&lt;/var&gt;
|arc cotangent
|
|
|-
|'''acoth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cotangent.
|
|
|-
| '''acsc''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc cosecant
|
|
|-
|'''acsch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosecant
|
|
|-
| '''asec''' &lt;var&gt;(x)&lt;/var&gt;
|arc secant.
|
|
|-
|'''asech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc secant
|
|
|-
|'''asin''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc sine
|
|
|-
|'''asinh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc sine
|
|
|-
|'''atan''' &lt;var&gt;(x)&lt;/var&gt;
|arc tangent
|
|
|-
|'''atan2''' &lt;var&gt;(y, x)&lt;/var&gt;
|returns the value of &lt;math display=&quot;inline&quot;&gt;\tan^{-1}(y/x) &lt;/math&gt;  in the interval &lt;math display=&quot;inline&quot;&gt;(- \pi) \ to\ (\pi) &lt;/math&gt; taking into consideration the quadrant of the point ''(x,y)''
|
|
|-
|'''atanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc tangent
|
|
|-
|'''cos''' &lt;var&gt;(x)&lt;/var&gt;
|cosine
|
|
|-
|'''cosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosine
|
|
|-
|'''cot''' &lt;var&gt;(x)&lt;/var&gt;
|cotangent
|
|
|-
|'''coth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cotangent
|
|
|-
|'''csc''' &lt;var&gt;(x)&lt;/var&gt;
|cosecant
|
|
|-
| '''csch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosecant
|
|
|-
|'''sec''' &lt;var&gt;(x)&lt;/var&gt;
|secant
|
|
|-
|'''sech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic secant
|
|
|-
|'''sin''' &lt;var&gt;(x)&lt;/var&gt;
|sine
|
|
|-
|'''sinh''' &lt;var&gt;(x&lt;/var&gt;
| hyperbolic sine
|
|
|-
|'''tan''' &lt;var&gt;(x)&lt;/var&gt;
|tangent
|
|
|-
|'''tanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic tangent
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Random&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|
|
|
|
|-
|
|
|
|
|}
;
;
;
;
; {{BookCat}}</text>
      <sha1>ndruqixq78rr4wcjv16pgego8q63eko</sha1>
    </revision>
    <revision>
      <id>4636857</id>
      <parentid>4636854</parentid>
      <timestamp>2026-05-21T12:26:49Z</timestamp>
      <contributor>
        <username>Idavidmiller</username>
        <id>3577687</id>
      </contributor>
      <comment>Work in progress. Saving Changes.</comment>
      <origin>4636857</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="21454" sha1="dpi6truegznqkn9p9nfeotx31bn7h0s" xml:space="preserve">== Getting Started Using Maxima - Some Essentials ==
This section is intended for those that are new to Maxima. It may or may not be of value or interest to those having prior experience.

=== The Maxima Way of doing Mathematics ===
Imagine that you want to create a computer application to perform some general mathematical tasks - not merely numerical calculations or &quot;number crunching&quot; as it is sometimes referred to somewhat pejoratively. It seems likely that it would be realized early on that, unlike humans that can interpret concepts and notation using context, computers and programming software generally are intolerant of any sort of ambiguity. Progress is being made in providing programming software with the ability to interpret based on context, but not here in Maxima. The Maxima expression syntax was created to be logical as well as unambiguous and precise in meaning and intention.

Another realization likely would be that mathematical expressions are the essential object on which mathematical concepts hinge, and that these concepts are conveyed using a conventional (if not entirely standard) system of notation. So, the means to compose mathematical expressions using some syntax for interpreting mathematical notation that your program could read and process as input would be essential. So Maxima is not a programming language in the conventional sense.

With the foregoing in mind, before starting to see examples of Maxima in action, keep the following in mind while learning and using Maxima:

* Expressions of various types (especially mathematical expressions) are the input to Maxima
* Every expression returns a value which is displayed as output unless the display is suppressed by some means
* Expressions as input are entered using an expression syntax that Maxima can read and process

==== Maxima expressions are of three types: ====

# Mathematical expressions
# Object expressions
# Programming expressions

==== Maxima expressions are comprised of two &quot;ingredients&quot; so to speak: ====

# Atoms
# Operators

==== Atoms: ====
These are one type of the built-in basic expression ingredients of Maxima. They are:

# Identifiers - names used alone or to identify other expressions by name
# Literal numerals for numbers - integer, fraction, and floating point literals
# Strings - quoted strings of one or more characters

==== Operators: ====
These are the second type of the built-in expression ingredients of Maxima. Including:

# Mathematical operators such as + , - , * ,  /, ^ , ! for addition, subtraction, negation, multiplication, division, exponentiation, factorial and the like. Internally to Maxima these are short-hand symbols for operators. Maxima operators also include &quot;functions&quot; such as sin(x), log(x), etc.
# Operators that are used to accomplish something other than for mathematical purposes 


'''Note:''' It is important to point out that there is a difference between operators, functions as used in the context of programming, and the mathematical concept of functions. In this book all Maxima functions in the programming sense of the word that are built-in to Maxima (that is &quot;out-of-the-box&quot; so to speak) will be referred to as operators, including those from loaded packages that are included with the Maxima distribution. Maxima functions in the programming sense of the word created by the user will be referred to as functions. The context should make it clear when the mathematical concept of a function is being referred to. It is unfortunately the case that the Maxima documentation refers to operators as functions. Like so much else, the word &quot;function&quot; has become overloaded.

=== A Brief Introduction to Expressions - Atoms, Identifiers and Operators ===
Below follows a brief introduction to Maxima expressions. All Maxima expressions are composed of '''''atoms''''' (including identifiers) and '''''operators''''', and every expression has a value.

With the foregoing information in mind, Maxima can be used to provide some examples of these various aspects of working with Maxima. This will be accomplished in the spirit of providing some insight and clarity for how to interact with Maxima, and how to compose expressions for input and how to interpret the values of expressions as output.

=== &lt;u&gt;Atoms&lt;/u&gt; ===
There are three types of atoms used as &quot;ingredients&quot; for composing Maxima expressions for input:

# Identifiers
# Numerical literals for representing numbers
# Strings

An elaboration of the technical details of each of these three types will follow in subsequent sections. In this section is a brief introduction, and examples of each of these types presented to gain a basic level of familiarity with each type of atom.

==== &lt;u&gt;Identifiers&lt;/u&gt; ====
Identifiers are one type of what are termed '''''atoms''''' as used in the context of Maxima expressions, but they are unique in that they are the only type of atom that can be assigned an expression other than their literal value.

Identifiers as atoms are used in Maxima expressions for two main purposes:

# To be unassigned an expression, and serve as a named variable
# To name an expression by way of an assignment operator

Try the following using Python:

&lt;code&gt;m + n&lt;/code&gt;&lt;syntaxhighlight lang=&quot;python3&quot;&gt;

&gt;&gt;&gt; m + n
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
NameError: name 'm' is not defined
&gt;&gt;&gt; 

&lt;/syntaxhighlight&gt;or using R:&lt;syntaxhighlight lang=&quot;r&quot;&gt;

&gt; m + n
Error: object 'm' not found
&gt;
&lt;/syntaxhighlight&gt;or using Octave:&lt;syntaxhighlight lang=&quot;octave&quot;&gt;

octave:1&gt; m + n
error: 'm' undefined near line 1, column 1
octave:2&gt; 

&lt;/syntaxhighlight&gt;Now, try this using Maxima:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
Maxima 5.49.0 https://maxima.sourceforge.io
using Lisp SBCL 2.0.1.debian
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) m + n;    
(%o1)                                n + m
&lt;/syntaxhighlight&gt;Take it on faith that the identifiers &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; are in the Maxima namespace as a consequence of this expression, and that each has a value assigned by Maxima merely as a consequence of being used in the &lt;code&gt;m + n&lt;/code&gt;  input expression – &lt;code&gt;m&lt;/code&gt; is &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; is &lt;code&gt;n&lt;/code&gt; in this case.&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i2)	m;
(%o2)	m

(%i3)	n;
(%o3)	n


&lt;/syntaxhighlight&gt;A value for any identifier (other than itself) may never be assigned while using Maxima no matter how many times it is referenced. That is perfectly okay. Maxima doesn't care.

But sometimes a value is assigned to an identifier – either the first time it is referenced or after it is first referenced:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i4)	m : n;
(m)	n

(%i5)	m;
(%o5)	n

(%i6)	remvalue(m);
(%o6)	[m]

(%i7)	m;
(%o7)	m


&lt;/syntaxhighlight&gt;In the above expressions, the identifier &lt;code&gt;m&lt;/code&gt; is assigned, using the &lt;code&gt;:&lt;/code&gt; assignment operator, the value of identifier &lt;code&gt;n&lt;/code&gt; (which is in this case &lt;code&gt;n&lt;/code&gt;), and then the value of &lt;code&gt;m&lt;/code&gt; is removed using the &lt;code&gt;remvalue()&lt;/code&gt; operator. Thus, the value of &lt;code&gt;m&lt;/code&gt; reverts to itself – &lt;code&gt;m&lt;/code&gt;.

These expressions, while trivial in a sense, provide some insight into an important way Maxima behaves. When identifiers are first referenced as input, they have a value – either a value through some sort of assignment, or merely the identifier name itself. Identifiers can be assigned values by different means as part of expressions as input.

Below follows some examples of Maxima identifiers as a very brief introduction:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;(%i1)	x; /* An unassigned identifier x */
(%o1)	x

(%i2)	mass; /* An unassigned identifier name of mass */
(%o2)	mass

(%i3)	f(x); /* An identifier f(x) for unassigned Maxima user-defined function */
(%o3)	f(x)

(%i4)	is(x = X); /* Identifiers are case-sensitive - x is not X */
(%o4)	false

(%i6)	y = x^2; /* Identifiers x and y used in an expression */
(%o6)	y=x^2

(%i7)	x : sqrt(2); /* Idenifier x assigned a value */
(x)	sqrt(2)

/* An identifier w(x,y,z) for a Maxima user-defined function */
(%i8)	w(x,w,z) := a*x^2 + b*y^2 + c*z^2;
(%o8)	w(x,w,z):=a*x^2+b*y^2+c*z^2&lt;/syntaxhighlight&gt;Maxima identifiers serve to name expressions as a value by means on some type of assignment, or they can be simply a name with a value of the name itself, in which case these unassigned identifiers may be considered to be variables. The technical details of Identifiers, assignment types, and expressions are elaborated upon in other book sections for each of these topics. 

==== &lt;u&gt;Numerical literals for representing numbers&lt;/u&gt; ====
There are four types of numerical literal atoms used to compose Maxima expressions:

# Integers
# Fractions (for rational numbers)
# Floating Point
# Bigfloat  (variable-precision floating point)

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i8)	1234; /* This is an integer type. */
(%o8)	1234

(%i9)	5/9; /* This is a fraction for a rational number type. */
(%o9)	5/9

(%i10)	3.14159; /* This is a floating point type. */
(%o10)	3.14159

(%i11)	5.532051841609784b-1; /* This is a bigfloat type. */
(%o11)	5.532051841609784b-1


&lt;/syntaxhighlight&gt;

==== &lt;u&gt;Strings&lt;/u&gt; ====
Strings are simply a quoted sequence of characters:

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i12)	&quot;a string atom&quot;;  /* This is a string atom. */
(%o12)	&quot;a string atom&quot;

(%i13)	&quot;Hello World!&quot;;  /* This is another string atom. */
(%o13)	&quot;Hello World!&quot;

(%i14)	&quot;Supercalifagilisticexpialidocious&quot;;  /* This is a longer string atom. */
(%o14)	&quot;Supercalifagilisticexpialidocious&quot;

(%i15)	&quot;C&quot;;  /* There is no Maxima character type. */
(%o15)	&quot;C&quot;
&lt;/syntaxhighlight&gt;

=== &lt;u&gt;Operators&lt;/u&gt; ===
Along with atoms, Maxima operators are the second ingredient used to form expressions used as input. There are many Maxima operators. Some are used frequently as a consequence of their utility for forming mathematical expressions. Many others are used infrequently as these operators are used for specialized purposes.   
{| class=&quot;wikitable&quot;
|+Operators
!Operator 
!Operation
!Notes
!Type
|-
|&lt;u&gt;'''Arithmetic'''&lt;/u&gt;
|
|
|
|-
| '''+'''
|addition
|also unary addition prefix
|n-ary
infix
commutative
|-
| '''-'''
|subtaction
|also unary negation prefix
|binary
infix
noncommutative
|-
|'''*'''
|multiplication
|
|n-ary infix
commutative
|-
|'''/'''
|division
|or fraction
|binary infix
noncommutative
|-
|'''^'''
|exponentiation
|
|binary postfix 
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Relational'''&lt;/u&gt;
|
|
|
|-
|'''&lt;'''
|less than
|
|binary infix
|-
|'''&lt;='''
|less than or equal
|
|binary infix
|-
|'''&gt;'''
|greater than
|
|binary infix
|-
|'''&gt;='''
|greater thanor equal
|
|binary infix
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Logical'''&lt;/u&gt;
|
|
|
|-
|'''and'''
|and
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
|'''not'''
|not
|Operand is a Boolean expression
Result is a Boolean value
|unary prefix
|-
|'''or'''
|or
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Equations'''&lt;/u&gt;
|
|
|
|-
|'''='''
|equality
|Unevaluated equation
| Syntactically equal
|-
|'''#'''
|negation of syntactic equality =
|Unevaluated negation of an equation
|Syntactically not equal
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Assignment'''&lt;/u&gt;
|
|
|
|-
|''':'''
|assignment to left hand side
|evaluates right hand side
|
|-
|'''::'''
|assignment to left hand side
|evaluates both sides
|
|-
|''':='''
|function definition
|does not evaluate right hand side
|
|-
|'''::='''
|macro function definition 
|
|
|-
|'''define''' ()
|function definition
|does evaluate right hand side
|
|}
{| class=&quot;wikitable&quot;
|+Mathematical Operators (Functions)
!Operators (Functions)
or
Option Variables
!Description
!Notes
!
|-
|'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''abs''' (''z'')
|mathematical absolute value
|works for both numerical and symbolic values
|
|-
|'''ceiling''' (x)
|returns the least integer that is greater than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''entier''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer less than or equal to &lt;var&gt;x&lt;/var&gt; where &lt;var&gt;x&lt;/var&gt; is numeric
|
|
|-
|'''floor''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer that is less than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''fix''' &lt;var&gt;(x)&lt;/var&gt; 
|a synonym for entier (x)
|
|
|-
|'''hstep''' &lt;var&gt;(x)&lt;/var&gt;
|the Heaviside unit step function
|
|
|-
|'''lmax''' &lt;var&gt;(L)&lt;/var&gt;
|when &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('max, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''lmin''' &lt;var&gt;(L)&lt;/var&gt;
|When &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('m&lt;/code&gt;&lt;code&gt;in, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''max''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt; 
|returns a simplified value for the numerical maximum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;
|
|
|-
|'''min''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt;
|returns a simplified value for the numerical minimum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;.
|
|
|-
|'''round''' &lt;var&gt;(x)&lt;/var&gt;
|when &lt;var&gt;x&lt;/var&gt; is a real number, returns the closest integer to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''signum''' &lt;var&gt;(x)&lt;/var&gt;
|for either real or complex numbers &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns 0 if &lt;var&gt;x&lt;/var&gt; is zero; for a nonzero numeric input &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns &lt;code&gt;x/abs(x)&lt;/code&gt;
|
|
|-
|'''truncate''' &lt;var&gt;(x)&lt;/var&gt;
|when x is a real number, return the closest integer to x not greater in absolute value than ''x''
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Complex&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''cabs''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the absolute value of an expression representing a complex number
|
|
|-
|'''carg''' &lt;var&gt;(z)&lt;/var&gt;
|returns the complex argument of ''z''
|
|
|-
|'''conjugate''' &lt;var&gt;(x)&lt;/var&gt;
|returns the complex conjugate of ''x''
|
|
|-
|'''imagpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the imaginary part of the expression ''expr''
|
|
|-
|'''polarform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;r %e^(%i theta)&lt;/code&gt; equivalent to ''expr'', such that ''r'' and ''theta'' are purely real
|
|
|-
|'''realpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the real part of &lt;var&gt;expr&lt;/var&gt;
|
|
|-
|'''rectform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;a + b %i&lt;/code&gt; equivalent to &lt;var&gt;expr&lt;/var&gt;, such that &lt;var&gt;a&lt;/var&gt; and &lt;var&gt;b&lt;/var&gt; are purely real
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Combinatorial&lt;/u&gt;'''
|
|
|
|-
|'''!!'''
|the double factorial operator
|
|
|-
|'''binomial''' &lt;var&gt;(x, y)&lt;/var&gt;
|returns the binomial coefficient &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!/(&lt;var&gt;y&lt;/var&gt;! (&lt;var&gt;x&lt;/var&gt; - &lt;var&gt;y&lt;/var&gt;)!)&lt;/code&gt;.
|
|
|-
|'''factcomb''' &lt;var&gt;(expr)&lt;/var&gt;
|tries to combine the coefficients of factorials in &lt;var&gt;expr&lt;/var&gt; with the factorials themselves
| by converting for example, &lt;code&gt;(n + 1)*n!&lt;/code&gt; into &lt;code&gt;(n + 1)!&lt;/code&gt;.
|
|-
|'''factorial''' ''(x)''

'''!'''
|returns the factorial of ''x''
|&lt;code&gt;factorial (&lt;var&gt;x&lt;/var&gt;)&lt;/code&gt; the same as &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!&lt;/code&gt;
|
|-
|'''factlim'''
|specifies the highest factorial which is automatically expanded
|option variable
default: 100000
|
|-
|'''factorial_expand'''
|controls the simplification of expressions like &lt;code&gt;(x+n)!&lt;/code&gt;, where &lt;code&gt;n&lt;/code&gt; is an integer
|option variable
default: false
|
|-
|'''genfact''' &lt;var&gt;(x, y, z)&lt;/var&gt;
|returns the generalized factorial, defined as &lt;code&gt;x (x-z) (x - 2 z) ... (x - (y - 1) z)&lt;/code&gt;
|when &lt;var&gt;x&lt;/var&gt; is an integer, &lt;code&gt;genfact (x, x, 1) = x!&lt;/code&gt; and &lt;code&gt;genfact (x, x/2, 2) = x!!&lt;/code&gt;
|
|-
|'''minfactorial''' &lt;var&gt;(expr)&lt;/var&gt;
|examines &lt;var&gt;expr&lt;/var&gt; for occurrences of two factorials which differ by an integer
|&lt;code&gt;minfactorial&lt;/code&gt;then turns one into a polynomial times the other
|
|-
|'''sumsplitfact'''
|when &lt;code&gt;sumsplitfact&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;, &lt;code&gt;minfactorial&lt;/code&gt; is applied after a &lt;code&gt;factcomb&lt;/code&gt;
|option variable
default: true
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Root&lt;/u&gt;'''
'''&lt;u&gt;Exponential&lt;/u&gt;'''
'''&lt;u&gt;Logarithmic&lt;/u&gt;'''
|
|
|
|-
|'''%e_to_numlog'''
|when &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;r&lt;/code&gt; some rational number, and &lt;code&gt;x&lt;/code&gt; some expression, &lt;code&gt;%e^(r*log(x))&lt;/code&gt; will be simplified into &lt;code&gt;x^r&lt;/code&gt;
|option variable
default: false
|
|-
|'''%emode'''
|when &lt;code&gt;%emode&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e^(%pi %i x)&lt;/code&gt; is simplified
|option variable
default: true
|
|-
|'''%enumer'''
|when &lt;code&gt;%enumer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e&lt;/code&gt; is replaced by its numeric value 2.718… whenever &lt;code&gt;numer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;.
|option variable
default: false
|
|-
|'''exp''' &lt;var&gt;(x)&lt;/var&gt;
|represents the exponential function
|
|
|-
|'''li''' &lt;var&gt;[s] (z)&lt;/var&gt;
|represents the polylogarithm function of order &lt;var&gt;s&lt;/var&gt; and argument &lt;var&gt;z&lt;/var&gt;, defined by an infinite series 
|
|
|-
|'''log''' &lt;var&gt;(x)&lt;/var&gt;
|represents the natural (base ) logarithm of &lt;var&gt;x&lt;/var&gt;.
|Maxima does not have a built-in function for the base 10 logarithm or other bases
|
|-
|'''logabs'''
|when doing indefinite integration where logs are generated, e.g. &lt;code&gt;integrate(1/x,x)&lt;/code&gt;, the answer is given in terms of &lt;code&gt;log(abs(...))&lt;/code&gt; if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, but in terms of &lt;code&gt;log(...)&lt;/code&gt;if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;
for definite integration, the &lt;code&gt;logabs:true&lt;/code&gt; setting is used, because here &quot;evaluation&quot; of the indefinite integral at the endpoints is often needed
|option variable
default: false
|
|-
|'''logarc''' &lt;var&gt;(expr)&lt;/var&gt;
|carries out the replacement of inverse circular and hyperbolic functions with equivalent logarithmic functions for an expression &lt;var&gt;expr&lt;/var&gt; without setting the global variable &lt;code&gt;logarc&lt;/code&gt;
|
|
|-
| '''logarc'''
|when the global variable &lt;code&gt;logarc&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, inverse circular and hyperbolic functions are replaced by equivalent logarithmic functions.
|option variable
default: false
|
|-
|'''logconcoeffp'''
|controls which coefficients are contracted when using &lt;code&gt;logcontract&lt;/code&gt;
|option variable
default: false
|
|-
|'''logcontract''' &lt;var&gt;(expr)&lt;/var&gt;
|recursively scans the expression &lt;var&gt;expr&lt;/var&gt;, transforming subexpressions of the form &lt;code&gt;a1*log(b1) + a2*log(b2) + c&lt;/code&gt; into &lt;code&gt;log(ratsimp(b1^a1 * b2^a2)) + c&lt;/code&gt;
|
|
|-
|'''logexpand'''
|if &lt;code&gt;true&lt;/code&gt;, that is the default value, causes &lt;code&gt;log(a^b)&lt;/code&gt; to become &lt;code&gt;b*log(a)&lt;/code&gt; 
If it is set to &lt;code&gt;all&lt;/code&gt;, &lt;code&gt;log(a*b)&lt;/code&gt; will also simplify to &lt;code&gt;log(a)+log(b)&lt;/code&gt;
If it is set to &lt;code&gt;super&lt;/code&gt;, then &lt;code&gt;log(a/b)&lt;/code&gt;will also simplify to &lt;code&gt;log(a)-log(b)&lt;/code&gt; for rational numbers &lt;code&gt;a/b&lt;/code&gt;, &lt;code&gt;a#1&lt;/code&gt;(&lt;code&gt;log(1/b)&lt;/code&gt;, for integer &lt;code&gt;b&lt;/code&gt;, always simplifies.) 

if it is set to &lt;code&gt;false&lt;/code&gt;, all of these simplifications will be turned off
|option variable
default: true
|
|-
|'''lognegint'''
|implements the rule &lt;code&gt;log(-n) -&gt; log(n)+%i*%pi&lt;/code&gt; for &lt;code&gt;n&lt;/code&gt; a positive integer if &lt;code&gt;true&lt;/code&gt; 
|option variable
default: false
|
|-
|'''logsimp'''
|if &lt;code&gt;false&lt;/code&gt; then no simplification of &lt;code&gt;%e&lt;/code&gt; to a power containing &lt;code&gt;log&lt;/code&gt; is done
|option variable
default: true
|
|-
| '''plog''' &lt;var&gt;(x)&lt;/var&gt;
|represents the principal branch of the complex-valued natural logarithm with &lt;code&gt;-%pi &lt; carg(&lt;var&gt;x&lt;/var&gt;) &lt;= +%pi&lt;/code&gt; 
|
|
|-
|'''sqrt''' &lt;var&gt;(x)&lt;/var&gt; 
|the square root of &lt;var&gt;x&lt;/var&gt;. It is represented internally by &lt;code&gt;&lt;var&gt;x&lt;/var&gt;^(1/2)&lt;/code&gt;
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Trigonometric&lt;/u&gt;'''
'''&lt;u&gt;Hyperbolic&lt;/u&gt;'''
|
|
|
|-
|'''acos''' &lt;var&gt;(x)&lt;/var&gt;
|arc cosine
|
|
|-
|'''acosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosine
|
|
|-
|'''acot''' &lt;var&gt;(x)&lt;/var&gt;
|arc cotangent
|
|
|-
|'''acoth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cotangent.
|
|
|-
| '''acsc''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc cosecant
|
|
|-
|'''acsch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosecant
|
|
|-
| '''asec''' &lt;var&gt;(x)&lt;/var&gt;
|arc secant.
|
|
|-
|'''asech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc secant
|
|
|-
|'''asin''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc sine
|
|
|-
|'''asinh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc sine
|
|
|-
|'''atan''' &lt;var&gt;(x)&lt;/var&gt;
|arc tangent
|
|
|-
|'''atan2''' &lt;var&gt;(y, x)&lt;/var&gt;
|returns the value of &lt;math display=&quot;inline&quot;&gt;\tan^{-1}(y/x) &lt;/math&gt;  in the interval &lt;math display=&quot;inline&quot;&gt;(- \pi) \ to\ (\pi) &lt;/math&gt; taking into consideration the quadrant of the point ''(x,y)''
|
|
|-
|'''atanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc tangent
|
|
|-
|'''cos''' &lt;var&gt;(x)&lt;/var&gt;
|cosine
|
|
|-
|'''cosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosine
|
|
|-
|'''cot''' &lt;var&gt;(x)&lt;/var&gt;
|cotangent
|
|
|-
|'''coth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cotangent
|
|
|-
|'''csc''' &lt;var&gt;(x)&lt;/var&gt;
|cosecant
|
|
|-
| '''csch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosecant
|
|
|-
|'''sec''' &lt;var&gt;(x)&lt;/var&gt;
|secant
|
|
|-
|'''sech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic secant
|
|
|-
|'''sin''' &lt;var&gt;(x)&lt;/var&gt;
|sine
|
|
|-
|'''sinh''' &lt;var&gt;(x&lt;/var&gt;
| hyperbolic sine
|
|
|-
|'''tan''' &lt;var&gt;(x)&lt;/var&gt;
|tangent
|
|
|-
|'''tanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic tangent
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Random&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''make_random_state''' ()
|a random state object represents the state of the random number generator
|
|
|-
|'''set_random_state''' &lt;var&gt;(s)&lt;/var&gt;
|copies &lt;var&gt;s&lt;/var&gt; to the random number generator state
|
|
|-
|'''random''' &lt;var&gt;(x)&lt;/var&gt; 
|returns a pseudorandom number
|
|
|-
|
|
|
|
|}
;
;
;
;
; {{BookCat}}</text>
      <sha1>dpi6truegznqkn9p9nfeotx31bn7h0s</sha1>
    </revision>
    <revision>
      <id>4636858</id>
      <parentid>4636857</parentid>
      <timestamp>2026-05-21T12:30:20Z</timestamp>
      <contributor>
        <username>Idavidmiller</username>
        <id>3577687</id>
      </contributor>
      <minor />
      <origin>4636858</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="21465" sha1="bsvic84tc0skxq11g6bmoltmv4i0xt3" xml:space="preserve">== Getting Started Using Maxima - Some Essentials ==
This section is intended for those that are new to Maxima. It may or may not be of value or interest to those having prior experience.

=== The Maxima Way of doing Mathematics ===
Imagine that you want to create a computer application to perform some general mathematical tasks - not merely numerical calculations or &quot;number crunching&quot; as it is sometimes referred to somewhat pejoratively. It seems likely that it would be realized early on that, unlike humans that can interpret concepts and notation using context, computers and programming software generally are intolerant of any sort of ambiguity. Progress is being made in providing programming software with the ability to interpret based on context, but not here in Maxima. The Maxima expression syntax was created to be logical as well as unambiguous and precise in meaning and intention.

Another realization likely would be that mathematical expressions are the essential object on which mathematical concepts hinge, and that these concepts are conveyed using a conventional (if not entirely standard) system of notation. So, the means to compose mathematical expressions using some syntax for interpreting mathematical notation that your program could read and process as input would be essential. So Maxima is not a programming language in the conventional sense.

With the foregoing in mind, before starting to see examples of Maxima in action, keep the following in mind while learning and using Maxima:

* Expressions of various types (especially mathematical expressions) are the input to Maxima
* Every expression returns a value which is displayed as output unless the display is suppressed by some means
* Expressions as input are entered using an expression syntax that Maxima can read and process

==== Maxima expressions are of three types: ====

# Mathematical expressions
# Object expressions
# Programming expressions

==== Maxima expressions are comprised of two &quot;ingredients&quot; so to speak: ====

# Atoms
# Operators

==== Atoms: ====
These are one type of the built-in basic expression ingredients of Maxima. They are:

# Identifiers - names used alone or to identify other expressions by name
# Literal numerals for numbers - integer, fraction, and floating point literals
# Strings - quoted strings of one or more characters

==== Operators: ====
These are the second type of the built-in expression ingredients of Maxima. Including:

# Mathematical operators such as + , - , * ,  /, ^ , ! for addition, subtraction, negation, multiplication, division, exponentiation, factorial and the like. Internally to Maxima these are short-hand symbols for operators. Maxima operators also include &quot;functions&quot; such as sin(x), log(x), etc.
# Operators that are used to accomplish something other than for mathematical purposes 


'''Note:''' It is important to point out that there is a difference between operators, functions as used in the context of programming, and the mathematical concept of functions. In this book all Maxima functions in the programming sense of the word that are built-in to Maxima (that is &quot;out-of-the-box&quot; so to speak) will be referred to as operators, including those from loaded packages that are included with the Maxima distribution. Maxima functions in the programming sense of the word created by the user will be referred to as functions. The context should make it clear when the mathematical concept of a function is being referred to. It is unfortunately the case that the Maxima documentation refers to operators as functions. Like so much else, the word &quot;function&quot; has become overloaded.

=== A Brief Introduction to Expressions - Atoms, Identifiers and Operators ===
Below follows a brief introduction to Maxima expressions. All Maxima expressions are composed of '''''atoms''''' (including identifiers) and '''''operators''''', and every expression has a value.

With the foregoing information in mind, Maxima can be used to provide some examples of these various aspects of working with Maxima. This will be accomplished in the spirit of providing some insight and clarity for how to interact with Maxima, and how to compose expressions for input and how to interpret the values of expressions as output.

=== &lt;u&gt;Atoms&lt;/u&gt; ===
There are three types of atoms used as &quot;ingredients&quot; for composing Maxima expressions for input:

# Identifiers
# Numerical literals for representing numbers
# Strings

An elaboration of the technical details of each of these three types will follow in subsequent sections. In this section is a brief introduction, and examples of each of these types presented to gain a basic level of familiarity with each type of atom.

==== &lt;u&gt;Identifiers&lt;/u&gt; ====
Identifiers are one type of what are termed '''''atoms''''' as used in the context of Maxima expressions, but they are unique in that they are the only type of atom that can be assigned an expression other than their literal value.

Identifiers as atoms are used in Maxima expressions for two main purposes:

# To be unassigned an expression, and serve as a named variable
# To name an expression by way of an assignment operator

Try the following using Python:

&lt;code&gt;m + n&lt;/code&gt;&lt;syntaxhighlight lang=&quot;python3&quot;&gt;

&gt;&gt;&gt; m + n
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
NameError: name 'm' is not defined
&gt;&gt;&gt; 

&lt;/syntaxhighlight&gt;or using R:&lt;syntaxhighlight lang=&quot;r&quot;&gt;

&gt; m + n
Error: object 'm' not found
&gt;
&lt;/syntaxhighlight&gt;or using Octave:&lt;syntaxhighlight lang=&quot;octave&quot;&gt;

octave:1&gt; m + n
error: 'm' undefined near line 1, column 1
octave:2&gt; 

&lt;/syntaxhighlight&gt;Now, try this using Maxima:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
Maxima 5.49.0 https://maxima.sourceforge.io
using Lisp SBCL 2.0.1.debian
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) m + n;    
(%o1)                                n + m
&lt;/syntaxhighlight&gt;Take it on faith that the identifiers &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; are in the Maxima namespace as a consequence of this expression, and that each has a value assigned by Maxima merely as a consequence of being used in the &lt;code&gt;m + n&lt;/code&gt;  input expression – &lt;code&gt;m&lt;/code&gt; is &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; is &lt;code&gt;n&lt;/code&gt; in this case.&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i2)	m;
(%o2)	m

(%i3)	n;
(%o3)	n


&lt;/syntaxhighlight&gt;A value for any identifier (other than itself) may never be assigned while using Maxima no matter how many times it is referenced. That is perfectly okay. Maxima doesn't care.

But sometimes a value is assigned to an identifier – either the first time it is referenced or after it is first referenced:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i4)	m : n;
(m)	n

(%i5)	m;
(%o5)	n

(%i6)	remvalue(m);
(%o6)	[m]

(%i7)	m;
(%o7)	m


&lt;/syntaxhighlight&gt;In the above expressions, the identifier &lt;code&gt;m&lt;/code&gt; is assigned, using the &lt;code&gt;:&lt;/code&gt; assignment operator, the value of identifier &lt;code&gt;n&lt;/code&gt; (which is in this case &lt;code&gt;n&lt;/code&gt;), and then the value of &lt;code&gt;m&lt;/code&gt; is removed using the &lt;code&gt;remvalue()&lt;/code&gt; operator. Thus, the value of &lt;code&gt;m&lt;/code&gt; reverts to itself – &lt;code&gt;m&lt;/code&gt;.

These expressions, while trivial in a sense, provide some insight into an important way Maxima behaves. When identifiers are first referenced as input, they have a value – either a value through some sort of assignment, or merely the identifier name itself. Identifiers can be assigned values by different means as part of expressions as input.

Below follows some examples of Maxima identifiers as a very brief introduction:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;(%i1)	x; /* An unassigned identifier x */
(%o1)	x

(%i2)	mass; /* An unassigned identifier name of mass */
(%o2)	mass

(%i3)	f(x); /* An identifier f(x) for unassigned Maxima user-defined function */
(%o3)	f(x)

(%i4)	is(x = X); /* Identifiers are case-sensitive - x is not X */
(%o4)	false

(%i6)	y = x^2; /* Identifiers x and y used in an expression */
(%o6)	y=x^2

(%i7)	x : sqrt(2); /* Idenifier x assigned a value */
(x)	sqrt(2)

/* An identifier w(x,y,z) for a Maxima user-defined function */
(%i8)	w(x,w,z) := a*x^2 + b*y^2 + c*z^2;
(%o8)	w(x,w,z):=a*x^2+b*y^2+c*z^2&lt;/syntaxhighlight&gt;Maxima identifiers serve to name expressions as a value by means on some type of assignment, or they can be simply a name with a value of the name itself, in which case these unassigned identifiers may be considered to be variables. The technical details of Identifiers, assignment types, and expressions are elaborated upon in other book sections for each of these topics. 

==== &lt;u&gt;Numerical literals for representing numbers&lt;/u&gt; ====
There are four types of numerical literal atoms used to compose Maxima expressions:

# Integers
# Fractions (for rational numbers)
# Floating Point
# Bigfloat  (variable-precision floating point)

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i8)	1234; /* This is an integer type. */
(%o8)	1234

(%i9)	5/9; /* This is a fraction for a rational number type. */
(%o9)	5/9

(%i10)	3.14159; /* This is a floating point type. */
(%o10)	3.14159

(%i11)	5.532051841609784b-1; /* This is a bigfloat type. */
(%o11)	5.532051841609784b-1


&lt;/syntaxhighlight&gt;

==== &lt;u&gt;Strings&lt;/u&gt; ====
Strings are simply a quoted sequence of characters:

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i12)	&quot;a string atom&quot;;  /* This is a string atom. */
(%o12)	&quot;a string atom&quot;

(%i13)	&quot;Hello World!&quot;;  /* This is another string atom. */
(%o13)	&quot;Hello World!&quot;

(%i14)	&quot;Supercalifagilisticexpialidocious&quot;;  /* This is a longer string atom. */
(%o14)	&quot;Supercalifagilisticexpialidocious&quot;

(%i15)	&quot;C&quot;;  /* There is no Maxima character type. */
(%o15)	&quot;C&quot;
&lt;/syntaxhighlight&gt;

=== &lt;u&gt;Operators&lt;/u&gt; ===
Along with atoms, Maxima operators are the second ingredient used to form expressions used as input. There are many Maxima operators. Some are used frequently as a consequence of their utility for forming mathematical expressions. Many others are used infrequently as these operators are used for specialized purposes.   
{| class=&quot;wikitable&quot;
|+Operators
!Operator 
!Operation
!Notes
!Type
|-
|&lt;u&gt;'''Arithmetic'''&lt;/u&gt;
|
|
|
|-
| '''+'''
|addition
|also unary addition prefix
|n-ary
infix
commutative
|-
| '''-'''
|subtaction
|also unary negation prefix
|binary
infix
noncommutative
|-
|'''*'''
|multiplication
|
|n-ary infix
commutative
|-
|'''/'''
|division
|or fraction
|binary infix
noncommutative
|-
|'''^'''
|exponentiation
|
|binary postfix 
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Relational'''&lt;/u&gt;
|
|
|
|-
|'''&lt;'''
|less than
|
|binary infix
|-
|'''&lt;='''
|less than or equal
|
|binary infix
|-
|'''&gt;'''
|greater than
|
|binary infix
|-
|'''&gt;='''
|greater thanor equal
|
|binary infix
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Logical'''&lt;/u&gt;
|
|
|
|-
|'''and'''
|and
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
|'''not'''
|not
|Operand is a Boolean expression
Result is a Boolean value
|unary prefix
|-
|'''or'''
|or
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Equations'''&lt;/u&gt;
|
|
|
|-
|'''='''
|equality
|Unevaluated equation
| Syntactically equal
|-
|'''#'''
|negation of syntactic equality =
|Unevaluated negation of an equation
|Syntactically not equal
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Assignment'''&lt;/u&gt;
|
|
|
|-
|''':'''
|assignment to left hand side
|evaluates right hand side
|
|-
|'''::'''
|assignment to left hand side
|evaluates both sides
|
|-
|''':='''
|function definition
|does not evaluate right hand side
|
|-
|'''::='''
|macro function definition 
|
|
|-
|'''define''' ()
|function definition
|does evaluate right hand side
|
|}
{| class=&quot;wikitable&quot;
|+Elementary Mathematical Operators (Functions)
!Operators (Functions)
or
Option Variables
!Description
!Notes
!
|-
|'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''abs''' (''z'')
|mathematical absolute value
|works for both numerical and symbolic values
|
|-
|'''ceiling''' (x)
|returns the least integer that is greater than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''entier''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer less than or equal to &lt;var&gt;x&lt;/var&gt; where &lt;var&gt;x&lt;/var&gt; is numeric
|
|
|-
|'''floor''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer that is less than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''fix''' &lt;var&gt;(x)&lt;/var&gt; 
|a synonym for entier (x)
|
|
|-
|'''hstep''' &lt;var&gt;(x)&lt;/var&gt;
|the Heaviside unit step function
|
|
|-
|'''lmax''' &lt;var&gt;(L)&lt;/var&gt;
|when &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('max, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''lmin''' &lt;var&gt;(L)&lt;/var&gt;
|When &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('m&lt;/code&gt;&lt;code&gt;in, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''max''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt; 
|returns a simplified value for the numerical maximum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;
|
|
|-
|'''min''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt;
|returns a simplified value for the numerical minimum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;.
|
|
|-
|'''round''' &lt;var&gt;(x)&lt;/var&gt;
|when &lt;var&gt;x&lt;/var&gt; is a real number, returns the closest integer to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''signum''' &lt;var&gt;(x)&lt;/var&gt;
|for either real or complex numbers &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns 0 if &lt;var&gt;x&lt;/var&gt; is zero; for a nonzero numeric input &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns &lt;code&gt;x/abs(x)&lt;/code&gt;
|
|
|-
|'''truncate''' &lt;var&gt;(x)&lt;/var&gt;
|when x is a real number, return the closest integer to x not greater in absolute value than ''x''
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Complex&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''cabs''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the absolute value of an expression representing a complex number
|
|
|-
|'''carg''' &lt;var&gt;(z)&lt;/var&gt;
|returns the complex argument of ''z''
|
|
|-
|'''conjugate''' &lt;var&gt;(x)&lt;/var&gt;
|returns the complex conjugate of ''x''
|
|
|-
|'''imagpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the imaginary part of the expression ''expr''
|
|
|-
|'''polarform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;r %e^(%i theta)&lt;/code&gt; equivalent to ''expr'', such that ''r'' and ''theta'' are purely real
|
|
|-
|'''realpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the real part of &lt;var&gt;expr&lt;/var&gt;
|
|
|-
|'''rectform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;a + b %i&lt;/code&gt; equivalent to &lt;var&gt;expr&lt;/var&gt;, such that &lt;var&gt;a&lt;/var&gt; and &lt;var&gt;b&lt;/var&gt; are purely real
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Combinatorial&lt;/u&gt;'''
|
|
|
|-
|'''!!'''
|the double factorial operator
|
|
|-
|'''binomial''' &lt;var&gt;(x, y)&lt;/var&gt;
|returns the binomial coefficient &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!/(&lt;var&gt;y&lt;/var&gt;! (&lt;var&gt;x&lt;/var&gt; - &lt;var&gt;y&lt;/var&gt;)!)&lt;/code&gt;.
|
|
|-
|'''factcomb''' &lt;var&gt;(expr)&lt;/var&gt;
|tries to combine the coefficients of factorials in &lt;var&gt;expr&lt;/var&gt; with the factorials themselves
| by converting for example, &lt;code&gt;(n + 1)*n!&lt;/code&gt; into &lt;code&gt;(n + 1)!&lt;/code&gt;.
|
|-
|'''factorial''' ''(x)''

'''!'''
|returns the factorial of ''x''
|&lt;code&gt;factorial (&lt;var&gt;x&lt;/var&gt;)&lt;/code&gt; the same as &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!&lt;/code&gt;
|
|-
|'''factlim'''
|specifies the highest factorial which is automatically expanded
|option variable
default: 100000
|
|-
|'''factorial_expand'''
|controls the simplification of expressions like &lt;code&gt;(x+n)!&lt;/code&gt;, where &lt;code&gt;n&lt;/code&gt; is an integer
|option variable
default: false
|
|-
|'''genfact''' &lt;var&gt;(x, y, z)&lt;/var&gt;
|returns the generalized factorial, defined as &lt;code&gt;x (x-z) (x - 2 z) ... (x - (y - 1) z)&lt;/code&gt;
|when &lt;var&gt;x&lt;/var&gt; is an integer, &lt;code&gt;genfact (x, x, 1) = x!&lt;/code&gt; and &lt;code&gt;genfact (x, x/2, 2) = x!!&lt;/code&gt;
|
|-
|'''minfactorial''' &lt;var&gt;(expr)&lt;/var&gt;
|examines &lt;var&gt;expr&lt;/var&gt; for occurrences of two factorials which differ by an integer
|&lt;code&gt;minfactorial&lt;/code&gt;then turns one into a polynomial times the other
|
|-
|'''sumsplitfact'''
|when &lt;code&gt;sumsplitfact&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;, &lt;code&gt;minfactorial&lt;/code&gt; is applied after a &lt;code&gt;factcomb&lt;/code&gt;
|option variable
default: true
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Root&lt;/u&gt;'''
'''&lt;u&gt;Exponential&lt;/u&gt;'''
'''&lt;u&gt;Logarithmic&lt;/u&gt;'''
|
|
|
|-
|'''%e_to_numlog'''
|when &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;r&lt;/code&gt; some rational number, and &lt;code&gt;x&lt;/code&gt; some expression, &lt;code&gt;%e^(r*log(x))&lt;/code&gt; will be simplified into &lt;code&gt;x^r&lt;/code&gt;
|option variable
default: false
|
|-
|'''%emode'''
|when &lt;code&gt;%emode&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e^(%pi %i x)&lt;/code&gt; is simplified
|option variable
default: true
|
|-
|'''%enumer'''
|when &lt;code&gt;%enumer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e&lt;/code&gt; is replaced by its numeric value 2.718… whenever &lt;code&gt;numer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;.
|option variable
default: false
|
|-
|'''exp''' &lt;var&gt;(x)&lt;/var&gt;
|represents the exponential function
|
|
|-
|'''li''' &lt;var&gt;[s] (z)&lt;/var&gt;
|represents the polylogarithm function of order &lt;var&gt;s&lt;/var&gt; and argument &lt;var&gt;z&lt;/var&gt;, defined by an infinite series 
|
|
|-
|'''log''' &lt;var&gt;(x)&lt;/var&gt;
|represents the natural (base ) logarithm of &lt;var&gt;x&lt;/var&gt;.
|Maxima does not have a built-in function for the base 10 logarithm or other bases
|
|-
|'''logabs'''
|when doing indefinite integration where logs are generated, e.g. &lt;code&gt;integrate(1/x,x)&lt;/code&gt;, the answer is given in terms of &lt;code&gt;log(abs(...))&lt;/code&gt; if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, but in terms of &lt;code&gt;log(...)&lt;/code&gt;if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;
for definite integration, the &lt;code&gt;logabs:true&lt;/code&gt; setting is used, because here &quot;evaluation&quot; of the indefinite integral at the endpoints is often needed
|option variable
default: false
|
|-
|'''logarc''' &lt;var&gt;(expr)&lt;/var&gt;
|carries out the replacement of inverse circular and hyperbolic functions with equivalent logarithmic functions for an expression &lt;var&gt;expr&lt;/var&gt; without setting the global variable &lt;code&gt;logarc&lt;/code&gt;
|
|
|-
| '''logarc'''
|when the global variable &lt;code&gt;logarc&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, inverse circular and hyperbolic functions are replaced by equivalent logarithmic functions.
|option variable
default: false
|
|-
|'''logconcoeffp'''
|controls which coefficients are contracted when using &lt;code&gt;logcontract&lt;/code&gt;
|option variable
default: false
|
|-
|'''logcontract''' &lt;var&gt;(expr)&lt;/var&gt;
|recursively scans the expression &lt;var&gt;expr&lt;/var&gt;, transforming subexpressions of the form &lt;code&gt;a1*log(b1) + a2*log(b2) + c&lt;/code&gt; into &lt;code&gt;log(ratsimp(b1^a1 * b2^a2)) + c&lt;/code&gt;
|
|
|-
|'''logexpand'''
|if &lt;code&gt;true&lt;/code&gt;, that is the default value, causes &lt;code&gt;log(a^b)&lt;/code&gt; to become &lt;code&gt;b*log(a)&lt;/code&gt; 
If it is set to &lt;code&gt;all&lt;/code&gt;, &lt;code&gt;log(a*b)&lt;/code&gt; will also simplify to &lt;code&gt;log(a)+log(b)&lt;/code&gt;
If it is set to &lt;code&gt;super&lt;/code&gt;, then &lt;code&gt;log(a/b)&lt;/code&gt;will also simplify to &lt;code&gt;log(a)-log(b)&lt;/code&gt; for rational numbers &lt;code&gt;a/b&lt;/code&gt;, &lt;code&gt;a#1&lt;/code&gt;(&lt;code&gt;log(1/b)&lt;/code&gt;, for integer &lt;code&gt;b&lt;/code&gt;, always simplifies.) 

if it is set to &lt;code&gt;false&lt;/code&gt;, all of these simplifications will be turned off
|option variable
default: true
|
|-
|'''lognegint'''
|implements the rule &lt;code&gt;log(-n) -&gt; log(n)+%i*%pi&lt;/code&gt; for &lt;code&gt;n&lt;/code&gt; a positive integer if &lt;code&gt;true&lt;/code&gt; 
|option variable
default: false
|
|-
|'''logsimp'''
|if &lt;code&gt;false&lt;/code&gt; then no simplification of &lt;code&gt;%e&lt;/code&gt; to a power containing &lt;code&gt;log&lt;/code&gt; is done
|option variable
default: true
|
|-
| '''plog''' &lt;var&gt;(x)&lt;/var&gt;
|represents the principal branch of the complex-valued natural logarithm with &lt;code&gt;-%pi &lt; carg(&lt;var&gt;x&lt;/var&gt;) &lt;= +%pi&lt;/code&gt; 
|
|
|-
|'''sqrt''' &lt;var&gt;(x)&lt;/var&gt; 
|the square root of &lt;var&gt;x&lt;/var&gt;. It is represented internally by &lt;code&gt;&lt;var&gt;x&lt;/var&gt;^(1/2)&lt;/code&gt;
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Trigonometric&lt;/u&gt;'''
'''&lt;u&gt;Hyperbolic&lt;/u&gt;'''
|
|
|
|-
|'''acos''' &lt;var&gt;(x)&lt;/var&gt;
|arc cosine
|
|
|-
|'''acosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosine
|
|
|-
|'''acot''' &lt;var&gt;(x)&lt;/var&gt;
|arc cotangent
|
|
|-
|'''acoth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cotangent.
|
|
|-
| '''acsc''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc cosecant
|
|
|-
|'''acsch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosecant
|
|
|-
| '''asec''' &lt;var&gt;(x)&lt;/var&gt;
|arc secant.
|
|
|-
|'''asech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc secant
|
|
|-
|'''asin''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc sine
|
|
|-
|'''asinh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc sine
|
|
|-
|'''atan''' &lt;var&gt;(x)&lt;/var&gt;
|arc tangent
|
|
|-
|'''atan2''' &lt;var&gt;(y, x)&lt;/var&gt;
|returns the value of &lt;math display=&quot;inline&quot;&gt;\tan^{-1}(y/x) &lt;/math&gt;  in the interval &lt;math display=&quot;inline&quot;&gt;(- \pi) \ to\ (\pi) &lt;/math&gt; taking into consideration the quadrant of the point ''(x,y)''
|
|
|-
|'''atanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc tangent
|
|
|-
|'''cos''' &lt;var&gt;(x)&lt;/var&gt;
|cosine
|
|
|-
|'''cosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosine
|
|
|-
|'''cot''' &lt;var&gt;(x)&lt;/var&gt;
|cotangent
|
|
|-
|'''coth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cotangent
|
|
|-
|'''csc''' &lt;var&gt;(x)&lt;/var&gt;
|cosecant
|
|
|-
| '''csch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosecant
|
|
|-
|'''sec''' &lt;var&gt;(x)&lt;/var&gt;
|secant
|
|
|-
|'''sech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic secant
|
|
|-
|'''sin''' &lt;var&gt;(x)&lt;/var&gt;
|sine
|
|
|-
|'''sinh''' &lt;var&gt;(x&lt;/var&gt;
| hyperbolic sine
|
|
|-
|'''tan''' &lt;var&gt;(x)&lt;/var&gt;
|tangent
|
|
|-
|'''tanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic tangent
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Random&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''make_random_state''' ()
|a random state object represents the state of the random number generator
|
|
|-
|'''set_random_state''' &lt;var&gt;(s)&lt;/var&gt;
|copies &lt;var&gt;s&lt;/var&gt; to the random number generator state
|
|
|-
|'''random''' &lt;var&gt;(x)&lt;/var&gt; 
|returns a pseudorandom number
|
|
|-
|
|
|
|
|}
;
;
;
;
; {{BookCat}}</text>
      <sha1>bsvic84tc0skxq11g6bmoltmv4i0xt3</sha1>
    </revision>
    <revision>
      <id>4636868</id>
      <parentid>4636858</parentid>
      <timestamp>2026-05-21T13:11:55Z</timestamp>
      <contributor>
        <username>Idavidmiller</username>
        <id>3577687</id>
      </contributor>
      <minor />
      <origin>4636868</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="21897" sha1="45uwumjt7sarnv923ied80sz7zv5n98" xml:space="preserve">== Getting Started Using Maxima - Some Essentials ==
This section is intended for those that are new to Maxima. It may or may not be of value or interest to those having prior experience.

=== The Maxima Way of doing Mathematics ===
Imagine that you want to create a computer application to perform some general mathematical tasks - not merely numerical calculations or &quot;number crunching&quot; as it is sometimes referred to somewhat pejoratively. It seems likely that it would be realized early on that, unlike humans that can interpret concepts and notation using context, computers and programming software generally are intolerant of any sort of ambiguity. Progress is being made in providing programming software with the ability to interpret based on context, but not here in Maxima. The Maxima expression syntax was created to be logical as well as unambiguous and precise in meaning and intention.

Another realization likely would be that mathematical expressions are the essential object on which mathematical concepts hinge, and that these concepts are conveyed using a conventional (if not entirely standard) system of notation. So, the means to compose mathematical expressions using some syntax for interpreting mathematical notation that your program could read and process as input would be essential. So Maxima is not a programming language in the conventional sense.

With the foregoing in mind, before starting to see examples of Maxima in action, keep the following in mind while learning and using Maxima:

* Expressions of various types (especially mathematical expressions) are the input to Maxima
* Every expression returns a value which is displayed as output unless the display is suppressed by some means
* Expressions as input are entered using an expression syntax that Maxima can read and process

==== Maxima expressions are of three types: ====

# Mathematical expressions
# Object expressions
# Programming expressions

==== Maxima expressions are comprised of two &quot;ingredients&quot; so to speak: ====

# Atoms
# Operators

==== Atoms: ====
These are one type of the built-in basic expression ingredients of Maxima. They are:

# Identifiers - names used alone or to identify other expressions by name
# Literal numerals for numbers - integer, fraction, and floating point literals
# Strings - quoted strings of one or more characters

==== Operators: ====
These are the second type of the built-in expression ingredients of Maxima. Including:

# Mathematical operators such as + , - , * ,  /, ^ , ! for addition, subtraction, negation, multiplication, division, exponentiation, factorial and the like. Internally to Maxima these are short-hand symbols for operators. Maxima operators also include &quot;functions&quot; such as sin(x), log(x), etc.
# Operators that are used to accomplish something other than for mathematical purposes 


'''Note:''' It is important to point out that there is a difference between operators, functions as used in the context of programming, and the mathematical concept of functions. In this book all Maxima functions in the programming sense of the word that are built-in to Maxima (that is &quot;out-of-the-box&quot; so to speak) will be referred to as operators, including those from loaded packages that are included with the Maxima distribution. Maxima functions in the programming sense of the word created by the user will be referred to as functions. The context should make it clear when the mathematical concept of a function is being referred to. It is unfortunately the case that the Maxima documentation refers to operators as functions. Like so much else, the word &quot;function&quot; has become overloaded.

=== A Brief Introduction to Expressions - Atoms, Identifiers and Operators ===
Below follows a brief introduction to Maxima expressions. All Maxima expressions are composed of '''''atoms''''' (including identifiers) and '''''operators''''', and every expression has a value.

With the foregoing information in mind, Maxima can be used to provide some examples of these various aspects of working with Maxima. This will be accomplished in the spirit of providing some insight and clarity for how to interact with Maxima, and how to compose expressions for input and how to interpret the values of expressions as output.

=== &lt;u&gt;Atoms&lt;/u&gt; ===
There are three types of atoms used as &quot;ingredients&quot; for composing Maxima expressions for input:

# Identifiers
# Numerical literals for representing numbers
# Strings

An elaboration of the technical details of each of these three types will follow in subsequent sections. In this section is a brief introduction, and examples of each of these types presented to gain a basic level of familiarity with each type of atom.

==== &lt;u&gt;Identifiers&lt;/u&gt; ====
Identifiers are one type of what are termed '''''atoms''''' as used in the context of Maxima expressions, but they are unique in that they are the only type of atom that can be assigned an expression other than their literal value.

Identifiers as atoms are used in Maxima expressions for two main purposes:

# To be unassigned an expression, and serve as a named variable
# To name an expression by way of an assignment operator

Try the following using Python:

&lt;code&gt;m + n&lt;/code&gt;&lt;syntaxhighlight lang=&quot;python3&quot;&gt;

&gt;&gt;&gt; m + n
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
NameError: name 'm' is not defined
&gt;&gt;&gt; 

&lt;/syntaxhighlight&gt;or using R:&lt;syntaxhighlight lang=&quot;r&quot;&gt;

&gt; m + n
Error: object 'm' not found
&gt;
&lt;/syntaxhighlight&gt;or using Octave:&lt;syntaxhighlight lang=&quot;octave&quot;&gt;

octave:1&gt; m + n
error: 'm' undefined near line 1, column 1
octave:2&gt; 

&lt;/syntaxhighlight&gt;Now, try this using Maxima:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
Maxima 5.49.0 https://maxima.sourceforge.io
using Lisp SBCL 2.0.1.debian
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) m + n;    
(%o1)                                n + m
&lt;/syntaxhighlight&gt;Take it on faith that the identifiers &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; are in the Maxima namespace as a consequence of this expression, and that each has a value assigned by Maxima merely as a consequence of being used in the &lt;code&gt;m + n&lt;/code&gt;  input expression – &lt;code&gt;m&lt;/code&gt; is &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; is &lt;code&gt;n&lt;/code&gt; in this case.&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i2)	m;
(%o2)	m

(%i3)	n;
(%o3)	n


&lt;/syntaxhighlight&gt;A value for any identifier (other than itself) may never be assigned while using Maxima no matter how many times it is referenced. That is perfectly okay. Maxima doesn't care.

But sometimes a value is assigned to an identifier – either the first time it is referenced or after it is first referenced:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i4)	m : n;
(m)	n

(%i5)	m;
(%o5)	n

(%i6)	remvalue(m);
(%o6)	[m]

(%i7)	m;
(%o7)	m


&lt;/syntaxhighlight&gt;In the above expressions, the identifier &lt;code&gt;m&lt;/code&gt; is assigned, using the &lt;code&gt;:&lt;/code&gt; assignment operator, the value of identifier &lt;code&gt;n&lt;/code&gt; (which is in this case &lt;code&gt;n&lt;/code&gt;), and then the value of &lt;code&gt;m&lt;/code&gt; is removed using the &lt;code&gt;remvalue()&lt;/code&gt; operator. Thus, the value of &lt;code&gt;m&lt;/code&gt; reverts to itself – &lt;code&gt;m&lt;/code&gt;.

These expressions, while trivial in a sense, provide some insight into an important way Maxima behaves. When identifiers are first referenced as input, they have a value – either a value through some sort of assignment, or merely the identifier name itself. Identifiers can be assigned values by different means as part of expressions as input.

Below follows some examples of Maxima identifiers as a very brief introduction:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;(%i1)	x; /* An unassigned identifier x */
(%o1)	x

(%i2)	mass; /* An unassigned identifier name of mass */
(%o2)	mass

(%i3)	f(x); /* An identifier f(x) for unassigned Maxima user-defined function */
(%o3)	f(x)

(%i4)	is(x = X); /* Identifiers are case-sensitive - x is not X */
(%o4)	false

(%i6)	y = x^2; /* Identifiers x and y used in an expression */
(%o6)	y=x^2

(%i7)	x : sqrt(2); /* Idenifier x assigned a value */
(x)	sqrt(2)

/* An identifier w(x,y,z) for a Maxima user-defined function */
(%i8)	w(x,w,z) := a*x^2 + b*y^2 + c*z^2;
(%o8)	w(x,w,z):=a*x^2+b*y^2+c*z^2&lt;/syntaxhighlight&gt;Maxima identifiers serve to name expressions as a value by means on some type of assignment, or they can be simply a name with a value of the name itself, in which case these unassigned identifiers may be considered to be variables. The technical details of Identifiers, assignment types, and expressions are elaborated upon in other book sections for each of these topics. 

==== &lt;u&gt;Numerical literals for representing numbers&lt;/u&gt; ====
There are four types of numerical literal atoms used to compose Maxima expressions:

# Integers
# Fractions (for rational numbers)
# Floating Point
# Bigfloat  (variable-precision floating point)

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i8)	1234; /* This is an integer type. */
(%o8)	1234

(%i9)	5/9; /* This is a fraction for a rational number type. */
(%o9)	5/9

(%i10)	3.14159; /* This is a floating point type. */
(%o10)	3.14159

(%i11)	5.532051841609784b-1; /* This is a bigfloat type. */
(%o11)	5.532051841609784b-1


&lt;/syntaxhighlight&gt;

==== &lt;u&gt;Strings&lt;/u&gt; ====
Strings are simply a quoted sequence of characters:

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i12)	&quot;a string atom&quot;;  /* This is a string atom. */
(%o12)	&quot;a string atom&quot;

(%i13)	&quot;Hello World!&quot;;  /* This is another string atom. */
(%o13)	&quot;Hello World!&quot;

(%i14)	&quot;Supercalifagilisticexpialidocious&quot;;  /* This is a longer string atom. */
(%o14)	&quot;Supercalifagilisticexpialidocious&quot;

(%i15)	&quot;C&quot;;  /* There is no Maxima character type. */
(%o15)	&quot;C&quot;
&lt;/syntaxhighlight&gt;

=== &lt;u&gt;Operators&lt;/u&gt; ===
Along with atoms, Maxima operators are the second ingredient used to form expressions used as input. There are many Maxima operators. Some are used frequently as a consequence of their utility for forming mathematical expressions. Many others are used infrequently as these operators are used for specialized purposes.   
{| class=&quot;wikitable&quot;
|+Operators
!Operator 
!Operation
!Notes
!Type
|-
|&lt;u&gt;'''Arithmetic'''&lt;/u&gt;
|
|
|
|-
| '''+'''
|addition
|also unary addition prefix
|n-ary
infix
commutative
|-
| '''-'''
|subtaction
|also unary negation prefix
|binary
infix
noncommutative
|-
|'''*'''
|multiplication
|
|n-ary infix
commutative
|-
|'''/'''
|division
|or fraction
|binary infix
noncommutative
|-
|'''^'''
|exponentiation
|
|binary postfix 
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Relational'''&lt;/u&gt;
|
|
|
|-
|'''&lt;'''
|less than
|
|binary infix
|-
|'''&lt;='''
|less than or equal
|
|binary infix
|-
|'''&gt;'''
|greater than
|
|binary infix
|-
|'''&gt;='''
|greater thanor equal
|
|binary infix
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Logical'''&lt;/u&gt;
|
|
|
|-
|'''and'''
|and
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
|'''not'''
|not
|Operand is a Boolean expression
Result is a Boolean value
|unary prefix
|-
|'''or'''
|or
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Equations'''&lt;/u&gt;
|
|
|
|-
|'''='''
|equality
|Unevaluated equation
| Syntactically equal
|-
|'''#'''
|negation of syntactic equality =
|Unevaluated negation of an equation
|Syntactically not equal
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Assignment'''&lt;/u&gt;
|
|
|
|-
|''':'''
|assignment to left hand side
|evaluates right hand side
|
|-
|'''::'''
|assignment to left hand side
|evaluates both sides
|
|-
|''':='''
|function definition
|does not evaluate right hand side
|
|-
|'''::='''
|macro function definition 
|
|
|-
|'''define''' ()
|function definition
|does evaluate right hand side
|
|}
{| class=&quot;wikitable&quot;
|+Elementary Mathematical Operators (Functions)
!Operators (Functions)
or
Option Variables
!Description
!Notes
!
|-
|'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''abs''' (''z'')
|mathematical absolute value
|works for both numerical and symbolic values
|
|-
|'''ceiling''' (x)
|returns the least integer that is greater than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''entier''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer less than or equal to &lt;var&gt;x&lt;/var&gt; where &lt;var&gt;x&lt;/var&gt; is numeric
|
|
|-
|'''floor''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer that is less than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''fix''' &lt;var&gt;(x)&lt;/var&gt; 
|a synonym for entier (x)
|
|
|-
|'''hstep''' &lt;var&gt;(x)&lt;/var&gt;
|the Heaviside unit step function
|
|
|-
|'''lmax''' &lt;var&gt;(L)&lt;/var&gt;
|when &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('max, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''lmin''' &lt;var&gt;(L)&lt;/var&gt;
|When &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('m&lt;/code&gt;&lt;code&gt;in, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''max''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt; 
|returns a simplified value for the numerical maximum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;
|
|
|-
|'''min''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt;
|returns a simplified value for the numerical minimum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;.
|
|
|-
|'''round''' &lt;var&gt;(x)&lt;/var&gt;
|when &lt;var&gt;x&lt;/var&gt; is a real number, returns the closest integer to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''signum''' &lt;var&gt;(x)&lt;/var&gt;
|for either real or complex numbers &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns 0 if &lt;var&gt;x&lt;/var&gt; is zero; for a nonzero numeric input &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns &lt;code&gt;x/abs(x)&lt;/code&gt;
|
|
|-
|'''truncate''' &lt;var&gt;(x)&lt;/var&gt;
|when x is a real number, return the closest integer to x not greater in absolute value than ''x''
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Complex&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''cabs''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the absolute value of an expression representing a complex number
|
|
|-
|'''carg''' &lt;var&gt;(z)&lt;/var&gt;
|returns the complex argument of ''z''
|
|
|-
|'''conjugate''' &lt;var&gt;(x)&lt;/var&gt;
|returns the complex conjugate of ''x''
|
|
|-
|'''imagpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the imaginary part of the expression ''expr''
|
|
|-
|'''polarform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;r %e^(%i theta)&lt;/code&gt; equivalent to ''expr'', such that ''r'' and ''theta'' are purely real
|
|
|-
|'''realpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the real part of &lt;var&gt;expr&lt;/var&gt;
|
|
|-
|'''rectform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;a + b %i&lt;/code&gt; equivalent to &lt;var&gt;expr&lt;/var&gt;, such that &lt;var&gt;a&lt;/var&gt; and &lt;var&gt;b&lt;/var&gt; are purely real
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Combinatorial&lt;/u&gt;'''
|
|
|
|-
|'''!!'''
|the double factorial operator
|
|
|-
|'''binomial''' &lt;var&gt;(x, y)&lt;/var&gt;
|returns the binomial coefficient &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!/(&lt;var&gt;y&lt;/var&gt;! (&lt;var&gt;x&lt;/var&gt; - &lt;var&gt;y&lt;/var&gt;)!)&lt;/code&gt;.
|
|
|-
|'''factcomb''' &lt;var&gt;(expr)&lt;/var&gt;
|tries to combine the coefficients of factorials in &lt;var&gt;expr&lt;/var&gt; with the factorials themselves
| by converting for example, &lt;code&gt;(n + 1)*n!&lt;/code&gt; into &lt;code&gt;(n + 1)!&lt;/code&gt;.
|
|-
|'''factorial''' ''(x)''

'''!'''
|returns the factorial of ''x''
|&lt;code&gt;factorial (&lt;var&gt;x&lt;/var&gt;)&lt;/code&gt; the same as &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!&lt;/code&gt;
|
|-
|'''factlim'''
|specifies the highest factorial which is automatically expanded
|option variable
default: 100000
|
|-
|'''factorial_expand'''
|controls the simplification of expressions like &lt;code&gt;(x+n)!&lt;/code&gt;, where &lt;code&gt;n&lt;/code&gt; is an integer
|option variable
default: false
|
|-
|'''genfact''' &lt;var&gt;(x, y, z)&lt;/var&gt;
|returns the generalized factorial, defined as &lt;code&gt;x (x-z) (x - 2 z) ... (x - (y - 1) z)&lt;/code&gt;
|when &lt;var&gt;x&lt;/var&gt; is an integer, &lt;code&gt;genfact (x, x, 1) = x!&lt;/code&gt; and &lt;code&gt;genfact (x, x/2, 2) = x!!&lt;/code&gt;
|
|-
|'''minfactorial''' &lt;var&gt;(expr)&lt;/var&gt;
|examines &lt;var&gt;expr&lt;/var&gt; for occurrences of two factorials which differ by an integer
|&lt;code&gt;minfactorial&lt;/code&gt;then turns one into a polynomial times the other
|
|-
|'''sumsplitfact'''
|when &lt;code&gt;sumsplitfact&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;, &lt;code&gt;minfactorial&lt;/code&gt; is applied after a &lt;code&gt;factcomb&lt;/code&gt;
|option variable
default: true
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Root&lt;/u&gt;'''
'''&lt;u&gt;Exponential&lt;/u&gt;'''
'''&lt;u&gt;Logarithmic&lt;/u&gt;'''
|
|
|
|-
|'''%e_to_numlog'''
|when &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;r&lt;/code&gt; some rational number, and &lt;code&gt;x&lt;/code&gt; some expression, &lt;code&gt;%e^(r*log(x))&lt;/code&gt; will be simplified into &lt;code&gt;x^r&lt;/code&gt;
|option variable
default: false
|
|-
|'''%emode'''
|when &lt;code&gt;%emode&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e^(%pi %i x)&lt;/code&gt; is simplified
|option variable
default: true
|
|-
|'''%enumer'''
|when &lt;code&gt;%enumer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e&lt;/code&gt; is replaced by its numeric value 2.718… whenever &lt;code&gt;numer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;.
|option variable
default: false
|
|-
|'''exp''' &lt;var&gt;(x)&lt;/var&gt;
|represents the exponential function
|
|
|-
|'''li''' &lt;var&gt;[s] (z)&lt;/var&gt;
|represents the polylogarithm function of order &lt;var&gt;s&lt;/var&gt; and argument &lt;var&gt;z&lt;/var&gt;, defined by an infinite series 
|
|
|-
|'''log''' &lt;var&gt;(x)&lt;/var&gt;
|represents the natural (base ) logarithm of &lt;var&gt;x&lt;/var&gt;.
|Maxima does not have a built-in function for the base 10 logarithm or other bases
|
|-
|'''logabs'''
|when doing indefinite integration where logs are generated, e.g. &lt;code&gt;integrate(1/x,x)&lt;/code&gt;, the answer is given in terms of &lt;code&gt;log(abs(...))&lt;/code&gt; if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, but in terms of &lt;code&gt;log(...)&lt;/code&gt;if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;
for definite integration, the &lt;code&gt;logabs:true&lt;/code&gt; setting is used, because here &quot;evaluation&quot; of the indefinite integral at the endpoints is often needed
|option variable
default: false
|
|-
|'''logarc''' &lt;var&gt;(expr)&lt;/var&gt;
|carries out the replacement of inverse circular and hyperbolic functions with equivalent logarithmic functions for an expression &lt;var&gt;expr&lt;/var&gt; without setting the global variable &lt;code&gt;logarc&lt;/code&gt;
|
|
|-
| '''logarc'''
|when the global variable &lt;code&gt;logarc&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, inverse circular and hyperbolic functions are replaced by equivalent logarithmic functions.
|option variable
default: false
|
|-
|'''logconcoeffp'''
|controls which coefficients are contracted when using &lt;code&gt;logcontract&lt;/code&gt;
|option variable
default: false
|
|-
|'''logcontract''' &lt;var&gt;(expr)&lt;/var&gt;
|recursively scans the expression &lt;var&gt;expr&lt;/var&gt;, transforming subexpressions of the form &lt;code&gt;a1*log(b1) + a2*log(b2) + c&lt;/code&gt; into &lt;code&gt;log(ratsimp(b1^a1 * b2^a2)) + c&lt;/code&gt;
|
|
|-
|'''logexpand'''
|if &lt;code&gt;true&lt;/code&gt;, that is the default value, causes &lt;code&gt;log(a^b)&lt;/code&gt; to become &lt;code&gt;b*log(a)&lt;/code&gt; 
If it is set to &lt;code&gt;all&lt;/code&gt;, &lt;code&gt;log(a*b)&lt;/code&gt; will also simplify to &lt;code&gt;log(a)+log(b)&lt;/code&gt;
If it is set to &lt;code&gt;super&lt;/code&gt;, then &lt;code&gt;log(a/b)&lt;/code&gt;will also simplify to &lt;code&gt;log(a)-log(b)&lt;/code&gt; for rational numbers &lt;code&gt;a/b&lt;/code&gt;, &lt;code&gt;a#1&lt;/code&gt;(&lt;code&gt;log(1/b)&lt;/code&gt;, for integer &lt;code&gt;b&lt;/code&gt;, always simplifies.) 

if it is set to &lt;code&gt;false&lt;/code&gt;, all of these simplifications will be turned off
|option variable
default: true
|
|-
|'''lognegint'''
|implements the rule &lt;code&gt;log(-n) -&gt; log(n)+%i*%pi&lt;/code&gt; for &lt;code&gt;n&lt;/code&gt; a positive integer if &lt;code&gt;true&lt;/code&gt; 
|option variable
default: false
|
|-
|'''logsimp'''
|if &lt;code&gt;false&lt;/code&gt; then no simplification of &lt;code&gt;%e&lt;/code&gt; to a power containing &lt;code&gt;log&lt;/code&gt; is done
|option variable
default: true
|
|-
| '''plog''' &lt;var&gt;(x)&lt;/var&gt;
|represents the principal branch of the complex-valued natural logarithm with &lt;code&gt;-%pi &lt; carg(&lt;var&gt;x&lt;/var&gt;) &lt;= +%pi&lt;/code&gt; 
|
|
|-
|'''sqrt''' &lt;var&gt;(x)&lt;/var&gt; 
|the square root of &lt;var&gt;x&lt;/var&gt;. It is represented internally by &lt;code&gt;&lt;var&gt;x&lt;/var&gt;^(1/2)&lt;/code&gt;
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Trigonometric&lt;/u&gt;'''
'''&lt;u&gt;Hyperbolic&lt;/u&gt;'''
|
|
|
|-
|'''acos''' &lt;var&gt;(x)&lt;/var&gt;
|arc cosine
|
|
|-
|'''acosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosine
|
|
|-
|'''acot''' &lt;var&gt;(x)&lt;/var&gt;
|arc cotangent
|
|
|-
|'''acoth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cotangent.
|
|
|-
| '''acsc''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc cosecant
|
|
|-
|'''acsch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosecant
|
|
|-
| '''asec''' &lt;var&gt;(x)&lt;/var&gt;
|arc secant.
|
|
|-
|'''asech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc secant
|
|
|-
|'''asin''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc sine
|
|
|-
|'''asinh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc sine
|
|
|-
|'''atan''' &lt;var&gt;(x)&lt;/var&gt;
|arc tangent
|
|
|-
|'''atan2''' &lt;var&gt;(y, x)&lt;/var&gt;
|returns the value of &lt;math display=&quot;inline&quot;&gt;\tan^{-1}(y/x) &lt;/math&gt;  in the interval &lt;math display=&quot;inline&quot;&gt;(- \pi) \ to\ (\pi) &lt;/math&gt; taking into consideration the quadrant of the point ''(x,y)''
|
|
|-
|'''atanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc tangent
|
|
|-
|'''cos''' &lt;var&gt;(x)&lt;/var&gt;
|cosine
|
|
|-
|'''cosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosine
|
|
|-
|'''cot''' &lt;var&gt;(x)&lt;/var&gt;
|cotangent
|
|
|-
|'''coth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cotangent
|
|
|-
|'''csc''' &lt;var&gt;(x)&lt;/var&gt;
|cosecant
|
|
|-
| '''csch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosecant
|
|
|-
|'''sec''' &lt;var&gt;(x)&lt;/var&gt;
|secant
|
|
|-
|'''sech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic secant
|
|
|-
|'''sin''' &lt;var&gt;(x)&lt;/var&gt;
|sine
|
|
|-
|'''sinh''' &lt;var&gt;(x&lt;/var&gt;
| O
|
|
|-
|'''tan''' &lt;var&gt;(x)&lt;/var&gt;
|tangent
|
|
|-
|'''tanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic tangent
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Random&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''make_random_state''' ()
|a random state object represents the state of the random number generator
|
|
|-
|'''set_random_state''' &lt;var&gt;(s)&lt;/var&gt;
|copies &lt;var&gt;s&lt;/var&gt; to the random number generator state
|
|
|-
|'''random''' &lt;var&gt;(x)&lt;/var&gt; 
|returns a pseudorandom number
|
|
|-
|
|
|
|
|}

=== Maxima Expressions ===
For the purpose of review, Maxima expressions are of three types:
# Mathematical expressions
# Object expressions
# Programming expressions
Object expressions and programming expressions are for use in support of the intended purpose of Maxima – a computer algebra system. Mathematical expressions are those that are the essential type for doing mathematics using Maxima.

==== Mathematical Expressions ====
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    <revision>
      <id>4636899</id>
      <parentid>4636868</parentid>
      <timestamp>2026-05-21T16:17:42Z</timestamp>
      <contributor>
        <username>Idavidmiller</username>
        <id>3577687</id>
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      <comment>Work in progress. Saving Changes.</comment>
      <origin>4636899</origin>
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      <text bytes="23865" sha1="2aj1hr6f2mq7irh1h9nslx3iy6taqyk" xml:space="preserve">== Getting Started Using Maxima - Some Essentials ==
This section is intended for those that are new to Maxima. It may or may not be of value or interest to those having prior experience.

=== The Maxima Way of doing Mathematics ===
Imagine that you want to create a computer application to perform some general mathematical tasks - not merely numerical calculations or &quot;number crunching&quot; as it is sometimes referred to somewhat pejoratively. It seems likely that it would be realized early on that, unlike humans that can interpret concepts and notation using context, computers and programming software generally are intolerant of any sort of ambiguity. Progress is being made in providing programming software with the ability to interpret based on context, but not here in Maxima. The Maxima expression syntax was created to be logical as well as unambiguous and precise in meaning and intention.

Another realization likely would be that mathematical expressions are the essential object on which mathematical concepts hinge, and that these concepts are conveyed using a conventional (if not entirely standard) system of notation. So, the means to compose mathematical expressions using some syntax for interpreting mathematical notation that your program could read and process as input would be essential. So Maxima is not a programming language in the conventional sense.

With the foregoing in mind, before starting to see examples of Maxima in action, keep the following in mind while learning and using Maxima:

* Expressions of various types (especially mathematical expressions) are the input to Maxima
* Every expression returns a value which is displayed as output unless the display is suppressed by some means
* Expressions as input are entered using an expression syntax that Maxima can read and process

==== Maxima expressions are of three types: ====

# Mathematical expressions
# Object expressions
# Programming expressions

==== Maxima expressions are comprised of two &quot;ingredients&quot; so to speak: ====

# Atoms
# Operators

==== Atoms: ====
These are one type of the built-in basic expression ingredients of Maxima. They are:

# Identifiers - names used alone or to identify other expressions by name
# Literal numerals for numbers - integer, fraction, and floating point literals
# Strings - quoted strings of one or more characters

==== Operators: ====
These are the second type of the built-in expression ingredients of Maxima. Including:

# Mathematical operators such as + , - , * ,  /, ^ , ! for addition, subtraction, negation, multiplication, division, exponentiation, factorial and the like. Internally to Maxima these are short-hand symbols for operators. Maxima operators also include &quot;functions&quot; such as sin(x), log(x), etc.
# Operators that are used to accomplish something other than for mathematical purposes 


'''Note:''' It is important to point out that there is a difference between operators, functions as used in the context of programming, and the mathematical concept of functions. In this book all Maxima functions in the programming sense of the word that are built-in to Maxima (that is &quot;out-of-the-box&quot; so to speak) will be referred to as operators, including those from loaded packages that are included with the Maxima distribution. Maxima functions in the programming sense of the word created by the user will be referred to as functions. The context should make it clear when the mathematical concept of a function is being referred to. It is unfortunately the case that the Maxima documentation refers to operators as functions. Like so much else, the word &quot;function&quot; has become overloaded.

=== A Brief Introduction to Expressions - Atoms, Identifiers and Operators ===
Below follows a brief introduction to Maxima expressions. All Maxima expressions are composed of '''''atoms''''' (including identifiers) and '''''operators''''', and every expression has a value.

With the foregoing information in mind, Maxima can be used to provide some examples of these various aspects of working with Maxima. This will be accomplished in the spirit of providing some insight and clarity for how to interact with Maxima, and how to compose expressions for input and how to interpret the values of expressions as output.

=== &lt;u&gt;Atoms&lt;/u&gt; ===
There are three types of atoms used as &quot;ingredients&quot; for composing Maxima expressions for input:

# Identifiers
# Numerical literals for representing numbers
# Strings

An elaboration of the technical details of each of these three types will follow in subsequent sections. In this section is a brief introduction, and examples of each of these types presented to gain a basic level of familiarity with each type of atom.

==== &lt;u&gt;Identifiers&lt;/u&gt; ====
Identifiers are one type of what are termed '''''atoms''''' as used in the context of Maxima expressions, but they are unique in that they are the only type of atom that can be assigned an expression other than their literal value.

Identifiers as atoms are used in Maxima expressions for two main purposes:

# To be unassigned an expression, and serve as a named variable
# To name an expression by way of an assignment operator

Try the following using Python:

&lt;code&gt;m + n&lt;/code&gt;&lt;syntaxhighlight lang=&quot;python3&quot;&gt;

&gt;&gt;&gt; m + n
Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
NameError: name 'm' is not defined
&gt;&gt;&gt; 

&lt;/syntaxhighlight&gt;or using R:&lt;syntaxhighlight lang=&quot;r&quot;&gt;

&gt; m + n
Error: object 'm' not found
&gt;
&lt;/syntaxhighlight&gt;or using Octave:&lt;syntaxhighlight lang=&quot;octave&quot;&gt;

octave:1&gt; m + n
error: 'm' undefined near line 1, column 1
octave:2&gt; 

&lt;/syntaxhighlight&gt;Now, try this using Maxima:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
Maxima 5.49.0 https://maxima.sourceforge.io
using Lisp SBCL 2.0.1.debian
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) m + n;    
(%o1)                                n + m
&lt;/syntaxhighlight&gt;Take it on faith that the identifiers &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; are in the Maxima namespace as a consequence of this expression, and that each has a value assigned by Maxima merely as a consequence of being used in the &lt;code&gt;m + n&lt;/code&gt;  input expression – &lt;code&gt;m&lt;/code&gt; is &lt;code&gt;m&lt;/code&gt; and &lt;code&gt;n&lt;/code&gt; is &lt;code&gt;n&lt;/code&gt; in this case.&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i2)	m;
(%o2)	m

(%i3)	n;
(%o3)	n


&lt;/syntaxhighlight&gt;A value for any identifier (other than itself) may never be assigned while using Maxima no matter how many times it is referenced. That is perfectly okay. Maxima doesn't care.

But sometimes a value is assigned to an identifier – either the first time it is referenced or after it is first referenced:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i4)	m : n;
(m)	n

(%i5)	m;
(%o5)	n

(%i6)	remvalue(m);
(%o6)	[m]

(%i7)	m;
(%o7)	m


&lt;/syntaxhighlight&gt;In the above expressions, the identifier &lt;code&gt;m&lt;/code&gt; is assigned, using the &lt;code&gt;:&lt;/code&gt; assignment operator, the value of identifier &lt;code&gt;n&lt;/code&gt; (which is in this case &lt;code&gt;n&lt;/code&gt;), and then the value of &lt;code&gt;m&lt;/code&gt; is removed using the &lt;code&gt;remvalue()&lt;/code&gt; operator. Thus, the value of &lt;code&gt;m&lt;/code&gt; reverts to itself – &lt;code&gt;m&lt;/code&gt;.

These expressions, while trivial in a sense, provide some insight into an important way Maxima behaves. When identifiers are first referenced as input, they have a value – either a value through some sort of assignment, or merely the identifier name itself. Identifiers can be assigned values by different means as part of expressions as input.

Below follows some examples of Maxima identifiers as a very brief introduction:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;(%i1)	x; /* An unassigned identifier x */
(%o1)	x

(%i2)	mass; /* An unassigned identifier name of mass */
(%o2)	mass

(%i3)	f(x); /* An identifier f(x) for unassigned Maxima user-defined function */
(%o3)	f(x)

(%i4)	is(x = X); /* Identifiers are case-sensitive - x is not X */
(%o4)	false

(%i6)	y = x^2; /* Identifiers x and y used in an expression */
(%o6)	y=x^2

(%i7)	x : sqrt(2); /* Idenifier x assigned a value */
(x)	sqrt(2)

/* An identifier w(x,y,z) for a Maxima user-defined function */
(%i8)	w(x,w,z) := a*x^2 + b*y^2 + c*z^2;
(%o8)	w(x,w,z):=a*x^2+b*y^2+c*z^2&lt;/syntaxhighlight&gt;Maxima identifiers serve to name expressions as a value by means on some type of assignment, or they can be simply a name with a value of the name itself, in which case these unassigned identifiers may be considered to be variables. The technical details of Identifiers, assignment types, and expressions are elaborated upon in other book sections for each of these topics. 

==== &lt;u&gt;Numerical literals for representing numbers&lt;/u&gt; ====
There are four types of numerical literals used to compose Maxima expressions:

# Integers
# Fractions (for rational numbers)
# Floating Point
# Bigfloat  (variable-precision floating point)

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i8)	1234; /* This is an integer type. An atom */
(%o8)	1234

(%i9)	5/9; /* This is a fraction for a rational number type. Not an atom. */
(%o9)	5/9

(%i10)	3.14159; /* This is a floating point type. An atom. */
(%o10)	3.14159

(%i11)	5.532051841609784b-1; /* This is a bigfloat type. An atom */
(%o11)	5.532051841609784b-1


&lt;/syntaxhighlight&gt;

==== &lt;u&gt;Strings&lt;/u&gt; ====
Strings are simply a quoted sequence of characters:

&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i12)	&quot;a string atom&quot;;  /* This is a string atom. */
(%o12)	&quot;a string atom&quot;

(%i13)	&quot;Hello World!&quot;;  /* This is another string atom. */
(%o13)	&quot;Hello World!&quot;

(%i14)	&quot;Supercalifagilisticexpialidocious&quot;;  /* This is a longer string atom. */
(%o14)	&quot;Supercalifagilisticexpialidocious&quot;

(%i15)	&quot;C&quot;;  /* There is no Maxima character type. */
(%o15)	&quot;C&quot;
&lt;/syntaxhighlight&gt;

=== &lt;u&gt;Operators&lt;/u&gt; ===
Along with atoms, Maxima operators are the second ingredient used to form expressions used as input. There are many Maxima operators. Some are used frequently as a consequence of their utility for forming mathematical expressions. Many others are used infrequently as these operators are used for specialized purposes.   
{| class=&quot;wikitable&quot;
|+Operators
!Operator 
!Operation
!Notes
!Type
|-
|&lt;u&gt;'''Arithmetic'''&lt;/u&gt;
|
|
|
|-
| '''+'''
|addition
|also unary addition prefix
|n-ary
infix
commutative
|-
| '''-'''
|subtaction
|also unary negation prefix
|binary
infix
noncommutative
|-
|'''*'''
|multiplication
|
|n-ary infix
commutative
|-
|'''/'''
|division
|or fraction
|binary infix
noncommutative
|-
|'''^'''
|exponentiation
|
|binary postfix 
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Relational'''&lt;/u&gt;
|
|
|
|-
|'''&lt;'''
|less than
|
|binary infix
|-
|'''&lt;='''
|less than or equal
|
|binary infix
|-
|'''&gt;'''
|greater than
|
|binary infix
|-
|'''&gt;='''
|greater thanor equal
|
|binary infix
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Logical'''&lt;/u&gt;
|
|
|
|-
|'''and'''
|and
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
|'''not'''
|not
|Operand is a Boolean expression
Result is a Boolean value
|unary prefix
|-
|'''or'''
|or
|Operands are Boolean expressions
Result is a Boolean value
|n-ary infix
noncommutative
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Equations'''&lt;/u&gt;
|
|
|
|-
|'''='''
|equality
|Unevaluated equation
| Syntactically equal
|-
|'''#'''
|negation of syntactic equality =
|Unevaluated negation of an equation
|Syntactically not equal
|-
| colspan=&quot;4&quot; |
|-
|&lt;u&gt;'''Assignment'''&lt;/u&gt;
|
|
|
|-
|''':'''
|assignment to left hand side
|evaluates right hand side
|
|-
|'''::'''
|assignment to left hand side
|evaluates both sides
|
|-
|''':='''
|function definition
|does not evaluate right hand side
|
|-
|'''::='''
|macro function definition 
|
|
|-
|'''define''' ()
|function definition
|does evaluate right hand side
|
|}
{| class=&quot;wikitable&quot;
|+Elementary Mathematical Operators (Functions)
!Operators (Functions)
or
Option Variables
!Description
!Notes
!
|-
|'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''abs''' (''z'')
|mathematical absolute value
|works for both numerical and symbolic values
|
|-
|'''ceiling''' (x)
|returns the least integer that is greater than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''entier''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer less than or equal to &lt;var&gt;x&lt;/var&gt; where &lt;var&gt;x&lt;/var&gt; is numeric
|
|
|-
|'''floor''' &lt;var&gt;(x)&lt;/var&gt;
|returns the largest integer that is less than or equal to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''fix''' &lt;var&gt;(x)&lt;/var&gt; 
|a synonym for entier (x)
|
|
|-
|'''hstep''' &lt;var&gt;(x)&lt;/var&gt;
|the Heaviside unit step function
|
|
|-
|'''lmax''' &lt;var&gt;(L)&lt;/var&gt;
|when &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('max, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''lmin''' &lt;var&gt;(L)&lt;/var&gt;
|When &lt;var&gt;L&lt;/var&gt; is a list or a set, return 
&lt;code&gt;apply ('m&lt;/code&gt;&lt;code&gt;in, args (&lt;var&gt;L&lt;/var&gt;))&lt;/code&gt;
|
|
|-
|'''max''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt; 
|returns a simplified value for the numerical maximum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;
|
|
|-
|'''min''' &lt;var&gt;(x_1, …, x_n)&lt;/var&gt;
|returns a simplified value for the numerical minimum of the expressions &lt;var&gt;x_1&lt;/var&gt; through &lt;var&gt;x_n&lt;/var&gt;.
|
|
|-
|'''round''' &lt;var&gt;(x)&lt;/var&gt;
|when &lt;var&gt;x&lt;/var&gt; is a real number, returns the closest integer to &lt;var&gt;x&lt;/var&gt;
|
|
|-
|'''signum''' &lt;var&gt;(x)&lt;/var&gt;
|for either real or complex numbers &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns 0 if &lt;var&gt;x&lt;/var&gt; is zero; for a nonzero numeric input &lt;var&gt;x&lt;/var&gt;, the '''signum''' function returns &lt;code&gt;x/abs(x)&lt;/code&gt;
|
|
|-
|'''truncate''' &lt;var&gt;(x)&lt;/var&gt;
|when x is a real number, return the closest integer to x not greater in absolute value than ''x''
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Complex&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''cabs''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the absolute value of an expression representing a complex number
|
|
|-
|'''carg''' &lt;var&gt;(z)&lt;/var&gt;
|returns the complex argument of ''z''
|
|
|-
|'''conjugate''' &lt;var&gt;(x)&lt;/var&gt;
|returns the complex conjugate of ''x''
|
|
|-
|'''imagpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the imaginary part of the expression ''expr''
|
|
|-
|'''polarform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;r %e^(%i theta)&lt;/code&gt; equivalent to ''expr'', such that ''r'' and ''theta'' are purely real
|
|
|-
|'''realpart''' &lt;var&gt;(expr)&lt;/var&gt;
|returns the real part of &lt;var&gt;expr&lt;/var&gt;
|
|
|-
|'''rectform''' &lt;var&gt;(expr)&lt;/var&gt;
|returns an expression &lt;code&gt;a + b %i&lt;/code&gt; equivalent to &lt;var&gt;expr&lt;/var&gt;, such that &lt;var&gt;a&lt;/var&gt; and &lt;var&gt;b&lt;/var&gt; are purely real
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Combinatorial&lt;/u&gt;'''
|
|
|
|-
|'''!!'''
|the double factorial operator
|
|
|-
|'''binomial''' &lt;var&gt;(x, y)&lt;/var&gt;
|returns the binomial coefficient &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!/(&lt;var&gt;y&lt;/var&gt;! (&lt;var&gt;x&lt;/var&gt; - &lt;var&gt;y&lt;/var&gt;)!)&lt;/code&gt;.
|
|
|-
|'''factcomb''' &lt;var&gt;(expr)&lt;/var&gt;
|tries to combine the coefficients of factorials in &lt;var&gt;expr&lt;/var&gt; with the factorials themselves
| by converting for example, &lt;code&gt;(n + 1)*n!&lt;/code&gt; into &lt;code&gt;(n + 1)!&lt;/code&gt;.
|
|-
|'''factorial''' ''(x)''

'''!'''
|returns the factorial of ''x''
|&lt;code&gt;factorial (&lt;var&gt;x&lt;/var&gt;)&lt;/code&gt; the same as &lt;code&gt;&lt;var&gt;x&lt;/var&gt;!&lt;/code&gt;
|
|-
|'''factlim'''
|specifies the highest factorial which is automatically expanded
|option variable
default: 100000
|
|-
|'''factorial_expand'''
|controls the simplification of expressions like &lt;code&gt;(x+n)!&lt;/code&gt;, where &lt;code&gt;n&lt;/code&gt; is an integer
|option variable
default: false
|
|-
|'''genfact''' &lt;var&gt;(x, y, z)&lt;/var&gt;
|returns the generalized factorial, defined as &lt;code&gt;x (x-z) (x - 2 z) ... (x - (y - 1) z)&lt;/code&gt;
|when &lt;var&gt;x&lt;/var&gt; is an integer, &lt;code&gt;genfact (x, x, 1) = x!&lt;/code&gt; and &lt;code&gt;genfact (x, x/2, 2) = x!!&lt;/code&gt;
|
|-
|'''minfactorial''' &lt;var&gt;(expr)&lt;/var&gt;
|examines &lt;var&gt;expr&lt;/var&gt; for occurrences of two factorials which differ by an integer
|&lt;code&gt;minfactorial&lt;/code&gt;then turns one into a polynomial times the other
|
|-
|'''sumsplitfact'''
|when &lt;code&gt;sumsplitfact&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;, &lt;code&gt;minfactorial&lt;/code&gt; is applied after a &lt;code&gt;factcomb&lt;/code&gt;
|option variable
default: true
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Root&lt;/u&gt;'''
'''&lt;u&gt;Exponential&lt;/u&gt;'''
'''&lt;u&gt;Logarithmic&lt;/u&gt;'''
|
|
|
|-
|'''%e_to_numlog'''
|when &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;r&lt;/code&gt; some rational number, and &lt;code&gt;x&lt;/code&gt; some expression, &lt;code&gt;%e^(r*log(x))&lt;/code&gt; will be simplified into &lt;code&gt;x^r&lt;/code&gt;
|option variable
default: false
|
|-
|'''%emode'''
|when &lt;code&gt;%emode&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e^(%pi %i x)&lt;/code&gt; is simplified
|option variable
default: true
|
|-
|'''%enumer'''
|when &lt;code&gt;%enumer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, &lt;code&gt;%e&lt;/code&gt; is replaced by its numeric value 2.718… whenever &lt;code&gt;numer&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;.
|option variable
default: false
|
|-
|'''exp''' &lt;var&gt;(x)&lt;/var&gt;
|represents the exponential function
|
|
|-
|'''li''' &lt;var&gt;[s] (z)&lt;/var&gt;
|represents the polylogarithm function of order &lt;var&gt;s&lt;/var&gt; and argument &lt;var&gt;z&lt;/var&gt;, defined by an infinite series 
|
|
|-
|'''log''' &lt;var&gt;(x)&lt;/var&gt;
|represents the natural (base ) logarithm of &lt;var&gt;x&lt;/var&gt;.
|Maxima does not have a built-in function for the base 10 logarithm or other bases
|
|-
|'''logabs'''
|when doing indefinite integration where logs are generated, e.g. &lt;code&gt;integrate(1/x,x)&lt;/code&gt;, the answer is given in terms of &lt;code&gt;log(abs(...))&lt;/code&gt; if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, but in terms of &lt;code&gt;log(...)&lt;/code&gt;if &lt;code&gt;logabs&lt;/code&gt; is &lt;code&gt;false&lt;/code&gt;
for definite integration, the &lt;code&gt;logabs:true&lt;/code&gt; setting is used, because here &quot;evaluation&quot; of the indefinite integral at the endpoints is often needed
|option variable
default: false
|
|-
|'''logarc''' &lt;var&gt;(expr)&lt;/var&gt;
|carries out the replacement of inverse circular and hyperbolic functions with equivalent logarithmic functions for an expression &lt;var&gt;expr&lt;/var&gt; without setting the global variable &lt;code&gt;logarc&lt;/code&gt;
|
|
|-
| '''logarc'''
|when the global variable &lt;code&gt;logarc&lt;/code&gt; is &lt;code&gt;true&lt;/code&gt;, inverse circular and hyperbolic functions are replaced by equivalent logarithmic functions.
|option variable
default: false
|
|-
|'''logconcoeffp'''
|controls which coefficients are contracted when using &lt;code&gt;logcontract&lt;/code&gt;
|option variable
default: false
|
|-
|'''logcontract''' &lt;var&gt;(expr)&lt;/var&gt;
|recursively scans the expression &lt;var&gt;expr&lt;/var&gt;, transforming subexpressions of the form &lt;code&gt;a1*log(b1) + a2*log(b2) + c&lt;/code&gt; into &lt;code&gt;log(ratsimp(b1^a1 * b2^a2)) + c&lt;/code&gt;
|
|
|-
|'''logexpand'''
|if &lt;code&gt;true&lt;/code&gt;, that is the default value, causes &lt;code&gt;log(a^b)&lt;/code&gt; to become &lt;code&gt;b*log(a)&lt;/code&gt; 
If it is set to &lt;code&gt;all&lt;/code&gt;, &lt;code&gt;log(a*b)&lt;/code&gt; will also simplify to &lt;code&gt;log(a)+log(b)&lt;/code&gt;
If it is set to &lt;code&gt;super&lt;/code&gt;, then &lt;code&gt;log(a/b)&lt;/code&gt;will also simplify to &lt;code&gt;log(a)-log(b)&lt;/code&gt; for rational numbers &lt;code&gt;a/b&lt;/code&gt;, &lt;code&gt;a#1&lt;/code&gt;(&lt;code&gt;log(1/b)&lt;/code&gt;, for integer &lt;code&gt;b&lt;/code&gt;, always simplifies.) 

if it is set to &lt;code&gt;false&lt;/code&gt;, all of these simplifications will be turned off
|option variable
default: true
|
|-
|'''lognegint'''
|implements the rule &lt;code&gt;log(-n) -&gt; log(n)+%i*%pi&lt;/code&gt; for &lt;code&gt;n&lt;/code&gt; a positive integer if &lt;code&gt;true&lt;/code&gt; 
|option variable
default: false
|
|-
|'''logsimp'''
|if &lt;code&gt;false&lt;/code&gt; then no simplification of &lt;code&gt;%e&lt;/code&gt; to a power containing &lt;code&gt;log&lt;/code&gt; is done
|option variable
default: true
|
|-
| '''plog''' &lt;var&gt;(x)&lt;/var&gt;
|represents the principal branch of the complex-valued natural logarithm with &lt;code&gt;-%pi &lt; carg(&lt;var&gt;x&lt;/var&gt;) &lt;= +%pi&lt;/code&gt; 
|
|
|-
|'''sqrt''' &lt;var&gt;(x)&lt;/var&gt; 
|the square root of &lt;var&gt;x&lt;/var&gt;. It is represented internally by &lt;code&gt;&lt;var&gt;x&lt;/var&gt;^(1/2)&lt;/code&gt;
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Trigonometric&lt;/u&gt;'''
'''&lt;u&gt;Hyperbolic&lt;/u&gt;'''
|
|
|
|-
|'''acos''' &lt;var&gt;(x)&lt;/var&gt;
|arc cosine
|
|
|-
|'''acosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosine
|
|
|-
|'''acot''' &lt;var&gt;(x)&lt;/var&gt;
|arc cotangent
|
|
|-
|'''acoth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cotangent.
|
|
|-
| '''acsc''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc cosecant
|
|
|-
|'''acsch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc cosecant
|
|
|-
| '''asec''' &lt;var&gt;(x)&lt;/var&gt;
|arc secant.
|
|
|-
|'''asech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc secant
|
|
|-
|'''asin''' &lt;var&gt;(x&lt;/var&gt;&lt;var&gt;)&lt;/var&gt;
|arc sine
|
|
|-
|'''asinh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc sine
|
|
|-
|'''atan''' &lt;var&gt;(x)&lt;/var&gt;
|arc tangent
|
|
|-
|'''atan2''' &lt;var&gt;(y, x)&lt;/var&gt;
|returns the value of &lt;math display=&quot;inline&quot;&gt;\tan^{-1}(y/x) &lt;/math&gt;  in the interval &lt;math display=&quot;inline&quot;&gt;(- \pi) \ to\ (\pi) &lt;/math&gt; taking into consideration the quadrant of the point ''(x,y)''
|
|
|-
|'''atanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic arc tangent
|
|
|-
|'''cos''' &lt;var&gt;(x)&lt;/var&gt;
|cosine
|
|
|-
|'''cosh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosine
|
|
|-
|'''cot''' &lt;var&gt;(x)&lt;/var&gt;
|cotangent
|
|
|-
|'''coth''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cotangent
|
|
|-
|'''csc''' &lt;var&gt;(x)&lt;/var&gt;
|cosecant
|
|
|-
| '''csch''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic cosecant
|
|
|-
|'''sec''' &lt;var&gt;(x)&lt;/var&gt;
|secant
|
|
|-
|'''sech''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic secant
|
|
|-
|'''sin''' &lt;var&gt;(x)&lt;/var&gt;
|sine
|
|
|-
|'''sinh''' &lt;var&gt;(x&lt;/var&gt;
| O
|
|
|-
|'''tan''' &lt;var&gt;(x)&lt;/var&gt;
|tangent
|
|
|-
|'''tanh''' &lt;var&gt;(x)&lt;/var&gt;
|hyperbolic tangent
|
|
|-
| colspan=&quot;4&quot; |
|-
|'''&lt;u&gt;Random&lt;/u&gt;'''
'''&lt;u&gt;Numbers&lt;/u&gt;'''
|
|
|
|-
|'''make_random_state''' ()
|a random state object represents the state of the random number generator
|
|
|-
|'''set_random_state''' &lt;var&gt;(s)&lt;/var&gt;
|copies &lt;var&gt;s&lt;/var&gt; to the random number generator state
|
|
|-
|'''random''' &lt;var&gt;(x)&lt;/var&gt; 
|returns a pseudorandom number
|
|
|-
|
|
|
|
|}

=== Maxima Expressions ===
For the purpose of review, Maxima expressions are of three types:
# Mathematical expressions
# Object expressions
# Programming expressions
Object expressions and programming expressions are for use in support of the intended purpose of Maxima – a computer algebra system. Mathematical expressions are those that are the essential type for doing mathematics using Maxima.

==== Mathematical Expressions ====
Mathematical expressions consist of atoms and operators that are of a mathematical nature. Mathematical expressions can be simple to relatively complex. 

The simplest expressions can consists of a single atom:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;(%i1)	5; /* an integer atom   */
(%o1)	5

(%i2)	3.14159; /* a floating point atom  */
(%o2)	3.14159

(%i3)	77.3987483627298298277627928389828329382983b0; /* a bigfloat atom  */
(%o3)	7.739874836272983b1

(%i4)	x; /* an unassigned identifier atom   */
(%o4)	x&lt;/syntaxhighlight&gt;Atoms are &quot;self-evaluating&quot; in the sense that they return themselves as values. Expressions such as these are not very useful, but they are the simplest example of mathematical expressions.

Fractions for literal rational numbers are simple expressions entered as follows, but are not atoms:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i5)	12/33; /* A fraction expression. Maxima simplfies the expression as output */
(%o5)	4/11

(%i6)	atom(12/33); /* The fraction expression is not an atom */
(%o6)	false

(%i8)	op(12/33); /* The overall operation of this expression is / */
(%o8)	/
&lt;/syntaxhighlight&gt;Maxima evaluates the division of integers as rational numbers, and simplifies the return value if possible:&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i09)	12/33 * 3/4; /* multiplication of fractions */
(%o09)	3/11

(%i10)	(12/33) / (4/3); /* division of fractions */
(%o10)	3/11

(%i11)	3/8 + 13/4; /* addition of fractions */
(%o11)	29/8
&lt;/syntaxhighlight&gt;Maxima will resolve mixed numerical types in expressions as returned values in a manner which might be expected :&lt;syntaxhighlight lang=&quot;maxima&quot;&gt;
(%i12)	3/2 * 5; /* fraction and an integer */
(%o12)	15/2

(%i13)	3/2 * 5.0; /* fraction and floating point */
(%o13)	7.5

(%i14)	12.0/33;              /* floating point and an integer */
(%o14)	0.36363636363636365

(%i15)	0.36363636363636365*0.36363636363636365b0;    /* floating point and bigfloat */
(%o15)	1.322314049586777b-1
&lt;/syntaxhighlight&gt;
; {{BookCat}}</text>
      <sha1>2aj1hr6f2mq7irh1h9nslx3iy6taqyk</sha1>
    </revision>
  </page>
  <page>
    <title>Wikibooks:Reading room/Archives/2026/March</title>
    <ns>4</ns>
    <id>483072</id>
    <revision>
      <id>4636917</id>
      <parentid>4636836</parentid>
      <timestamp>2026-05-21T18:29:53Z</timestamp>
      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>/* Regarding the project's FlaggedRevs extension */ archive from [[Wikibooks:Reading room/General]] ([[mw:c:Special:MyLanguage/User:JWBTH/CD|CD]])</comment>
      <origin>4636917</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="17874" sha1="tqo5e5j7mlkfylexzn8g0h0b0ooaef0" xml:space="preserve">{{talk archive}}

== Correspondence between John Belton and the Continental Congress ==

Hello. [[s:Correspondence between John Belton and the Continental Congress]] is probably going to be deleted from Wikisource as out of scope, would Wikibooks be interested in its import? -- [[User:Jan.Kamenicek|Jan.Kamenicek]] ([[User talk:Jan.Kamenicek|discuss]] • [[Special:Contributions/Jan.Kamenicek|contribs]]) 19:27, 3 March 2026 (UTC)

:@[[User:Jan.Kamenicek|Jan.Kamenicek]] Thank you for checking! We do not host source texts, so it doesn't look like this would be in scope at Wikibooks. Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:55, 3 March 2026 (UTC)
== Templates: Refbegin and Refend. ==

These DO NOT seem to work as the documentation indicates throwing lints when used with the form indicated. 

These templates need to be behave consistently, or thrown out and re-written entirely.  

It would be NICE to have ONE set of templates and documentation to accompany them, currently this does not apparently exist, with the relevant templates getting confused between definition lists &lt;nowiki&gt;:&lt;/nowiki&gt; and standard lists {{*}}. 

CONSISTENT behaviour would also be nice.

[[User:ShakespeareFan00|ShakespeareFan00]] ([[User talk:ShakespeareFan00|discuss]] • [[Special:Contributions/ShakespeareFan00|contribs]]) 09:39, 19 March 2026 (UTC)

:@[[User:ShakespeareFan00|ShakespeareFan00]] I temporarily reduced the protection down for these templates (semi-protection), so you can do the necessary changes. :) [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 17:38, 21 March 2026 (UTC)

: Thats the thing I'm not sure what the 'stable' repair is, without breaking other stuff :( [[User:ShakespeareFan00|ShakespeareFan00]] ([[User talk:ShakespeareFan00|discuss]] • [[Special:Contributions/ShakespeareFan00|contribs]]) 11:44, 22 March 2026 (UTC)
== Upcoming deployment of CampaignEvents extension to Wikibooks ==

&lt;section begin=&quot;message&quot;/&gt;
Hello everyone,

We are writing to inform you that the [[mw:Help:Extension:CampaignEvents|CampaignEvents extension]] will be deployed to all Wikibooks projects during the week of '''23 March 2026'''.
This follows last year’s broader rollout across Wikimedia projects. We realized that Wikibooks was not included at the time, and we’re now addressing that to ensure consistency across all communities.

The CampaignEvents extension provides tools to support event and campaign organization on-wiki, including features like on-wiki event registration and collaboration lists(global event list).

We welcome any questions, feedback, or concerns you may have. We are also happy to support anyone interested in trying out the tools. 
''Apologies if this message is not in your preferred language. If you’re able to help translate it for your community, please feel free to do so.''
&lt;section end=&quot;message&quot;/&gt;

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot;&gt;[[User:Udehb-WMF|Udehb-WMF]] ([[User talk:Udehb-WMF|discuss]]) 18:22, 19 March 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Udehb-WMF@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=User:Udehb-WMF/sandbox/MM_target&amp;oldid=30284073 --&gt;

== Regarding the project's FlaggedRevs extension ==

Hello, everyone. I want to discuss with the community about the use of this project's FlaggedRevs (flagged revisions) extension, which was deployed many years ago (and configured recently).

=== Many unreviewed edits, and edit quality options ===
According to [[Special:PendingChanges]], there are almost 4000 unreviewed edits (per the standard FlaggedRevs configuration). In addition, on the edit review interface when evaluating a diff, there are three radio buttons that determine the quality of the edit (minimal, average, good). Do we have to utilize these buttons if the quality of the edit or the book matters, according to [[WB:REVIEW]]? This proposal is to whether discontinue the edit rating buttons or not.

One way to reduce such a large amount of unreviewed edits is to set the following to &lt;code&gt;true&lt;/code&gt;:
* &lt;code&gt;wgFlaggedRevsProtection&lt;/code&gt; (pending changes protection, to be used on Wikijunior pages; this might negate the need to show the stable version by default)
* (optional) &lt;code&gt;wgSimpleFlaggedRevsUI&lt;/code&gt; (simpler, icon-based UI on the edit review interface)
We should also include the following configuration (partially based from English Wikipedia), if this proposal passes:
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
elseif ( $wgDBname == 'enwikibooks' ) {
		// Limited to the main, Cookbook, and Wikijunior namespaces (T408110)
		$wgFlaggedRevsNamespaces = [ NS_MAIN, 102, 110 ];
		# We have only one tag with one level
		$wgFlaggedRevsTags = [ 'status' =&gt; [ 'levels' =&gt; 1 ] ];
		# Restrict autoconfirmed to flagging semi-protected
		$wgFlaggedRevsTagsRestrictions = [
			'status' =&gt; [ 'review' =&gt; 1, 'autoreview' =&gt; 1 ],
		];
		# Restriction levels for auto-review/review rights
		$wgFlaggedRevsRestrictionLevels = [ 'autoreview' ];
		# Remove 'validate' from reviewers
		$wgGroupPermissions['reviewer']['validate'] = false;
		# Group permissions for sysops
		$wgGroupPermissions['sysop']['review'] = true;
		$wgGroupPermissions['sysop']['stablesettings'] = true;
		# Allow sysops to add and remove the 'reviewer' group
		$wgAddGroups['sysop'][] = 'reviewer';
		$wgRemoveGroups['sysop'][] = 'reviewer';
		# Remove the 'editor' user group
		unset( $wgGroupPermissions['editor'] );
	}
&lt;/syntaxhighlight&gt;

=== Inactive reviewers ===
After conducting an audit of over 1000 reviewers, most, if not many of them are completely inactive.

=== User group changes for reviewers ===
The reviewer user group is known to the software as &lt;code&gt;editor&lt;/code&gt;, which might sound misleading (the actual [[MediaWiki:Group-editor/qqq|/qqq definition]] is &quot;Editors&quot;). To fix that, we might have to consider switching to &lt;code&gt;reviewer&lt;/code&gt; and unset &lt;code&gt;editor&lt;/code&gt;.

I am also not sure whether administrators should have the &lt;code&gt;validate&lt;/code&gt; user right, since &lt;code&gt;reviewer&lt;/code&gt; has it on by default (but it is currently disabled). On the above configuration I proposed, administrators (and users in the &lt;code&gt;reviewer&lt;/code&gt; user group) would no longer have &lt;code&gt;validate&lt;/code&gt;.

=== Page patrolling ===
Currently, only administrators can mark new pages as patrolled (&lt;code&gt;patrol&lt;/code&gt;) by using the MediaWiki page patrol software, but clicking on &quot;Accept revision&quot; (via FlaggedRevs) would also mark the page as patrolled, in question. I believe that using FlaggedRevs to patrol new pages is redundant, given that we might not want to use one or the other.

If we are considering on switching to pending changes, we should also allow reviewers to mark new pages as patrolled, as they are trusted to have the &lt;code&gt;autopatrol&lt;/code&gt; right in addition to administrators and autoreviewed users.

Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 04:05, 21 March 2026 (UTC)

:I agree on replacing &lt;code&gt;editor&lt;/code&gt; with &lt;code&gt;reviewer&lt;/code&gt; to avoid confusion. Reviewers don't need to have patrol permissions as a reviewed page would be patrolled as well. I don't think people will use it much as a page or edit being reviewed already means that it has been checked by someone else. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:00, 22 March 2026 (UTC)
::When I said that reviewers would have &lt;code&gt;patrol&lt;/code&gt;, they can review new pages that other users created, but not any new pages they create themselves. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:16, 22 March 2026 (UTC)
:::How can that be the case if they have &lt;code&gt;autopatrol&lt;/code&gt;? [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 18:26, 22 March 2026 (UTC)
::::I will give you an example. On the English Wikiquote, there are two user groups that have &lt;code&gt;autopatrol&lt;/code&gt;: autopatrollers and patrollers. Autopatrollers have their page creations marked as patrolled by the software, while patrollers (whilst also having their page creations marked as patrolled) can mark new pages as patrolled (in addition to administrators). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:39, 22 March 2026 (UTC)
:::::But what is the point of giving reviewers &lt;code&gt;patrol&lt;/code&gt; if we are already using FlaggedRevs? I think that we won't need patrol because we already have reviewing, and patrol only seems to be a confirmation that the page is up to policy from what I have seen, so giving them reviewers to mark pages as patrolled seems pointless to me when we already have FlaggedRevs. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 19:06, 22 March 2026 (UTC)
::::::I understand, but my proposal was to convert FlaggedRevs into a protection-like mechanism which would be used alongside page protection; it might turn off FlaggedRevs's ability to patrol new pages for reviewers, hence why I suggested this above. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 23:30, 22 March 2026 (UTC)
::::::: @[[User:Kingofnuthin|Kingofnuthin]] I will summarize what you said from above:
:::::::* You agree about the reviewer user group to be moved from &lt;code&gt;editor&lt;/code&gt; to &lt;code&gt;reviewer&lt;/code&gt; to avoid confusion (technically).
:::::::* However, you probably disagree about allowing reviewers to patrol new pages ''and'' having their page creations automatically marked as patrolled, because FlaggedRevs can do all of this, and &lt;code&gt;$wgUseNPPatrol&lt;/code&gt; might seem to be redundant.
::::::: A compromise about your disagreement is that we might have to consider removing &lt;code&gt;autopatrol&lt;/code&gt; and/or &lt;code&gt;patrol&lt;/code&gt; from our existing user groups, similar to [[phab:T423461]].
::::::: I started this because in addition to that, one of my concerns was the extreme backlog of unreviewed edits and pages [4000!]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 20:31, 19 April 2026 (UTC)
:I may be missing some things here, so let me know if I haven't answered any points here:
:# I don't think we currently need to have the review status indicate the quality of the edit (i.e. minimal, average, good). I don't think this is used at all anymore.
:# I think it makes sense to reassign the reviewer user group to &lt;code&gt;editor&lt;/code&gt;. I always like clarity in language.
:# Are you saying that pages marked as reviewed are currently also classed as patrolled? If that's the case, I think we should not have reviewed pages automatically classed as patrolled, and we should keep reviewing and patrolling separate.
:I'll note that honestly don't know much about patrolling, since I've never engaged with it—I have only ever referenced the reviewing system. If there is a significant functional difference, I would love to know it. Cheers! —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 03:00, 23 March 2026 (UTC)
::When someone clicks &quot;Accept revision&quot; on an unreviewed page, it is listed under [[Special:Log/review]]; if an admin marks a page as patrolled with &quot;Mark this page as patrolled&quot;, it will show up under [[Special:Log/patrol]], which is not really logged much compared to the former log (review). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 03:12, 23 March 2026 (UTC)
:I agree to your thoughts about the &lt;code&gt;editor&lt;/code&gt; group and edit quality ratings, but I don't understand what this proposal changes for FlaggedRevs, since I don't have much technical knowledge. Can you explain what the proposal changes here, how are we going to convert FlaggedRevs into a &quot;protection-like mechanism&quot;? [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 17:24, 23 March 2026 (UTC)
::The proposal of changing FlaggedRevs into a protection-like feature (pending changes) is when an editor (unregistered/one not holding autoreviewer, reviewer, or administrator permissions) makes an edit, but their edit will be hidden from the public until it is approved by a reviewer or an administrator, and it will solely apply to Wikijunior pages. The configuration above is similar to what English Wikipedia uses.
{{quote|::I think it makes sense to reassign the reviewer user group to &lt;code&gt;editor&lt;/code&gt;.}}
::@[[User:Kittycataclysm|Kittycataclysm]]: I believe you might have misunderstood. What I meant is that &lt;code&gt;(editor)&lt;/code&gt; will be changed to &lt;code&gt;(reviewer)&lt;/code&gt; to avoid confusion, but I plan to remove &lt;code&gt;editor&lt;/code&gt; from all inactive reviewers, then do the same for recently active reviewers. However, given that there are a lot of reviewers, a script will possibly do all the work (under {{no ping|Maintenance script}} or similar). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 23:29, 23 March 2026 (UTC)
:::Gotcha! I can't currently foresee an issue with this —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 01:09, 30 March 2026 (UTC)
:'''Re FlaggedRevs generally: '''The [[mw:Extension:FlaggedRevs|Mediawiki page of the extension]] says it is not being maintained and not recommended for production use. We should consider whether we need this extension at all. 
:What is the actual policy justification for having FlaggedRevs? 
:[[Help:Tracking_changes#Reviewing_pages]] says it's &quot;our primary counter-vandalism tool&quot;. I don't know if it is that: it doesn't prevent vandalism or reduce exposure to vandalism (as with stable versions). The &quot;counter-vandalism&quot; bit comes from human editors looking at the edits, identifying vandalism, and reverting. FlaggedRevs isn't necessary for that. Maybe it makes it a little easier to spot edits in recent changes from new editors that may need a little more help (wikicode etc, not just spam), but can that be achieved just with the patrolled edits functionality? 
:If we still want something like FlaggedRevs, as an anti-vandalism tool or for draft control, then Mediawiki has a [[mw:Content approval extensions|list of alternatives]] that may be more suited and better maintained. 
:'''Re minimal/average/good specifically:''' I agree that we don't need the three categories. I thought I read somewhere that these were intended to show the quality of the REVIEW not of the page? That is, a &quot;minimal&quot; review is &quot;I checked there was no obvious vandalism&quot; and a &quot;good&quot; review was &quot;I've thoroughly fact-checked everything&quot;. [[User:JCrue|JCrue]] ([[User talk:JCrue|discuss]] • [[Special:Contributions/JCrue|contribs]]) 11:34, 5 April 2026 (UTC)
:: This was enabled back in 2008, which resulted in [[Wikibooks:New page patrol]] currently being obsolete. To be honest, I would keep FlaggedRevs, but I was proposing to change it to pending changes protection, similar to how Wikipedia utilizes it. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 21:04, 19 April 2026 (UTC)
:Pinging &lt;span class=&quot;template-ping&quot;&gt;@[[:User:JJPMaster|JJPMaster]]:&lt;/span&gt; and &lt;span class=&quot;template-ping&quot;&gt;@[[:User:Kittycataclysm|Kittycataclysm]]:&lt;/span&gt; for additional input. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) &lt;span style=&quot;font-size: smaller;&quot; class=&quot;autosigned&quot;&gt;—Preceding [[w:Wikipedia:Signatures|undated]] comment added 22:29, 22 March 2026.&lt;/span&gt;&lt;!--Template:Undated--&gt;
: After considering, I went ahead and created a separate proposal about FlaggedRevs; [[Wikibooks:Reading room/Proposals#Proposal related to FlaggedRevs|here you go]]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 13:48, 6 May 2026 (UTC)

== Global ban for Faster than Thunder ==

* {{user|Faster than Thunder}}
Hello, this message is to notify that [[User:Faster than Thunder|Faster than Thunder]] has been nominated for a global ban at [[m:Requests for comment/Global ban for Faster than Thunder]]. You are receiving this notification as required per the [[m:global ban|global ban]] policy as they have made at least 1 edit on this wiki. Thanks, --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 01:52, 22 March 2026 (UTC)</text>
      <sha1>tqo5e5j7mlkfylexzn8g0h0b0ooaef0</sha1>
    </revision>
    <revision>
      <id>4636924</id>
      <parentid>4636917</parentid>
      <timestamp>2026-05-21T19:01:20Z</timestamp>
      <contributor>
        <username>Codename Noreste</username>
        <id>3441010</id>
      </contributor>
      <comment>/* Upcoming Wikimedia Café meetup regarding the the 2026-2027 Wikimedia Foundation Annual Plan */ archive from [[Wikibooks:Reading room/General]] ([[mw:c:Special:MyLanguage/User:JWBTH/CD|CD]])</comment>
      <origin>4636924</origin>
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      <text bytes="19619" sha1="isttyk48j2ikk88ow3k16mgd2idykur" xml:space="preserve">{{talk archive}}

== Correspondence between John Belton and the Continental Congress ==

Hello. [[s:Correspondence between John Belton and the Continental Congress]] is probably going to be deleted from Wikisource as out of scope, would Wikibooks be interested in its import? -- [[User:Jan.Kamenicek|Jan.Kamenicek]] ([[User talk:Jan.Kamenicek|discuss]] • [[Special:Contributions/Jan.Kamenicek|contribs]]) 19:27, 3 March 2026 (UTC)

:@[[User:Jan.Kamenicek|Jan.Kamenicek]] Thank you for checking! We do not host source texts, so it doesn't look like this would be in scope at Wikibooks. Cheers —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 21:55, 3 March 2026 (UTC)
== Templates: Refbegin and Refend. ==

These DO NOT seem to work as the documentation indicates throwing lints when used with the form indicated. 

These templates need to be behave consistently, or thrown out and re-written entirely.  

It would be NICE to have ONE set of templates and documentation to accompany them, currently this does not apparently exist, with the relevant templates getting confused between definition lists &lt;nowiki&gt;:&lt;/nowiki&gt; and standard lists {{*}}. 

CONSISTENT behaviour would also be nice.

[[User:ShakespeareFan00|ShakespeareFan00]] ([[User talk:ShakespeareFan00|discuss]] • [[Special:Contributions/ShakespeareFan00|contribs]]) 09:39, 19 March 2026 (UTC)

:@[[User:ShakespeareFan00|ShakespeareFan00]] I temporarily reduced the protection down for these templates (semi-protection), so you can do the necessary changes. :) [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 17:38, 21 March 2026 (UTC)

: Thats the thing I'm not sure what the 'stable' repair is, without breaking other stuff :( [[User:ShakespeareFan00|ShakespeareFan00]] ([[User talk:ShakespeareFan00|discuss]] • [[Special:Contributions/ShakespeareFan00|contribs]]) 11:44, 22 March 2026 (UTC)
== Upcoming deployment of CampaignEvents extension to Wikibooks ==

&lt;section begin=&quot;message&quot;/&gt;
Hello everyone,

We are writing to inform you that the [[mw:Help:Extension:CampaignEvents|CampaignEvents extension]] will be deployed to all Wikibooks projects during the week of '''23 March 2026'''.
This follows last year’s broader rollout across Wikimedia projects. We realized that Wikibooks was not included at the time, and we’re now addressing that to ensure consistency across all communities.

The CampaignEvents extension provides tools to support event and campaign organization on-wiki, including features like on-wiki event registration and collaboration lists(global event list).

We welcome any questions, feedback, or concerns you may have. We are also happy to support anyone interested in trying out the tools. 
''Apologies if this message is not in your preferred language. If you’re able to help translate it for your community, please feel free to do so.''
&lt;section end=&quot;message&quot;/&gt;

&lt;bdi lang=&quot;en&quot; dir=&quot;ltr&quot;&gt;[[User:Udehb-WMF|Udehb-WMF]] ([[User talk:Udehb-WMF|discuss]]) 18:22, 19 March 2026 (UTC)&lt;/bdi&gt;
&lt;!-- Message sent by User:Udehb-WMF@metawiki using the list at https://meta.wikimedia.org/w/index.php?title=User:Udehb-WMF/sandbox/MM_target&amp;oldid=30284073 --&gt;

== Regarding the project's FlaggedRevs extension ==

Hello, everyone. I want to discuss with the community about the use of this project's FlaggedRevs (flagged revisions) extension, which was deployed many years ago (and configured recently).

=== Many unreviewed edits, and edit quality options ===
According to [[Special:PendingChanges]], there are almost 4000 unreviewed edits (per the standard FlaggedRevs configuration). In addition, on the edit review interface when evaluating a diff, there are three radio buttons that determine the quality of the edit (minimal, average, good). Do we have to utilize these buttons if the quality of the edit or the book matters, according to [[WB:REVIEW]]? This proposal is to whether discontinue the edit rating buttons or not.

One way to reduce such a large amount of unreviewed edits is to set the following to &lt;code&gt;true&lt;/code&gt;:
* &lt;code&gt;wgFlaggedRevsProtection&lt;/code&gt; (pending changes protection, to be used on Wikijunior pages; this might negate the need to show the stable version by default)
* (optional) &lt;code&gt;wgSimpleFlaggedRevsUI&lt;/code&gt; (simpler, icon-based UI on the edit review interface)
We should also include the following configuration (partially based from English Wikipedia), if this proposal passes:
&lt;syntaxhighlight lang=&quot;php&quot;&gt;
elseif ( $wgDBname == 'enwikibooks' ) {
		// Limited to the main, Cookbook, and Wikijunior namespaces (T408110)
		$wgFlaggedRevsNamespaces = [ NS_MAIN, 102, 110 ];
		# We have only one tag with one level
		$wgFlaggedRevsTags = [ 'status' =&gt; [ 'levels' =&gt; 1 ] ];
		# Restrict autoconfirmed to flagging semi-protected
		$wgFlaggedRevsTagsRestrictions = [
			'status' =&gt; [ 'review' =&gt; 1, 'autoreview' =&gt; 1 ],
		];
		# Restriction levels for auto-review/review rights
		$wgFlaggedRevsRestrictionLevels = [ 'autoreview' ];
		# Remove 'validate' from reviewers
		$wgGroupPermissions['reviewer']['validate'] = false;
		# Group permissions for sysops
		$wgGroupPermissions['sysop']['review'] = true;
		$wgGroupPermissions['sysop']['stablesettings'] = true;
		# Allow sysops to add and remove the 'reviewer' group
		$wgAddGroups['sysop'][] = 'reviewer';
		$wgRemoveGroups['sysop'][] = 'reviewer';
		# Remove the 'editor' user group
		unset( $wgGroupPermissions['editor'] );
	}
&lt;/syntaxhighlight&gt;

=== Inactive reviewers ===
After conducting an audit of over 1000 reviewers, most, if not many of them are completely inactive.

=== User group changes for reviewers ===
The reviewer user group is known to the software as &lt;code&gt;editor&lt;/code&gt;, which might sound misleading (the actual [[MediaWiki:Group-editor/qqq|/qqq definition]] is &quot;Editors&quot;). To fix that, we might have to consider switching to &lt;code&gt;reviewer&lt;/code&gt; and unset &lt;code&gt;editor&lt;/code&gt;.

I am also not sure whether administrators should have the &lt;code&gt;validate&lt;/code&gt; user right, since &lt;code&gt;reviewer&lt;/code&gt; has it on by default (but it is currently disabled). On the above configuration I proposed, administrators (and users in the &lt;code&gt;reviewer&lt;/code&gt; user group) would no longer have &lt;code&gt;validate&lt;/code&gt;.

=== Page patrolling ===
Currently, only administrators can mark new pages as patrolled (&lt;code&gt;patrol&lt;/code&gt;) by using the MediaWiki page patrol software, but clicking on &quot;Accept revision&quot; (via FlaggedRevs) would also mark the page as patrolled, in question. I believe that using FlaggedRevs to patrol new pages is redundant, given that we might not want to use one or the other.

If we are considering on switching to pending changes, we should also allow reviewers to mark new pages as patrolled, as they are trusted to have the &lt;code&gt;autopatrol&lt;/code&gt; right in addition to administrators and autoreviewed users.

Thoughts? [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 04:05, 21 March 2026 (UTC)

:I agree on replacing &lt;code&gt;editor&lt;/code&gt; with &lt;code&gt;reviewer&lt;/code&gt; to avoid confusion. Reviewers don't need to have patrol permissions as a reviewed page would be patrolled as well. I don't think people will use it much as a page or edit being reviewed already means that it has been checked by someone else. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 16:00, 22 March 2026 (UTC)
::When I said that reviewers would have &lt;code&gt;patrol&lt;/code&gt;, they can review new pages that other users created, but not any new pages they create themselves. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:16, 22 March 2026 (UTC)
:::How can that be the case if they have &lt;code&gt;autopatrol&lt;/code&gt;? [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 18:26, 22 March 2026 (UTC)
::::I will give you an example. On the English Wikiquote, there are two user groups that have &lt;code&gt;autopatrol&lt;/code&gt;: autopatrollers and patrollers. Autopatrollers have their page creations marked as patrolled by the software, while patrollers (whilst also having their page creations marked as patrolled) can mark new pages as patrolled (in addition to administrators). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 18:39, 22 March 2026 (UTC)
:::::But what is the point of giving reviewers &lt;code&gt;patrol&lt;/code&gt; if we are already using FlaggedRevs? I think that we won't need patrol because we already have reviewing, and patrol only seems to be a confirmation that the page is up to policy from what I have seen, so giving them reviewers to mark pages as patrolled seems pointless to me when we already have FlaggedRevs. [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 19:06, 22 March 2026 (UTC)
::::::I understand, but my proposal was to convert FlaggedRevs into a protection-like mechanism which would be used alongside page protection; it might turn off FlaggedRevs's ability to patrol new pages for reviewers, hence why I suggested this above. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 23:30, 22 March 2026 (UTC)
::::::: @[[User:Kingofnuthin|Kingofnuthin]] I will summarize what you said from above:
:::::::* You agree about the reviewer user group to be moved from &lt;code&gt;editor&lt;/code&gt; to &lt;code&gt;reviewer&lt;/code&gt; to avoid confusion (technically).
:::::::* However, you probably disagree about allowing reviewers to patrol new pages ''and'' having their page creations automatically marked as patrolled, because FlaggedRevs can do all of this, and &lt;code&gt;$wgUseNPPatrol&lt;/code&gt; might seem to be redundant.
::::::: A compromise about your disagreement is that we might have to consider removing &lt;code&gt;autopatrol&lt;/code&gt; and/or &lt;code&gt;patrol&lt;/code&gt; from our existing user groups, similar to [[phab:T423461]].
::::::: I started this because in addition to that, one of my concerns was the extreme backlog of unreviewed edits and pages [4000!]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 20:31, 19 April 2026 (UTC)
:I may be missing some things here, so let me know if I haven't answered any points here:
:# I don't think we currently need to have the review status indicate the quality of the edit (i.e. minimal, average, good). I don't think this is used at all anymore.
:# I think it makes sense to reassign the reviewer user group to &lt;code&gt;editor&lt;/code&gt;. I always like clarity in language.
:# Are you saying that pages marked as reviewed are currently also classed as patrolled? If that's the case, I think we should not have reviewed pages automatically classed as patrolled, and we should keep reviewing and patrolling separate.
:I'll note that honestly don't know much about patrolling, since I've never engaged with it—I have only ever referenced the reviewing system. If there is a significant functional difference, I would love to know it. Cheers! —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 03:00, 23 March 2026 (UTC)
::When someone clicks &quot;Accept revision&quot; on an unreviewed page, it is listed under [[Special:Log/review]]; if an admin marks a page as patrolled with &quot;Mark this page as patrolled&quot;, it will show up under [[Special:Log/patrol]], which is not really logged much compared to the former log (review). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 03:12, 23 March 2026 (UTC)
:I agree to your thoughts about the &lt;code&gt;editor&lt;/code&gt; group and edit quality ratings, but I don't understand what this proposal changes for FlaggedRevs, since I don't have much technical knowledge. Can you explain what the proposal changes here, how are we going to convert FlaggedRevs into a &quot;protection-like mechanism&quot;? [[User:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: lime&quot;&gt;kingofnuthin&lt;/span&gt;]] ([[User talk:kingofnuthin|&lt;span style=&quot;font-family: Georgia; color: teal&quot;&gt;talk&lt;/span&gt;]]) 17:24, 23 March 2026 (UTC)
::The proposal of changing FlaggedRevs into a protection-like feature (pending changes) is when an editor (unregistered/one not holding autoreviewer, reviewer, or administrator permissions) makes an edit, but their edit will be hidden from the public until it is approved by a reviewer or an administrator, and it will solely apply to Wikijunior pages. The configuration above is similar to what English Wikipedia uses.
{{quote|::I think it makes sense to reassign the reviewer user group to &lt;code&gt;editor&lt;/code&gt;.}}
::@[[User:Kittycataclysm|Kittycataclysm]]: I believe you might have misunderstood. What I meant is that &lt;code&gt;(editor)&lt;/code&gt; will be changed to &lt;code&gt;(reviewer)&lt;/code&gt; to avoid confusion, but I plan to remove &lt;code&gt;editor&lt;/code&gt; from all inactive reviewers, then do the same for recently active reviewers. However, given that there are a lot of reviewers, a script will possibly do all the work (under {{no ping|Maintenance script}} or similar). [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 23:29, 23 March 2026 (UTC)
:::Gotcha! I can't currently foresee an issue with this —[[User:Kittycataclysm|Kittycataclysm]] ([[User talk:Kittycataclysm|discuss]] • [[Special:Contributions/Kittycataclysm|contribs]]) 01:09, 30 March 2026 (UTC)
:'''Re FlaggedRevs generally: '''The [[mw:Extension:FlaggedRevs|Mediawiki page of the extension]] says it is not being maintained and not recommended for production use. We should consider whether we need this extension at all. 
:What is the actual policy justification for having FlaggedRevs? 
:[[Help:Tracking_changes#Reviewing_pages]] says it's &quot;our primary counter-vandalism tool&quot;. I don't know if it is that: it doesn't prevent vandalism or reduce exposure to vandalism (as with stable versions). The &quot;counter-vandalism&quot; bit comes from human editors looking at the edits, identifying vandalism, and reverting. FlaggedRevs isn't necessary for that. Maybe it makes it a little easier to spot edits in recent changes from new editors that may need a little more help (wikicode etc, not just spam), but can that be achieved just with the patrolled edits functionality? 
:If we still want something like FlaggedRevs, as an anti-vandalism tool or for draft control, then Mediawiki has a [[mw:Content approval extensions|list of alternatives]] that may be more suited and better maintained. 
:'''Re minimal/average/good specifically:''' I agree that we don't need the three categories. I thought I read somewhere that these were intended to show the quality of the REVIEW not of the page? That is, a &quot;minimal&quot; review is &quot;I checked there was no obvious vandalism&quot; and a &quot;good&quot; review was &quot;I've thoroughly fact-checked everything&quot;. [[User:JCrue|JCrue]] ([[User talk:JCrue|discuss]] • [[Special:Contributions/JCrue|contribs]]) 11:34, 5 April 2026 (UTC)
:: This was enabled back in 2008, which resulted in [[Wikibooks:New page patrol]] currently being obsolete. To be honest, I would keep FlaggedRevs, but I was proposing to change it to pending changes protection, similar to how Wikipedia utilizes it. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 21:04, 19 April 2026 (UTC)
:Pinging &lt;span class=&quot;template-ping&quot;&gt;@[[:User:JJPMaster|JJPMaster]]:&lt;/span&gt; and &lt;span class=&quot;template-ping&quot;&gt;@[[:User:Kittycataclysm|Kittycataclysm]]:&lt;/span&gt; for additional input. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) &lt;span style=&quot;font-size: smaller;&quot; class=&quot;autosigned&quot;&gt;—Preceding [[w:Wikipedia:Signatures|undated]] comment added 22:29, 22 March 2026.&lt;/span&gt;&lt;!--Template:Undated--&gt;
: After considering, I went ahead and created a separate proposal about FlaggedRevs; [[Wikibooks:Reading room/Proposals#Proposal related to FlaggedRevs|here you go]]. [[User:Codename Noreste|&lt;span style=&quot;color:#0024FF&quot;&gt;Codename Noreste&lt;/span&gt;]] ([[User talk:Codename Noreste|discuss]] • [[Special:Contributions/Codename Noreste|contribs]]) 13:48, 6 May 2026 (UTC)

== Global ban for Faster than Thunder ==

* {{user|Faster than Thunder}}
Hello, this message is to notify that [[User:Faster than Thunder|Faster than Thunder]] has been nominated for a global ban at [[m:Requests for comment/Global ban for Faster than Thunder]]. You are receiving this notification as required per the [[m:global ban|global ban]] policy as they have made at least 1 edit on this wiki. Thanks, --[[User:SHB2000|SHB2000]] ([[User talk:SHB2000|discuss]] • [[Special:Contributions/SHB2000|contribs]]) 01:52, 22 March 2026 (UTC)

== Upcoming Wikimedia Café meetup regarding the [[:meta:Wikimedia Foundation Annual Plan/2026-2027|the 2026-2027 Wikimedia Foundation Annual Plan]] ==

{{tmbox
| image = [[File:Wikimedia Café logo in plain SVG format.svg|45px]]
| type=notice
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&lt;span style=&quot;white-space:nowrap;&quot;&gt;[[User:Pine|&lt;span style=&quot;color:#01796f; text-shadow:#00BFFF 0 0 1.0em&quot;&gt;↠Pine&lt;/span&gt;]] [[User talk:Pine|&lt;span style=&quot;color:DeepSkyBlue&quot;&gt;(&lt;b style=&quot;color:#FFDF00;text-shadow:#FFDF00 0 0 1.0em&quot;&gt;✉&lt;/b&gt;)&lt;/span&gt;]]&lt;/span&gt; 05:23, 29 March 2026 (UTC)</text>
      <sha1>isttyk48j2ikk88ow3k16mgd2idykur</sha1>
    </revision>
  </page>
  <page>
    <title>Transportation Planning Casebook/Africa's Free-Market Bus Systems</title>
    <ns>0</ns>
    <id>483108</id>
    <revision>
      <id>4636971</id>
      <parentid>4634059</parentid>
      <timestamp>2026-05-22T07:23:01Z</timestamp>
      <contributor>
        <username>Yyhiris</username>
        <id>3591938</id>
      </contributor>
      <comment>add some details about Tanzania</comment>
      <origin>4636971</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="7420" sha1="1zpe0xfj7rs4xecwpgyi53iqykwvm3p" xml:space="preserve">= A history of free market busses in Africa =

&lt;nowiki&gt;&lt;mapframe latitude=&quot;48.85&quot; longitude=&quot;2.35&quot; zoom=&quot;12&quot; width=&quot;400&quot; height=&quot;300&quot;&gt; {  &quot;type&quot;: &quot;Feature&quot;,  &quot;geometry&quot;: { &quot;type&quot;: &quot;Point&quot;, &quot;coordinates&quot;: [2.35, 48.85] } } &lt;/mapframe&gt;&lt;/nowiki&gt;

{{BookCat}}

== Summary ==

== Annotated List of Actors ==

==== Tanzania ====
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Actor
| valign=&quot;center&quot; |Actor Type
| valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
Key Historical Timeline of Transit Transformation in Dar es Salaam，Tanzania
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Year
| valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

== Discussion Questions ==

== Complete References ==</text>
      <sha1>1zpe0xfj7rs4xecwpgyi53iqykwvm3p</sha1>
    </revision>
    <revision>
      <id>4636972</id>
      <parentid>4636971</parentid>
      <timestamp>2026-05-22T07:40:39Z</timestamp>
      <contributor>
        <username>Yyhiris</username>
        <id>3591938</id>
      </contributor>
      <comment>/* Maps of Locations */</comment>
      <origin>4636972</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="7502" sha1="jptgtdchpkrudpdqy7nlyd7k6632c72" xml:space="preserve">= A history of free market busses in Africa =

&lt;nowiki&gt;&lt;mapframe latitude=&quot;48.85&quot; longitude=&quot;2.35&quot; zoom=&quot;12&quot; width=&quot;400&quot; height=&quot;300&quot;&gt; {  &quot;type&quot;: &quot;Feature&quot;,  &quot;geometry&quot;: { &quot;type&quot;: &quot;Point&quot;, &quot;coordinates&quot;: [2.35, 48.85] } } &lt;/mapframe&gt;&lt;/nowiki&gt;

{{BookCat}}

== Summary ==

== Annotated List of Actors ==

==== Tanzania ====
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Actor
| valign=&quot;center&quot; |Actor Type
| valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
Key Historical Timeline of Transit Transformation in Dar es Salaam，Tanzania
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Year
| valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

== Discussion Questions ==

== Complete References ==</text>
      <sha1>jptgtdchpkrudpdqy7nlyd7k6632c72</sha1>
    </revision>
    <revision>
      <id>4636973</id>
      <parentid>4636972</parentid>
      <timestamp>2026-05-22T07:40:43Z</timestamp>
      <contributor>
        <username>Mrpearsonw</username>
        <id>3581081</id>
      </contributor>
      <minor />
      <comment>/* A history of free market busses in Africa */</comment>
      <origin>4636973</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="10446" sha1="cjcs12j6jrle77o04q6g8und5yduuce" xml:space="preserve">= A history of free market busses in Africa =

=== Summary ===
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence and corruption controversies since its inception, despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety. 

=== List of actors ===
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues. 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations. 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry 
|-
| rowspan=&quot;3&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}

=== Timeline of events ===

=== Policy Issues ===

=== Discussion questions and further reading ===
&lt;nowiki&gt;&lt;mapframe latitude=&quot;48.85&quot; longitude=&quot;2.35&quot; zoom=&quot;12&quot; width=&quot;400&quot; height=&quot;300&quot;&gt; {  &quot;type&quot;: &quot;Feature&quot;,  &quot;geometry&quot;: { &quot;type&quot;: &quot;Point&quot;, &quot;coordinates&quot;: [2.35, 48.85] } } &lt;/mapframe&gt;&lt;/nowiki&gt;

{{BookCat}}

== Summary ==

== Annotated List of Actors ==

==== Tanzania ====
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Actor
| valign=&quot;center&quot; |Actor Type
| valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
Key Historical Timeline of Transit Transformation in Dar es Salaam，Tanzania
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Year
| valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

== Discussion Questions ==

== Complete References ==</text>
      <sha1>cjcs12j6jrle77o04q6g8und5yduuce</sha1>
    </revision>
    <revision>
      <id>4636974</id>
      <parentid>4636973</parentid>
      <timestamp>2026-05-22T07:49:24Z</timestamp>
      <contributor>
        <username>Mrpearsonw</username>
        <id>3581081</id>
      </contributor>
      <origin>4636974</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="10489" sha1="6gilsq3v16j92c1oxpt8qzt2wcaoi7o" xml:space="preserve">= A history of free market busses in Africa =

=== Summary === 

=== List of actors ===
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+South Africa
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues. 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations. 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry 
|-
| rowspan=&quot;3&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}

== Summary ==
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence and corruption controversies since its inception, despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety.

== Annotated List of Actors ==

==== Tanzania ====
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |Actor
| valign=&quot;center&quot; |Actor Type
| valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
{| class=&quot;wikitable mw-collapsible&quot;
|+Key Historical Timeline of Transit transformation in South Africa
!Year
!Event description
|-
|1970
|The federal government introduces bill 
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Nairobi, Kenya
!Year
!Event description
|-
|
|
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Key Historical Timeline of Transit Transformation in Dar es Salaam，Tanzania
! valign=&quot;center&quot; |Year
! valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

== Discussion Questions ==

== Complete References ==</text>
      <sha1>6gilsq3v16j92c1oxpt8qzt2wcaoi7o</sha1>
    </revision>
    <revision>
      <id>4636995</id>
      <parentid>4636974</parentid>
      <timestamp>2026-05-22T09:55:20Z</timestamp>
      <contributor>
        <username>Mrpearsonw</username>
        <id>3581081</id>
      </contributor>
      <origin>4636995</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="18234" sha1="7ctzysgpiarq7u98q23kotkowafwa9p" xml:space="preserve">= A brief history of free market busses in Africa =

== Summary ==
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence, corruption and controversies since its inception, yet despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety.

== Annotated List of Actors ==

{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+South Africa
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations&lt;ref name=&quot;:4&quot;&gt;Schuler C. Kings of the road fuel deadly taxi war: The fight to control south africa's lucrative routes has left 1,120 people dead. A hit on a driver can cost as little as $1,200: [national edition]. National Post. Nov 06 1999:A14. Available from: &lt;nowiki&gt;https://www.proquest.com/newspapers/kings-road-fuel-deadly-taxi-war-fight-control/docview/329616964/se-2&lt;/nowiki&gt;.&lt;/ref&gt; 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry&lt;ref name=&quot;:4&quot; /&gt; 
|-
| rowspan=&quot;5&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Vehicle manufacturers
|Toyota is the main proponent of this category, as many of the taxis in the industry are the Toyota HiAce passenger vehicle. Since they are one of the only options, Toyota has increased the price rapidly in recent years - exacerbating economic impacts upon the drivers. 
|-
|Banks providing loans
|Some banks allowed taxi drivers or associations to file for loans to help them purchase newer, more roadworthy vehicles
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}
{| class=&quot;wikitable mw-collapsible&quot;
|+Tanzania
! valign=&quot;center&quot; |Actor
! valign=&quot;center&quot; |Actor Type
! valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
{| class=&quot;wikitable mw-collapsible&quot;
|+Timeline of the &quot;Taxi wars&quot; in South Africa
!Year
!Event description
|-
|1977
|The federal government signs the &quot;Road Transportation Act of 1977&quot; into law&lt;ref&gt;{{Cite web |title=Road Transportation Act 74 of 1977 {{!}} South African Government |url=https://www.gov.za/documents/road-transportation-act-16-apr-2015-0812 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; - failing to define minibus as a category, allowing taxi operators to operate them
|-
|1986-1987
|The number of informal taxi permits nation wide raises from 7,093 to 34, 378&lt;ref name=&quot;:5&quot;&gt;{{Cite journal |date=2013-03-01 |title=The lurch towards formalisation: Lessons from the implementation of BRT in Johannesburg, South Africa |url=https://www.sciencedirect.com/science/article/abs/pii/S0739885912000753 |journal=Research in Transportation Economics |language=en-US |volume=39 |issue=1 |pages=114–120 |doi=10.1016/j.retrec.2012.06.003 |issn=0739-8859}}&lt;/ref&gt;
|-
|1988
|The federal government signs the &quot;Transport Deregulation Act of 1988&quot; into law&lt;ref&gt;{{Cite web |title=Transport Deregulation Act 80 of 1988 {{!}} South African Government |url=https://www.gov.za/documents/transport-deregulation-act-18-may-2015-1306#:~:text=Transport%20Deregulation%20Act%2080%20of%201988%20%7C%20South%20African%20Government |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; 
|-
|1993
|Taxi wars death toll was 330 deaths in 1993&lt;ref name=&quot;:5&quot; /&gt;
|-
| rowspan=&quot;2&quot; |1994
|Apartheid in South Africa ends
|-
|In Cape Town, the taxi association Codeta splits and CATA is formed, starting an intense and violent rivalry&lt;ref&gt;{{Cite news |last=Wines |first=Michael |date=2006-09-17 |title=Cartels Battle for Supremacy in South Africa’s Taxi Wars |language=en-US |work=The New York Times |url=https://www.nytimes.com/2006/09/17/world/africa/cartels-battle-for-supremacy-in-south-africas-taxi-wars.html |access-date=2026-05-22 |issn=0362-4331}}&lt;/ref&gt;
|-
|1996
|The government produces a whitepaper on the state of the transportation industry in South Africa&lt;ref&gt;{{Cite web |title=National Transport Policy White Paper {{!}} South African Government |url=https://www.gov.za/documents/white-papers/national-transport-policy-white-paper-20-aug-1996 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt;
one of the key recommendation is the taxi recapitalization plan (TRP) which aimed to help decommission the older and less safe vehicles that were used at the time. (A timeline was set for all older models to be replaced by 2005) 
|-
|2001
|The South African National Taxi Council (SANTACO) is formed
|-
|2003
|Informal transit collectively reaches a 60 percent market share&lt;ref name=&quot;:5&quot; /&gt;
|-
|2007
|South Africa's first Bus Rapid Transit (BRT) line is planned to open in Johannesburg, where the government and local taxi  associations came to a tentative agreement to replace the informal service along the corridor, allowing the affected associations and drivers to convert to the BRT operator&lt;ref name=&quot;:5&quot; /&gt;&lt;ref name=&quot;:6&quot;&gt;{{Cite journal |last=Bähre |first=Erik |date=2014-11 |title=A TRICKLE-UP ECONOMY: MUTUALITY, FREEDOM AND VIOLENCE IN CAPE TOWN'S TAXI ASSOCIATIONS |url=https://www.cambridge.org/core/journals/africa/article/abs/trickleup-economy-mutuality-freedom-and-violence-in-cape-towns-taxi-associations/E6FF741B122E54F9F84AF4119EF89ECD |journal=Africa |language=en |volume=84 |issue=4 |pages=576–594 |doi=10.1017/S000197201400045X |issn=0001-9720}}&lt;/ref&gt;
|-
| rowspan=&quot;2&quot; |2009
|three days after opening [Rea Vaya], violence erupted from disgruntled taxi drivers fearing loss of income&lt;ref name=&quot;:5&quot; /&gt;
|-
|The chairman of SANTACO was gunned down, the organization was accused of taking bribes from the government by rival associations&lt;ref name=&quot;:6&quot; /&gt; 
|-
|2010
|A new contract was signed [Rea Vaya], where 313 taxi operators became operators for the BRT company&lt;ref name=&quot;:5&quot; /&gt;
|-
|2012
|SANTACO president Kabulani Mthembu steps down after an audit revealed he had stolen nearly one million rand from the association&lt;ref name=&quot;:6&quot; /&gt;
|-
|2017
|An Uber driver dies after their car is set alight&lt;ref name=&quot;:7&quot;&gt;Rampedi M. War for the streets: Maponya mall becomes latest frontline in Taxi–E-hailing clash. Spotcovery [BLOG]. 2025. &lt;nowiki&gt;https://www.proquest.com/blogs-podcasts-websites/war-streets-maponya-mall-becomes-latest-frontline/docview/3240276444/se-2&lt;/nowiki&gt;.&lt;/ref&gt;
|-
|2024
|Piotrans - the private firm which bid and won the contract to operate the Rey Vaya BRT - goes bankrupt. The company had an alleged history of gross mismanagement dating back to around 2016&lt;ref&gt;{{Cite web |title=Gale - Institution Finder |url=https://galeapps.gale.com/apps/auth?userGroupName=&amp;sid=summon&amp;origURL=https%3A%2F%2Fgo.gale.com%2Fps%2Fi.do%3Fid%3DGALE%257CA779855589%26v%3D2.1%26it%3Dr%26sid%3Dsummon%26asid%3D0bd92d4c.%26u%3D%26p%3DSTND&amp;prodId=STND |access-date=2026-05-22 |website=galeapps.gale.com}}&lt;/ref&gt; A report finds that taxi operators owned a significant share in the company, which could have been used to undermine the operations from the inside
|-
|2025
|two e-hailing taxi drivers were attacked, one shot and the others car torched&lt;ref name=&quot;:7&quot; /&gt;
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Nairobi, Kenya
!Year
!Event description
|-
|
|
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Key Historical Timeline of Transit Transformation in Dar es Salaam, Tanzania
! valign=&quot;center&quot; |Year
! valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

==== South Africa ====
1. Top down approach to formalization

Many of the governments top down approaches to formalizing the industry have failed to meet their goals for a multitude of reasons, and have even created more unintended consequences that will need to be rectified before widespread formalization can be complete. For instance, the taxi recapitalization program aimed at modernizing the ageing and often poorly maintained fleet, failed to address the underlying cause of the issue - maintenance was on each owner, and they were already strapped for cash. In addition, the program unintentionally made the taxy associations into very powerful middlemen between banks, the government and the vehicle manufacturers, which increased their influence further&lt;ref name=&quot;:6&quot; /&gt;. 

2. Failure of the governments approach to inclusion in policy making 

Even though the government of South Africa had set up the NTT and had promoted SANTACO to a quasi governmental organization, they failed to listen to the needs of the taxi associations on multiple occasions, leading to a further erosion in trust that the government was actin in the best interests of the industry as a whole. As an example, a large multimodal transit hub was planned and constructed in Bloemfontein at a cost of 400 million rands. The goal of this facility was to help ease congestion on narrow CBD roads and to help passengers interchange with more modes of public transit more easily. However, the facility was woefully under designed to handle the amount of taxi bus traffic that was to use the facility&lt;ref&gt;{{Cite journal |last=Matebesi |first=Sethulego Z. |date=2019-01-08 |title=Insurgent Citizenship and Sustained Resistance of a Local Taxi Association |url=https://czasopisma.uni.lodz.pl/qualit/article/view/3986 |journal=Qualitative Sociology Review |language=en |volume=14 |issue=4 |pages=168–185 |doi=10.18778/1733-8077.14.4.11 |issn=1733-8077}}&lt;/ref&gt;. 

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

== Discussion Questions ==

== Complete References ==</text>
      <sha1>7ctzysgpiarq7u98q23kotkowafwa9p</sha1>
    </revision>
    <revision>
      <id>4636998</id>
      <parentid>4636995</parentid>
      <timestamp>2026-05-22T10:12:03Z</timestamp>
      <contributor>
        <username>Mrpearsonw</username>
        <id>3581081</id>
      </contributor>
      <origin>4636998</origin>
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      <format>text/x-wiki</format>
      <text bytes="19829" sha1="c5cr7z51nxjkgqm1zbxui2th2kixlq7" xml:space="preserve">= A brief history of free market busses in Africa =

== Summary ==
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence, corruption and controversies since its inception, yet despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety.

== Annotated List of Actors ==

{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+South Africa
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations&lt;ref name=&quot;:4&quot;&gt;Schuler C. Kings of the road fuel deadly taxi war: The fight to control south africa's lucrative routes has left 1,120 people dead. A hit on a driver can cost as little as $1,200: [national edition]. National Post. Nov 06 1999:A14. Available from: &lt;nowiki&gt;https://www.proquest.com/newspapers/kings-road-fuel-deadly-taxi-war-fight-control/docview/329616964/se-2&lt;/nowiki&gt;.&lt;/ref&gt; 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry&lt;ref name=&quot;:4&quot; /&gt; 
|-
| rowspan=&quot;5&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Vehicle manufacturers
|Toyota is the main proponent of this category, as many of the taxis in the industry are the Toyota HiAce passenger vehicle. Since they are one of the only options, Toyota has increased the price rapidly in recent years - exacerbating economic impacts upon the drivers. 
|-
|Banks providing loans
|Some banks allowed taxi drivers or associations to file for loans to help them purchase newer, more roadworthy vehicles
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}
{| class=&quot;wikitable mw-collapsible&quot;
|+Tanzania
! valign=&quot;center&quot; |Actor
! valign=&quot;center&quot; |Actor Type
! valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
{| class=&quot;wikitable mw-collapsible&quot;
|+Timeline of the &quot;Taxi wars&quot; in South Africa
!Year
!Event description
|-
|1977
|The federal government signs the &quot;Road Transportation Act of 1977&quot; into law&lt;ref&gt;{{Cite web |title=Road Transportation Act 74 of 1977 {{!}} South African Government |url=https://www.gov.za/documents/road-transportation-act-16-apr-2015-0812 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; - failing to define minibus as a category, allowing taxi operators to operate them
|-
|1986-1987
|The number of informal taxi permits nation wide raises from 7,093 to 34, 378&lt;ref name=&quot;:5&quot;&gt;{{Cite journal |date=2013-03-01 |title=The lurch towards formalisation: Lessons from the implementation of BRT in Johannesburg, South Africa |url=https://www.sciencedirect.com/science/article/abs/pii/S0739885912000753 |journal=Research in Transportation Economics |language=en-US |volume=39 |issue=1 |pages=114–120 |doi=10.1016/j.retrec.2012.06.003 |issn=0739-8859}}&lt;/ref&gt;
|-
|1988
|The federal government signs the &quot;Transport Deregulation Act of 1988&quot; into law&lt;ref&gt;{{Cite web |title=Transport Deregulation Act 80 of 1988 {{!}} South African Government |url=https://www.gov.za/documents/transport-deregulation-act-18-may-2015-1306#:~:text=Transport%20Deregulation%20Act%2080%20of%201988%20%7C%20South%20African%20Government |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; 
|-
|1993
|Taxi wars death toll was 330 deaths in 1993&lt;ref name=&quot;:5&quot; /&gt;
|-
| rowspan=&quot;2&quot; |1994
|Apartheid in South Africa ends - however, its legacy on the spatial layout of cities will go on to affect urban transport for decades still
|-
|In Cape Town, the taxi association Codeta splits and CATA is formed, starting an intense and violent rivalry&lt;ref&gt;{{Cite news |last=Wines |first=Michael |date=2006-09-17 |title=Cartels Battle for Supremacy in South Africa’s Taxi Wars |language=en-US |work=The New York Times |url=https://www.nytimes.com/2006/09/17/world/africa/cartels-battle-for-supremacy-in-south-africas-taxi-wars.html |access-date=2026-05-22 |issn=0362-4331}}&lt;/ref&gt;
|-
|1996
|The government produces a whitepaper on the state of the transportation industry in South Africa&lt;ref&gt;{{Cite web |title=National Transport Policy White Paper {{!}} South African Government |url=https://www.gov.za/documents/white-papers/national-transport-policy-white-paper-20-aug-1996 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt;
one of the key recommendation is the taxi recapitalization plan (TRP) which aimed to help decommission the older and less safe vehicles that were used at the time. (A timeline was set for all older models to be replaced by 2005) 
|-
|2001
|The South African National Taxi Council (SANTACO) is formed
|-
|2003
|Informal transit collectively reaches a 60 percent market share&lt;ref name=&quot;:5&quot; /&gt;
|-
|2004
|A revised version of the TRP is introduced, providing more money for replacing older busses - However, this does not do anything to curb the overtrading of routes, forcing drivers to operate newer and more costly vehicles on the same routes with the same low profit margins&lt;ref&gt;{{Cite journal |last=McKay |first=Tracey |last2=Simpson |first2=Zach |last3=Patel |first3=Naeem |date=2017-03-01 |title=Spatial politics and infrastructure development: Analysis of historical transportation data in Gauteng - South Africa (1975–2003) |url=https://www.sciendo.com/article/10.1515/mgrsd-2017-0003 |journal=Miscellanea Geographica |language=en |volume=21 |issue=1 |pages=35–43 |doi=10.1515/mgrsd-2017-0003 |issn=2084-6118}}&lt;/ref&gt;
|-
|2007
|South Africa's first Bus Rapid Transit (BRT) line is planned to open in Johannesburg, where the government and local taxi  associations came to a tentative agreement to replace the informal service along the corridor, allowing the affected associations and drivers to convert to the BRT operator&lt;ref name=&quot;:5&quot; /&gt;&lt;ref name=&quot;:6&quot;&gt;{{Cite journal |last=Bähre |first=Erik |date=2014-11 |title=A TRICKLE-UP ECONOMY: MUTUALITY, FREEDOM AND VIOLENCE IN CAPE TOWN'S TAXI ASSOCIATIONS |url=https://www.cambridge.org/core/journals/africa/article/abs/trickleup-economy-mutuality-freedom-and-violence-in-cape-towns-taxi-associations/E6FF741B122E54F9F84AF4119EF89ECD |journal=Africa |language=en |volume=84 |issue=4 |pages=576–594 |doi=10.1017/S000197201400045X |issn=0001-9720}}&lt;/ref&gt;
|-
| rowspan=&quot;2&quot; |2009
|three days after opening [Rea Vaya], violence erupted from disgruntled taxi drivers fearing loss of income&lt;ref name=&quot;:5&quot; /&gt;
|-
|The chairman of SANTACO was gunned down, the organization was accused of taking bribes from the government by rival associations&lt;ref name=&quot;:6&quot; /&gt; 
|-
|2010
|A new contract was signed [Rea Vaya], where 313 taxi operators became operators for the BRT company&lt;ref name=&quot;:5&quot; /&gt;
|-
|2012
|SANTACO president Kabulani Mthembu steps down after an audit revealed he had stolen nearly one million rand from the association&lt;ref name=&quot;:6&quot; /&gt;
|-
|2017
|An Uber driver dies after their car is set alight&lt;ref name=&quot;:7&quot;&gt;Rampedi M. War for the streets: Maponya mall becomes latest frontline in Taxi–E-hailing clash. Spotcovery [BLOG]. 2025. &lt;nowiki&gt;https://www.proquest.com/blogs-podcasts-websites/war-streets-maponya-mall-becomes-latest-frontline/docview/3240276444/se-2&lt;/nowiki&gt;.&lt;/ref&gt;
|-
|2024
|Piotrans - the private firm which bid and won the contract to operate the Rey Vaya BRT - goes bankrupt. The company had an alleged history of gross mismanagement dating back to around 2016&lt;ref&gt;{{Cite web |title=Gale - Institution Finder |url=https://galeapps.gale.com/apps/auth?userGroupName=&amp;sid=summon&amp;origURL=https%3A%2F%2Fgo.gale.com%2Fps%2Fi.do%3Fid%3DGALE%257CA779855589%26v%3D2.1%26it%3Dr%26sid%3Dsummon%26asid%3D0bd92d4c.%26u%3D%26p%3DSTND&amp;prodId=STND |access-date=2026-05-22 |website=galeapps.gale.com}}&lt;/ref&gt; A report finds that taxi operators owned a significant share in the company, which could have been used to undermine the operations from the inside
|-
|2025
|two e-hailing taxi drivers were attacked, one shot and the others car torched&lt;ref name=&quot;:7&quot; /&gt;
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Nairobi, Kenya
!Year
!Event description
|-
|
|
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Key Historical Timeline of Transit Transformation in Dar es Salaam, Tanzania
! valign=&quot;center&quot; |Year
! valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

==== South Africa ====
1. Top down approach to formalization

Many of the governments top down approaches to formalizing the industry have failed to meet their goals for a multitude of reasons, and have even created more unintended consequences that will need to be rectified before widespread formalization can be complete. For instance, the taxi recapitalization program aimed at modernizing the ageing and often poorly maintained fleet, failed to address the underlying cause of the issue - maintenance was on each owner, and they were already strapped for cash. In addition, the program unintentionally made the taxy associations into very powerful middlemen between banks, the government and the vehicle manufacturers, which increased their influence further&lt;ref name=&quot;:6&quot; /&gt;. 

2. Failure of the governments approach to inclusion in policy making 

Even though the government of South Africa had set up the NTT and had promoted SANTACO to a quasi governmental organization, they failed to listen to the needs of the taxi associations on multiple occasions, leading to a further erosion in trust that the government was actin in the best interests of the industry as a whole. As an example, a large multimodal transit hub was planned and constructed in Bloemfontein at a cost of 400 million rands. The goal of this facility was to help ease congestion on narrow CBD roads and to help passengers interchange with more modes of public transit more easily. However, the facility was woefully under designed to handle the amount of taxi bus traffic that was to use the facility&lt;ref&gt;{{Cite journal |last=Matebesi |first=Sethulego Z. |date=2019-01-08 |title=Insurgent Citizenship and Sustained Resistance of a Local Taxi Association |url=https://czasopisma.uni.lodz.pl/qualit/article/view/3986 |journal=Qualitative Sociology Review |language=en |volume=14 |issue=4 |pages=168–185 |doi=10.18778/1733-8077.14.4.11 |issn=1733-8077}}&lt;/ref&gt;. 

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

==== South Africa: ====
Public transport in South Africa continues to be dominated by the informal and often politically powerful taxi associations. Over the last few decades many attempts to re-regulate the industry or formalize the corporations has met resistance, and has slowed the progress of expansion of even traditional bus services into some areas. Taxi drivers fear for their income, and the mafia like entities that are the taxi associations want to keep control to maintain their economic and political power. The government has a history of going with a far to heavy handed top down approach, instead of working with the taxi associations in a more clear and open way, to provide both job security and better transport to its citizens. 

== Discussion Questions ==

== Complete References ==</text>
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      <text bytes="20042" sha1="2hzfwgmcghwfzu5uhz0vml1nb4xc3o4" xml:space="preserve">= A brief history of free market busses in Africa =

== Summary ==
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence, corruption and controversies since its inception, yet despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety.

== Annotated List of Actors ==

{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+South Africa
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations&lt;ref name=&quot;:4&quot;&gt;Schuler C. Kings of the road fuel deadly taxi war: The fight to control south africa's lucrative routes has left 1,120 people dead. A hit on a driver can cost as little as $1,200: [national edition]. National Post. Nov 06 1999:A14. Available from: &lt;nowiki&gt;https://www.proquest.com/newspapers/kings-road-fuel-deadly-taxi-war-fight-control/docview/329616964/se-2&lt;/nowiki&gt;.&lt;/ref&gt; 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry&lt;ref name=&quot;:4&quot; /&gt; 
|-
| rowspan=&quot;5&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Vehicle manufacturers
|Toyota is the main proponent of this category, as many of the taxis in the industry are the Toyota HiAce passenger vehicle. Since they are one of the only options, Toyota has increased the price rapidly in recent years - exacerbating economic impacts upon the drivers. 
|-
|Banks providing loans
|Some banks allowed taxi drivers or associations to file for loans to help them purchase newer, more roadworthy vehicles
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}
{| class=&quot;wikitable mw-collapsible&quot;
|+Tanzania
! valign=&quot;center&quot; |Actor
! valign=&quot;center&quot; |Actor Type
! valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
{| class=&quot;wikitable mw-collapsible&quot;
|+Timeline of the &quot;Taxi wars&quot; in South Africa
!Year
!Event description
|-
|1977
|The federal government signs the &quot;Road Transportation Act of 1977&quot; into law&lt;ref&gt;{{Cite web |title=Road Transportation Act 74 of 1977 {{!}} South African Government |url=https://www.gov.za/documents/road-transportation-act-16-apr-2015-0812 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; - failing to define minibus as a category, allowing taxi operators to operate them
|-
|1986-1987
|The number of informal taxi permits nation wide raises from 7,093 to 34, 378&lt;ref name=&quot;:5&quot;&gt;{{Cite journal |date=2013-03-01 |title=The lurch towards formalisation: Lessons from the implementation of BRT in Johannesburg, South Africa |url=https://www.sciencedirect.com/science/article/abs/pii/S0739885912000753 |journal=Research in Transportation Economics |language=en-US |volume=39 |issue=1 |pages=114–120 |doi=10.1016/j.retrec.2012.06.003 |issn=0739-8859}}&lt;/ref&gt;
|-
|1988
|The federal government signs the &quot;Transport Deregulation Act of 1988&quot; into law&lt;ref&gt;{{Cite web |title=Transport Deregulation Act 80 of 1988 {{!}} South African Government |url=https://www.gov.za/documents/transport-deregulation-act-18-may-2015-1306#:~:text=Transport%20Deregulation%20Act%2080%20of%201988%20%7C%20South%20African%20Government |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; 
|-
|1993
|Taxi wars death toll was 330 deaths in 1993&lt;ref name=&quot;:5&quot; /&gt;
|-
| rowspan=&quot;2&quot; |1994
|Apartheid in South Africa ends - however, its legacy on the spatial layout of cities will go on to affect urban transport for decades still
|-
|In Cape Town, the taxi association Codeta splits and CATA is formed, starting an intense and violent rivalry&lt;ref&gt;{{Cite news |last=Wines |first=Michael |date=2006-09-17 |title=Cartels Battle for Supremacy in South Africa’s Taxi Wars |language=en-US |work=The New York Times |url=https://www.nytimes.com/2006/09/17/world/africa/cartels-battle-for-supremacy-in-south-africas-taxi-wars.html |access-date=2026-05-22 |issn=0362-4331}}&lt;/ref&gt;
|-
|1996
|The government produces a whitepaper on the state of the transportation industry in South Africa&lt;ref&gt;{{Cite web |title=National Transport Policy White Paper {{!}} South African Government |url=https://www.gov.za/documents/white-papers/national-transport-policy-white-paper-20-aug-1996 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt;
one of the key recommendation is the taxi recapitalization plan (TRP) which aimed to help decommission the older and less safe vehicles that were used at the time. (A timeline was set for all older models to be replaced by 2005) 
|-
|2001
|The South African National Taxi Council (SANTACO) is formed
|-
|2003
|Informal transit collectively reaches a 60 percent market share&lt;ref name=&quot;:5&quot; /&gt;
|-
|2004
|A revised version of the TRP is introduced, providing more money for replacing older busses - However, this does not do anything to curb the overtrading of routes, forcing drivers to operate newer and more costly vehicles on the same routes with the same low profit margins&lt;ref&gt;{{Cite journal |last=McKay |first=Tracey |last2=Simpson |first2=Zach |last3=Patel |first3=Naeem |date=2017-03-01 |title=Spatial politics and infrastructure development: Analysis of historical transportation data in Gauteng - South Africa (1975–2003) |url=https://www.sciendo.com/article/10.1515/mgrsd-2017-0003 |journal=Miscellanea Geographica |language=en |volume=21 |issue=1 |pages=35–43 |doi=10.1515/mgrsd-2017-0003 |issn=2084-6118}}&lt;/ref&gt;
|-
|2007
|South Africa's first Bus Rapid Transit (BRT) line is planned to open in Johannesburg, where the government and local taxi  associations came to a tentative agreement to replace the informal service along the corridor, allowing the affected associations and drivers to convert to the BRT operator&lt;ref name=&quot;:5&quot; /&gt;&lt;ref name=&quot;:6&quot;&gt;{{Cite journal |last=Bähre |first=Erik |date=2014-11 |title=A TRICKLE-UP ECONOMY: MUTUALITY, FREEDOM AND VIOLENCE IN CAPE TOWN'S TAXI ASSOCIATIONS |url=https://www.cambridge.org/core/journals/africa/article/abs/trickleup-economy-mutuality-freedom-and-violence-in-cape-towns-taxi-associations/E6FF741B122E54F9F84AF4119EF89ECD |journal=Africa |language=en |volume=84 |issue=4 |pages=576–594 |doi=10.1017/S000197201400045X |issn=0001-9720}}&lt;/ref&gt;
|-
| rowspan=&quot;2&quot; |2009
|three days after opening [Rea Vaya], violence erupted from disgruntled taxi drivers fearing loss of income&lt;ref name=&quot;:5&quot; /&gt;
|-
|The chairman of SANTACO was gunned down, the organization was accused of taking bribes from the government by rival associations&lt;ref name=&quot;:6&quot; /&gt; 
|-
|2010
|A new contract was signed [Rea Vaya], where 313 taxi operators became operators for the BRT company&lt;ref name=&quot;:5&quot; /&gt;
|-
|2012
|SANTACO president Kabulani Mthembu steps down after an audit revealed he had stolen nearly one million rand from the association&lt;ref name=&quot;:6&quot; /&gt;
|-
|2017
|An Uber driver dies after their car is set alight&lt;ref name=&quot;:7&quot;&gt;Rampedi M. War for the streets: Maponya mall becomes latest frontline in Taxi–E-hailing clash. Spotcovery [BLOG]. 2025. &lt;nowiki&gt;https://www.proquest.com/blogs-podcasts-websites/war-streets-maponya-mall-becomes-latest-frontline/docview/3240276444/se-2&lt;/nowiki&gt;.&lt;/ref&gt;
|-
|2024
|Piotrans - the private firm which bid and won the contract to operate the Rey Vaya BRT - goes bankrupt. The company had an alleged history of gross mismanagement dating back to around 2016&lt;ref&gt;{{Cite web |title=Gale - Institution Finder |url=https://galeapps.gale.com/apps/auth?userGroupName=&amp;sid=summon&amp;origURL=https%3A%2F%2Fgo.gale.com%2Fps%2Fi.do%3Fid%3DGALE%257CA779855589%26v%3D2.1%26it%3Dr%26sid%3Dsummon%26asid%3D0bd92d4c.%26u%3D%26p%3DSTND&amp;prodId=STND |access-date=2026-05-22 |website=galeapps.gale.com}}&lt;/ref&gt; A report finds that taxi operators owned a significant share in the company, which could have been used to undermine the operations from the inside
|-
|2025
|two e-hailing taxi drivers were attacked, one shot and the others car torched&lt;ref name=&quot;:7&quot; /&gt;
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Nairobi, Kenya
!Year
!Event description
|-
|
|
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Key Historical Timeline of Transit Transformation in Dar es Salaam, Tanzania
! valign=&quot;center&quot; |Year
! valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

==== South Africa ====
1. Top down approach to formalization

Many of the governments top down approaches to formalizing the industry have failed to meet their goals for a multitude of reasons, and have even created more unintended consequences that will need to be rectified before widespread formalization can be complete. For instance, the taxi recapitalization program aimed at modernizing the ageing and often poorly maintained fleet, failed to address the underlying cause of the issue - maintenance was on each owner, and they were already strapped for cash. In addition, the program unintentionally made the taxy associations into very powerful middlemen between banks, the government and the vehicle manufacturers, which increased their influence further&lt;ref name=&quot;:6&quot; /&gt;. 

2. Failure of the governments approach to inclusion in policy making 

Even though the government of South Africa had set up the NTT and had promoted SANTACO to a quasi governmental organization, they failed to listen to the needs of the taxi associations on multiple occasions, leading to a further erosion in trust that the government was actin in the best interests of the industry as a whole. As an example, a large multimodal transit hub was planned and constructed in Bloemfontein at a cost of 400 million rands. The goal of this facility was to help ease congestion on narrow CBD roads and to help passengers interchange with more modes of public transit more easily. However, the facility was woefully under designed to handle the amount of taxi bus traffic that was to use the facility&lt;ref&gt;{{Cite journal |last=Matebesi |first=Sethulego Z. |date=2019-01-08 |title=Insurgent Citizenship and Sustained Resistance of a Local Taxi Association |url=https://czasopisma.uni.lodz.pl/qualit/article/view/3986 |journal=Qualitative Sociology Review |language=en |volume=14 |issue=4 |pages=168–185 |doi=10.18778/1733-8077.14.4.11 |issn=1733-8077}}&lt;/ref&gt;. 

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

==== South Africa: ====
Public transport in South Africa continues to be dominated by the informal and often politically powerful taxi associations. Over the last few decades many attempts to re-regulate the industry or formalize the corporations has met resistance, and has slowed the progress of expansion of even traditional bus services into some areas. Taxi drivers fear for their income, and the mafia like entities that are the taxi associations want to keep control to maintain their economic and political power. The government has a history of going with a far to heavy handed top down approach, instead of working with the taxi associations in a more clear and open way, to provide both job security and better transport to its citizens. 

== Discussion Questions ==

# What approach would you take to regulate or formalize and industry like this?
# Would a single organization be able to effectively regulate this type of transport across one city, let alone an entire country? 

== Complete References ==</text>
      <sha1>2hzfwgmcghwfzu5uhz0vml1nb4xc3o4</sha1>
    </revision>
    <revision>
      <id>4637004</id>
      <parentid>4637000</parentid>
      <timestamp>2026-05-22T10:43:46Z</timestamp>
      <contributor>
        <username>Yyhiris</username>
        <id>3591938</id>
      </contributor>
      <origin>4637004</origin>
      <model>wikitext</model>
      <format>text/x-wiki</format>
      <text bytes="20154" sha1="5hohjz7wfjvo2anx6a3ojfctg81thax" xml:space="preserve">= A brief history of free market busses in Africa =

== Summary ==
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence, corruption and controversies since its inception, yet despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety.

== Annotated List of Actors ==

{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+South Africa
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations&lt;ref name=&quot;:4&quot;&gt;Schuler C. Kings of the road fuel deadly taxi war: The fight to control south africa's lucrative routes has left 1,120 people dead. A hit on a driver can cost as little as $1,200: [national edition]. National Post. Nov 06 1999:A14. Available from: &lt;nowiki&gt;https://www.proquest.com/newspapers/kings-road-fuel-deadly-taxi-war-fight-control/docview/329616964/se-2&lt;/nowiki&gt;.&lt;/ref&gt; 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry&lt;ref name=&quot;:4&quot; /&gt; 
|-
| rowspan=&quot;5&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Vehicle manufacturers
|Toyota is the main proponent of this category, as many of the taxis in the industry are the Toyota HiAce passenger vehicle. Since they are one of the only options, Toyota has increased the price rapidly in recent years - exacerbating economic impacts upon the drivers. 
|-
|Banks providing loans
|Some banks allowed taxi drivers or associations to file for loans to help them purchase newer, more roadworthy vehicles
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}
{| class=&quot;wikitable mw-collapsible&quot;
|+Tanzania
! valign=&quot;center&quot; |Actor
! valign=&quot;center&quot; |Actor Type
! valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
{| class=&quot;wikitable mw-collapsible&quot;
|+Timeline of the &quot;Taxi wars&quot; in South Africa
!Year
!Event description
|-
|1977
|The federal government signs the &quot;Road Transportation Act of 1977&quot; into law&lt;ref&gt;{{Cite web |title=Road Transportation Act 74 of 1977 {{!}} South African Government |url=https://www.gov.za/documents/road-transportation-act-16-apr-2015-0812 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; - failing to define minibus as a category, allowing taxi operators to operate them
|-
|1986-1987
|The number of informal taxi permits nation wide raises from 7,093 to 34, 378&lt;ref name=&quot;:5&quot;&gt;{{Cite journal |date=2013-03-01 |title=The lurch towards formalisation: Lessons from the implementation of BRT in Johannesburg, South Africa |url=https://www.sciencedirect.com/science/article/abs/pii/S0739885912000753 |journal=Research in Transportation Economics |language=en-US |volume=39 |issue=1 |pages=114–120 |doi=10.1016/j.retrec.2012.06.003 |issn=0739-8859}}&lt;/ref&gt;
|-
|1988
|The federal government signs the &quot;Transport Deregulation Act of 1988&quot; into law&lt;ref&gt;{{Cite web |title=Transport Deregulation Act 80 of 1988 {{!}} South African Government |url=https://www.gov.za/documents/transport-deregulation-act-18-may-2015-1306#:~:text=Transport%20Deregulation%20Act%2080%20of%201988%20%7C%20South%20African%20Government |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; 
|-
|1993
|Taxi wars death toll was 330 deaths in 1993&lt;ref name=&quot;:5&quot; /&gt;
|-
| rowspan=&quot;2&quot; |1994
|Apartheid in South Africa ends - however, its legacy on the spatial layout of cities will go on to affect urban transport for decades still
|-
|In Cape Town, the taxi association Codeta splits and CATA is formed, starting an intense and violent rivalry&lt;ref&gt;{{Cite news |last=Wines |first=Michael |date=2006-09-17 |title=Cartels Battle for Supremacy in South Africa’s Taxi Wars |language=en-US |work=The New York Times |url=https://www.nytimes.com/2006/09/17/world/africa/cartels-battle-for-supremacy-in-south-africas-taxi-wars.html |access-date=2026-05-22 |issn=0362-4331}}&lt;/ref&gt;
|-
|1996
|The government produces a whitepaper on the state of the transportation industry in South Africa&lt;ref&gt;{{Cite web |title=National Transport Policy White Paper {{!}} South African Government |url=https://www.gov.za/documents/white-papers/national-transport-policy-white-paper-20-aug-1996 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt;
one of the key recommendation is the taxi recapitalization plan (TRP) which aimed to help decommission the older and less safe vehicles that were used at the time. (A timeline was set for all older models to be replaced by 2005) 
|-
|2001
|The South African National Taxi Council (SANTACO) is formed
|-
|2003
|Informal transit collectively reaches a 60 percent market share&lt;ref name=&quot;:5&quot; /&gt;
|-
|2004
|A revised version of the TRP is introduced, providing more money for replacing older busses - However, this does not do anything to curb the overtrading of routes, forcing drivers to operate newer and more costly vehicles on the same routes with the same low profit margins&lt;ref&gt;{{Cite journal |last=McKay |first=Tracey |last2=Simpson |first2=Zach |last3=Patel |first3=Naeem |date=2017-03-01 |title=Spatial politics and infrastructure development: Analysis of historical transportation data in Gauteng - South Africa (1975–2003) |url=https://www.sciendo.com/article/10.1515/mgrsd-2017-0003 |journal=Miscellanea Geographica |language=en |volume=21 |issue=1 |pages=35–43 |doi=10.1515/mgrsd-2017-0003 |issn=2084-6118}}&lt;/ref&gt;
|-
|2007
|South Africa's first Bus Rapid Transit (BRT) line is planned to open in Johannesburg, where the government and local taxi  associations came to a tentative agreement to replace the informal service along the corridor, allowing the affected associations and drivers to convert to the BRT operator&lt;ref name=&quot;:5&quot; /&gt;&lt;ref name=&quot;:6&quot;&gt;{{Cite journal |last=Bähre |first=Erik |date=2014-11 |title=A TRICKLE-UP ECONOMY: MUTUALITY, FREEDOM AND VIOLENCE IN CAPE TOWN'S TAXI ASSOCIATIONS |url=https://www.cambridge.org/core/journals/africa/article/abs/trickleup-economy-mutuality-freedom-and-violence-in-cape-towns-taxi-associations/E6FF741B122E54F9F84AF4119EF89ECD |journal=Africa |language=en |volume=84 |issue=4 |pages=576–594 |doi=10.1017/S000197201400045X |issn=0001-9720}}&lt;/ref&gt;
|-
| rowspan=&quot;2&quot; |2009
|three days after opening [Rea Vaya], violence erupted from disgruntled taxi drivers fearing loss of income&lt;ref name=&quot;:5&quot; /&gt;
|-
|The chairman of SANTACO was gunned down, the organization was accused of taking bribes from the government by rival associations&lt;ref name=&quot;:6&quot; /&gt; 
|-
|2010
|A new contract was signed [Rea Vaya], where 313 taxi operators became operators for the BRT company&lt;ref name=&quot;:5&quot; /&gt;
|-
|2012
|SANTACO president Kabulani Mthembu steps down after an audit revealed he had stolen nearly one million rand from the association&lt;ref name=&quot;:6&quot; /&gt;
|-
|2017
|An Uber driver dies after their car is set alight&lt;ref name=&quot;:7&quot;&gt;Rampedi M. War for the streets: Maponya mall becomes latest frontline in Taxi–E-hailing clash. Spotcovery [BLOG]. 2025. &lt;nowiki&gt;https://www.proquest.com/blogs-podcasts-websites/war-streets-maponya-mall-becomes-latest-frontline/docview/3240276444/se-2&lt;/nowiki&gt;.&lt;/ref&gt;
|-
|2024
|Piotrans - the private firm which bid and won the contract to operate the Rey Vaya BRT - goes bankrupt. The company had an alleged history of gross mismanagement dating back to around 2016&lt;ref&gt;{{Cite web |title=Gale - Institution Finder |url=https://galeapps.gale.com/apps/auth?userGroupName=&amp;sid=summon&amp;origURL=https%3A%2F%2Fgo.gale.com%2Fps%2Fi.do%3Fid%3DGALE%257CA779855589%26v%3D2.1%26it%3Dr%26sid%3Dsummon%26asid%3D0bd92d4c.%26u%3D%26p%3DSTND&amp;prodId=STND |access-date=2026-05-22 |website=galeapps.gale.com}}&lt;/ref&gt; A report finds that taxi operators owned a significant share in the company, which could have been used to undermine the operations from the inside
|-
|2025
|two e-hailing taxi drivers were attacked, one shot and the others car torched&lt;ref name=&quot;:7&quot; /&gt;
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Nairobi, Kenya
!Year
!Event description
|-
|
|
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Timeline of Transit Transformation in Dar es Salaam, Tanzania
! valign=&quot;center&quot; |Year
! valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

==== South Africa ====
1. Top down approach to formalization

Many of the governments top down approaches to formalizing the industry have failed to meet their goals for a multitude of reasons, and have even created more unintended consequences that will need to be rectified before widespread formalization can be complete. For instance, the taxi recapitalization program aimed at modernizing the ageing and often poorly maintained fleet, failed to address the underlying cause of the issue - maintenance was on each owner, and they were already strapped for cash. In addition, the program unintentionally made the taxy associations into very powerful middlemen between banks, the government and the vehicle manufacturers, which increased their influence further&lt;ref name=&quot;:6&quot; /&gt;. 

2. Failure of the governments approach to inclusion in policy making 

Even though the government of South Africa had set up the NTT and had promoted SANTACO to a quasi governmental organization, they failed to listen to the needs of the taxi associations on multiple occasions, leading to a further erosion in trust that the government was actin in the best interests of the industry as a whole. As an example, a large multimodal transit hub was planned and constructed in Bloemfontein at a cost of 400 million rands. The goal of this facility was to help ease congestion on narrow CBD roads and to help passengers interchange with more modes of public transit more easily. However, the facility was woefully under designed to handle the amount of taxi bus traffic that was to use the facility&lt;ref&gt;{{Cite journal |last=Matebesi |first=Sethulego Z. |date=2019-01-08 |title=Insurgent Citizenship and Sustained Resistance of a Local Taxi Association |url=https://czasopisma.uni.lodz.pl/qualit/article/view/3986 |journal=Qualitative Sociology Review |language=en |volume=14 |issue=4 |pages=168–185 |doi=10.18778/1733-8077.14.4.11 |issn=1733-8077}}&lt;/ref&gt;. 

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

==== South Africa: ====
Public transport in South Africa continues to be dominated by the informal and often politically powerful taxi associations. Over the last few decades many attempts to re-regulate the industry or formalize the corporations has met resistance, and has slowed the progress of expansion of even traditional bus services into some areas. Taxi drivers fear for their income, and the mafia like entities that are the taxi associations want to keep control to maintain their economic and political power. The government has a history of going with a far to heavy handed top down approach, instead of working with the taxi associations in a more clear and open way, to provide both job security and better transport to its citizens. 

== Discussion Questions ==

# What approach would you take to regulate or formalize and industry like this?
# Would a single organization be able to effectively regulate this type of transport across one city, let alone an entire country? 
# Why did the project like DART struggle to fit local conditions, and how did weak land-use planning reduce its effectiveness?

== Complete References ==</text>
      <sha1>5hohjz7wfjvo2anx6a3ojfctg81thax</sha1>
    </revision>
    <revision>
      <id>4637007</id>
      <parentid>4637004</parentid>
      <timestamp>2026-05-22T11:02:27Z</timestamp>
      <contributor>
        <username>Yyhiris</username>
        <id>3591938</id>
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      <format>text/x-wiki</format>
      <text bytes="21024" sha1="hl52t7qswrts41dm971gtqnfm0w820w" xml:space="preserve">= A brief history of free market busses in Africa =

== Summary ==
Many African countries public transportation systems are dominated by informal, private systems that operate using small to medium size vehicles that do not follow regular routes and/or stop locations. The informal industry has been mired in violence, corruption and controversies since its inception, yet despite these drawbacks the system thrives because they offer increased flexibility and decreased cost of service compared to more traditional rigid structured public transit systems. In recent years, in addition to  increasing government pressure to formalize, the industry also faces stiff competition from ride hailing services such as Uber and other local options which can offer an increased sense of safety.

== Annotated List of Actors ==

{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+South Africa
!Sector
!Name of stakeholder/Actor
!Role
|-
| rowspan=&quot;2&quot; |Informal bus industry
|Bus operators
|Often each driver is an owner operator of just one minibus who joins an association which then dictates which route they service. This assignment can determine the amount of money each driver earns so competition for the best routes often ensues 
|-
|Taxi associations 
|These associations are made up of many owner operators and provide the routes to the drivers. They also offer &quot;protection&quot; to their drivers and enforce boundaries of their territory from other rival associations&lt;ref name=&quot;:4&quot;&gt;Schuler C. Kings of the road fuel deadly taxi war: The fight to control south africa's lucrative routes has left 1,120 people dead. A hit on a driver can cost as little as $1,200: [national edition]. National Post. Nov 06 1999:A14. Available from: &lt;nowiki&gt;https://www.proquest.com/newspapers/kings-road-fuel-deadly-taxi-war-fight-control/docview/329616964/se-2&lt;/nowiki&gt;.&lt;/ref&gt; 
|-
| rowspan=&quot;4&quot; |Government
|National governments
|Introduces the unregulated industry - Then tries to reregulate it when complications arise
|-
|State governments
|Laws and regulation attempts/willingness vary by state
|-
|Municipal governments
|Cities often complain about the effects of the industry on local areas, such as increased traffic congestion and road safety concerns - They cannot usually do much to regulate - but they can set where the taxi stands go. Some do try to work with the industry to reform them into regular bus operators. 
|-
|Police agencies
|In the past, these agencies have often been corrupt and complacent allowing violence to continue within the informal industry&lt;ref name=&quot;:4&quot; /&gt; 
|-
| rowspan=&quot;5&quot; |Private Firms
|Regular bus operators
|These are the service providers of the regular scheduled transit systems, and BRT systems that the informal industry often cites as competing with them with unfair advantages (they are usually subsidized) 
|-
|Uber/Ride hailing
|Provides a similar service as the informal taxi bus industry, creating more competition 
|-
|Long distance bus operators
|The informal industry may also receive competition from intercity bus operators such as greyhound
|-
|Vehicle manufacturers
|Toyota is the main proponent of this category, as many of the taxis in the industry are the Toyota HiAce passenger vehicle. Since they are one of the only options, Toyota has increased the price rapidly in recent years - exacerbating economic impacts upon the drivers. 
|-
|Banks providing loans
|Some banks allowed taxi drivers or associations to file for loans to help them purchase newer, more roadworthy vehicles
|-
|Industry groups
|National or local groups aimed at lobbying the government in favor of the industry
|groups like SANTACO which aim to provide the industry with a more formal structure, in order to help facilitate the growth of the industry 
|}
{| class=&quot;wikitable mw-collapsible&quot;
|+Tanzania
! valign=&quot;center&quot; |Actor
! valign=&quot;center&quot; |Actor Type
! valign=&quot;center&quot; |Description
|-
| valign=&quot;center&quot; |UDA (Shirika la Usafiri Dar es Salaam)
| valign=&quot;center&quot; |State-Owned Enterprise (SOE)
| valign=&quot;center&quot; |The state-owned bus enterprise that held a statutory monopoly following 1974 nationalization. It suffered an operational collapse in the early 1980s due to economic crises and a lack of foreign exchange for fleet maintenance.&lt;ref name=&quot;:0&quot;&gt;{{Cite book |last=Kanyama |first=Ahmad |title=Public transport in Dar es Salaam, Tanzania: institutional challenges and opportunities for a sustainable transportation system |date=2004 |publisher=Totalförsvarets forskningsinstitut, Institutionen för miljöstrategiska studier |isbn=978-91-7323-103-9 |location=Stockholm}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |Private Paratransit Operators (Daladala Group)
| valign=&quot;center&quot; |Informal Private Sector
| valign=&quot;center&quot; |Informal free-market actors who dominated transit post-1983. Operating under a deregulated &quot;Target System&quot; , they maximized supply efficiency but created severe negative externalities. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |SUMATRA / LATRA
| valign=&quot;center&quot; |Statutory Regulatory Authority
| valign=&quot;center&quot; |The government regulatory body established in 2001 (operational in 2006). It marked the end of absolute laissez-faire, re-introducing mandatory vehicle inspections, maximum route fares, and supply licensing as a &quot;re-regulation&quot; mechanism.&lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Ka'bange |first=Abdi |last2=Mfinanga |first2=David |last3=Hema |first3=Edwin |date=2014-12 |title=Paradoxes of establishing mass rapid transit systems in african cities – A case of Dar es Salaam Rapid Transit (DART) system, Tanzania |url=https://doi.org/10.1016/j.retrec.2014.09.040 |journal=Research in Transportation Economics |volume=48 |pages=176–183 |doi=10.1016/j.retrec.2014.09.040 |issn=0739-8859}}&lt;/ref&gt; 
|-
| valign=&quot;center&quot; |IPT Micro-modes (Bodaboda &amp; Bajaj)
| valign=&quot;center&quot; |Informal Micro-Mobility Sector
| valign=&quot;center&quot; |Informal motorcycle (bodaboda) and tricycle (bajaj) operators. They serve as critical life support for low-income non-CBD travel and provide essential door-to-door flexibility under poor road conditions.&lt;ref&gt;{{Cite journal |last=Joseph |first=Lucy |last2=Neven |first2=An |last3=Martens |first3=Karel |last4=Kweka |first4=Opportuna |last5=Wets |first5=Geert |last6=Janssens |first6=Davy |date=2020-09-10 |title=Activity Participation and Perceptions on Informal Public Transport and Bus Rapid Transit in Dar es Salaam |url=https://doi.org/10.1177/0361198120948058 |journal=Transportation Research Record: Journal of the Transportation Research Board |volume=2674 |issue=11 |pages=573–583 |doi=10.1177/0361198120948058 |issn=0361-1981}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |DART Agency
| valign=&quot;center&quot; |Public Asset &amp; Planning Authority
| valign=&quot;center&quot; |A government asset-owning planning authority under the Prime Minister's Office (PO-RALG). It is responsible for BRT infrastructure delivery and concession oversight. &lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |UDART
| valign=&quot;center&quot; |PPP Concessionaire (SPV)
| valign=&quot;center&quot; |The special purpose vehicle (SPV) operating the BRT Phase 1 concession. It was formed as a PPP model, integrating the private Daladala Operators Association (DARCOBOA) to engage informal stakeholders.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Hoyos Guerrero |first=Alejandro |url=https://doi.org/10.1596/978-1-4648-1682-6 |title=Public-Private Partnerships in Urban Bus Systems: An Analytical Framework for Project Identification and Preparation |last2=Lopez Dodero |first2=Abel |date=2021-06-28 |publisher=The World Bank |isbn=978-1-4648-1682-6}}&lt;/ref&gt;
|-
| valign=&quot;center&quot; |International Financial Institutions (World Bank &amp; AfDB)
| valign=&quot;center&quot; |Multilateral Development Bank (MDB) 

| valign=&quot;center&quot; |The primary funding sources and facilitators of global &quot;policy mobility,&quot; transferring Latin American BRT models to sub-Saharan Africa.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal |last=Wood |first=Astrid |date=2015-02-04 |title=Competing for Knowledge: Leaders and Laggards of Bus Rapid Transit in South Africa |url=https://doi.org/10.1007/s12132-014-9248-y |journal=Urban Forum |volume=26 |issue=2 |pages=203–221 |doi=10.1007/s12132-014-9248-y |issn=1015-3802}}&lt;/ref&gt; 
|}

== Timeline of Events ==
{| class=&quot;wikitable mw-collapsible&quot;
|+Timeline of the &quot;Taxi wars&quot; in South Africa
!Year
!Event description
|-
|1977
|The federal government signs the &quot;Road Transportation Act of 1977&quot; into law&lt;ref&gt;{{Cite web |title=Road Transportation Act 74 of 1977 {{!}} South African Government |url=https://www.gov.za/documents/road-transportation-act-16-apr-2015-0812 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; - failing to define minibus as a category, allowing taxi operators to operate them
|-
|1986-1987
|The number of informal taxi permits nation wide raises from 7,093 to 34, 378&lt;ref name=&quot;:5&quot;&gt;{{Cite journal |date=2013-03-01 |title=The lurch towards formalisation: Lessons from the implementation of BRT in Johannesburg, South Africa |url=https://www.sciencedirect.com/science/article/abs/pii/S0739885912000753 |journal=Research in Transportation Economics |language=en-US |volume=39 |issue=1 |pages=114–120 |doi=10.1016/j.retrec.2012.06.003 |issn=0739-8859}}&lt;/ref&gt;
|-
|1988
|The federal government signs the &quot;Transport Deregulation Act of 1988&quot; into law&lt;ref&gt;{{Cite web |title=Transport Deregulation Act 80 of 1988 {{!}} South African Government |url=https://www.gov.za/documents/transport-deregulation-act-18-may-2015-1306#:~:text=Transport%20Deregulation%20Act%2080%20of%201988%20%7C%20South%20African%20Government |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt; 
|-
|1993
|Taxi wars death toll was 330 deaths in 1993&lt;ref name=&quot;:5&quot; /&gt;
|-
| rowspan=&quot;2&quot; |1994
|Apartheid in South Africa ends - however, its legacy on the spatial layout of cities will go on to affect urban transport for decades still
|-
|In Cape Town, the taxi association Codeta splits and CATA is formed, starting an intense and violent rivalry&lt;ref&gt;{{Cite news |last=Wines |first=Michael |date=2006-09-17 |title=Cartels Battle for Supremacy in South Africa’s Taxi Wars |language=en-US |work=The New York Times |url=https://www.nytimes.com/2006/09/17/world/africa/cartels-battle-for-supremacy-in-south-africas-taxi-wars.html |access-date=2026-05-22 |issn=0362-4331}}&lt;/ref&gt;
|-
|1996
|The government produces a whitepaper on the state of the transportation industry in South Africa&lt;ref&gt;{{Cite web |title=National Transport Policy White Paper {{!}} South African Government |url=https://www.gov.za/documents/white-papers/national-transport-policy-white-paper-20-aug-1996 |access-date=2026-05-22 |website=www.gov.za}}&lt;/ref&gt;
one of the key recommendation is the taxi recapitalization plan (TRP) which aimed to help decommission the older and less safe vehicles that were used at the time. (A timeline was set for all older models to be replaced by 2005) 
|-
|2001
|The South African National Taxi Council (SANTACO) is formed
|-
|2003
|Informal transit collectively reaches a 60 percent market share&lt;ref name=&quot;:5&quot; /&gt;
|-
|2004
|A revised version of the TRP is introduced, providing more money for replacing older busses - However, this does not do anything to curb the overtrading of routes, forcing drivers to operate newer and more costly vehicles on the same routes with the same low profit margins&lt;ref&gt;{{Cite journal |last=McKay |first=Tracey |last2=Simpson |first2=Zach |last3=Patel |first3=Naeem |date=2017-03-01 |title=Spatial politics and infrastructure development: Analysis of historical transportation data in Gauteng - South Africa (1975–2003) |url=https://www.sciendo.com/article/10.1515/mgrsd-2017-0003 |journal=Miscellanea Geographica |language=en |volume=21 |issue=1 |pages=35–43 |doi=10.1515/mgrsd-2017-0003 |issn=2084-6118}}&lt;/ref&gt;
|-
|2007
|South Africa's first Bus Rapid Transit (BRT) line is planned to open in Johannesburg, where the government and local taxi  associations came to a tentative agreement to replace the informal service along the corridor, allowing the affected associations and drivers to convert to the BRT operator&lt;ref name=&quot;:5&quot; /&gt;&lt;ref name=&quot;:6&quot;&gt;{{Cite journal |last=Bähre |first=Erik |date=2014-11 |title=A TRICKLE-UP ECONOMY: MUTUALITY, FREEDOM AND VIOLENCE IN CAPE TOWN'S TAXI ASSOCIATIONS |url=https://www.cambridge.org/core/journals/africa/article/abs/trickleup-economy-mutuality-freedom-and-violence-in-cape-towns-taxi-associations/E6FF741B122E54F9F84AF4119EF89ECD |journal=Africa |language=en |volume=84 |issue=4 |pages=576–594 |doi=10.1017/S000197201400045X |issn=0001-9720}}&lt;/ref&gt;
|-
| rowspan=&quot;2&quot; |2009
|three days after opening [Rea Vaya], violence erupted from disgruntled taxi drivers fearing loss of income&lt;ref name=&quot;:5&quot; /&gt;
|-
|The chairman of SANTACO was gunned down, the organization was accused of taking bribes from the government by rival associations&lt;ref name=&quot;:6&quot; /&gt; 
|-
|2010
|A new contract was signed [Rea Vaya], where 313 taxi operators became operators for the BRT company&lt;ref name=&quot;:5&quot; /&gt;
|-
|2012
|SANTACO president Kabulani Mthembu steps down after an audit revealed he had stolen nearly one million rand from the association&lt;ref name=&quot;:6&quot; /&gt;
|-
|2017
|An Uber driver dies after their car is set alight&lt;ref name=&quot;:7&quot;&gt;Rampedi M. War for the streets: Maponya mall becomes latest frontline in Taxi–E-hailing clash. Spotcovery [BLOG]. 2025. &lt;nowiki&gt;https://www.proquest.com/blogs-podcasts-websites/war-streets-maponya-mall-becomes-latest-frontline/docview/3240276444/se-2&lt;/nowiki&gt;.&lt;/ref&gt;
|-
|2024
|Piotrans - the private firm which bid and won the contract to operate the Rey Vaya BRT - goes bankrupt. The company had an alleged history of gross mismanagement dating back to around 2016&lt;ref&gt;{{Cite web |title=Gale - Institution Finder |url=https://galeapps.gale.com/apps/auth?userGroupName=&amp;sid=summon&amp;origURL=https%3A%2F%2Fgo.gale.com%2Fps%2Fi.do%3Fid%3DGALE%257CA779855589%26v%3D2.1%26it%3Dr%26sid%3Dsummon%26asid%3D0bd92d4c.%26u%3D%26p%3DSTND&amp;prodId=STND |access-date=2026-05-22 |website=galeapps.gale.com}}&lt;/ref&gt; A report finds that taxi operators owned a significant share in the company, which could have been used to undermine the operations from the inside
|-
|2025
|two e-hailing taxi drivers were attacked, one shot and the others car torched&lt;ref name=&quot;:7&quot; /&gt;
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Nairobi, Kenya
!Year
!Event description
|-
|
|
|-
|
|
|-
|
|
|}
{| class=&quot;wikitable mw-collapsible mw-collapsed&quot;
|+Timeline of Transit Transformation in Dar es Salaam, Tanzania
! valign=&quot;center&quot; |Year
! valign=&quot;center&quot; |Event Description
|-
| valign=&quot;center&quot; |1949
| valign=&quot;center&quot; |The British-owned Dar es Salaam Motor Transport (DMT) initiates formal private bus services under low-demand colonial spatial limits.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1974
| valign=&quot;center&quot; |The Tanzanian government nationalizes DMT to form UDA, pursuing a socialist, state-controlled transit monopoly.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |Late 1970s – 1983
| valign=&quot;center&quot; |Macroeconomic crises paralyze UDA. The active fleet drops below 100 buses, forcing citizens to rely on illegal, informal vans—the precursor to Daladalas.&lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |1983
| valign=&quot;center&quot; |The Transport Licensing Act Amendment de-criminalizes private paratransit. Daladalas gain legal entry, initiating an era of free-market deregulation.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |1980s – 2000s
| valign=&quot;center&quot; |Total market dominance by Daladalas. Extreme traffic congestion ensues, bringing central corridor travel speeds to a critical crawl.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2004
| valign=&quot;center&quot; |The SUMATRA Act is passed and enforced, re-establishing route-licensing and maximum tariff controls over informal minibuses.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2012
| valign=&quot;center&quot; |Construction begins on Phase 1 of the DART BRT system, funded by a World Bank loan.&lt;ref name=&quot;:1&quot; /&gt;
|-
| valign=&quot;center&quot; |2016 – Present
| valign=&quot;center&quot; |DART Phase 1 launches under a PPP framework. Main corridors transition to regulated electronic ticketing, while Daladalas and bajajis motor tricycle are pushed to peripheral feeder markets.&lt;ref name=&quot;:2&quot; /&gt;
|}

== Maps of Locations ==
[[File:Tanzania_transport_map-fr.svg|thumb|204x204px|Tanzania transport map]]


== Clear Identification of Policy Issues ==

==== Tanzania： ====
1. Market Efficiency vs. Social Equity: Student Exclusion

Under a deregulated system with zero financial subsidies, profit-driven private minibuses systematically reject, evict, and abuse low-fare students during peak hours, causing a severe failure in basic public transit equity.&lt;ref name=&quot;:0&quot; /&gt;

2. The &quot;Implementation Gap&quot; within the Bus PPP Framework.

Top down BRT design is independent of local regulatory capacity; the implementation of the fleet has been hampered by the absence of strict public oversight and the protracted fare clearinghouse disagreements, which has kept the fleet grounded with modern buses and excessive passenger delays. &lt;ref name=&quot;:2&quot; /&gt;

3. Fragmented Multimodal Integration Authority

There is no unified transit authority for the city. The BRT, conventional paratransit, ferries and new Standard Gauge Railway (SGR) all operate within their own silos, thus preventing the development of an integrated electronic ticketing system and synergy of the multimodal system.&lt;ref name=&quot;:0&quot; /&gt;

==== South Africa ====
1. Top down approach to formalization

Many of the governments top down approaches to formalizing the industry have failed to meet their goals for a multitude of reasons, and have even created more unintended consequences that will need to be rectified before widespread formalization can be complete. For instance, the taxi recapitalization program aimed at modernizing the ageing and often poorly maintained fleet, failed to address the underlying cause of the issue - maintenance was on each owner, and they were already strapped for cash. In addition, the program unintentionally made the taxy associations into very powerful middlemen between banks, the government and the vehicle manufacturers, which increased their influence further&lt;ref name=&quot;:6&quot; /&gt;. 

2. Failure of the governments approach to inclusion in policy making 

Even though the government of South Africa had set up the NTT and had promoted SANTACO to a quasi governmental organization, they failed to listen to the needs of the taxi associations on multiple occasions, leading to a further erosion in trust that the government was actin in the best interests of the industry as a whole. As an example, a large multimodal transit hub was planned and constructed in Bloemfontein at a cost of 400 million rands. The goal of this facility was to help ease congestion on narrow CBD roads and to help passengers interchange with more modes of public transit more easily. However, the facility was woefully under designed to handle the amount of taxi bus traffic that was to use the facility&lt;ref&gt;{{Cite journal |last=Matebesi |first=Sethulego Z. |date=2019-01-08 |title=Insurgent Citizenship and Sustained Resistance of a Local Taxi Association |url=https://czasopisma.uni.lodz.pl/qualit/article/view/3986 |journal=Qualitative Sociology Review |language=en |volume=14 |issue=4 |pages=168–185 |doi=10.18778/1733-8077.14.4.11 |issn=1733-8077}}&lt;/ref&gt;. 

== Narrative of the case ==

==== Tanzania： ====
Public transport in Dar es Salaam was once a failed state owned monopoly under UDA, but following the economic crisis it was deregulated and became an informal Daladala minibus system. While Daladalas grew mobility quickly, the lack of regulation led to unregulated competition, pollution and congestion.&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:1&quot; /&gt; The government introduced the DART BRT in 2016 to address these issues and introduced the former Daladala operators into the new system, however the informal system is still used by many in peripheral areas.&lt;ref name=&quot;:2&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;

==== South Africa: ====
Public transport in South Africa continues to be dominated by the informal and often politically powerful taxi associations. Over the last few decades many attempts to re-regulate the industry or formalize the corporations has met resistance, and has slowed the progress of expansion of even traditional bus services into some areas. Taxi drivers fear for their income, and the mafia like entities that are the taxi associations want to keep control to maintain their economic and political power. The government has a history of going with a far to heavy handed top down approach, instead of working with the taxi associations in a more clear and open way, to provide both job security and better transport to its citizens. 

== Discussion Questions ==

# What approach would you take to regulate or formalize and industry like this?
# Would a single organization be able to effectively regulate this type of transport across one city, let alone an entire country? 
# Why did the project like DART struggle to fit local conditions, and how did weak land-use planning reduce its effectiveness?

== Complete References ==</text>
      <sha1>hl52t7qswrts41dm971gtqnfm0w820w</sha1>
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  </page>
  <page>
    <title>Transportation Planning Casebook/Stroget, Copenhagen</title>
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      <contributor>
        <username>Arocketdog</username>
        <id>3501123</id>
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      <comment>/* Timeline of events */</comment>
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      <text bytes="14637" sha1="jfdmtpsx5ogclxogva70iogr9wfm3eq" xml:space="preserve">== Summary ==
Strøget(Danish pronunciation: &amp;#x5B;ˈstʁʌjˀð̩&amp;#x5D;) is a pedestrian-only street network located in central Copenhagen, Denmark. First pedestrianised in 1962, it is widely recognised as one of the earliest large-scale pedestrianisation projects in the world. The project transformed a car-dominated city centre into a people-focused public space and became an influential example of pedestrian-first urban planning globally.

== Annotated list of actors ==
RL

Political courage and leadership: The planning officials in Copenhagen at that time overcame the strong opposition from local retailers and firmly pushed forward the initial car-free experiment. 

Progressive planning strategy: The project adopts the approach of conducting pilot evaluations first, obtaining data support, and then implementing permanently. This effectively alleviated the public's resistance.

Reconfiguration of spatial functions: After the streets were de-automated, they were given high-quality paving, and outdoor cafes and public seating were introduced, enhancing the social nature of the space.

== Timeline of events ==
RL; BC table update
{| class=&quot;wikitable&quot;
|+
!Time period
!Event
|-
|1950s–1960s
|Copenhagen’s city centre faced rising car traffic, congestion, and declining public life, prompting debate about traffic management. This period of urban challenge laid the groundwork for exploring pedestrianisation as a transportation solution.
|-
|November 1962
|Temporary pedestrian closure of Strøget began as a pilot project, initially limited to the Christmas shopping season. The pilot was a targeted test to assess feasibility without long-term disruption.
|-
|1962–1964
|Trial period results showed increased foot traffic, retail sales, and public support for the car-free zone. These positive outcomes provided the data needed to justify permanent pedestrianisation.
|-
|February 1964
|The city council voted to make Strøget’s pedestrianisation permanent, marking a formal policy shift toward people-first transportation planning in Copenhagen.
|-
|1960s–1970s
|Jan Gehl’s ongoing research on Strøget’s public life documented the benefits of pedestrianisation, informing Copenhagen’s expansion of car-free streets and bicycle infrastructure. This research expanded the project’s impact beyond Strøget to city-wide transportation policy.
|-
|Late 20th century
|Strøget’s success inspired pedestrianisation projects globally, becoming a benchmark for people-first urban planning and pedestrian-focused transportation design.
|-
|Present
|Strøget remains a core pedestrian corridor, evolving to include improved accessibility, seasonal events, and sustainable design updates. It continues to adapt to modern transportation and urban needs while preserving its original purpose.
|}

== Maps of locations ==

== Identification of policy issues ==
RL

The core policy controversy faced by this project in its early stage was the conflict between protecting commercial interests and redistributing public space.&lt;ref&gt;{{Cite book |last=Hass-Klau, C. |title=The Pedestrian and the City. Routledge. |year=2015}}&lt;/ref&gt; Local retailers were extremely concerned that prohibiting cars from entering would lead to a loss of customers and a sharp decline in sales.&lt;ref name=&quot;:0&quot;&gt;{{Cite web |last=Project for Public Spaces (PPS). |date=2007 |title=Strøget District. |url=https://www.pps.org.//}}&lt;/ref&gt; Moreover, the early planning also faced the daunting challenge of how to change the long-standing transportation habits of the citizens, who had been overly dependent on car travel.&lt;ref name=&quot;:1&quot;&gt;{{Cite book |last=Newman, P., &amp; Kenworthy, J. |title=Sustainability and Cities: Overcoming Automobile Dependence. |publisher=Island Press. |year=1999}}&lt;/ref&gt; However, later economic data proved that a high-quality pedestrian environment not only significantly prolonged people's stay time but also greatly promoted the local retail economy.&lt;ref name=&quot;:1&quot; /&gt;

MK

While its long‑term outcomes are generally viewed as positive, the project raised a series of policy issues that remain directly relevant to contemporary transport, land‑use and public‑realm decision‑making.

'''1. Economic Impact and Retail Viability'''

A central policy concern prior to pedestrianisation was the risk that removing vehicles would reduce retail trade and business viability. Local merchants strongly opposed the proposal, arguing that car access was essential for customer footfall and deliveries. Copenhagen responded by implementing pedestrianisation initially as a trial, allowing economic impacts to be observed rather than assumed. Subsequent monitoring showed that footfall increased and retail performance stabilised or improved, challenging conventional assumptions linking commercial success to vehicle access.&lt;ref&gt;{{Cite web |last=Huescar |first=Jaime Ruiz |date=2025-08-12 |title=From Resistance to Resilience: Strøget and the Long-Term Payoff of Pedestrianisation |url=https://www.citiesforum.org/news/from-resistance-to-resilience-stroget-and-the-long-term-payoff-of-pedestrianisation/ |access-date=2026-05-11 |website=citiesforum.org |language=en-US}}&lt;/ref&gt;

'''2. Public and Political Acceptance'''

Pedestrianisation of Strøget faced strong resistance from residents, traders, engineers and politicians, with scepticism that a vibrant pedestrian culture could succeed in a Scandinavian climate and social context. The City of Copenhagen mitigated political risk by framing the intervention as temporary and reversible, which reduced opposition and allowed public opinion to evolve once benefits became visible.&lt;ref name=&quot;:4&quot;&gt;{{Cite web |title=Strøget District {{!}} |url=https://www.pps.org/places/strooget-district |access-date=2026-05-11 |website=www.pps.org}}&lt;/ref&gt;

'''3. Reallocation of Street Space and Network Effects'''

The conversion of Strøget required a deliberate policy decision to prioritise pedestrians over vehicular movement in a key city‑centre corridor. This raised broader issues around network performance, congestion displacement, and accessibility. Copenhagen complemented pedestrianisation with wider investment in cycling infrastructure and public transport, ensuring that access to the city centre was preserved without reliance on private cars.&lt;ref name=&quot;:3&quot;&gt;{{Cite web |title=Pedestrian Only Streets: Case Study {{!}} Stroget, Copenhagen |url=https://globaldesigningcities.org/publication/global-street-design-guide/streets/pedestrian-priority-spaces/pedestrian-only-streets/pedestrian-streets-case-study-stroget-copenhagen/ |access-date=2026-05-11 |website=Global Designing Cities Initiative |language=en-US}}&lt;/ref&gt;&lt;ref&gt;{{Cite web |title=K-Shift Profile: Strøget |url=https://kshift.au/k-shift-profile-stroget/ |access-date=2026-05-11 |website=Project K-Shift |language=en-AU}}&lt;/ref&gt;

'''4. Freight, Servicing, and Emergency Access'''

A practical policy challenge was maintaining freight access, waste collection, and emergency services within a car‑free environment. Strøget addressed this through time‑restricted servicing windows and regulated vehicle access, requiring ongoing operational management rather than a one‑off design solution.&lt;ref name=&quot;:3&quot; /&gt;

'''5. Commercialisation, Tourism, and Place Quality'''

Over time, Strøget’s success generated secondary policy challenges, including high tourist volumes, rising rents, and retail homogenisation favouring global brands over local businesses. These pressures raised concerns about the long‑term balance between economic success, local character, and everyday use by residents.&lt;ref&gt;{{Cite web |last=Wiener |first=Nathaniel |date=2017-03-02 |title=Pedestrian streets: The scalability of Strøget |url=https://planetforward.org/story/pedestrian-streets-the-scalability-of-stroget/ |access-date=2026-05-11 |website=Planet Forward |language=en-US}}&lt;/ref&gt;

'''6. Alignment with Environmental and Public Health Objectives'''

Although environmental and health benefits were not the primary drivers of pedestrianisation in the early 1960s, Strøget later became closely aligned with Copenhagen’s broader climate, air‑quality, and public‑health objectives. Reduced vehicle traffic contributed to lower noise and emissions, while increased walking supported active‑transport outcomes and public life.&lt;ref&gt;{{Citation |last=Gehl |first=Jan |title=Public Life Studies and Urban Policy |date=2013 |url=https://doi.org/10.5822/978-1-61091-525-0_7 |work=How To Study Public Life |pages=149–160 |editor-last=Gehl |editor-first=Jan |access-date=2026-05-11 |place=Washington, DC |publisher=Island Press/Center for Resource Economics |language=en |doi=10.5822/978-1-61091-525-0_7 |isbn=978-1-61091-525-0 |last2=Svarre |first2=Birgitte |editor2-last=Svarre |editor2-first=Birgitte}}&lt;/ref&gt;

While Strøget raises a range of individual issues—economic, political, operational, spatial and environmental—many of these point to a smaller number of shared policy lessons. These lessons are best understood as cross‑cutting themes, rather than stand‑alone findings.

'''Evidence‑led and Incremental Decision‑Making'''

''(Pilots, trials, and feedback loops)''

A recurring policy lesson from Strøget is that contested street reallocation is more politically and economically feasible when implemented incrementally and supported by empirical evidence. Temporary trials reduced perceived irreversibility, allowed real‑world impacts to be measured, and provided a basis for public and political learning before permanent decisions were made.

This theme underpins:

* Economic impact concerns (Section 1), and
* Public and political acceptance (Section 2).

Strøget demonstrates that pedestrianisation succeeds when embedded within a broader transport strategy that maintains city‑centre accessibility. Complementary investment in cycling and public transport absorbed displaced vehicle demand and prevented access loss, ensuring that benefits accrued at the network level rather than being offset by congestion elsewhere.

'''Integration with the Wider Transport and Land‑Use System'''

''(Network effects, access, and mode substitution)''

Strøget demonstrates that pedestrianisation succeeds when embedded within a broader transport strategy that maintains city‑centre accessibility. Complementary investment in cycling and public transport absorbed displaced vehicle demand and prevented access loss, ensuring that benefits accrued at the network level rather than being offset by congestion elsewhere.

This theme underpins:

* Redistribution of street space (Section 3), and
* Long‑term environmental and health outcomes (Section 6).

'''Ongoing Governance and Operational Management'''

''(Not just a capital works project)''

Another consistent lesson is that pedestrian streets require continuous governance, not a one‑off design intervention. Freight access, emergency response, cleansing, and event management all required active regulation through time‑based access controls and operational oversight.

This theme underpins:

* Freight and servicing access (Section 4).

'''Managing Success and Secondary Effects'''

''(Over‑use, commercialisation, and place identity)''

Strøget illustrates that successful pedestrianisation can generate second‑order policy challenges, including tourism pressure, rising rents, and retail homogenisation. These outcomes necessitate complementary land‑use, tenancy, and place‑management policies to preserve local character and everyday functionality.

This theme underpins:

* Tourism and commercialisation pressures (Section 5).

== Narrative of the case ==
MK 

Strøget is a 1.1 kilometre pedestrian‑only street network in central Copenhagen (Denmark), which was fully pedestrianised in 1962.&lt;ref&gt;{{Cite web |title=Global Street Design Guide |url=https://globaldesigningcities.org/publication/global-street-design-guide/ |access-date=2026-05-04 |website=Global Designing Cities Initiative |language=en-US}}&lt;/ref&gt; It is widely regarded as one of the world’s earliest and most influential pedestrianisation projects, serving as a landmark example of large‑scale, people‑first urban design.&lt;ref name=&quot;:4&quot; /&gt;&lt;ref&gt;{{Cite web |title=Strøget District {{!}} |url=https://www.pps.org/places/strooget-district |access-date=2026-05-04 |website=www.pps.org}}&lt;/ref&gt;

Located in the historic city centre, Strøget forms a continuous, car‑free corridor running from City Hall Square (Rådhuspladsen) to Kongens Nytorv.&lt;ref&gt;{{Cite web |title=Global Street Design Guide |url=https://globaldesigningcities.org/publication/global-street-design-guide/ |access-date=2026-05-04 |website=Global Designing Cities Initiative |language=en-US}}&lt;/ref&gt; Rather than a single street, it comprises a linked sequence of streets and public squares that together function as a coherent and highly legible pedestrian network.

Since its pedestrianisation in the early 1960s, Strøget has prioritised walking, social activity and public life over vehicle movement. Wide, level paving and active retail and café frontages support high pedestrian volumes and encourage people to linger, gather, and interact. The street accommodates everyday movement as well as street performance, events, and outdoor dining, reinforcing its role as both a transport corridor and a civic space.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Gehl |first=J |title=Cities for people |publisher=Island Press |year=2010}}&lt;/ref&gt;

Internationally, Strøget is significant for demonstrating that removing cars from city centres can enhance economic activity, urban vitality, and quality of life. Its success has influenced pedestrian‑first streets and city‑centre revitalisation projects around the world and remains a benchmark for strong pedestrian network design.

RL

The transformation of Strøget has proven internationally that reducing car access in the city center is not only feasible but also brings significant social and economic benefits.&lt;ref name=&quot;:2&quot; /&gt; Long-term observational data from urban planning scholar Jan Gehl show that after the implementation of pedestrianization, the proportion of people spending time, communicating, and participating in public activities on the streets has experienced a dramatic increase.&lt;ref name=&quot;:0&quot; /&gt; Today, this case has become the gold standard for major cities around the world to revitalize their central areas and implement &quot;pedestrian-first&quot; street designs.&lt;ref&gt;{{Cite book |last=Global Designing Cities Initiative. |title=Global Street Design Guide. |publisher=Island Press. |year=2016}}&lt;/ref&gt;

== References ==

{{BookCat}}</text>
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      <text bytes="14764" sha1="hkpxl1zxmdrusskt2t4pmpdo81af45r" xml:space="preserve">== Summary ==
Strøget(Danish pronunciation: &amp;#x5B;ˈstʁʌjˀð̩&amp;#x5D;) is a pedestrian-only street network located in central Copenhagen, Denmark. First pedestrianised in 1962, it is widely recognised as one of the earliest large-scale pedestrianisation projects in the world. The project transformed a car-dominated city centre into a people-focused public space and became an influential example of pedestrian-first urban planning globally.

== Annotated list of actors ==
RL

Political courage and leadership: The planning officials in Copenhagen at that time overcame the strong opposition from local retailers and firmly pushed forward the initial car-free experiment. 

Progressive planning strategy: The project adopts the approach of conducting pilot evaluations first, obtaining data support, and then implementing permanently. This effectively alleviated the public's resistance.

Reconfiguration of spatial functions: After the streets were de-automated, they were given high-quality paving, and outdoor cafes and public seating were introduced, enhancing the social nature of the space.
{| class=&quot;wikitable&quot;
|+
!Sector
!Actor
!Roles and Concerns
|-
|Government
|City Council
|
|-
|Academia
|Jan Gehl
|
|-
|
|
|
|}

== Timeline of events ==
RL; BC table update
{| class=&quot;wikitable&quot;
|+
!Time period
!Event
|-
|1950s–1960s
|Copenhagen’s city centre faced rising car traffic, congestion, and declining public life, prompting debate about traffic management. This period of urban challenge laid the groundwork for exploring pedestrianisation as a transportation solution.
|-
|November 1962
|Temporary pedestrian closure of Strøget began as a pilot project, initially limited to the Christmas shopping season. The pilot was a targeted test to assess feasibility without long-term disruption.
|-
|1962–1964
|Trial period results showed increased foot traffic, retail sales, and public support for the car-free zone. These positive outcomes provided the data needed to justify permanent pedestrianisation.
|-
|February 1964
|The city council voted to make Strøget’s pedestrianisation permanent, marking a formal policy shift toward people-first transportation planning in Copenhagen.
|-
|1960s–1970s
|Jan Gehl’s ongoing research on Strøget’s public life documented the benefits of pedestrianisation, informing Copenhagen’s expansion of car-free streets and bicycle infrastructure. This research expanded the project’s impact beyond Strøget to city-wide transportation policy.
|-
|Late 20th century
|Strøget’s success inspired pedestrianisation projects globally, becoming a benchmark for people-first urban planning and pedestrian-focused transportation design.
|-
|Present
|Strøget remains a core pedestrian corridor, evolving to include improved accessibility, seasonal events, and sustainable design updates. It continues to adapt to modern transportation and urban needs while preserving its original purpose.
|}

== Maps of locations ==

== Identification of policy issues ==
RL

The core policy controversy faced by this project in its early stage was the conflict between protecting commercial interests and redistributing public space.&lt;ref&gt;{{Cite book |last=Hass-Klau, C. |title=The Pedestrian and the City. Routledge. |year=2015}}&lt;/ref&gt; Local retailers were extremely concerned that prohibiting cars from entering would lead to a loss of customers and a sharp decline in sales.&lt;ref name=&quot;:0&quot;&gt;{{Cite web |last=Project for Public Spaces (PPS). |date=2007 |title=Strøget District. |url=https://www.pps.org.//}}&lt;/ref&gt; Moreover, the early planning also faced the daunting challenge of how to change the long-standing transportation habits of the citizens, who had been overly dependent on car travel.&lt;ref name=&quot;:1&quot;&gt;{{Cite book |last=Newman, P., &amp; Kenworthy, J. |title=Sustainability and Cities: Overcoming Automobile Dependence. |publisher=Island Press. |year=1999}}&lt;/ref&gt; However, later economic data proved that a high-quality pedestrian environment not only significantly prolonged people's stay time but also greatly promoted the local retail economy.&lt;ref name=&quot;:1&quot; /&gt;

MK

While its long‑term outcomes are generally viewed as positive, the project raised a series of policy issues that remain directly relevant to contemporary transport, land‑use and public‑realm decision‑making.

'''1. Economic Impact and Retail Viability'''

A central policy concern prior to pedestrianisation was the risk that removing vehicles would reduce retail trade and business viability. Local merchants strongly opposed the proposal, arguing that car access was essential for customer footfall and deliveries. Copenhagen responded by implementing pedestrianisation initially as a trial, allowing economic impacts to be observed rather than assumed. Subsequent monitoring showed that footfall increased and retail performance stabilised or improved, challenging conventional assumptions linking commercial success to vehicle access.&lt;ref&gt;{{Cite web |last=Huescar |first=Jaime Ruiz |date=2025-08-12 |title=From Resistance to Resilience: Strøget and the Long-Term Payoff of Pedestrianisation |url=https://www.citiesforum.org/news/from-resistance-to-resilience-stroget-and-the-long-term-payoff-of-pedestrianisation/ |access-date=2026-05-11 |website=citiesforum.org |language=en-US}}&lt;/ref&gt;

'''2. Public and Political Acceptance'''

Pedestrianisation of Strøget faced strong resistance from residents, traders, engineers and politicians, with scepticism that a vibrant pedestrian culture could succeed in a Scandinavian climate and social context. The City of Copenhagen mitigated political risk by framing the intervention as temporary and reversible, which reduced opposition and allowed public opinion to evolve once benefits became visible.&lt;ref name=&quot;:4&quot;&gt;{{Cite web |title=Strøget District {{!}} |url=https://www.pps.org/places/strooget-district |access-date=2026-05-11 |website=www.pps.org}}&lt;/ref&gt;

'''3. Reallocation of Street Space and Network Effects'''

The conversion of Strøget required a deliberate policy decision to prioritise pedestrians over vehicular movement in a key city‑centre corridor. This raised broader issues around network performance, congestion displacement, and accessibility. Copenhagen complemented pedestrianisation with wider investment in cycling infrastructure and public transport, ensuring that access to the city centre was preserved without reliance on private cars.&lt;ref name=&quot;:3&quot;&gt;{{Cite web |title=Pedestrian Only Streets: Case Study {{!}} Stroget, Copenhagen |url=https://globaldesigningcities.org/publication/global-street-design-guide/streets/pedestrian-priority-spaces/pedestrian-only-streets/pedestrian-streets-case-study-stroget-copenhagen/ |access-date=2026-05-11 |website=Global Designing Cities Initiative |language=en-US}}&lt;/ref&gt;&lt;ref&gt;{{Cite web |title=K-Shift Profile: Strøget |url=https://kshift.au/k-shift-profile-stroget/ |access-date=2026-05-11 |website=Project K-Shift |language=en-AU}}&lt;/ref&gt;

'''4. Freight, Servicing, and Emergency Access'''

A practical policy challenge was maintaining freight access, waste collection, and emergency services within a car‑free environment. Strøget addressed this through time‑restricted servicing windows and regulated vehicle access, requiring ongoing operational management rather than a one‑off design solution.&lt;ref name=&quot;:3&quot; /&gt;

'''5. Commercialisation, Tourism, and Place Quality'''

Over time, Strøget’s success generated secondary policy challenges, including high tourist volumes, rising rents, and retail homogenisation favouring global brands over local businesses. These pressures raised concerns about the long‑term balance between economic success, local character, and everyday use by residents.&lt;ref&gt;{{Cite web |last=Wiener |first=Nathaniel |date=2017-03-02 |title=Pedestrian streets: The scalability of Strøget |url=https://planetforward.org/story/pedestrian-streets-the-scalability-of-stroget/ |access-date=2026-05-11 |website=Planet Forward |language=en-US}}&lt;/ref&gt;

'''6. Alignment with Environmental and Public Health Objectives'''

Although environmental and health benefits were not the primary drivers of pedestrianisation in the early 1960s, Strøget later became closely aligned with Copenhagen’s broader climate, air‑quality, and public‑health objectives. Reduced vehicle traffic contributed to lower noise and emissions, while increased walking supported active‑transport outcomes and public life.&lt;ref&gt;{{Citation |last=Gehl |first=Jan |title=Public Life Studies and Urban Policy |date=2013 |url=https://doi.org/10.5822/978-1-61091-525-0_7 |work=How To Study Public Life |pages=149–160 |editor-last=Gehl |editor-first=Jan |access-date=2026-05-11 |place=Washington, DC |publisher=Island Press/Center for Resource Economics |language=en |doi=10.5822/978-1-61091-525-0_7 |isbn=978-1-61091-525-0 |last2=Svarre |first2=Birgitte |editor2-last=Svarre |editor2-first=Birgitte}}&lt;/ref&gt;

While Strøget raises a range of individual issues—economic, political, operational, spatial and environmental—many of these point to a smaller number of shared policy lessons. These lessons are best understood as cross‑cutting themes, rather than stand‑alone findings.

'''Evidence‑led and Incremental Decision‑Making'''

''(Pilots, trials, and feedback loops)''

A recurring policy lesson from Strøget is that contested street reallocation is more politically and economically feasible when implemented incrementally and supported by empirical evidence. Temporary trials reduced perceived irreversibility, allowed real‑world impacts to be measured, and provided a basis for public and political learning before permanent decisions were made.

This theme underpins:

* Economic impact concerns (Section 1), and
* Public and political acceptance (Section 2).

Strøget demonstrates that pedestrianisation succeeds when embedded within a broader transport strategy that maintains city‑centre accessibility. Complementary investment in cycling and public transport absorbed displaced vehicle demand and prevented access loss, ensuring that benefits accrued at the network level rather than being offset by congestion elsewhere.

'''Integration with the Wider Transport and Land‑Use System'''

''(Network effects, access, and mode substitution)''

Strøget demonstrates that pedestrianisation succeeds when embedded within a broader transport strategy that maintains city‑centre accessibility. Complementary investment in cycling and public transport absorbed displaced vehicle demand and prevented access loss, ensuring that benefits accrued at the network level rather than being offset by congestion elsewhere.

This theme underpins:

* Redistribution of street space (Section 3), and
* Long‑term environmental and health outcomes (Section 6).

'''Ongoing Governance and Operational Management'''

''(Not just a capital works project)''

Another consistent lesson is that pedestrian streets require continuous governance, not a one‑off design intervention. Freight access, emergency response, cleansing, and event management all required active regulation through time‑based access controls and operational oversight.

This theme underpins:

* Freight and servicing access (Section 4).

'''Managing Success and Secondary Effects'''

''(Over‑use, commercialisation, and place identity)''

Strøget illustrates that successful pedestrianisation can generate second‑order policy challenges, including tourism pressure, rising rents, and retail homogenisation. These outcomes necessitate complementary land‑use, tenancy, and place‑management policies to preserve local character and everyday functionality.

This theme underpins:

* Tourism and commercialisation pressures (Section 5).

== Narrative of the case ==
MK 

Strøget is a 1.1 kilometre pedestrian‑only street network in central Copenhagen (Denmark), which was fully pedestrianised in 1962.&lt;ref&gt;{{Cite web |title=Global Street Design Guide |url=https://globaldesigningcities.org/publication/global-street-design-guide/ |access-date=2026-05-04 |website=Global Designing Cities Initiative |language=en-US}}&lt;/ref&gt; It is widely regarded as one of the world’s earliest and most influential pedestrianisation projects, serving as a landmark example of large‑scale, people‑first urban design.&lt;ref name=&quot;:4&quot; /&gt;&lt;ref&gt;{{Cite web |title=Strøget District {{!}} |url=https://www.pps.org/places/strooget-district |access-date=2026-05-04 |website=www.pps.org}}&lt;/ref&gt;

Located in the historic city centre, Strøget forms a continuous, car‑free corridor running from City Hall Square (Rådhuspladsen) to Kongens Nytorv.&lt;ref&gt;{{Cite web |title=Global Street Design Guide |url=https://globaldesigningcities.org/publication/global-street-design-guide/ |access-date=2026-05-04 |website=Global Designing Cities Initiative |language=en-US}}&lt;/ref&gt; Rather than a single street, it comprises a linked sequence of streets and public squares that together function as a coherent and highly legible pedestrian network.

Since its pedestrianisation in the early 1960s, Strøget has prioritised walking, social activity and public life over vehicle movement. Wide, level paving and active retail and café frontages support high pedestrian volumes and encourage people to linger, gather, and interact. The street accommodates everyday movement as well as street performance, events, and outdoor dining, reinforcing its role as both a transport corridor and a civic space.&lt;ref name=&quot;:2&quot;&gt;{{Cite book |last=Gehl |first=J |title=Cities for people |publisher=Island Press |year=2010}}&lt;/ref&gt;

Internationally, Strøget is significant for demonstrating that removing cars from city centres can enhance economic activity, urban vitality, and quality of life. Its success has influenced pedestrian‑first streets and city‑centre revitalisation projects around the world and remains a benchmark for strong pedestrian network design.

RL

The transformation of Strøget has proven internationally that reducing car access in the city center is not only feasible but also brings significant social and economic benefits.&lt;ref name=&quot;:2&quot; /&gt; Long-term observational data from urban planning scholar Jan Gehl show that after the implementation of pedestrianization, the proportion of people spending time, communicating, and participating in public activities on the streets has experienced a dramatic increase.&lt;ref name=&quot;:0&quot; /&gt; Today, this case has become the gold standard for major cities around the world to revitalize their central areas and implement &quot;pedestrian-first&quot; street designs.&lt;ref&gt;{{Cite book |last=Global Designing Cities Initiative. |title=Global Street Design Guide. |publisher=Island Press. |year=2016}}&lt;/ref&gt;

== References ==

{{BookCat}}</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==

== Identification of policy issues ==

== Narrative of the case ==

== References ==

{{BookCat}}</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026b).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

== Narrative of the case ==

== References ==

{{BookCat}}</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026b).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

== Narrative of the case ==

== References ==

{{BookCat}}
* Australian Broadcasting Corporation. (2026, March 19). ''Great Western Highway taskforce established to manage major closure''. ABC News.
* Australian Broadcasting Corporation. (2026, March 25). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News.
* Australian Broadcasting Corporation. (2026, April 10). ''Geotechnical study shows gaps under Great Western Highway''. ABC News.
* Australian Broadcasting Corporation. (2026, May 5). ''Great Western Highway solution options shortlisted after major failure''. ABC News.</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026b).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

== Narrative of the case ==


==References==

* Australian Broadcasting Corporation. (2026, March 19). ''Great Western Highway taskforce established to manage major closure''. ABC News.
* Australian Broadcasting Corporation. (2026, March 25). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News.
* Australian Broadcasting Corporation. (2026, April 10). ''Geotechnical study shows gaps under Great Western Highway''. ABC News.
* Australian Broadcasting Corporation. (2026, May 5). ''Great Western Highway solution options shortlisted after major failure''. ABC News.</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026b).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

== Narrative of the case ==


==References==

* Australian Broadcasting Corporation. (2026a, March 19). ''Great Western Highway taskforce established to manage major closure''. ABC News.
* Australian Broadcasting Corporation. (2026b, March 25). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News.
* Australian Broadcasting Corporation. (2026c, April 10). ''Geotechnical study shows gaps under Great Western Highway''. ABC News.
* Australian Broadcasting Corporation. (2026d, May 5). ''Great Western Highway solution options shortlisted after major failure''. ABC News.</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026b).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News.
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News.
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News.
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News.
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026b).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026a).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026a).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026b).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026c).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026d).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==
The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route.
Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).
Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
The Great Western Highway is a major transport corridor linking Sydney with western New South Wales through the Blue Mountains. The structural failure occurred at Victoria Pass near Mitchell’s Causeway (also known as the Convict Bridge), a steep and historically significant section of the highway.

Key locations associated with the closure include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge (structural instability zone), Chifley Road, Darling Causeway, Bells Line of Road, and the Lithgow town approaches, which have become the primary traffic redistribution routes during the closure. Traffic travelling between Sydney and western New South Wales has been diverted from the Great Western Highway through Lithgow via Chifley Road and the Darling Causeway to reconnect with Bells Line of Road, resulting in increased congestion, longer travel times, and additional pressure on local and regional roads across the Blue Mountains corridor(ABC, 2026).
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
The Great Western Highway is a major transport corridor linking Sydney with western New South Wales through the Blue Mountains. The structural failure occurred at Victoria Pass near Mitchell’s Causeway (also known as the Convict Bridge), a steep and historically significant section of the highway.

Key locations associated with the closure include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge (structural instability zone), Chifley Road, Darling Causeway, Bells Line of Road, and the Lithgow town approaches, which have become the primary traffic redistribution routes during the closure. Traffic travelling between Sydney and western New South Wales has been diverted from the Great Western Highway through Lithgow via Chifley Road and the Darling Causeway to reconnect with Bells Line of Road, resulting in increased congestion, longer travel times, and additional pressure on local and regional roads across the Blue Mountains corridor (ABC, 2026).
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor linking Sydney with western New South Wales through the Blue Mountains. The structural failure occurred at Victoria Pass near Mitchell’s Causeway (also known as the Convict Bridge), a steep and historically significant section of the highway.

Key locations associated with the closure include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge (structural instability zone), Chifley Road, Darling Causeway, Bells Line of Road, and the Lithgow town approaches, which have become the primary traffic redistribution routes during the closure. Traffic travelling between Sydney and western New South Wales has been diverted from the Great Western Highway through Lithgow via Chifley Road and the Darling Causeway to reconnect with Bells Line of Road, resulting in increased congestion, longer travel times, and additional pressure on local and regional roads across the Blue Mountains corridor(ABC, 2026).
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026). Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==


==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026). Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses (Trust, n.d.).

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management (2). In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours (Government, 2026).

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive (Guardian, 2026).

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns (Gazette, 2026).

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances (Government, 2026).

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026). Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses (Trust, n.d.).

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management (2). In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours (Government, 2026).

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive (Guardian, 2026).

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns (Gazette, 2026).

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances (Government, 2026).

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026). Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses (Trust, n.d.).

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management (2). In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours (Government, 2026).

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive (Guardian, 2026).

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns (Gazette, 2026).

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances (Government, 2026).

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
==Further reading==
==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026). Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

URL:&lt;nowiki&gt;https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf&lt;/nowiki&gt; 

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''.'''

Historical primary source documenting early colonial exploration and road development.

URL: &lt;nowiki&gt;https://gutenberg.net.au/ebooks/e00036.html&lt;/nowiki&gt;

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

URL: &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/sydney-to-central-west-corridors-white-paper&lt;/nowiki&gt;

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

URL: &lt;nowiki&gt;https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/&lt;/nowiki&gt;

5. '''MDPI and ACS Style'''

Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' '''2024''', ''9'', 114.

DOI: &lt;nowiki&gt;https://doi.org/10.3390/infrastructures9070114&lt;/nowiki&gt;

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026). Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

URL:&lt;nowiki&gt;https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf&lt;/nowiki&gt; 

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''.'''

Historical primary source documenting early colonial exploration and road development.

URL: &lt;nowiki&gt;https://gutenberg.net.au/ebooks/e00036.html&lt;/nowiki&gt;

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

URL: &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/sydney-to-central-west-corridors-white-paper&lt;/nowiki&gt;

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

URL: &lt;nowiki&gt;https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/&lt;/nowiki&gt;

5. '''MDPI and ACS Style'''

Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' '''2024''', ''9'', 114.

DOI: &lt;nowiki&gt;https://doi.org/10.3390/infrastructures9070114&lt;/nowiki&gt;

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026&lt;ref&gt;{{Cite news |date=2026-03-19 |title=Highway closure not a 'natural' disaster, NSW government says |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918 |access-date=2026-05-22}}&lt;/ref&gt;).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026&lt;ref&gt;{{Cite news |date=2026-03-19 |title=Highway closure not a 'natural' disaster, NSW government says |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918 |access-date=2026-05-22}}&lt;/ref&gt;).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt;).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026)&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;.
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

URL:&lt;nowiki&gt;https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf&lt;/nowiki&gt; 

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''.'''

Historical primary source documenting early colonial exploration and road development.

URL: &lt;nowiki&gt;https://gutenberg.net.au/ebooks/e00036.html&lt;/nowiki&gt;

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

URL: &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/sydney-to-central-west-corridors-white-paper&lt;/nowiki&gt;

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

URL: &lt;nowiki&gt;https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/&lt;/nowiki&gt;

5. '''MDPI and ACS Style'''

Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' '''2024''', ''9'', 114.

DOI: &lt;nowiki&gt;https://doi.org/10.3390/infrastructures9070114&lt;/nowiki&gt;

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
* Early March 2026: Structural concerns identified at Victoria Pass section of the Great Western Highway following signs of cracking and instability (Australian Broadcasting Corporation [ABC], 2026&lt;ref&gt;{{Cite news |date=2026-03-19 |title=Highway closure not a 'natural' disaster, NSW government says |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918 |access-date=2026-05-22}}&lt;/ref&gt;).
* 19 March 2026: NSW Government established a multi-agency taskforce to coordinate response and manage disruption impacts (ABC, 2026&lt;ref&gt;{{Cite news |date=2026-03-19 |title=Highway closure not a 'natural' disaster, NSW government says |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918 |access-date=2026-05-22}}&lt;/ref&gt;).
* 25 March 2026: A $50 million package was announced to upgrade detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt;).
* Late March 2026: The affected section of highway was closed due to escalating safety risks associated with structural instability.
* 10 April 2026: Geotechnical investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026)&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;.
* April 2026: Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
* 5 May 2026: Engineering solutions were shortlisted for detailed evaluation, marking progression into the design phase (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
{| class=&quot;wikitable&quot;
|+ Timeline of Victoria Pass (Convict Bridge) and 2026 Great Western Highway Events
! Period / Date !! Event !! Description
|-
| 1829–1833 || Planning, construction and early completion of Victoria Pass (Convict Bridge) || Surveyor-General Thomas Mitchell planned the western route over the Blue Mountains (1829–1830). Construction of Victoria Pass and associated sandstone structures, including the Convict Bridge, began in 1830 using convict labour. The route opened in 1832, providing a key connection between Sydney and the Central West. Final completion works and early repairs continued through 1832–1833 due to steep terrain, engineering constraints, and early structural challenges (NSW Government Heritage Inventory, 2024; State Library of NSW, 2023).
|-
| 1999 || Heritage listing || The Victoria Pass precinct, including the Convict Bridge area, was listed on the New South Wales State Heritage Register (NSW Heritage Register, 1999).
|-
| Early March 2026 || Structural concerns identified || Cracking and instability were identified at the Victoria Pass section of the Great Western Highway (ABC, 2026).
|-
| 19 March 2026 || Taskforce established || NSW Government established a multi-agency taskforce to manage response and disruption impacts (ABC, 2026).
|-
| 25 March 2026 || Detour funding announced || A $50 million package was announced to upgrade key detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
|-
| Late March 2026 || Highway closure || The affected section of the highway was closed due to escalating safety risks from structural instability.
|-
| 10 April 2026 || Geotechnical investigations || Investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
|-
| April 2026 || Monitoring phase || Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
|-
| 5 May 2026 || Engineering solutions shortlisted || Engineering options were shortlisted for detailed evaluation, progressing toward the design phase (ABC, 2026).
|}

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day (ABC News, 2026d). Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric (Heritage NSW, n.d.). That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure (ABC News, 2026c). Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass (ABC News, 2026e). In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing (NSW Government, 2026a). That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street (NSW Government, 2026a, 2026c). Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options (ABC News, 2026d; NSW Government, 2026e). Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised (ABC News, 2026e; NSW Government, 2026a).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure (ABC News, 2026d; NSW Government, 2026a; NSW Government, 2026e).
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road (ABC News, 2026a; ABC News, 2026d; NSW Government, 2026a).
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption (ABC News, 2026a; NSW Government, 2026b).
|}

== Timeline of events ==
{| class=&quot;wikitable&quot;
|+ Timeline of Victoria Pass (Convict Bridge) and 2026 Great Western Highway Events
! Period / Date !! Event !! Description
|-
| 1829–1833 || Planning, construction and early completion of Victoria Pass (Convict Bridge) || Surveyor-General Thomas Mitchell planned the western route over the Blue Mountains (1829–1830). Construction of Victoria Pass and associated sandstone structures, including the Convict Bridge, began in 1830 using convict labour. The route opened in 1832, providing a key connection between Sydney and the Central West. Final completion works and early repairs continued through 1832–1833 due to steep terrain, engineering constraints, and early structural challenges (NSW Government, n.d.).
|-
| 1999 || Heritage listing || The Victoria Pass precinct, including the Convict Bridge area, was listed on the New South Wales State Heritage Register (NSW Heritage Register, 1999).
|-
| Early March 2026 || Structural concerns identified || Cracking and instability were identified at the Victoria Pass section of the Great Western Highway (ABC, 2026).
|-
| 19 March 2026 || Taskforce established || NSW Government established a multi-agency taskforce to manage response and disruption impacts (ABC, 2026).
|-
| 25 March 2026 || Detour funding announced || A $50 million package was announced to upgrade key detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
|-
| Late March 2026 || Highway closure || The affected section of the highway was closed due to escalating safety risks from structural instability.
|-
| 10 April 2026 || Geotechnical investigations || Investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
|-
| April 2026 || Monitoring phase || Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
|-
| 5 May 2026 || Engineering solutions shortlisted || Engineering options were shortlisted for detailed evaluation, progressing toward the design phase (ABC, 2026).
|}

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day &lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;. Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric&lt;ref&gt;{{Cite web |title=Victoria Pass {{!}} Heritage NSW |url=https://apps.environment.nsw.gov.au/dpcheritageapp/ViewHeritageItemDetails.aspx?ID=4301023 |access-date=2026-05-22 |website=apps.environment.nsw.gov.au}}&lt;/ref&gt;. That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;. Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass&lt;ref&gt;{{Cite news |date=2026-03-10 |title=Government warned now-closed 'horse and cart' Convict Bridge unfit for modern traffic |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |access-date=2026-05-22}}&lt;/ref&gt;. In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;. Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised(Heritage NSW, n.d.).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;.
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption&lt;ref&gt;{{Cite journal |last=Authority |first=NSW Reconstruction |date=2026-03-19 |title=New Taskforce to coordinate support for Great Western Highway communities {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/new-taskforce-to-coordinate-support-for-great-western-highway-communities-0 |language=en-AU}}&lt;/ref&gt;.
|}

== Timeline of events ==
{| class=&quot;wikitable&quot;
|+ Timeline of Victoria Pass (Convict Bridge) and 2026 Great Western Highway Events
! Period / Date !! Event !! Description
|-
| 1829–1833 || Planning, construction and early completion of Victoria Pass (Convict Bridge) || Surveyor-General Thomas Mitchell planned the western route over the Blue Mountains (1829–1830). Construction of Victoria Pass and associated sandstone structures, including the Convict Bridge, began in 1830 using convict labour. The route opened in 1832, providing a key connection between Sydney and the Central West. Final completion works and early repairs continued through 1832–1833 due to steep terrain, engineering constraints, and early structural challenges (NSW Government, n.d.).
|-
| 1999 || Heritage listing || The Victoria Pass precinct, including the Convict Bridge area, was listed on the New South Wales State Heritage Register (NSW Heritage Register, 1999).
|-
| Early March 2026 || Structural concerns identified || Cracking and instability were identified at the Victoria Pass section of the Great Western Highway (ABC, 2026).
|-
| 19 March 2026 || Taskforce established || NSW Government established a multi-agency taskforce to manage response and disruption impacts (ABC, 2026).
|-
| 25 March 2026 || Detour funding announced || A $50 million package was announced to upgrade key detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
|-
| Late March 2026 || Highway closure || The affected section of the highway was closed due to escalating safety risks from structural instability.
|-
| 10 April 2026 || Geotechnical investigations || Investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
|-
| April 2026 || Monitoring phase || Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
|-
| 5 May 2026 || Engineering solutions shortlisted || Engineering options were shortlisted for detailed evaluation, progressing toward the design phase (ABC, 2026).
|}

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day &lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;. Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric&lt;ref&gt;{{Cite web |title=Victoria Pass {{!}} Heritage NSW |url=https://apps.environment.nsw.gov.au/dpcheritageapp/ViewHeritageItemDetails.aspx?ID=4301023 |access-date=2026-05-22 |website=apps.environment.nsw.gov.au}}&lt;/ref&gt;. That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;. Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass&lt;ref&gt;{{Cite news |date=2026-03-10 |title=Government warned now-closed 'horse and cart' Convict Bridge unfit for modern traffic |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |access-date=2026-05-22}}&lt;/ref&gt;. In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;. Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised(Heritage NSW, n.d.).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;.
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption&lt;ref&gt;{{Cite journal |last=Authority |first=NSW Reconstruction |date=2026-03-19 |title=New Taskforce to coordinate support for Great Western Highway communities {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/new-taskforce-to-coordinate-support-for-great-western-highway-communities-0 |language=en-AU}}&lt;/ref&gt;.
|}

== Timeline of events ==
{| class=&quot;wikitable&quot;
|+ Timeline of Victoria Pass (Convict Bridge) and 2026 Great Western Highway Events
! Period / Date !! Event !! Description
|-
| 1829–1833 || Planning, construction and early completion of Victoria Pass (Convict Bridge) || Surveyor-General Thomas Mitchell planned the western route over the Blue Mountains (1829–1830). Construction of Victoria Pass and associated sandstone structures, including the Convict Bridge, began in 1830 using convict labour. The route opened in 1832, providing a key connection between Sydney and the Central West. Final completion works and early repairs continued through 1832–1833 due to steep terrain, engineering constraints, and early structural challenges (NSW Government, n.d.).
|-
| 1999 || Heritage listing || The Victoria Pass precinct, including the Convict Bridge area, was listed on the New South Wales State Heritage Register (NSW Government, n.d.).
|-
| Early March 2026 || Structural concerns identified || Cracking and instability were identified at the Victoria Pass section of the Great Western Highway (ABC, 2026).
|-
| 19 March 2026 || Taskforce established || NSW Government established a multi-agency taskforce to manage response and disruption impacts (ABC, 2026).
|-
| 25 March 2026 || Detour funding announced || A $50 million package was announced to upgrade key detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
|-
| Late March 2026 || Highway closure || The affected section of the highway was closed due to escalating safety risks from structural instability.
|-
| 10 April 2026 || Geotechnical investigations || Investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
|-
| April 2026 || Monitoring phase || Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
|-
| 5 May 2026 || Engineering solutions shortlisted || Engineering options were shortlisted for detailed evaluation, progressing toward the design phase (ABC, 2026).
|}

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day &lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;. Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric&lt;ref&gt;{{Cite web |title=Victoria Pass {{!}} Heritage NSW |url=https://apps.environment.nsw.gov.au/dpcheritageapp/ViewHeritageItemDetails.aspx?ID=4301023 |access-date=2026-05-22 |website=apps.environment.nsw.gov.au}}&lt;/ref&gt;. That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;. Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass&lt;ref&gt;{{Cite news |date=2026-03-10 |title=Government warned now-closed 'horse and cart' Convict Bridge unfit for modern traffic |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |access-date=2026-05-22}}&lt;/ref&gt;. In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;. Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised(Heritage NSW, n.d.).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;.
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption&lt;ref&gt;{{Cite journal |last=Authority |first=NSW Reconstruction |date=2026-03-19 |title=New Taskforce to coordinate support for Great Western Highway communities {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/new-taskforce-to-coordinate-support-for-great-western-highway-communities-0 |language=en-AU}}&lt;/ref&gt;.
|}

== Timeline of events ==
{| class=&quot;wikitable&quot;
|+ Timeline of Victoria Pass (Convict Bridge) and 2026 Great Western Highway Events
! Period / Date !! Event !! Description
|-
| 1829–1833 || Planning, construction and early completion of Victoria Pass (Convict Bridge) || Surveyor-General Thomas Mitchell planned the western route over the Blue Mountains (1829–1830). Construction of Victoria Pass and associated sandstone structures, including the Convict Bridge, began in 1830 using convict labour. The route opened in 1832, providing a key connection between Sydney and the Central West. Final completion works and early repairs continued through 1832–1833 due to steep terrain, engineering constraints, and early structural challenges (NSW Government, n.d.).
|-
| 1999 || Heritage listing || The Victoria Pass precinct, including the Convict Bridge area, was listed on the New South Wales State Heritage Register (NSW Government, n.d.).
|-
| Early March 2026 || Structural concerns identified || Cracking and instability were identified at the Victoria Pass section of the Great Western Highway (ABC, 2026).
|-
| 19 March 2026 || Taskforce established || NSW Government established a multi-agency taskforce to manage response and disruption impacts (ABC, 2026).
|-
| 25 March 2026 || Detour funding announced || A $50 million package was announced to upgrade key detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026).
|-
| Late March 2026 || Highway closure || The affected section of the highway was closed due to escalating safety risks from structural instability.
|-
| 10 April 2026 || Geotechnical investigations || Investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026).
|-
| April 2026 || Monitoring phase || Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
|-
| 5 May 2026 || Engineering solutions shortlisted || Engineering options were shortlisted for detailed evaluation, progressing toward the design phase (ABC, 2026).
|}

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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== Summary ==
In early March 2026, Mitchell's Causeway at Victoria Pass suffered serious structural damage, abruptly closing a critical highway link between Sydney and the Central West. Known locally as the Convict Bridge, the causeway carries the Great Western Highway between Little Hartley and Mount Victoria, where around 12,000 vehicles normally passed each day &lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;. Once the road closed, that traffic had to move through longer and less suitable mountain detours.
The problem was not just that an old bridge cracked. More uncomfortable is the fact that this old bridge was still doing the job of a modern strategic road.
Mitchell's Causeway is historically valuable because it remains a rare example of colonial road engineering. Heritage NSW records that the Victoria Pass Causeway was built between 1829 and 1832 and has retained much of its original form and fabric&lt;ref&gt;{{Cite web |title=Victoria Pass {{!}} Heritage NSW |url=https://apps.environment.nsw.gov.au/dpcheritageapp/ViewHeritageItemDetails.aspx?ID=4301023 |access-date=2026-05-22 |website=apps.environment.nsw.gov.au}}&lt;/ref&gt;. That heritage value matters, but it also makes the present-day transport problem harder. A normal road asset can be rebuilt with fewer constraints; a convict-built causeway on the State Heritage Register cannot be treated so casually. Safety, heritage and traffic function all sit on the same narrow piece of road.
By April, geotechnical work had confirmed that the issue was deeper than surface pavement damage. Minister Jenny Aitchison said the fill underneath the road had deteriorated and that there were &quot;voids and gaps&quot; within the causeway structure&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;. Earlier warning signs also matter here. ABC reported that local business groups had raised concerns about the safety and durability of the Convict Bridge before the closure, while broader corridor planning had already identified reliability problems at Victoria Pass&lt;ref&gt;{{Cite news |date=2026-03-10 |title=Government warned now-closed 'horse and cart' Convict Bridge unfit for modern traffic |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |access-date=2026-05-22}}&lt;/ref&gt;. In other words, the shutdown did not come from nowhere.
Official advice suggested that the Darling Causeway and Bells Line of Road detour could add up to 25 minutes to a Blue Mountains crossing&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. That figure is tidy, but real life was not. For a person making one flexible trip, 25 minutes may be manageable. For students, workers, freight drivers, medical trips and small businesses relying on passing traffic, the cost was repeated every day. The detour became part of people's routines, not just a line in a traffic update.
The state moved quickly once the road was closed. Extra rail, coach and school bus services followed, agencies formed an incident management team, and the government committed A$50 million to improving detour routes such as Darling Causeway, Chifley Road and Lithgow Main Street&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Later, Transport for NSW received ten engineering submissions and shortlisted consortia led by Seymour Whyte and Gamuda to develop repair options&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;. Those responses were necessary. Yet their timing is hard to ignore: the detour network became urgent only after the main route had already failed.
In short, this is less a heritage repair problem than a failure of transport resilience: a known vulnerable link lacked a robust fallback before it failed. The road can eventually reopen, but reopening alone will not explain why that fallback was missing.

== Annotated list of factors ==
{| class=&quot;wikitable&quot;
! Actor / Stakeholder group
! Role in the case
! Main interests, concerns and policy relevance
|-
| '''Transport for NSW, engineers and heritage specialists'''
| Led the operational response, including road closure, monitoring, detours and technical assessment.
| Transport for NSW had to prioritise public safety once movement was detected at Mitchell’s Causeway. The closure itself was difficult to dispute, but the harder issue sits before the closure: whether the agency had clear enough trigger points for earlier intervention, especially after local concerns about the bridge’s safety had already been raised(Heritage NSW, n.d.).
|-
| '''Heritage NSW and conservation interests'''
| Defined the heritage value of Victoria Pass Causeway and shaped the limits of repair.
| Heritage NSW gives the site its historical weight. The causeway matters because much of its colonial engineering remains legible, but that is exactly what complicates repair. Current policy protects the heritage asset, yet it does not clearly answer how that asset should function when it is still part of a freight and commuter route (Heritage NSW, n.d.).
|-
| '''NSW Government, Minister Jenny Aitchison and the repair decision'''
| Managed the political response, public messaging, funding and repair procurement.
| The government’s safety-first message was reasonable, but it also narrowed the public conversation. Once the issue was framed mainly as “do not risk lives,” less attention was given to why a known fragile cross-mountain link had no pre-prepared detour capacity strong enough to absorb the failure. The repair decision also has to balance speed, durability, cost, heritage approval and political pressure&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-05-13 |title=Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/victoria-pass-engineering-solutions-shortlisted |language=en-AU}}&lt;/ref&gt;.
|-
| '''Those who carried the cost: communities, businesses, councils and freight'''
| Experienced the practical impacts of the closure on daily travel, local trade and freight movement.
| The closure landed unevenly. Local councils had to manage congestion and road wear even though the highway was a state responsibility&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-25 |title=Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/minns-government-commits-50-million-to-strengthen-detour-routes-during-great-western-highway-closure |language=en-AU}}&lt;/ref&gt;. Families faced longer school and work trips. Businesses lost customers who used to arrive because the highway brought them past the front door. Freight users were pushed onto less suitable routes through Lithgow, Chifley Road, Darling Causeway and Bells Line of Road&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| '''NSW Reconstruction Authority and the Community Coordination Taskforce'''
| Coordinated communication between government, councils, industry and affected communities.
| The taskforce gave councils, industry and community groups a clearer contact point during the disruption. Its role was narrower than Transport for NSW’s technical role, but it showed how unusual the closure was: the event did not fit neatly into normal disaster arrangements, while affected towns experienced it as a major regional disruption&lt;ref&gt;{{Cite journal |last=Authority |first=NSW Reconstruction |date=2026-03-19 |title=New Taskforce to coordinate support for Great Western Highway communities {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/new-taskforce-to-coordinate-support-for-great-western-highway-communities-0 |language=en-AU}}&lt;/ref&gt;.
|}

== Timeline of events ==
{| class=&quot;wikitable&quot;
|+ Timeline of Victoria Pass (Convict Bridge) and 2026 Great Western Highway Events
! Period / Date !! Event !! Description
|-
| 1829–1833 || Planning, construction and early completion of Victoria Pass (Convict Bridge) || Surveyor-General Thomas Mitchell planned the western route over the Blue Mountains (1829–1830). Construction of Victoria Pass and associated sandstone structures, including the Convict Bridge, began in 1830 using convict labour. The route opened in 1832, providing a key connection between Sydney and the Central West. Final completion works and early repairs continued through 1832–1833 due to steep terrain, engineering constraints, and early structural challenges (NSW Government, n.d.)&lt;ref&gt;{{Cite web |title=Victoria Pass {{!}} Heritage NSW |url=https://apps.environment.nsw.gov.au/dpcheritageapp/ViewHeritageItemDetails.aspx?id=4301023 |access-date=2026-05-22 |website=apps.environment.nsw.gov.au}}&lt;/ref&gt;.
|-
| 1999 || Heritage listing || The Victoria Pass precinct, including the Convict Bridge area, was listed on the New South Wales State Heritage Register (NSW Government, n.d.&lt;ref&gt;{{Cite web |title=Heritage |url=https://www.environment.nsw.gov.au/topics/heritage |access-date=2026-05-22 |website=Environment and Heritage |language=en}}&lt;/ref&gt;).
|-
| Early March 2026 || Structural concerns identified || Cracking and instability were identified at the Victoria Pass section of the Great Western Highway (ABC, 2026)&lt;ref&gt;{{Cite news |date=2026-03-19 |title=Highway closure not a 'natural' disaster, NSW government says |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| 19 March 2026 || Taskforce established || NSW Government established a multi-agency taskforce to manage response and disruption impacts (ABC, 2026)&lt;ref&gt;{{Cite news |date=2026-03-19 |title=Highway closure not a 'natural' disaster, NSW government says |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| 25 March 2026 || Detour funding announced || A $50 million package was announced to upgrade key detour routes including Bells Line of Road, Chifley Road, and Darling Causeway (ABC, 2026&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt;).
|-
| Late March 2026 || Highway closure || The affected section of the highway was closed due to escalating safety risks from structural instability.
|-
| 10 April 2026 || Geotechnical investigations || Investigations confirmed subsurface voids and significant ground instability beneath the roadway (ABC, 2026)&lt;ref&gt;{{Cite news |date=2026-04-10 |title=Minister says there is no 'proper timetable' for reopening NSW highway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768 |access-date=2026-05-22}}&lt;/ref&gt;.
|-
| April 2026 || Monitoring phase || Ongoing monitoring and assessment of structural conditions continued while long-term solutions were evaluated.
|-
| 5 May 2026 || Engineering solutions shortlisted || Engineering options were shortlisted for detailed evaluation, progressing toward the design phase (ABC, 2026&lt;ref&gt;{{Cite news |date=2026-05-05 |title=Great Western Highway fix in sight almost 60 days after road shut |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888 |access-date=2026-05-22}}&lt;/ref&gt;).
|}

== Maps of locations ==

The Great Western Highway is a major transport corridor connecting Sydney to western New South Wales through the Blue Mountains. The failure occurred at Victoria Pass, a steep and historically significant section of the route. Key locations include Victoria Pass (failure point), Mitchell’s Causeway / Convict Bridge area (structural weakness zone), Bells Line of Road (northern detour), Chifley Road (southern detour), and Lithgow approaches (traffic redistribution routes) (ABC, 2026).&lt;ref&gt;{{Cite news |date=2026-03-25 |title=$50m for Great Western Highway detour routes, as road remains 'unstable' |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330 |access-date=2026-05-22}}&lt;/ref&gt; Traffic has been diverted across these alternative routes, increasing congestion and travel times across the Blue Mountains corridor due to closure of the primary highway link.
[[File:Convict Bridge Location - 22 May 2026.jpg|thumb|This map shows the location of the Convict Bridge and the associated traffic disruption.]]

== Identification of policy issues ==

=== Heritage Listing as Structural Lock-In ===
The NSW Heritage Act 1977 establishes the State Heritage Register and defines conditions under which listed assets may be altered. The heritage listing for Victoria Pass and Berghofers Pass includes exemptions only for specific works, including emergency stabilisation activities where a structure has been damaged and poses a safety risk (TfNSW, 2026). Everything below that threshold falls outside permissible intervention under normal conditions, including the urgently required structural reinforcement of a masonry retained embankment that has been overly exposed to loads beyond its structural capacity.

The fundamental incompatibility between a rubble-filled sandstone embankment and 12,000 vehicles per day (including semi-trailer trucks) could not be easily addressed by Transport for NSW without interventions the listing prohibited. Heritage listing without a parallel structural compatibility assessment has converted the bridge from a living piece of infrastructure into a frozen liability. The asset must be preserved as-is while continuing to carry loads it cannot tolerate, with intervention only permitted after the point of failure. The NSW Government’s own geotechnical investigations confirmed that the 200-year-old fill had deteriorated significantly, creating voids and gaps throughout the substructure. It was even acknowledged that without enhanced monitoring installed in late 2025, the structure could have collapsed before defects were detected (NSW Government, 2026). 

That monitoring was installed three months before failure on a structure that had been carrying highway-grade traffic for over a century. It indicates that the asset management program was operating reactively rather than condition-based mode at this site.

=== The Substructure Monitoring Deficit ===
The  deterioration of the site was not being tracked through substructure inspection. Enhanced monitoring was installed in December 2025, presenting as proactive stewardship in TfNSW’s public communications, but the fact that real-time structural monitoring was not in place on a known-risk heritage asset carrying primary freight traffic until three months before catastrophic failure indicates an inspection and asset management programme that had not matched its cadence to the risk profile of the structure.

=== The Announcement-Commitment Gap ===
The bypass tunnel cancellation is the most politically visible element of the state-level failure, but it sits within a longer pattern of interrupted commitment on the Great Western Highway that substantially predates the Minns government.

A prime example of “strategic misrepresentation” in megaproject approval, where proponents deliberately underestimate costs and overestimate benefits to secure political commitment, knowing the commitment will not survive contact with delivery (Flyvberj, 2013).

Australian governments are prone to announcing projects they have no realistic intention of building within their term, generating regional goodwill at low political cost, while deferring the fiscal and delivery burden to successors who then cancel and repeat the cycle. Flyvbjerg identifies systematic problems in the development process, whereby proponents intentionally misrepresent information and deliberately disregard risks, instigating projects that result in fewer benefits and higher costs than promised (Flyvberj, 2013). 

The inverse also applies: announced projects that were always underfunded relative to delivery requirements.

This is evident in the proposed twin-tunnel upgrade for the Great Western Highway. In the September 2023 state budget, the Minns government reallocated state funding commitments for the upgrade. In November 2023, the federal government confirmed it would also reallocate its funding commitment, redirecting it to other priorities (TfNSW, 2024).

The tunnels were formally cancelled in favour of softer commitments. The causeway failed six weeks later. The planning investment was sunk, but the corridor problem it was designed to solve remained.

Transport for NSW ultimately paused all work on upgrades to the Great Western Highway between Katoomba and Lithgow, apart from the Medlow Bath and Coxs River Road upgrades, with state and federal funding commitments redirected to other projects (TfNSW, 2026)

=== Metro Spending Bias ===
Sydney Metro alone comprised over a quarter of NSW’s total four-year infrastructure spend in the 2023–24 budget, at $24.9 billion over four years (Infrastructure Partnerships Australia, 2023).  The bulk of NSW road funding was directed toward the Western Harbour Tunnel and Princes Highway Corridor. The same organisation went on to note that NSW may experience a deficit in the medium to long-term regional pipeline (Infrastructure Partnerships Australia, 2024).

The Great Western Highway bypass, at a total project cost estimated at $12 billion over an eight-to-ten year build, was cancelled due to being ‘fiscally unachievable’ in the same budget environment that continued to fund cost overruns in the Greater Sydney metropolitan area. The Sydney Metro City and Southwest line alone exceeded its original budget by approximately $5.1 billion, yet an additional $1 billion in interim funding was allocated to the project (Duboudin, 2022).

Metropolitan projects concentrate benefits in large, media-visible electorates, while regional corridor projects benefit smaller, dispersed populations. Successive budgets treated the Great Western Highway as a maintenance problem rather than a capital investment priority, while overruns in metro-context projects were absorbed without similar scrutiny.

This asymmetry was flagged explicitly before the 2023 election, arguing that Labor’s stated intention to redirect Great Western Highway funding to Western Sydney infrastructure would leave the Central West without a safe and productive link to Sydney (Lachlan Shire Council, 2023). 

=== Short-Termism and the Electoral Cycle ===
Major transport infrastructure in Australia runs on a 10–15 year development and delivery horizon. NSW state electoral terms run to four years. No government that announces a major regional infrastructure project opens it. The announcement is the political event; delivery is not.

Political short-termism is formally defined in the literature as the systematic prioritisation of short-term net policy benefits over long-term outcomes, hindering policy investments that impose short-term costs on society to address long-term challenges (Ogami, 2024). Infrastructure costs are immediate, visible, and attributable; benefits are diffuse, delayed, and frequently credited to successors. 

The short-term actor announces rather than builds, the incoming government cancels an adversary’s political monument.

Contributing traits such as short electoral cycles, voters’ discounting of future policy benefits, and partisanship are particularly acute in the Australian context of short electoral terms and adversarial two-party politics (Ogami, 2024).

There is no institutional obligation on a NSW government to honour prior infrastructure commitments not yet under contract. Independent authorities have no more than advisory power over infrastructure pipelines. Infrastructure NSW and Infrastructure Australia can recommend and prioritise, but not prevent the government from redirecting committed funding upon taking office. 

=== Heritage-Infrastructure Compatibility Framework ===
The heritage listing at Victoria Pass was the correct cultural heritage decision. However, the systematic framework for assessing and managing compatibility and longevity of heritage-listed infrastructures continues to be absent. 

The NSW Heritage Act 1977 and its associated guidelines do not require ongoing assessment of whether a listed asset’s structural characteristics remain compatible with the loads placed upon it, or mandate intervention thresholds short of emergency conditions.

The NSW State Infrastructure Strategy 2018–2038 recommended introducing an asset management policy with a new assurance model, but its focus was on capital growth and network efficiency, with no meaningful attention on infrastructure compatibility (Affan, 2019).

The gap is not owned by a single agency: Heritage NSW administers the listing conditions; Transport for NSW manages the asset; Treasury funds maintenance allocations. 

All of which are not required to jointly assess whether a heritage listing, a loading profile, and a maintenance budget are mutually compatible over time. 

=== The Procurement Model and Policy Continuity ===
Love et. al. argue that the traditional procurement model used by Australian state governments fails to deliver expected benefits for large-scale transport projects, and that a focused policy-making pathway is largely absent. Especially in future-proofing complex infrastructure assets against unanticipated changes in load, use, or structural condition (Love et. al., 2021) .

The structural consequence is that major transport assets are managed transactionally, without a long-horizon framework for assessing when a structure has moved beyond the envelope of maintainability and requires replacement or bypass. Mitchell’s Causeway is the reductio ad absurdum of this model: a structure well past its design life, carrying loads it was never intended for, preserved by heritage listing from the interventions that would have resolved the incompatibility, and sustained by a maintenance programme that could not address what the listing prevented.

Politicisation, inconsistent engagement, and short-termism undermine public trust, and erode reform capability in Australian infrastructure governance. These barriers are embedded in the institutional design of the system, not attributable to the decisions of particular governments (ANU, 2025).

== Narrative of the case ==

The Convict Bridge, also known as Mitchell’s Causeway, highlights a classic infrastructure paradox: a historically significant asset continues to perform a modern, high-demand transport function long after its design life has expired. Built in 1832 during the colonial era using convict labour, the bridge is one of Australia’s earliest and most significant transport assets. For almost two centuries, it has played a vital role in connecting communities across the Blue Mountains and supporting movement between Sydney and inland New South Wales.

Over time, the bridge became an essential transport link within the regional road network. However, its original design was never intended to accommodate the heavy traffic volumes and vehicle loads associated with contemporary transport systems. As decades passed, increasing pressure placed stress on the sandstone retaining walls and the underlying structure. Although engineers had identified signs of deterioration in earlier years, intervention was limited due to heritage restrictions and funding priorities. As a result, most works focused on surface-level upgrades rather than major structural improvements. Eventually, geotechnical instability emerged, with reports identifying movement in retaining walls and buttresses&lt;ref&gt;{{Cite web |title= |url=https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/? |access-date= |website=}}&lt;/ref&gt; .

Concerns intensified in late 2025 when local stakeholders warned that the bridge could potentially fail under modern loading conditions. Despite these warnings, immediate policy action was limited. Instead, authorities relied primarily on monitoring technologies, reflecting a reactive rather than preventative approach to infrastructure management&lt;ref&gt;{{Cite journal |last= |first= |date= |title=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |url=https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242 |journal= |language=en-AU}}&lt;/ref&gt; . In early March 2026, visible structural movement and cracking appeared along the roadway surface. In response, authorities closed Victoria Pass to protect public safety. The closure immediately disrupted a major transport corridor used by approximately 12,000 people daily and forced motorists and freight operators to take lengthy detours&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

The closure also revealed broader systemic issues within regional infrastructure planning. It exposed weaknesses such as insufficient network redundancy, delayed investment in alternative routes, and limited long-term planning for aging infrastructure. Local communities experienced longer travel times, economic impacts, and reduced accessibility, while freight transport became less efficient and more expensive&lt;ref&gt;{{Cite news |last=Buckley |first=Penry |last2=Larkin |first2=Jack |date=2026-03-13 |title=A key Blue Mountains road closure is blowing out travel times – and causing ‘red hot anger’ among locals |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel |access-date=2026-05-22 |issn=0261-3077}}&lt;/ref&gt; .

Importantly, the incident demonstrated how vulnerable regional transport systems in New South Wales can become when they depend heavily on a single piece of infrastructure. Alternative routes, including the Bells Line of Road, were not designed to accommodate the sudden increase in redirected freight and traffic volumes, creating additional congestion and safety concerns&lt;ref&gt;{{Cite web |title=Client Challenge |url=https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/ |access-date=2026-05-22 |website=www.hawkesburygazette.com}}&lt;/ref&gt;.

From a governance perspective, the response further underscores systemic weaknesses. While the NSW Government implemented short-term mitigation measures—such as increased public transport services—these actions addressed symptoms rather than underlying causes. The urgency of post-failure engineering procurement highlights how crisis conditions often accelerate decision-making that had been deferred under normal circumstances&lt;ref&gt;{{Cite journal |last=NSW |first=Transport for |date=2026-03-13 |title=“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure |language=en-AU}}&lt;/ref&gt;.

Ultimately, the Convict Bridge case reflects a wider issue in infrastructure planning and asset management: the disconnect between long-term infrastructure needs and short-term political, financial, and policy constraints. Rather than being an unexpected failure, closure can be understood as the result of years of deferred intervention, competing priorities between heritage preservation and operational performance, and limited proactive investment in resilient transport infrastructure.
==Discussion Questions==
1: Is the announcement-commitment gap a failure of political will, or an inevitable product of democratic institutional design?

2: Did the heritage listing of Victoria Pass serve the public interest, or did it subordinate infrastructure safety to cultural preservation in a way that was never transparently debated?

3: Existing Cost-Benefit Analysis process justifies projects based on actual usage and density, which is naturally unfavourable for infrastructure funding in regional and remote areas, how can we close this gap?

4: The causeway’s failure was physically gradual but politically sudden, and it can be traced back to the absence of political accountability. What measures can be put in place in the existing decision making framework that will meaningfully mitigate this?

==Further reading==
'''1. Transport for NSW. (2023). ''Crossing the Blue Mountains: The Great Western Road'''''&lt;ref&gt;{{Cite web |last=NSW |first=Transport |title=Crossing the Blue Mountains |url=https://www.transport.nsw.gov.au/system/files/media/documents/2023/crossing_the_blue_mountains_the_great_western_road.pdf}}&lt;/ref&gt; '''.'''

Official NSW Government historical report on the development of transport infrastructure across the Blue Mountains.

'''2. Project Gutenberg Australia. ''Three Expeditions into the Interior of Eastern Australia – Thomas Mitchell''''' &lt;ref&gt;{{Cite web |title=Three Expeditions into the Interior V2 |url=https://gutenberg.net.au/ebooks/e00036.html |access-date=2026-05-22 |website=gutenberg.net.au}}&lt;/ref&gt;'''.'''

Historical primary source documenting early colonial exploration and road development.

3. '''Sydney to Central West Corridors White Paper (Transport for NSW)'''&lt;ref&gt;{{Cite web |last=NSW |first=Transport for |date=2025-12-03 |title=Sydney to Central West Corridors White Paper |url=https://www.transport.nsw.gov.au/node/31741 |access-date=2026-05-22 |website=www.transport.nsw.gov.au |language=en-AU}}&lt;/ref&gt; 

A strategic planning document assessing capacity, safety, and resilience challenges along the Great Western Highway and alternative routes.

4. '''Australia’s Longest Road Tunnel Proposal – Blue Mountains'''&lt;ref&gt;{{Cite web |last=Walker |first=Nicole |date=2022-05-23 |title=Australia's longest road tunnel through Blue Mountains |url=https://concreteinstitute.com.au/australias-longest-road-tunnel-through-blue-mountains/ |access-date=2026-05-22 |website=Concrete Institute of Australia |language=en-AU}}&lt;/ref&gt;

Discusses proposed large-scale infrastructure solutions to improve safety, reduce travel times, and increase resilience.

5.  '''Salah, R.; Szép, J.; Ajtayné Károlyfi, K.; Géczy, N. An Investigation of Historic Transportation Infrastructure Preservation and Improvement through Historic Building Information Modeling. ''Infrastructures'' 2024, ''9'', 114''' .

==References==

* Affan R. (2019) Getting asset management right: a new framework. Infrastructure Journalist. &lt;nowiki&gt;https://127.0.0.1/getting-asset-management-right-a-new-framework/&lt;/nowiki&gt;
*ANU Institute for Infrastructure in Society (2025). Strengthening Australia’s capacity for policy reform.   &lt;nowiki&gt;https://infrastructure.anu.edu.au/strengthening-australias-capacity-policy-reform&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway taskforce established to manage major closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-19/great-western-highway-taskforce/106471918&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''$50 million funding to maintain detour roads in Great Western Highway closure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-25/funding-to-maintain-detour-roads-in-great-western-highway/106495330&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Geotechnical study shows gaps under Great Western Highway''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-04-10/great-western-highway-geotechnical-study-shows-gaps-under-road/106549768&lt;/nowiki&gt;
* Australian Broadcasting Corporation. (2026). ''Great Western Highway solution options shortlisted after major failure''. ABC News. &lt;nowiki&gt;https://www.abc.net.au/news/2026-05-05/great-western-highway-solution/106641888&lt;/nowiki&gt;
*Flyvbjerg, B. (2013). Survival of the Unfittest: Why the Worst Infrastructure Gets Built, And What We Can Do about It. DOI: 10.48550/arXiv.1303.6571.
*Infrastructure Partnerships Australia (2023). Australian Infrastructure Budget Monitor 2023–24.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2023-24/&lt;/nowiki&gt;
*Infrastructure Partnerships Australia (2024). Australian Infrastructure Budget Monitor 2024–25.  &lt;nowiki&gt;https://infrastructure.org.au/policy-research/major-reports/australian-infrastructure-budget-monitor-2024-25/&lt;/nowiki&gt;
*Lachlan Shire Council (2023). Regional transport and roads could decide State Election.  &lt;nowiki&gt;https://www.lachlan.nsw.gov.au/News-articles/Regional-transport-and-roads-could-decide-State-Election&lt;/nowiki&gt;
*Love, et al. (2021). A Procurement Policy-Making pathway to future-proof large-scale transport infrastructure assets. Research in Transportation Economics, volume 90. ISSN 0739-8859. &lt;nowiki&gt;https://doi.org/10.1016/j.retrec.2021.101069&lt;/nowiki&gt;
*Ogami M. (2024). The Conditionality of Political Short-Termism: A Review of Empirical and Experimental Studies. Vol 12 (2024): Considering Future Generations in Democratic Governance. Cogitatio Press. ISSN: 2183-2463  &lt;nowiki&gt;https://www.cogitatiopress.com/politicsandgovernance/article/view/7764&lt;/nowiki&gt;
*Transport Australia (2023). RA NSW Budget Brief.  &lt;nowiki&gt;https://transportaustralia.org.au/news/ra-nsw-budget-brief/&lt;/nowiki&gt;
*Transport for NSW (2024). Blackheath to Little Hartley Upgrade.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/blackheath-to-little-hartley-upgrade&lt;/nowiki&gt;
*Transport for NSW (2026). Geotechnical data to inform long-term solution for Great Western Highway. Minister for Roads.  &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/geotechnical-data-to-inform-long-term-solution-for-great-western-highway&lt;/nowiki&gt;
*Transport for NSW (2026). Great Western Highway.  &lt;nowiki&gt;https://www.transport.nsw.gov.au/projects/current-projects/great-western-highway&lt;/nowiki&gt;
*ABC News. (2026a, March 19). ''Taskforce to help communities hit by Great Western Highway closure''. Australian Broadcasting Corporation.
*ABC News. (2026b, March 25). ''$50 million to upgrade detour roads during Great Western Highway’s closure''. Australian Broadcasting Corporation.
*ABC News. (2026c, April 10). ''No “proper timetable” for reopening Great Western Highway, NSW roads minister says''. Australian Broadcasting Corporation.
*ABC News. (2026d, May 5). ''Transport for NSW shortlists possible fixes to a failed section of the Great Western Highway''. Australian Broadcasting Corporation.
*ABC News. (2026e, March 10). ''Push for investigation into safety, durability of Great Western Highway’s historic Convict Bridge''. Australian Broadcasting Corporation.
*Heritage NSW. (n.d.). ''Victoria Pass''. State Heritage Inventory.
*NSW Government. (2026a, March 13). ''“We will not risk lives”: Extra rail and transport services to be rolled out as Great Western Highway closure to remain in place for at least three months''.
*NSW Government. (2026b, March 19). ''New taskforce to coordinate support for Great Western Highway communities''.
*NSW Government. (2026c, March 25). ''Minns Government commits $50 million to strengthen detour routes during Great Western Highway closure''.
*NSW Government. (2026e, May 13). ''Two engineering solutions shortlisted to restore Great Western Highway at Victoria Pass''.
*Gazette, H. (2026, April 8). ''Hawkesbury Gazette''. Retrieved from &lt;nowiki&gt;https://www.hawkesburygazette.com/victoria-pass-closure-sends-shockwaves-along-blor-to-richmond-and-beyond/&lt;/nowiki&gt;
*Government, N. (2026, March 13). ''NSW Government''. Retrieved from &lt;nowiki&gt;https://www.nsw.gov.au/ministerial-releases/great-western-highway-closure&lt;/nowiki&gt;
*Gregory, X. (2026, March 10). ''ABC News''. Retrieved from &lt;nowiki&gt;https://www.abc.net.au/news/2026-03-10/great-western-highway-convict-bridge-closed/106432242&lt;/nowiki&gt;
*Guardian, T. (2026, March 14). ''The Guardian''. Retrieved from &lt;nowiki&gt;https://www.theguardian.com/australia-news/2026/mar/14/blue-mountains-road-convict-bridge-closure-nsw-travel&lt;/nowiki&gt;
*Trust, N. (n.d.). ''National Trust''. Retrieved from &lt;nowiki&gt;https://www.nationaltrust.org.au/conservation-landscape-mitchells-causeway/&lt;/nowiki&gt;? &lt;br /&gt;  &lt;br /&gt;</text>
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      <text bytes="7828" sha1="9c89f48yk5tm86yo2g4hgzclfkxbbce" xml:space="preserve">&lt;div align=&quot;center&quot;&gt;&lt;big&gt;'''Faraz Forghan Parast, Kyle Dase, Thomas Sherriff, Tahmineh Farnoud, Alan Colin Arce, Brittany Amell, Graham Jensen, Tim Sobie, and Ray Siemens, with the Implementing New Knowledge Environments (INKE) and Electronic Textual Cultures Lab (ETCL) Research Groups'''&lt;/big&gt;&lt;/div&gt;

==Table of Contents==
{{Book Search}}
===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas | Essential Ideas]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas#Executive Summary: A Snapshot of this Work | Executive Summary]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas#Summative Overview: A More Detailed Snapshot | Summative Overview]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas#Recommendations: Summarized the from the Analytical Overview | Recommendations]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction |Introduction: A Detailed Analytical Overview]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Mapping the Terrain | Mapping the Terrain]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Four Cross-Cutting Tensions | Four Cross-Cutting Tensions]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Fundamentals and Ideologies of AI | Fundamentals and Ideologies of AI]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Geographic Diversity in AI Imaginaries | Geographic Diversity in AI Imaginaries]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Knowledge Foundations | Knowledge Foundations]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Open Social Scholarship Principles | Open Social Scholarship Principles]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#AI and Open | AI and “Open”]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#AI and Social | AI and “Social”]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#AI and Scholarship | AI and “Scholarship”]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Audiences and Differential Impacts | Audiences and Differential Impacts]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Phenomena, Relations, and Ongoing Inquiry | Phenomena, Relations, and Ongoing Inquiry]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Conceptual Mapping | Conceptual Mapping]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Focused Areas for Further Intervention | Focused Areas for Further Intervention]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts | Essential Contexts]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Histories and Theories of AI | Histories &amp; Theories of AI]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Past relation to OSS-aligned communities | Past relation to OSS-aligned communities]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Bias and Technological Determinism | Bias and Technological Determinism]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Knowledge Foundations | Knowledge Foundations]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Open Social Scholarship | Open Social Scholarship]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open | AI and “Open”]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Access | Open Access]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Data | Open Data]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Source | Open Source]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Science | Open Science]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social | AI and “Social”]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Platforms | Platforms]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Governance, Leadership, and Policy | Governance, Leadership, and Policy]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Critical Literacies | Critical Literacies]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Globalism, Colonialism and Influence | Globalism, Colonialism and Influence]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Diversity, Determinism, Bias and Justice | Diversity, Determinism, Bias and Justice]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Community, Connection and the Human | Community, Connection and the Human]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Human, Labour and Environmental Costs | Human, Labour and Environmental Costs]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship | AI and “Scholarship”]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Research Methods and Practices | Research Methods and Practices]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Forms of Research Output | Forms of Research Output]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Teaching and Pedagogy | Teaching and Pedagogy]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Service and Peer Review | Service and Peer Review]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Infrastructures | Infrastructures]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Audience | Audience]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Complete Alphabetical List of References | Complete Alphabetical List of References]]===
{{div col end}}

{{shelves|Humanities}}</text>
      <sha1>9c89f48yk5tm86yo2g4hgzclfkxbbce</sha1>
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==Table of Contents==
{{Book Search}}
===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas | Essential Ideas]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas#Executive Summary: A Snapshot of this Work | Executive Summary]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas#Summative Overview: A More Detailed Snapshot | Summative Overview]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Ideas#Recommendations: Summarized the from the Analytical Overview | Recommendations]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction |Introduction: A Detailed Analytical Overview]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Mapping the Terrain | Mapping the Terrain]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Four Cross-Cutting Tensions | Four Cross-Cutting Tensions]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Fundamentals and Ideologies of AI | Fundamentals and Ideologies of AI]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Geographic Diversity in AI Imaginaries | Geographic Diversity in AI Imaginaries]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Knowledge Foundations | Knowledge Foundations]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Open Social Scholarship Principles | Open Social Scholarship Principles]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#AI and Open | AI and “Open”]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#AI and Social | AI and “Social”]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#AI and Scholarship | AI and “Scholarship”]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Audiences and Differential Impacts | Audiences and Differential Impacts]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Phenomena, Relations, and Ongoing Inquiry | Phenomena, Relations, and Ongoing Inquiry]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Conceptual Mapping | Conceptual Mapping]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Introduction#Focused Areas for Further Intervention | Focused Areas for Further Intervention]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts | Essential Contexts]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Histories and Theories of AI | Histories &amp; Theories of AI]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Past Relation to OSS-Aligned Communities | Past Relation to OSS-Aligned Communities]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Bias and Technological Determinism | Bias and Technological Determinism]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Knowledge Foundations | Knowledge Foundations]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Essential Contexts#Open Social Scholarship | Open Social Scholarship]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open | AI and “Open”]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Access | Open Access]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Data | Open Data]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Source | Open Source]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Open#Open Science | Open Science]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social | AI and “Social”]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Platforms | Platforms]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Governance, Leadership, and Policy | Governance, Leadership, and Policy]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Critical Literacies | Critical Literacies]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Globalism, Colonialism and Influence | Globalism, Colonialism and Influence]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Diversity, Determinism, Bias and Justice | Diversity, Determinism, Bias and Justice]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Community, Connection and the Human | Community, Connection and the Human]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Social#Human, Labour and Environmental Costs | Human, Labour and Environmental Costs]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship | AI and “Scholarship”]]===
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Research Methods and Practices | Research Methods and Practices]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Forms of Research Output | Forms of Research Output]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Teaching and Pedagogy | Teaching and Pedagogy]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Service and Peer Review | Service and Peer Review]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Infrastructures | Infrastructures]]
*[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/AI and Scholarship#Audience | Audience]]

===[[Taking Bearings: Artificial Intelligence in Knowledge Platforms and Open, Social Scholarship/Complete Alphabetical List of References | Complete Alphabetical List of References]]===
{{div col end}}

{{shelves|Humanities}}</text>
      <sha1>mvtcl80fgqzeufnfzdamsjp4k8wiesl</sha1>
    </revision>
  </page>
  <page>
    <title>Chess Opening Theory/1. e4/1...c5/2. Nf3/2...d6/3. d4/3...cxd4/4. Nxd4/4...Nf6/5. Nc3/5...g6/6. Be3/6...Bg7/7. f3/7...a3</title>
    <ns>0</ns>
    <id>483364</id>
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      <id>4636976</id>
      <parentid>4636127</parentid>
      <timestamp>2026-05-22T07:53:37Z</timestamp>
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        <username>TotalNoob69</username>
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      <text bytes="59" sha1="g113hgostx1enzl221yd0lfeimilb5z" xml:space="preserve">{{ delete | 7...a3 is not a valid move }}

TBA

{{BookCat}}</text>
      <sha1>g113hgostx1enzl221yd0lfeimilb5z</sha1>
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  </page>
  <page>
    <title>Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4</title>
    <ns>0</ns>
    <id>483439</id>
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      <text bytes="1474" sha1="0ie8naluylxyp0felyg71zkw0nzjvym" xml:space="preserve">{{Chess Opening Theory/Position|von der Lasa gambit
|eco=[[Chess/ECOC|C21]]
|parent=[[../|Center game accepted]]}}
== 3. Bc4 · von der Lasa gambit ==
White gambits their d4 pawn. After either 3...Nf6 or 3...Nc6, this will transpose into other openings.

[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nf6|'''3...Nf6''']] is Black's most common move, transposing to the Urusov gambit which is more normally seen from the Bishop's opening with 1. e4 e5 2. Bc4 Nf6 3. d4 exd4.

[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nc6|'''3...Nc6''']] is another good move developing the queenside knight. This often transposes to the Scotch gambit after the normal and common developing move 4. Nf3.

== Theory table ==
{{Chess Opening Theory/Table}}
{|
!
!3
!4
!
|-
!Urusov gambit&lt;br&gt;&lt;small&gt;(by transposition)&lt;/small&gt;
|...
[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nf6|Nf6]]
|[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nf6/4. Nf3|Nf3]]
[[Chess Opening Theory/1. e4/1...e5/2. Bc4/2...Nf6/3. d4/3...exd4/4. Nf3/4...Bb4|Bb4+]]
|=
|-
!Dubois Réti defence&lt;br&gt;&lt;small&gt;(by transposition)&lt;/small&gt;
|...
[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nc6|Nc6]]
|[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nf6/4. Nf3|Nf3]]
[[Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. d4/3...exd4/4. Bc4/4...Nf6|Nf6]]
|=
|}

== References ==
{{ChessMid}}{{Chess Opening Theory/Footer}}
{{BookCat}}</text>
      <sha1>0ie8naluylxyp0felyg71zkw0nzjvym</sha1>
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  </page>
  <page>
    <title>Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nf6</title>
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      <text bytes="77" sha1="g16vpm4omr7gmculzp7g5tpeuzvvuza" xml:space="preserve">#REDIRECT [[Chess Opening Theory/1. e4/1...e5/2. Bc4/2...Nf6/3. d4/3...exd4]]</text>
      <sha1>g16vpm4omr7gmculzp7g5tpeuzvvuza</sha1>
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  <page>
    <title>Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nc6</title>
    <ns>0</ns>
    <id>483442</id>
    <revision>
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      <contributor>
        <username>Y7at7Y</username>
        <id>3582263</id>
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      <comment>Expanded page.</comment>
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      <text bytes="813" sha1="d0gpbkdboiz7y7ena9rrpsw798208w6" xml:space="preserve">{{Chess Opening Theory/Position|von der Lasa Gambit
|eco=[[Chess/ECOC|C21]]
|parent=[[../|von der Lasa gambit]]}}
== 3...Nc6 ==
Black develops their knight on b8. 4. Nf3 transposes to the Scotch gambit.

[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nc6/4. Nf3|'''4. Nf3''']] is the most common move, which transposes into the well-known Scotch gambit, more often seen from the move order 1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Bc4.

== Theory table ==
{{Chess Opening Theory/Table}}
{|
!
!4
!
|-
!Dubois Réti defence&lt;br&gt;&lt;small&gt;(by transposition)&lt;/small&gt;
|[[Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. Bc4/3...Nc6/4. Nf3|Nf3]]
[[Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. d4/3...exd4/4. Bc4/4...Nf6|Nf6]]
|=
|}

== References ==
{{ChessMid}}{{Chess Opening Theory/Footer}}
{{BookCat}}</text>
      <sha1>d0gpbkdboiz7y7ena9rrpsw798208w6</sha1>
    </revision>
  </page>
  <page>
    <title>Transportation Planning Casebook/Rede Integrada de Transporte (RIT), Curitiba, Brazil</title>
    <ns>0</ns>
    <id>483450</id>
    <revision>
      <id>4636864</id>
      <parentid>4636846</parentid>
      <timestamp>2026-05-21T12:38:51Z</timestamp>
      <contributor>
        <username>MathXplore</username>
        <id>3097823</id>
      </contributor>
      <minor />
      <comment>Added {{[[Template:BookCat|BookCat]]}} using [[User:1234qwer1234qwer4/BookCat.js|BookCat.js]]</comment>
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      <text bytes="16223" sha1="qtpp1tp54yk43nqwjjaecf2hgkfy8m3" xml:space="preserve">== Summary ==

== List of Actors ==

== Timeline of Events ==
{| class=&quot;wikitable&quot;
|+
!Time Period
!Event
!Description
|-
|1965–1966
|Master Plan and IPPUC founded
|During the peak of Brazil's rapid urbanization a master plan competition was held. The winning plan proposed city growth along radial structural axes that integrated land use, road design and mass transit as a single system &lt;ref name=&quot;:0&quot;&gt;{{Cite journal |last=Rabinovitch |first=Jonas |date=1992 |title=Curitiba: towards sustainable urban development |url=https://journals.sagepub.com/doi/10.1177/095624789200400206 |journal=Environment &amp; Urbanization |volume=4 |issue=2 |pages=62-73}}&lt;/ref&gt;. The municipal authority adopted the plan and created IPPUC.
|-
|1971
|Jaime Lerner appointed mayor
|Brazil's Military government installed the 33-year-old architect, who activated IPPUC's plans &lt;ref name=&quot;:0&quot; /&gt;.
|-
|1972
|Rua XV de Novembro pedestrianised
|Lerner converted Curitiba's busiest commercial street into a pedestrian area in just 72 hours, establishing the principle that public space could be reallocated from cars to people&lt;ref&gt;{{Cite web |title=Spatial Agency: Jaime Lerner |url=https://www.spatialagency.net/database/jaime.lerner |access-date=2026-05-21 |website=www.spatialagency.net |language=en}}&lt;/ref&gt;.
|-
|1974
|First BRT corridor opens
|The Norte–Sul axis launched with 20 km of dedicated busway, carrying 54,000 daily passengers in its first year &lt;ref&gt;{{Cite web |last=Daher |first=Ariadne dos Santos |date=2024-10-17 |title=Curitiba: 50 Years of Lessons from the World’s First 'Bus Rapid Transit' |url=https://usa.streetsblog.org/2024/10/17/curitiba-50-years-of-lessons-from-the-worlds-first-bus-rapid-transit |access-date=2026-05-21 |website=Streetsblog USA |language=en-US}}&lt;/ref&gt;, given the title of the world's first true Bus Rapid Transit line &lt;ref&gt;{{Cite web |date=2016-05-18 |title=What the World's First Bus Rapid Transit System Can Teach Us |url=https://development.asia/case-study/what-worlds-first-bus-rapid-transit-system-can-teach-us |access-date=2026-05-21 |website=Development Asia |language=en}}&lt;/ref&gt;. 
|-
|1970s
|Zoning Laws enacted
|The laws tied building density to proximity to the structural axes with the aim of directing linear growth along the transit system. &lt;ref&gt;{{Cite journal |last=Rabinovitch |first=Jonas |date=1996 |title=Urban Planning in Curitiba |url=https://www.jstor.org/stable/24989439 |journal=Scientific American |volume=274 |issue=3 |pages=46-53}}&lt;/ref&gt;
|-
|1980
|Single-fare integration and opening of Leste Oeste
|The opening of the Leste–Oeste corridor came with the launch of an integrated network; all existing services were consolidated under a single flat fare with free transfers at terminals 
|-
|Early 1900s
|Tube stations and bi-articulated buses introduced
|The iconic glass tube stations enabled off-vehicle fare payment and platform-level boarding, cutting dwell times. At the same time, Volvo and Curitiba co-developed the world's first commercial bi-articulated bus (200 passenger capacity) &lt;ref name=&quot;:3&quot;&gt;{{Cite web |last=Brasil |first=Volvo |date=2022-08-15 |title=Biarticulado Volvo completa três décadas de revolução no transporte de passageiros |url=https://saladeimprensavolvo.com.br/biarticulado-volvo-completa-tres-decadas-de-revolucao-no-transporte-de-passageiros/ |access-date=2026-05-21 |website=Sala de Imprensa Volvo |language=pt-BR}}&lt;/ref&gt;.
|-
|2009
|Green Line (Linha Verde) opens
|The sixth BRT corridor of the RIT, conceived in 2002, began operations in May 2009 along a 9.4 km initial stretch at an estimated cost of US$60 million &lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Lindau |first=Luis Antonio |last2=Hidalgo |first2=Dario |last3=Facchini |first3=Daniela |date=2010 |title=Curitiba, the Cradle of Bus Rapid Transit |url=https://www.jstor.org/stable/23289717 |journal=Built Environment (1978-) |volume=36 |issue=3 |pages=274–282 |issn=0263-7960}}&lt;/ref&gt;. It was built along a former federal roadway (BR-116), and was the first RIT corridor to incorporate overtaking lanes for a mix of express and direct BRT services&lt;ref name=&quot;:1&quot; /&gt;. 
|-
|2015
|Metropolitan integration collapses
|The political dispute between former mayor Fruet (PDT) and Governor Richa (PSDB) ended the transport integration between the capital and the metropolitan region. In February 2015 the single fare was abolished. Management of 106 lines linking neighbouring municipalities to the capital was transferred to COMEC&lt;ref name=&quot;:4&quot;&gt;{{Cite web |date=2017-10-10 |title=O declínio do sistema de ônibus de Curitiba |url=https://www.gazetadopovo.com.br/politica/parana/de-modelo-a-defasadoo-declinio-do-sistema-de-onibus-de-curitiba-eiptbg8t5o8ks4uv419gaczg1/ |access-date=2026-05-21 |website=Gazeta do Povo |language=pt-BR}}&lt;/ref&gt;.
|}

== Maps of Locations ==

== Policy Issues ==
The first major policy issue was rapid urbanisation and overcrowding. With the development and expansion of Curitiba, the population of its metropolitan area has grown from less than 200,000 in the 1950s to 3.7 million today. The city is renowned in the global planning community for its Bus Rapid Transit (BRT) network and sustainable development credentials&lt;ref name=&quot;:2&quot;&gt;{{Cite web |title=Case study: Curitiba {{!}} The Royal Town Planning Institute |url=https://www.rtpi.org.uk/policy-and-research/futureproof-new-towns-international-lessons-on-how-to-build-flexible-and-adaptable-new-towns-in-england/7-case-study-curitiba/ |access-date=2026-05-21 |website=www.rtpi.org.uk |language=en-GB}}&lt;/ref&gt;. However, due to a reduced fleet and lack of maintenance, buses account for only 1% of the total number of vehicles. Moreover, Curitiba has the highest per capita car ownership among Brazilian capitals, with 1.2 million vehicles for 1.8 million residents, which is a major cause of frequent traffic congestion in the city &lt;ref name=&quot;:5&quot;&gt;{{Cite web |title=Curitiba é capital com mais carros por pessoa – veja ranking |url=https://quatrorodas.abril.com.br/noticias/curitiba-e-capital-com-mais-carros-por-pessoa-veja-ranking/ |access-date=2026-05-21 |website=Quatro Rodas |language=pt-BR}}&lt;/ref&gt;. Given that overcrowding prevents users from boarding buses, citizens are forced to find alternative ways to reach their destinations. The policy issue was not simply how to operate buses, but how to create a public transport network strong enough to compete with private car use. Therefore, the government's planning department should establish an integrated regional transportation system and utilize structural axes to support linear urban expansion, and concentrate higher-density development along public transportation corridors &lt;ref&gt;{{Cite web |title=Good Practices in City Energy Efficiency: Eco2 Cities: Curitiba, Brazil - Cost Is No Barrier to Ecological and Economic Urban Planning, Development, and Management {{!}} ESMAP |url=https://www.esmap.org/node/1232 |access-date=2026-05-21 |website=www.esmap.org}}&lt;/ref&gt;.

The second issue is social equity and accessibility. A public transport system becomes a policy issue because it affects who can access jobs, education, services and public life. Transport equity should not only be assessed through speed and efficiency, but also through how fairly transport benefits and burdens are distributed across different social groups &lt;ref&gt;{{Cite journal |last=Pereira |first=Rafael H. M. |last2=Schwanen |first2=Tim |last3=Banister |first3=David |date=2017-03-04 |title=Distributive justice and equity in transportation |url=https://www.tandfonline.com/doi/full/10.1080/01441647.2016.1257660 |journal=Transport Reviews |language=en |volume=37 |issue=2 |pages=170–191 |doi=10.1080/01441647.2016.1257660 |issn=0144-1647}}&lt;/ref&gt;. RIT attempted to reduce this problem by creating an integrated network where passengers could move across the city through coordinated routes and fare integration. This is important because transport policy is also social policy: it determines whether mobility is treated as a public service or mainly as an individual responsibility. However, equity remains a continuing issue because transport systems can become overcrowded, underfunded or less accessible as metropolitan areas expand. The research on transit-oriented development in Curitiba also suggests that accessibility benefits may not always be evenly distributed, especially when lower-income groups are pushed towards peripheral areas with weaker access to high-quality transit &lt;ref&gt;{{Cite journal |last=Turbay |first=André L.B. |last2=Pereira |first2=Rafael H.M. |last3=Firmino |first3=Rodrigo |date=2024-06 |title=The equity implications of TOD in Curitiba |url=https://linkinghub.elsevier.com/retrieve/pii/S2213624X2400066X |journal=Case Studies on Transport Policy |language=en |volume=16 |pages=101211 |doi=10.1016/j.cstp.2024.101211}}&lt;/ref&gt;.

The third policy issue concerns governance and institutional coordination. RIT required cooperation between the municipal government, planning authorities, transport agencies and private bus operators. The RTPI case study argues that Curitiba’s planning success depended not only on having a plan, but also on ongoing strategic and problem-solving capacity, including a strong relationship between political leadership, planning bodies and transport authorities &lt;ref name=&quot;:2&quot; /&gt;. This shows that the policy challenge was institutional as well as technical. A BRT system cannot succeed only because buses and stations are built; it also requires regulation, funding, service coordination, land-use control and long-term adaptation.

There are also clear trade-offs in this case. One trade-off is between cost and capacity. BRT is generally cheaper and faster to implement than rail, but it may face capacity limits if demand grows beyond the system’s design. Another trade-off is between bus priority and road space for private vehicles. The exclusive bus lanes can improve reliability and service quality, but they require the city to allocate valuable road space away from cars and may also reduce road capacity for mixed traffic and create resistance from car users&lt;ref&gt;{{Cite book |last=Transportation Research Board |url=https://www.nationalacademies.org/publications/14518 |title=Cost/Benefit Analysis of Converting a Lane for Bus Rapid Transit--Phase II Evaluation and Methodology |last2=National Cooperative Highway Research Program |last3=Transportation Research Board |date=2011 |publisher=National Academies Press |isbn=978-0-309-28149-2 |location=Washington, D.C. |doi=10.17226/14518}}&lt;/ref&gt;. A third trade-off is between affordability and financial sustainability. Low fares support social inclusion, but the system still needs enough revenue and public support to maintain service quality.

Overall, the RIT case identifies several connected policy issues: how to manage rapid urban growth, provide affordable mass transit, integrate land use with transport, and improve accessibility. Curitiba’s main lesson is that public transport policy should not be analysed only as an engineering or service-delivery issue. Instead, it should be understood as part of wider urban policy. The RIT was important because it connected transport with land development, social inclusion, environmental goals and governance. At the same time, the case also shows that even a successful transport model requires continuous adaptation, funding and institutional coordination to remain effective.

== Narrative of the Case ==
Curitiba’s Rede Integrada de Transporte, or RIT, developed from a wider attempt to manage urban growth rather than from a single transport project. In the 1960s, Curitiba’s planning strategy directed development along structural axes, where higher-density land use was connected with major public transport corridors&lt;ref name=&quot;:0&quot; /&gt;. This meant that the bus system was planned together with the shape of the city, rather than added after urban growth had already occurred.

The first major BRT corridor opened in the 1970s, using dedicated busways as a lower-cost alternative to rail&lt;ref name=&quot;:1&quot; /&gt;. Later, the system became more integrated through terminals, a single-fare structure, tube stations and bi-articulated buses&lt;ref name=&quot;:3&quot; /&gt;. These features helped the RIT carry large numbers of passengers while keeping the system relatively simple for users. The important point is that the RIT was not just a faster bus service. It became part of Curitiba’s urban model by linking transport planning, zoning, and daily access to jobs and services.

The system also depended on a specific governance structure. IPPUC provided the planning vision, URBS managed routes, fares and private operators, and bus companies provided services under public regulation&lt;ref name=&quot;:2&quot; /&gt;. This arrangement helped Curitiba coordinate land use and public transport for a long period. However, it also meant that the system required stable institutional cooperation. As travel demand expanded beyond Curitiba into the wider metropolitan region, coordination became more difficult. The 2015 breakdown of metropolitan integration showed that political and institutional conflict could directly affect passengers, especially commuters travelling from surrounding municipalities&lt;ref name=&quot;:4&quot; /&gt;.

In recent years, the RIT has faced pressures that were not as visible during its earlier period of success. Rising car ownership and competition from ride-hailing placed new pressure on the RIT&lt;ref name=&quot;:5&quot; /&gt;. The COVID-19 ridership shock further weakened the financial base of the system&lt;ref&gt;{{Cite web |last=Curitiba |first=Prefeitura de |title=Pandemia fez transporte coletivo perder quase 100 mi de passageiros em um ano |url=https://www.curitiba.pr.gov.br/noticias/pandemia-fez-transporte-coletivo-perder-quase-100-mi-de-passageiros-em-um-ano/57745 |access-date=2026-05-21 |website=www.curitiba.pr.gov.br |language=pt-BR}}&lt;/ref&gt;. Fare increases created another problem: higher fares may help cover costs in the short term, but they can also push some users away and make public transport less affordable. This creates a difficult cycle between revenue, ridership and service quality.

Current reforms, including electric buses&lt;ref&gt;{{Cite web |title=BYD entrega seis ônibus elétricos para Curitiba |url=https://technibus.com.br/2024/06/24/byd-entrega-seis-onibus-eletricos-para-curitiba |access-date=2026-05-21 |website=Technibus |language=pt-BR}}&lt;/ref&gt;, changes to the concession model and improvements to Linha Verde&lt;ref&gt;{{Cite web |date=2024-06-10 |title=Após 17 anos, prefeitura de Curitiba entrega obra da Linha Verde |url=https://www.gazetadopovo.com.br/parana/apos-17-anos-prefeitura-de-curitiba-inaugura-obra-da-linha-verde/ |access-date=2026-05-21 |website=Gazeta do Povo |language=pt-BR}}&lt;/ref&gt;, show that the RIT is still adapting. However, the case suggests that technology alone will not solve the system’s problems. The future of the RIT depends on whether Curitiba can maintain the original strengths of the model — integrated land use, affordable access and strong public coordination — while responding to new metropolitan, financial and environmental pressures.

== Discussion Questions ==
1.To what extent was Curitiba’s RIT successful because of BRT technology, and to what extent was it successful because of land-use planning along structural axes?

2.How did the single-fare and transfer system improve accessibility for lower-income and peripheral residents? What financial risks did this create when ridership declined?

3.What does the 2015 breakdown of metropolitan integration show about the role of governance in public transport systems?

4.Can BRT remain a strong alternative to rail as Curitiba’s metropolitan region continues to grow, or are there limits to what BRT can provide?

5.How should Curitiba balance bus priority with rising private car ownership and pressure on road space?

6.Are electric buses and new infrastructure enough to address the RIT’s current problems, or are deeper reforms in fares, contracts and metropolitan coordination needed?

7.Which parts of Curitiba’s RIT model can be transferred to other cities, and which parts depend on Curitiba’s specific planning institutions and political context?

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      <text bytes="17002" sha1="31e92fcuxsizv1pr319nwij7ilrma5s" xml:space="preserve">== Summary ==

== List of Actors ==

== Timeline of Events ==
{| class=&quot;wikitable&quot;
|+
!Time Period
!Event
!Description
|-
|1965–1966
|Master Plan and IPPUC founded
|During the peak of Brazil's rapid urbanization a master plan competition was held. The winning plan proposed city growth along radial structural axes that integrated land use, road design and mass transit as a single system &lt;ref name=&quot;:0&quot;&gt;{{Cite journal |last=Rabinovitch |first=Jonas |date=1992 |title=Curitiba: towards sustainable urban development |url=https://journals.sagepub.com/doi/10.1177/095624789200400206 |journal=Environment &amp; Urbanization |volume=4 |issue=2 |pages=62-73}}&lt;/ref&gt;. The municipal authority adopted the plan and created IPPUC.
|-
|1971
|Jaime Lerner appointed mayor
|Brazil's Military government installed the 33-year-old architect, who activated IPPUC's plans &lt;ref name=&quot;:0&quot; /&gt;.
|-
|1972
|Rua XV de Novembro pedestrianised
|Lerner converted Curitiba's busiest commercial street into a pedestrian area in just 72 hours, establishing the principle that public space could be reallocated from cars to people&lt;ref&gt;{{Cite web |title=Spatial Agency: Jaime Lerner |url=https://www.spatialagency.net/database/jaime.lerner |access-date=2026-05-21 |website=www.spatialagency.net |language=en}}&lt;/ref&gt;.
|-
|1974
|First BRT corridor opens
|The Norte–Sul axis launched with 20 km of dedicated busway, carrying 54,000 daily passengers in its first year &lt;ref&gt;{{Cite web |last=Daher |first=Ariadne dos Santos |date=2024-10-17 |title=Curitiba: 50 Years of Lessons from the World’s First 'Bus Rapid Transit' |url=https://usa.streetsblog.org/2024/10/17/curitiba-50-years-of-lessons-from-the-worlds-first-bus-rapid-transit |access-date=2026-05-21 |website=Streetsblog USA |language=en-US}}&lt;/ref&gt;, given the title of the world's first true Bus Rapid Transit line &lt;ref&gt;{{Cite web |date=2016-05-18 |title=What the World's First Bus Rapid Transit System Can Teach Us |url=https://development.asia/case-study/what-worlds-first-bus-rapid-transit-system-can-teach-us |access-date=2026-05-21 |website=Development Asia |language=en}}&lt;/ref&gt;. 
|-
|1970s
|Zoning Laws enacted
|The laws tied building density to proximity to the structural axes with the aim of directing linear growth along the transit system. &lt;ref&gt;{{Cite journal |last=Rabinovitch |first=Jonas |date=1996 |title=Urban Planning in Curitiba |url=https://www.jstor.org/stable/24989439 |journal=Scientific American |volume=274 |issue=3 |pages=46-53}}&lt;/ref&gt;
|-
|1980
|Single-fare integration and opening of Leste Oeste
|The opening of the Leste–Oeste corridor came with the launch of an integrated network; all existing services were consolidated under a single flat fare with free transfers at terminals&lt;ref&gt;{{Cite web |title=História do transporte |url=https://urbs.curitiba.pr.gov.br/transporte/historia-transporte |access-date=2026-05-22 |website=www.urbs.curitiba.pr.gov.br |language=pt-br}}&lt;/ref&gt;
|-
|Early 1900s
|Tube stations and bi-articulated buses introduced
|The iconic glass tube stations enabled off-vehicle fare payment and platform-level boarding, cutting dwell times. At the same time, Volvo and Curitiba co-developed the world's first commercial bi-articulated bus (200 passenger capacity) &lt;ref name=&quot;:3&quot;&gt;{{Cite web |last=Brasil |first=Volvo |date=2022-08-15 |title=Biarticulado Volvo completa três décadas de revolução no transporte de passageiros |url=https://saladeimprensavolvo.com.br/biarticulado-volvo-completa-tres-decadas-de-revolucao-no-transporte-de-passageiros/ |access-date=2026-05-21 |website=Sala de Imprensa Volvo |language=pt-BR}}&lt;/ref&gt;.
|-
|2009
|Green Line (Linha Verde) opens
|The sixth BRT corridor of the RIT, conceived in 2002, began operations in May 2009 along a 9.4 km initial stretch at an estimated cost of US$60 million &lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Lindau |first=Luis Antonio |last2=Hidalgo |first2=Dario |last3=Facchini |first3=Daniela |date=2010 |title=Curitiba, the Cradle of Bus Rapid Transit |url=https://www.jstor.org/stable/23289717 |journal=Built Environment (1978-) |volume=36 |issue=3 |pages=274–282 |issn=}}&lt;/ref&gt;. It was built along a former federal roadway (BR-116), and was the first RIT corridor to incorporate overtaking lanes for a mix of express and direct BRT services&lt;ref name=&quot;:1&quot; /&gt;. 
|-
|2015
|Metropolitan integration collapses
|The political dispute between former mayor Fruet (PDT) and Governor Richa (PSDB) ended the transport integration between the capital and the metropolitan region. In February 2015 the single fare was abolished. Management of 106 lines linking neighbouring municipalities to the capital was transferred to COMEC&lt;ref name=&quot;:4&quot;&gt;{{Cite web |date=2017-10-10 |title=O declínio do sistema de ônibus de Curitiba |url=https://www.gazetadopovo.com.br/politica/parana/de-modelo-a-defasadoo-declinio-do-sistema-de-onibus-de-curitiba-eiptbg8t5o8ks4uv419gaczg1/ |access-date=2026-05-21 |website=Gazeta do Povo |language=pt-BR}}&lt;/ref&gt;.
|}

== Maps of Locations ==
[[File:Curitiba PublicTransport.png|center|frame|The map shows the Expresso Biarticulado and Linhas Direta network as of 2005, with the left panel showing express routes operating in dedicated busways along five structural axes. While the right panel overlays the silver direct lines, with services stopping at tube stations approximately every 3 km &lt;ref&gt;{{Cite web |title=Rede Integrada de Transporte |url=https://www.urbs.curitiba.pr.gov.br/transporte/rede-integrada-de-transporte |access-date=2026-05-22 |website=www.urbs.curitiba.pr.gov.br |language=pt-br}}&lt;/ref&gt;.]]

== Policy Issues ==
The first major policy issue was rapid urbanisation and overcrowding. With the development and expansion of Curitiba, the population of its metropolitan area has grown from less than 200,000 in the 1950s to 3.7 million today. The city is renowned in the global planning community for its Bus Rapid Transit (BRT) network and sustainable development credentials&lt;ref name=&quot;:2&quot;&gt;{{Cite web |title=Case study: Curitiba {{!}} The Royal Town Planning Institute |url=https://www.rtpi.org.uk/policy-and-research/futureproof-new-towns-international-lessons-on-how-to-build-flexible-and-adaptable-new-towns-in-england/7-case-study-curitiba/ |access-date=2026-05-21 |website=www.rtpi.org.uk |language=en-GB}}&lt;/ref&gt;. However, due to a reduced fleet and lack of maintenance, buses account for only 1% of the total number of vehicles. Moreover, Curitiba has the highest per capita car ownership among Brazilian capitals, with 1.2 million vehicles for 1.8 million residents, which is a major cause of frequent traffic congestion in the city &lt;ref name=&quot;:5&quot;&gt;{{Cite web |title=Curitiba é capital com mais carros por pessoa – veja ranking |url=https://quatrorodas.abril.com.br/noticias/curitiba-e-capital-com-mais-carros-por-pessoa-veja-ranking/ |access-date=2026-05-21 |website=Quatro Rodas |language=pt-BR}}&lt;/ref&gt;. Given that overcrowding prevents users from boarding buses, citizens are forced to find alternative ways to reach their destinations. The policy issue was not simply how to operate buses, but how to create a public transport network strong enough to compete with private car use. Therefore, the government's planning department should establish an integrated regional transportation system and utilize structural axes to support linear urban expansion, and concentrate higher-density development along public transportation corridors &lt;ref&gt;{{Cite web |title=Good Practices in City Energy Efficiency: Eco2 Cities: Curitiba, Brazil - Cost Is No Barrier to Ecological and Economic Urban Planning, Development, and Management {{!}} ESMAP |url=https://www.esmap.org/node/1232 |access-date=2026-05-21 |website=www.esmap.org}}&lt;/ref&gt;.

The second issue is social equity and accessibility. A public transport system becomes a policy issue because it affects who can access jobs, education, services and public life. Transport equity should not only be assessed through speed and efficiency, but also through how fairly transport benefits and burdens are distributed across different social groups &lt;ref&gt;{{Cite journal |last=Pereira |first=Rafael H. M. |last2=Schwanen |first2=Tim |last3=Banister |first3=David |date=2017-03-04 |title=Distributive justice and equity in transportation |url=https://www.tandfonline.com/doi/full/10.1080/01441647.2016.1257660 |journal=Transport Reviews |language=en |volume=37 |issue=2 |pages=170–191 |doi=10.1080/01441647.2016.1257660 |issn=0144-1647}}&lt;/ref&gt;. RIT attempted to reduce this problem by creating an integrated network where passengers could move across the city through coordinated routes and fare integration. This is important because transport policy is also social policy: it determines whether mobility is treated as a public service or mainly as an individual responsibility. However, equity remains a continuing issue because transport systems can become overcrowded, underfunded or less accessible as metropolitan areas expand. The research on transit-oriented development in Curitiba also suggests that accessibility benefits may not always be evenly distributed, especially when lower-income groups are pushed towards peripheral areas with weaker access to high-quality transit &lt;ref&gt;{{Cite journal |last=Turbay |first=André L.B. |last2=Pereira |first2=Rafael H.M. |last3=Firmino |first3=Rodrigo |date=June 2024 |title=The equity implications of TOD in Curitiba |url=https://linkinghub.elsevier.com/retrieve/pii/S2213624X2400066X |journal=Case Studies on Transport Policy |language=en |volume=16 |pages=101211 |doi=10.1016/j.cstp.2024.101211}}&lt;/ref&gt;.

The third policy issue concerns governance and institutional coordination. RIT required cooperation between the municipal government, planning authorities, transport agencies and private bus operators. The RTPI case study argues that Curitiba’s planning success depended not only on having a plan, but also on ongoing strategic and problem-solving capacity, including a strong relationship between political leadership, planning bodies and transport authorities &lt;ref name=&quot;:2&quot; /&gt;. This shows that the policy challenge was institutional as well as technical. A BRT system cannot succeed only because buses and stations are built; it also requires regulation, funding, service coordination, land-use control and long-term adaptation.

There are also clear trade-offs in this case. One trade-off is between cost and capacity. BRT is generally cheaper and faster to implement than rail, but it may face capacity limits if demand grows beyond the system’s design. Another trade-off is between bus priority and road space for private vehicles. The exclusive bus lanes can improve reliability and service quality, but they require the city to allocate valuable road space away from cars and may also reduce road capacity for mixed traffic and create resistance from car users&lt;ref&gt;{{Cite book |last=Transportation Research Board |url=https://www.nationalacademies.org/publications/14518 |title=Cost/Benefit Analysis of Converting a Lane for Bus Rapid Transit--Phase II Evaluation and Methodology |last2=National Cooperative Highway Research Program |last3=Transportation Research Board |date=2011 |publisher=National Academies Press |isbn=978-0-309-28149-2 |location=Washington, D.C. |doi=10.17226/14518}}&lt;/ref&gt;. A third trade-off is between affordability and financial sustainability. Low fares support social inclusion, but the system still needs enough revenue and public support to maintain service quality.

Overall, the RIT case identifies several connected policy issues: how to manage rapid urban growth, provide affordable mass transit, integrate land use with transport, and improve accessibility. Curitiba’s main lesson is that public transport policy should not be analysed only as an engineering or service-delivery issue. Instead, it should be understood as part of wider urban policy. The RIT was important because it connected transport with land development, social inclusion, environmental goals and governance. At the same time, the case also shows that even a successful transport model requires continuous adaptation, funding and institutional coordination to remain effective.

== Narrative of the Case ==
Curitiba’s Rede Integrada de Transporte, or RIT, developed from a wider attempt to manage urban growth rather than from a single transport project. In the 1960s, Curitiba’s planning strategy directed development along structural axes, where higher-density land use was connected with major public transport corridors&lt;ref name=&quot;:0&quot; /&gt;. This meant that the bus system was planned together with the shape of the city, rather than added after urban growth had already occurred.

The first major BRT corridor opened in the 1970s, using dedicated busways as a lower-cost alternative to rail&lt;ref name=&quot;:1&quot; /&gt;. Later, the system became more integrated through terminals, a single-fare structure, tube stations and bi-articulated buses&lt;ref name=&quot;:3&quot; /&gt;. These features helped the RIT carry large numbers of passengers while keeping the system relatively simple for users. The important point is that the RIT was not just a faster bus service. It became part of Curitiba’s urban model by linking transport planning, zoning, and daily access to jobs and services.

The system also depended on a specific governance structure. IPPUC provided the planning vision, URBS managed routes, fares and private operators, and bus companies provided services under public regulation&lt;ref name=&quot;:2&quot; /&gt;. This arrangement helped Curitiba coordinate land use and public transport for a long period. However, it also meant that the system required stable institutional cooperation. As travel demand expanded beyond Curitiba into the wider metropolitan region, coordination became more difficult. The 2015 breakdown of metropolitan integration showed that political and institutional conflict could directly affect passengers, especially commuters travelling from surrounding municipalities&lt;ref name=&quot;:4&quot; /&gt;.

In recent years, the RIT has faced pressures that were not as visible during its earlier period of success. Rising car ownership and competition from ride-hailing placed new pressure on the RIT&lt;ref name=&quot;:5&quot; /&gt;. The COVID-19 ridership shock further weakened the financial base of the system&lt;ref&gt;{{Cite web |last=Curitiba |first=Prefeitura de |title=Pandemia fez transporte coletivo perder quase 100 mi de passageiros em um ano |url=https://www.curitiba.pr.gov.br/noticias/pandemia-fez-transporte-coletivo-perder-quase-100-mi-de-passageiros-em-um-ano/57745 |access-date=2026-05-21 |website=www.curitiba.pr.gov.br |language=pt-BR}}&lt;/ref&gt;. Fare increases created another problem: higher fares may help cover costs in the short term, but they can also push some users away and make public transport less affordable. This creates a difficult cycle between revenue, ridership and service quality.

Current reforms, including electric buses&lt;ref&gt;{{Cite web |title=BYD entrega seis ônibus elétricos para Curitiba |url=https://technibus.com.br/2024/06/24/byd-entrega-seis-onibus-eletricos-para-curitiba |access-date=2026-05-21 |website=Technibus |language=pt-BR}}&lt;/ref&gt;, changes to the concession model and improvements to Linha Verde&lt;ref&gt;{{Cite web |date=2024-06-10 |title=Após 17 anos, prefeitura de Curitiba entrega obra da Linha Verde |url=https://www.gazetadopovo.com.br/parana/apos-17-anos-prefeitura-de-curitiba-inaugura-obra-da-linha-verde/ |access-date=2026-05-21 |website=Gazeta do Povo |language=pt-BR}}&lt;/ref&gt;, show that the RIT is still adapting. However, the case suggests that technology alone will not solve the system’s problems. The future of the RIT depends on whether Curitiba can maintain the original strengths of the model — integrated land use, affordable access and strong public coordination — while responding to new metropolitan, financial and environmental pressures.

== Discussion Questions ==
1.To what extent was Curitiba’s RIT successful because of BRT technology, and to what extent was it successful because of land-use planning along structural axes?

2.How did the single-fare and transfer system improve accessibility for lower-income and peripheral residents? What financial risks did this create when ridership declined?

3.What does the 2015 breakdown of metropolitan integration show about the role of governance in public transport systems?

4.Can BRT remain a strong alternative to rail as Curitiba’s metropolitan region continues to grow, or are there limits to what BRT can provide?

5.How should Curitiba balance bus priority with rising private car ownership and pressure on road space?

6.Are electric buses and new infrastructure enough to address the RIT’s current problems, or are deeper reforms in fares, contracts and metropolitan coordination needed?

7.Which parts of Curitiba’s RIT model can be transferred to other cities, and which parts depend on Curitiba’s specific planning institutions and political context?

== References ==
{{BookCat}}</text>
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      <text bytes="19215" sha1="erndlf56xsjept384gbw0a5bz8sgbp0" xml:space="preserve">== Summary ==
The Rede Integrada de Transporte (RIT) is the integrated public transit network of Curitiba, Brazil, and is recognised as the world's first Bus Rapid Transit system &lt;ref name=&quot;:6&quot; /&gt;. The system was developed as part of a 1965 master plan that directed urban growth along five radial corridors, with zoning regulations tying building density to proximity to bus routes &lt;ref name=&quot;:7&quot; /&gt;.  The plan was implemented primarily under mayor Jaime Lerner, an architect who served three terms between 1971 and 1992 &lt;ref&gt;{{Cite journal |last=Bleviss |first=Deborah |date=18 May 2022 |title=The legacy of Jaime Lerner and Curitiba, Brazil |url=https://wires.onlinelibrary.wiley.com/doi/10.1002/wene.436 |journal=WIREs Energy and Environment |volume=11 |issue=5}}&lt;/ref&gt; . 

The RIT operates as a hierarchical network with high-capacity express buses on dedicated busways, supported by the direct line, inter-neighborhood and feeder routes linking terminals to residential areas &lt;ref&gt;{{Cite web |last=urbs |title=Line Catagories |url=https://www.urbs.curitiba.pr.gov.br/transporte/rede-integrada-de-transporte/24 |access-date=2026-05-22 |website=www.urbs.curitiba.pr.gov.br |language=pt-br}}&lt;/ref&gt;. The system spans approximately 83 km of segregated busway with over 337 tube stations with platforms that enable pre-paid, level boarding &lt;ref&gt;{{Cite web |last=urbs |date=May 2026 |title=RIT Characteristics |url=https://www.urbs.curitiba.pr.gov.br/transporte/rede-integrada-de-transporte/18}}&lt;/ref&gt;. The BRT system has been used as a reference for cities world wide, with roughly 200 cities using it for inspiration &lt;ref name=&quot;:8&quot; /&gt;.

However, the system is now under pressure. Ridership has fallen significantly from its 2014 peak as car ownership has risen, ride-hailing apps have drawn away passengers, and the COVID-19 pandemic caused a sharp drop in travel. In 2015, a political dispute between the state government and city government split the metropolitan bus network apart, ending the single fare system &lt;ref name=&quot;:4&quot; /&gt;. This brings to question whether the institutional and design innovations that made Curitiba a global model can be renewed to address these contemporary pressures.

== List of Actors ==

== Timeline of Events ==
{| class=&quot;wikitable&quot;
|+
!Time Period
!Event
!Description
|-
|1965–1966
|Master Plan and IPPUC founded
|During the peak of Brazil's rapid urbanization a master plan competition was held. The winning plan proposed city growth along radial structural axes that integrated land use, road design and mass transit as a single system &lt;ref name=&quot;:0&quot;&gt;{{Cite journal |last=Rabinovitch |first=Jonas |date=1992 |title=Curitiba: towards sustainable urban development |url=https://journals.sagepub.com/doi/10.1177/095624789200400206 |journal=Environment &amp; Urbanization |volume=4 |issue=2 |pages=62-73}}&lt;/ref&gt;. The municipal authority adopted the plan and created IPPUC.
|-
|1971
|Jaime Lerner appointed mayor
|Brazil's Military government installed the 33-year-old architect, who activated IPPUC's plans &lt;ref name=&quot;:0&quot; /&gt;.
|-
|1972
|Rua XV de Novembro pedestrianised
|Lerner converted Curitiba's busiest commercial street into a pedestrian area in just 72 hours, establishing the principle that public space could be reallocated from cars to people&lt;ref&gt;{{Cite web |title=Spatial Agency: Jaime Lerner |url=https://www.spatialagency.net/database/jaime.lerner |access-date=2026-05-21 |website=www.spatialagency.net |language=en}}&lt;/ref&gt;.
|-
|1974
|First BRT corridor opens
|The Norte–Sul axis launched with 20 km of dedicated busway, carrying 54,000 daily passengers in its first year &lt;ref name=&quot;:8&quot;&gt;{{Cite web |last=Daher |first=Ariadne dos Santos |date=2024-10-17 |title=Curitiba: 50 Years of Lessons from the World’s First 'Bus Rapid Transit' |url=https://usa.streetsblog.org/2024/10/17/curitiba-50-years-of-lessons-from-the-worlds-first-bus-rapid-transit |access-date=2026-05-21 |website=Streetsblog USA |language=en-US}}&lt;/ref&gt;, given the title of the world's first true Bus Rapid Transit line &lt;ref name=&quot;:6&quot;&gt;{{Cite web |date=2016-05-18 |title=What the World's First Bus Rapid Transit System Can Teach Us |url=https://development.asia/case-study/what-worlds-first-bus-rapid-transit-system-can-teach-us |access-date=2026-05-21 |website=Development Asia |language=en}}&lt;/ref&gt;. 
|-
|1970s
|Zoning Laws enacted
|The laws tied building density to proximity to the structural axes with the aim of directing linear growth along the transit system. &lt;ref name=&quot;:7&quot;&gt;{{Cite journal |last=Rabinovitch |first=Jonas |date=1996 |title=Urban Planning in Curitiba |url=https://www.jstor.org/stable/24989439 |journal=Scientific American |volume=274 |issue=3 |pages=46-53}}&lt;/ref&gt;
|-
|1980
|Single-fare integration and opening of Leste Oeste
|The opening of the Leste–Oeste corridor came with the launch of an integrated network; all existing services were consolidated under a single flat fare with free transfers at terminals&lt;ref&gt;{{Cite web |title=História do transporte |url=https://urbs.curitiba.pr.gov.br/transporte/historia-transporte |access-date=2026-05-22 |website=www.urbs.curitiba.pr.gov.br |language=pt-br}}&lt;/ref&gt;
|-
|Early 1900s
|Tube stations and bi-articulated buses introduced
|The iconic glass tube stations enabled off-vehicle fare payment and platform-level boarding, cutting dwell times. At the same time, Volvo and Curitiba co-developed the world's first commercial bi-articulated bus (200 passenger capacity) &lt;ref name=&quot;:3&quot;&gt;{{Cite web |last=Brasil |first=Volvo |date=2022-08-15 |title=Biarticulado Volvo completa três décadas de revolução no transporte de passageiros |url=https://saladeimprensavolvo.com.br/biarticulado-volvo-completa-tres-decadas-de-revolucao-no-transporte-de-passageiros/ |access-date=2026-05-21 |website=Sala de Imprensa Volvo |language=pt-BR}}&lt;/ref&gt;.
|-
|2009
|Green Line (Linha Verde) opens
|The sixth BRT corridor of the RIT, conceived in 2002, began operations in May 2009 along a 9.4 km initial stretch at an estimated cost of US$60 million &lt;ref name=&quot;:1&quot;&gt;{{Cite journal |last=Lindau |first=Luis Antonio |last2=Hidalgo |first2=Dario |last3=Facchini |first3=Daniela |date=2010 |title=Curitiba, the Cradle of Bus Rapid Transit |url=https://www.jstor.org/stable/23289717 |journal=Built Environment (1978-) |volume=36 |issue=3 |pages=274–282 |issn=}}&lt;/ref&gt;. It was built along a former federal roadway (BR-116), and was the first RIT corridor to incorporate overtaking lanes for a mix of express and direct BRT services&lt;ref name=&quot;:1&quot; /&gt;. 
|-
|2015
|Metropolitan integration collapses
|The political dispute between former mayor Fruet (PDT) and Governor Richa (PSDB) ended the transport integration between the capital and the metropolitan region. In February 2015 the single fare was abolished. Management of 106 lines linking neighbouring municipalities to the capital was transferred to COMEC&lt;ref name=&quot;:4&quot;&gt;{{Cite web |date=2017-10-10 |title=O declínio do sistema de ônibus de Curitiba |url=https://www.gazetadopovo.com.br/politica/parana/de-modelo-a-defasadoo-declinio-do-sistema-de-onibus-de-curitiba-eiptbg8t5o8ks4uv419gaczg1/ |access-date=2026-05-21 |website=Gazeta do Povo |language=pt-BR}}&lt;/ref&gt;.
|}

== Map of Locations ==
[[File:Curitiba PublicTransport.png|center|frame|The map shows the Expresso Biarticulado and Linhas Direta network as of 2005, with the left panel showing express routes operating in dedicated busways along five structural axes. While the right panel overlays the silver direct lines, with services stopping at tube stations approximately every 3 km &lt;ref&gt;{{Cite web |title=Rede Integrada de Transporte |url=https://www.urbs.curitiba.pr.gov.br/transporte/rede-integrada-de-transporte |access-date=2026-05-22 |website=www.urbs.curitiba.pr.gov.br |language=pt-br}}&lt;/ref&gt;.]]

== Policy Issues ==
The first major policy issue was rapid urbanisation and overcrowding. With the development and expansion of Curitiba, the population of its metropolitan area has grown from less than 200,000 in the 1950s to 3.7 million today. The city is renowned in the global planning community for its Bus Rapid Transit (BRT) network and sustainable development credentials&lt;ref name=&quot;:2&quot;&gt;{{Cite web |title=Case study: Curitiba {{!}} The Royal Town Planning Institute |url=https://www.rtpi.org.uk/policy-and-research/futureproof-new-towns-international-lessons-on-how-to-build-flexible-and-adaptable-new-towns-in-england/7-case-study-curitiba/ |access-date=2026-05-21 |website=www.rtpi.org.uk |language=en-GB}}&lt;/ref&gt;. However, due to a reduced fleet and lack of maintenance, buses account for only 1% of the total number of vehicles. Moreover, Curitiba has the highest per capita car ownership among Brazilian capitals, with 1.2 million vehicles for 1.8 million residents, which is a major cause of frequent traffic congestion in the city &lt;ref name=&quot;:5&quot;&gt;{{Cite web |title=Curitiba é capital com mais carros por pessoa – veja ranking |url=https://quatrorodas.abril.com.br/noticias/curitiba-e-capital-com-mais-carros-por-pessoa-veja-ranking/ |access-date=2026-05-21 |website=Quatro Rodas |language=pt-BR}}&lt;/ref&gt;. Given that overcrowding prevents users from boarding buses, citizens are forced to find alternative ways to reach their destinations. The policy issue was not simply how to operate buses, but how to create a public transport network strong enough to compete with private car use. Therefore, the government's planning department should establish an integrated regional transportation system and utilize structural axes to support linear urban expansion, and concentrate higher-density development along public transportation corridors &lt;ref&gt;{{Cite web |title=Good Practices in City Energy Efficiency: Eco2 Cities: Curitiba, Brazil - Cost Is No Barrier to Ecological and Economic Urban Planning, Development, and Management {{!}} ESMAP |url=https://www.esmap.org/node/1232 |access-date=2026-05-21 |website=www.esmap.org}}&lt;/ref&gt;.

The second issue is social equity and accessibility. A public transport system becomes a policy issue because it affects who can access jobs, education, services and public life. Transport equity should not only be assessed through speed and efficiency, but also through how fairly transport benefits and burdens are distributed across different social groups &lt;ref&gt;{{Cite journal |last=Pereira |first=Rafael H. M. |last2=Schwanen |first2=Tim |last3=Banister |first3=David |date=2017-03-04 |title=Distributive justice and equity in transportation |url=https://www.tandfonline.com/doi/full/10.1080/01441647.2016.1257660 |journal=Transport Reviews |language=en |volume=37 |issue=2 |pages=170–191 |doi=10.1080/01441647.2016.1257660 |issn=0144-1647}}&lt;/ref&gt;. RIT attempted to reduce this problem by creating an integrated network where passengers could move across the city through coordinated routes and fare integration. This is important because transport policy is also social policy: it determines whether mobility is treated as a public service or mainly as an individual responsibility. However, equity remains a continuing issue because transport systems can become overcrowded, underfunded or less accessible as metropolitan areas expand. The research on transit-oriented development in Curitiba also suggests that accessibility benefits may not always be evenly distributed, especially when lower-income groups are pushed towards peripheral areas with weaker access to high-quality transit &lt;ref&gt;{{Cite journal |last=Turbay |first=André L.B. |last2=Pereira |first2=Rafael H.M. |last3=Firmino |first3=Rodrigo |date=June 2024 |title=The equity implications of TOD in Curitiba |url=https://linkinghub.elsevier.com/retrieve/pii/S2213624X2400066X |journal=Case Studies on Transport Policy |language=en |volume=16 |pages=101211 |doi=10.1016/j.cstp.2024.101211}}&lt;/ref&gt;.

The third policy issue concerns governance and institutional coordination. RIT required cooperation between the municipal government, planning authorities, transport agencies and private bus operators. The RTPI case study argues that Curitiba’s planning success depended not only on having a plan, but also on ongoing strategic and problem-solving capacity, including a strong relationship between political leadership, planning bodies and transport authorities &lt;ref name=&quot;:2&quot; /&gt;. This shows that the policy challenge was institutional as well as technical. A BRT system cannot succeed only because buses and stations are built; it also requires regulation, funding, service coordination, land-use control and long-term adaptation.

There are also clear trade-offs in this case. One trade-off is between cost and capacity. BRT is generally cheaper and faster to implement than rail, but it may face capacity limits if demand grows beyond the system’s design. Another trade-off is between bus priority and road space for private vehicles. The exclusive bus lanes can improve reliability and service quality, but they require the city to allocate valuable road space away from cars and may also reduce road capacity for mixed traffic and create resistance from car users&lt;ref&gt;{{Cite book |last=Transportation Research Board |url=https://www.nationalacademies.org/publications/14518 |title=Cost/Benefit Analysis of Converting a Lane for Bus Rapid Transit--Phase II Evaluation and Methodology |last2=National Cooperative Highway Research Program |last3=Transportation Research Board |date=2011 |publisher=National Academies Press |isbn=978-0-309-28149-2 |location=Washington, D.C. |doi=10.17226/14518}}&lt;/ref&gt;. A third trade-off is between affordability and financial sustainability. Low fares support social inclusion, but the system still needs enough revenue and public support to maintain service quality.

Overall, the RIT case identifies several connected policy issues: how to manage rapid urban growth, provide affordable mass transit, integrate land use with transport, and improve accessibility. Curitiba’s main lesson is that public transport policy should not be analysed only as an engineering or service-delivery issue. Instead, it should be understood as part of wider urban policy. The RIT was important because it connected transport with land development, social inclusion, environmental goals and governance. At the same time, the case also shows that even a successful transport model requires continuous adaptation, funding and institutional coordination to remain effective.

== Narrative of the Case ==
Curitiba’s Rede Integrada de Transporte, or RIT, developed from a wider attempt to manage urban growth rather than from a single transport project. In the 1960s, Curitiba’s planning strategy directed development along structural axes, where higher-density land use was connected with major public transport corridors&lt;ref name=&quot;:0&quot; /&gt;. This meant that the bus system was planned together with the shape of the city, rather than added after urban growth had already occurred.

The first major BRT corridor opened in the 1970s, using dedicated busways as a lower-cost alternative to rail&lt;ref name=&quot;:1&quot; /&gt;. Later, the system became more integrated through terminals, a single-fare structure, tube stations and bi-articulated buses&lt;ref name=&quot;:3&quot; /&gt;. These features helped the RIT carry large numbers of passengers while keeping the system relatively simple for users. The important point is that the RIT was not just a faster bus service. It became part of Curitiba’s urban model by linking transport planning, zoning, and daily access to jobs and services.

The system also depended on a specific governance structure. IPPUC provided the planning vision, URBS managed routes, fares and private operators, and bus companies provided services under public regulation&lt;ref name=&quot;:2&quot; /&gt;. This arrangement helped Curitiba coordinate land use and public transport for a long period. However, it also meant that the system required stable institutional cooperation. As travel demand expanded beyond Curitiba into the wider metropolitan region, coordination became more difficult. The 2015 breakdown of metropolitan integration showed that political and institutional conflict could directly affect passengers, especially commuters travelling from surrounding municipalities&lt;ref name=&quot;:4&quot; /&gt;.

In recent years, the RIT has faced pressures that were not as visible during its earlier period of success. Rising car ownership and competition from ride-hailing placed new pressure on the RIT&lt;ref name=&quot;:5&quot; /&gt;. The COVID-19 ridership shock further weakened the financial base of the system&lt;ref&gt;{{Cite web |last=Curitiba |first=Prefeitura de |title=Pandemia fez transporte coletivo perder quase 100 mi de passageiros em um ano |url=https://www.curitiba.pr.gov.br/noticias/pandemia-fez-transporte-coletivo-perder-quase-100-mi-de-passageiros-em-um-ano/57745 |access-date=2026-05-21 |website=www.curitiba.pr.gov.br |language=pt-BR}}&lt;/ref&gt;. Fare increases created another problem: higher fares may help cover costs in the short term, but they can also push some users away and make public transport less affordable. This creates a difficult cycle between revenue, ridership and service quality.

Current reforms, including electric buses&lt;ref&gt;{{Cite web |title=BYD entrega seis ônibus elétricos para Curitiba |url=https://technibus.com.br/2024/06/24/byd-entrega-seis-onibus-eletricos-para-curitiba |access-date=2026-05-21 |website=Technibus |language=pt-BR}}&lt;/ref&gt;, changes to the concession model and improvements to Linha Verde&lt;ref&gt;{{Cite web |date=2024-06-10 |title=Após 17 anos, prefeitura de Curitiba entrega obra da Linha Verde |url=https://www.gazetadopovo.com.br/parana/apos-17-anos-prefeitura-de-curitiba-inaugura-obra-da-linha-verde/ |access-date=2026-05-21 |website=Gazeta do Povo |language=pt-BR}}&lt;/ref&gt;, show that the RIT is still adapting. However, the case suggests that technology alone will not solve the system’s problems. The future of the RIT depends on whether Curitiba can maintain the original strengths of the model — integrated land use, affordable access and strong public coordination — while responding to new metropolitan, financial and environmental pressures.

== Discussion Questions ==
1.To what extent was Curitiba’s RIT successful because of BRT technology, and to what extent was it successful because of land-use planning along structural axes?

2.How did the single-fare and transfer system improve accessibility for lower-income and peripheral residents? What financial risks did this create when ridership declined?

3.What does the 2015 breakdown of metropolitan integration show about the role of governance in public transport systems?

4.Can BRT remain a strong alternative to rail as Curitiba’s metropolitan region continues to grow, or are there limits to what BRT can provide?

5.How should Curitiba balance bus priority with rising private car ownership and pressure on road space?

6.Are electric buses and new infrastructure enough to address the RIT’s current problems, or are deeper reforms in fares, contracts and metropolitan coordination needed?

7.Which parts of Curitiba’s RIT model can be transferred to other cities, and which parts depend on Curitiba’s specific planning institutions and political context?

== References ==
{{BookCat}}</text>
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      <text bytes="1298" sha1="2wq1s3vx37tv9hh5oi0ttqh17tqwi0g" xml:space="preserve">= Bunnies/Rabbits =
Rabbits are a mob in the game [[Minecraft]].

== Description ==
Rabbits are a small half block tall mobs that spawn in most biomes, with different variants according to the environment. 

Rabbits can be a variety colors, including: gold (desert biome); white, black and white (both snowy biomes); brown, black, and salt &amp; pepper (temperate biomes). 

Special variants can be obtained by naming a rabbit Toast, changing its fur to a black and white custom skin. Through commands in Java, it is possible to summon a hostile white rabbit with red eyes (The Killer Bunny) through the commands: /summon rabbit ~ ~ ~ {RabbitType:99}.

Baby rabbits are much smaller than adult ones, topping at only a quarter a block.

== Drops ==
Rabbits can be killed for rabbit hide, rabbit meat, and the rare rabbit’s foot. Rabbits drop between 1 and 3 experience orbs. 

Killing a baby rabbit does not give any experience points or food and material.

== Taming ==
Rabbits can be tamed as pets like many other mobs. This can be done with carrots. Rabbits can also be led with carrots, so if building a rabbit farm, use carrots to lure rabbits towards it. 

Do note that rabbits run relatively fast, and are easily startled.

== See Also ==

* [[Minecraft]]
* [[Minecraft/Mobs|Mobs]]

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      <text bytes="1299" sha1="j1brmzzpkr5l9hp2j0ujk77p14da1da" xml:space="preserve">= Bunnies/Rabbits =
Rabbits are a mob in the game [[Minecraft]].

== Description ==
Rabbits are a passive half block tall mob that spawn in most biomes, with different variants according to the environment. 

Rabbits can be a variety colors, including: gold (desert biome); white, black and white (both snowy biomes); brown, black, and salt &amp; pepper (temperate biomes). 

Special variants can be obtained by naming a rabbit Toast, changing its fur to a black and white custom skin. Through commands in Java, it is possible to summon a hostile white rabbit with red eyes (The Killer Bunny) through the commands: /summon rabbit ~ ~ ~ {RabbitType:99}.

Baby rabbits are much smaller than adult ones, topping at only a quarter a block.

== Drops ==
Rabbits can be killed for rabbit hide, rabbit meat, and the rare rabbit’s foot. Rabbits drop between 1 and 3 experience orbs. 

Killing a baby rabbit does not give any experience points or food and material.

== Taming ==
Rabbits can be tamed as pets like many other mobs. This can be done with carrots. Rabbits can also be led with carrots, so if building a rabbit farm, use carrots to lure rabbits towards it. 

Do note that rabbits run relatively fast, and are easily startled.

== See Also ==

* [[Minecraft]]
* [[Minecraft/Mobs|Mobs]]

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== I have added a tag to a page you created ==
Hi! I'm MathXplore, and I recently reviewed your page, [[:Cookie Run: Kingdom]]. I have added a tag to the page, because it &lt;strong&gt;may meet the [[Wikibooks:Deletion policy#Speedy deletions|criteria for speedy deletion]].&lt;/strong&gt; This means that it can be deleted at any time. The reason I provided was: &lt;blockquote&gt;&lt;strong&gt;Test page&lt;/strong&gt;&lt;/blockquote&gt; If you believe that your page should not be deleted, please post a message on [[Talk:Cookie Run: Kingdom|the page's talk page]] explaining why. &lt;strong&gt;If your reasoning is convincing, your page may be saved.&lt;/strong&gt; If you have any questions or concerns, please [[User talk:MathXplore|let me know]]. Thank you! &lt;!-- Substituted from User:JJPMaster/CurateThisPage/authorMsg --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:38, 21 May 2026 (UTC)</text>
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      <contributor>
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      <comment>Notifying author of speedy deletion nomination</comment>
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== I have added a tag to a page you created ==
Hi! I'm MathXplore, and I recently reviewed your page, [[:Cookie Run: Kingdom]]. I have added a tag to the page, because it &lt;strong&gt;may meet the [[Wikibooks:Deletion policy#Speedy deletions|criteria for speedy deletion]].&lt;/strong&gt; This means that it can be deleted at any time. The reason I provided was: &lt;blockquote&gt;&lt;strong&gt;Test page&lt;/strong&gt;&lt;/blockquote&gt; If you believe that your page should not be deleted, please post a message on [[Talk:Cookie Run: Kingdom|the page's talk page]] explaining why. &lt;strong&gt;If your reasoning is convincing, your page may be saved.&lt;/strong&gt; If you have any questions or concerns, please [[User talk:MathXplore|let me know]]. Thank you! &lt;!-- Substituted from User:JJPMaster/CurateThisPage/authorMsg --&gt; [[User:MathXplore|MathXplore]] ([[User talk:MathXplore|discuss]] • [[Special:Contributions/MathXplore|contribs]]) 12:38, 21 May 2026 (UTC)
== I have added a tag to a page you created ==
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      <text bytes="50937" sha1="ld257oh4rzja1ebayy9cij1ncdsbypd" xml:space="preserve">==Histories &amp; Theories of AI==

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Ali, Syed Mustafa, Stephanie Dick, Sarah Dillon, Matthew L. Jones, Jonnie Penn, and Richard Staley. 2023. “Histories of Artificial Intelligence: A Genealogy of Power.” ''BJHS Themes'' 8: 1–18. https://doi.org/10.1017/bjt.2023.15.'''
&lt;/div&gt;

The work of these authors seeks to move beyond “conventional origin myths” of AI by contextualizing the academic historical approach within their interdisciplinary backgrounds. As a result, Ali et al. argue that histories of broader processes (like industrialization, colonialism, and social science) can represent the “genealogy” of AI, which is not identified as a specific object but as a grouping of diverse technologies under a loose banner, requiring an equally diverse approach. Although AI is the “flagship of the Information Age”, it was clearly conditioned by the “Management Age”, as these “genealogies” feature four common thematic threads of “hidden labour”, “encoded behaviour”, “disingenuous rhetoric” and “cognitive injustice”. AI is therefore not only situated within the history of computing, but the history of control, the product of the interacting formalist and empiricist views of “intelligence” within Cold War epistemology. In many ways, AI’s refinement of formal abstraction reinforces and impresses Western systems and structures, so these authors do not critique AI with the goal of improvement, but to clarify what AI “is”, “is not”, and perhaps “should not” be.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Anderson, Marc M. 2024. “AI as Philosophical Ideology: A Critical Look Back at John McCarthy’s Program.” ''Philosophy &amp; Technology'' 37 (2): 44. https://doi.org/10.1007/s13347-024-00731-1.'''
&lt;/div&gt;

This paper critically analyzes the synthesis of McCarthy’s AI development program, identifying its goals’ nature, purpose, relationship to society, and implications upon morality and social control. Firstly, Anderson considers the most problematic themes of McCarthy’s early and middle writings, then arguing that McCarthy’s later works consolidated his stance by replacing “tentative assumptions” with “statements whose linkages with contemporaneous analytic philosophy are made unequivocally” and thereby present AI as “the outcome of a certain philosophical way of looking at the world”. Here, Anderson emphasizes McCarthy’s biases towards objectivism, scientism, and analytic behaviourism; tendency to enable progress in AI by waiting to identify risks; positioning of philosophy as subordinate “handmaiden” to science; and uneasy presupposition humans have innate knowledge of the world’s object character (which AI will need added). To Anderson, the sum of the “ethical” aspects, “philosophical” aspects, and “competitive” nature of McCarthy’s program give it all the fundamental “characteristics of an ideological program”. This ideology has had deep direct influence, for example by joining AI ethics to consequentialist dilemmas like the “Trolley problem”, and deep indirect influence, for example by influencing a modular and component technical approach. Anderson argues this “ideology” was caused by McCarthy’s motive of making a “servile” and “stripped down model of human mental engagement without emotional qualities”. Overall, Anderson argues McCarthy’s conception of AI as a “perfectly rational abstraction of human thinking” involves severe misconceptions around rationality, and has “come to serve as a blind for increasing techno-corporate control of society” with its propagation of the belief that “AI systems should be controlled as servants”.

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'''Bender, Emily M., Timnit Gebru, Angelina McMillan-Major, and Shmargaret Shmitchell. 2021. “On the Dangers of Stochastic Parrots: Can Language Models Be Too Big? 🦜.” In ''Proceedings of the 2021 ACM Conference on Fairness, Accountability, and Transparency'', 610–23. https://doi.org/10.1145/3442188.3445922.'''
&lt;/div&gt;

Bender et al. critically analyze the environmental and social risks of ever larger language models trained with huge uncurated datasets from the web. Their first concern is the environmental costs of training language models, which require increasing energy and compute requirements that further environmental damages that are more likely to fall on marginalized populations. Their social concerns are that language models have the potential to reproduce hegemonic views, reinforce stereotypes, and further reify inequality due to the unrepresentativeness of their training data. Despite the increasing amounts of data ingested in these models, the authors argue that size does not guarantee diversity because there are people who are not on the web (and therefore not included in training data), the content of marginalized people online is less likely to be included in these large datasets and, if it is, it might be filtered out during the data preparation process. Therefore, the authors urge developers to stop using larger training datasets if they cannot be documented. As an alternative, they suggest curating and documenting smaller datasets created for specific purposes, evaluating models by the amount of resources they consume, and developing research that centers the people who are more likely to be adversely affected by the resulting technology.

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'''Berry, David M. 2025. “Synthetic Media and Computational Capitalism: Towards a Critical Theory of Artificial Intelligence.” ''AI &amp; Society'' 40: 5257–5269. DOI: https://doi.org/10.1007/s00146-025-02265-2'''
&lt;/div&gt;

Berry develops a critical theory of artificial intelligence centered on what he terms the &quot;algorithmic condition&quot;—a historical moment when computational systems generate cultural content indistinguishable from human production, thereby destabilizing traditional markers of authenticity and authorship. Engaging with Frankfurt School critical theory, particularly concepts of false consciousness and reification, Berry argues that contemporary AI represents a qualitative transformation he calls &quot;the Inversion,&quot; where machine-generated works not only replicate but actively reshape the grounds upon which experience and meaning are constituted. This moves beyond mechanical reproduction (Benjamin) or cybernetic feedback (Wiener) toward what Berry theorizes as &quot;post-consciousness,&quot; where boundaries between individual and synthetic consciousness become porous. His concept of &quot;diffusionisation&quot; describes how AI systems dissolve cultural forms into probabilistic vector spaces and reconstitute them through latent space manipulation, producing &quot;AI slop&quot;—low-quality synthetic content that infiltrates information ecosystems with garbled meaning. Berry positions this transformation within &quot;computational capitalism,&quot; arguing that algorithmic mediation now structures forms of life in ways that demand new critical methods. His &quot;constellational analysis&quot; proposes mapping the interdependencies among technical systems, cultural production, and political-economic structures to resist subsumption into algorithmic logics. Where earlier automation debates focused on task substitution, Berry foregrounds how synthetic media transforms the infrastructure of meaning-making itself, rendering questions of interpretability and embedded bias not as technical problems but as symptoms of deeper epistemic and political reconfigurations under computational conditions.

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'''Chun, J., &amp; Elkins, K. (2023). “The Crisis of Artificial Intelligence: A New Digital Humanities Curriculum for Human-Centred AI.” ''International Journal of Humanities and Arts Computing'' 17 (2). DOI: https://doi.org/10.3366/ijhac.2023.0310'''
&lt;/div&gt;

Chun and Elkins position AI's rapid advancement as precipitating multiple interlocking crises—in higher education, in diversity and inclusion within technology fields, and in the broader socioeconomic fabric—that demand a specifically humanities-oriented pedagogical response. Their intervention challenges the prevalent assumption that AI literacy should emerge from STEM-dominated curricula, arguing instead that Digital Humanities offers distinctive pathways for cultivating critical engagement with computational systems. Where conventional computer science education treats AI as primarily a technical phenomenon requiring engineering skills, Chun and Elkins foreground reflective and collaborative meaning-making, insisting that the most effective AI tools amplify rather than replace human intellectual engagement. Their framework explicitly connects pedagogical design to civic preparation, positioning students not as mere consumers or operators of AI systems but as critically engaged citizens capable of interrogating the social and economic implications of algorithmic mediation. Drawing on theories of human-centered computing, they articulate an AI DH curriculum structured around two core commitments: opening meaningful research avenues for humanities scholars working with computational methods and addressing DEI shortcomings by engaging students traditionally alienated by conventional STEM pathways. Their approach implicitly challenges the epistemic authority claims embedded in AI discourse—the fantasy that technical expertise alone can adjudicate questions about algorithmic deployment—by insisting that humanistic inquiry offers essential resources for navigating AI's transformative effects on knowledge production, labor organization, and cultural representation.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Chung, Hiu-Fung. 2025. “Betting on (Un)Certain Futures: Sociotechnical Imaginaries of AI and Varieties of Techno-Developmentalism in Asia.” ''Information, Communication &amp; Society'', 1–18. https://doi.org/10.1080/1369118X.2025.2535427.'''
&lt;/div&gt;

Chung redirects scholarly attention from dominant AI powers—China, the United States—to economically advanced but geographically non-dominant Asian societies: Singapore, Hong Kong, and Taiwan. Mobilizing the concept of &quot;techno-developmentalism&quot; to analyze how developmental states harness technological innovation for political-economic projects, Chung identifies three distinct imaginaries that emerge from specific historical, institutional, and geopolitical conditions. Singapore's &quot;cybernetic pragmatism&quot; deploys AI to legitimize neoliberal authoritarianism, embedding computational governance as a continuation of technocratic rule. Hong Kong's &quot;techno-entrepreneurship&quot; imaginary seeks to refashion financial capitalism through AI-driven innovation, positioning the territory as a global fintech hub amid shifting relationships with mainland China. Taiwan's &quot;defensive survival modality&quot; frames AI development as simultaneously addressing internal socioeconomic instability and external threats from superpower rivalry, particularly cross-strait tensions. Chung's analysis challenges the Global North/South binary that structures much AI governance literature, revealing how small advanced economies navigate strategic coupling with global tech industries while managing profound uncertainties about AI-centric reforms. His discourse analysis of policy documents from the early 2010s through 2024 demonstrates how national imaginaries encode assumptions about automation's effects on labor markets, the appropriate balance between state coordination and market mechanisms, and the role of computational infrastructure in securing geopolitical position. This comparative framework illuminates how different state formations mobilize AI to address divergent crises of legitimacy, capital accumulation, and sovereign security.

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'''van Es, Karin, and Dennis Nguyen. 2024. “‘Your Friendly AI Assistant’: The Anthropomorphic Self-Representations of ChatGPT and Its Implications for Imagining AI.” ''AI &amp; Society'' 40: 3591–3603. https://doi.org/10.1007/s00146-024-02108-6.'''
&lt;/div&gt;

van Es and Nguyen analyze how “social-technical imaginaries” invoked by “self-representations” of GenAI could influence public perception of the technology. These “socio-technical imaginaries” are a category of trending concept, which can exist in contrast, as both utopian and dystopian conceptions of AI are present in public discourse. These are dynamically changeable, often strategically promoted by tech companies to influence regulation, and influenced by a variety of media technologies and ecologies with equally diverse social, cultural, and political implications. The authors identify a range of current “socio-technical imaginaries” of AI. This includes: misconceived “magical thinking”, largely produced by poor terminology; speculative, exaggerative debates on AI capabilities, which distract from actualized and present risks; visual motifs correlating intelligence, efficiency, logic, duty, and trust, which are not inherent to Generative AI; and anthropomorphism, which brings a slew of problems surrounding social biases. To study AI “self-representations”, van Es and Nguyen have ChatGPT generate fifty images and fifty-eight sections of text, responding to several variations of the prompt “create an image of yourself”. The authors then perform an empirical, qualitative-exploratory analysis of this content to examine which “socio-technical imaginaries” dominate the material. These images most significantly emphasized ChatGPT’s alleged “social intelligence”, depicted as a friendly research assistant possessing “real” intellect - ironically often surrounded by books. Anthropomorphism was usually present, with eighty-two percent of images portraying AI as humanoid, and a further six percent as a human brain. Futuristic motifs like holograms, metallic shades, and the cosmos portrayed AI as near-magical. Textual responses expressed these same themes, demonstrating consistent messaging. Taken together, these generated responses encourage overlooking the ethical and legal challenges posed by trending GenAI technologies, “overestimate their capabilities”, and “potentially lead to mistakenly perceive them as trustworthy companions”. This raises questions as to what extent specific guidelines to these responses were programmed by OpenAI, or indicative of popular opinion.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Jones, Matthew L. 2023. “AI in History.” ''American Historical Review'' 128 (3): 1360–67. https://doi.org/10.1093/ahr/rhad361.'''
&lt;/div&gt;

Jones explores how evolving approaches to AI research reflect upon the importance of studying artificial intelligence’s history. He believes traditional attempts to produce “symbolic” AI have been proven as misguided, comparing their failures to the traditionally unpopular “empiricist” approach. This approach is now dominant and involves the use of large-scale algorithms to capitalize upon the “unreasonable effectiveness of data” via “machine learning”. However, this shift in trends has also forced the meaning and capabilities of “artificial intelligence” to be reconsidered, now threatening “professions centred on particularity” like history. In response, Jones argues modern AI cannot be considered a “neutral substratum” but as a reflection of human creations - including their best and worst traits. Historians are experts at detecting bias, and this understanding of AI’s historical context is clearly necessary for its appropriate application, so historians should be playing a fundamental role in ensuring AI’s critical use. Jones believes historians can best do this by highlighting the “traces of labour” that can illustrate the “granular complex reality” of AI.

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'''Klein, L., M. Martin, A. Brock, M. Antoniak, M. Walsh, J. M. Johnson, L. Tilton, and D. Mimno. 2025. “Provocations from the Humanities for Generative AI Research.” ''arXiv'' preprint. https://arxiv.org/abs/2502.19190.'''
&lt;/div&gt;

Klein et al. explore the stakes of engaging with AI by juxtaposing the humanistic scholar’s investigation of the ‘human’ with the ‘anti-human’ approach of AI, a dichotomy they contextualize within late-stage capitalism. Klein et al. argue that AI’s generalist, binary approach ‘distorts “culture’ to content’. AI programs thereby conduct a ‘statistical enactment of… ideology’, imposing an objectivist European modernist framework of understanding upon the data. This binary conception of data is highlighted within ideas of ‘pure’ versus ‘toxic’ training data, which dismiss that the material inherently ‘reflects cultures and consists of expressions of those cultures’. Even content not being included ‘biases’ the rest of the data, so the best practices of open scholarship cannot fix the root issue - the only way to resolve the issues caused by ‘bias’ is to target the sources of the underlying structural problems. Klein et al. argue this flawed situation was fueled by ‘corporate spokespeople parroting AI hype’ to research - and that this relationship’s politicization should be a particular source of concern. Klein et al. argue AI can still serve a purpose, however. They propose AI with smaller datasets will produce more accurate information when tailored for specific topics and with input from experts of the humanities. Humanists cannot solely effect change, however, as ‘technical researchers must recognize the institutional asymmetries’ of administrative support and funding available to ensure development of ‘humanistic’ AI is a truly equal and interdisciplinary effort. 

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'''McIntosh, Timothy R., Susnjak, Teo, Liu, Tong, Watters, Paul, and Halgamuge, Malka N.. 2023. “From Google Gemini to OpenAI Q* (Q-Star): A Survey of Reshaping the Generative Artificial Intelligence (AI) Research Landscape.” ''Technologies''. https://doi.org/10.3390/technologies13020051 '''
&lt;/div&gt;

McIntosh et al. offer a survey of AI development’s frontiers targeted at fellow experts of the field, focussing on evolving “agentic” AI and its resulting research applications. Covering developments, they primarily employ case studies to demonstrate how multimodal AI could eclipse undynamic LLMs, but various “advanced learning techniques” and developments in model architecture are also outlined. On this topic, a table is presented to quantify the relevance of research fields and subfields of AI development. Agentic AI’s possible applications include aiding research by bolstering academic integrity, its market relevance, and its “creative” purposes. McIntosh et al. even argue that development of AGI with “symbolic reasoning” and “probabilistic inference” could handle issues like climate change, considered as a long-term but significant possibility. Therefore, this work is primarily theoretical, with McIntosh et al. centralizing AI’s idealistic applications. However, they do acknowledge AI must be developed with ethical and social principles, for which interdisciplinary cooperation is necessary. 

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'''Richter, V., Katzenbach, C., &amp; Schäfer, M. S. (2025). “Imaginaries of Artificial Intelligence.” ''Computers in Human Behavior''. https://doi.org/10.1016/j.chb.2025.108682'''
&lt;/div&gt;

Richter, Katzenbach, and Schäfer systematize the concept of &quot;sociotechnical imaginaries&quot; as an analytical framework for understanding how collective visions of AI futures shape governance, investment, and public discourse. Engaging explicitly with science and technology studies scholarship—particularly Jasanoff and Kim's formulation of imaginaries as &quot;collectively held, institutionally stabilized, and publicly performed visions&quot;—they demonstrate how AI's meaning emerges through contested negotiations among stakeholders from industry, government, academia, media, and civil society. Their comparative analysis across the United States, China, and Germany challenges simplistic national characterizations, revealing heterogeneous and often contradictory imaginaries even within single regulatory regimes. Where US discourse fragments across multiple geographic AI hubs, German imaginaries center on EU policy compliance and regulatory frameworks, while Chinese articulations align tightly with party-state directives that minimize local variation. Richter and colleagues argue that these imaginaries function performatively, not merely representing AI's future but actively mobilizing resources, legitimating interventions, and establishing trajectories for development. Their framework illuminates how benchmark cultures, optimization narratives, and investor expectations become embedded in technical choices through discursive processes that precede and exceed engineering decisions. By foregrounding stakeholder co-dependencies and cross-national dynamics, the authors position AI imaginaries as sites where epistemological assumptions about intelligence, automation, and progress become institutionalized through political-economic mechanisms—a contribution that connects discourse analysis to questions of power, accountability, and the material reorganization of labor and knowledge production.

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'''Whiteley, Paul. 2023. “Why Artificial Intelligence Is a Misnomer.” ''London School of Economics and Political Science Politics and Policy Blog'', October 19. https://blogs.lse.ac.uk/politicsandpolicy/why-artificial-intelligence-is-a-misnomer/'''
&lt;/div&gt;

Whiteley criticizes the use of the term artificial intelligence, noting that while such technologies can be valuable for automating specific tasks, the term John McCarthy used in the 1950s was a “disservice.” He argues that the term anthropomorphizes what is essentially a form of computer-assisted statistical analysis. Much of what we call AI functions as a sophisticated prediction system that processes vast amounts of data to produce answers, without any real understanding of the underlying concepts or theories. Whiteley further distinguishes between algorithms, which follow set procedures to identify patterns and make predictions, and inference, which involves interpreting and explaining why those patterns occur. He concludes that the ultimate goal in the field of AI is to create systems capable of predicting behavior across diverse problems. However, he emphasizes that current AI algorithms remain highly specialized, excelling in narrow tasks but lacking the flexibility and understanding required for true general intelligence.

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'''Zeffiro, A. 2024. “Automating (In)securities: Cybersecurity’s AI Imaginaries.” Paper presented at EASST/4S, 2024. https://nomadit.co.uk/conference/easst-4s2024/p/14156.'''
&lt;/div&gt;

Zeffiro interrogates cybersecurity's AI imaginaries through case studies of IBM Watson for Cybersecurity, CrowdStrike's Charlotte AI, and Google's Sec-PaLM, revealing how corporate narratives of AI as &quot;game changer&quot; and &quot;democratizing force&quot; systematically obscure differential vulnerabilities and normative biases. Her analysis challenges the prevalent framing of AI-driven threat detection as technically neutral automation, arguing instead that these systems encode and amplify assumptions about what constitutes risk, who merits protection, and whose insecurities remain invisible. Drawing on critical security studies and science and technology studies, Zeffiro demonstrates how generative AI applications in cybersecurity automate not merely data collection and pattern recognition but also the normative judgments about threat hierarchies embedded in training regimes and performance metrics. Her concept of &quot;automating insecurities&quot; captures this dual process: while AI tools promise enhanced security through real-time threat response with minimal human intervention, they simultaneously institutionalize particular understandings of vulnerability that reflect corporate priorities and market positioning in the &quot;AI arms race.&quot; Zeffiro's analysis connects these imaginaries to epistemic claims about AI's inevitability, showing how IBM, CrowdStrike, and Google construct future visions that naturalize their technological approaches while marginalizing alternative security paradigms. By foregrounding what these imaginaries omit—the differential distribution of cyber vulnerabilities across social positions, the political economy of security infrastructure, the discretionary authority embedded in algorithmic triage—Zeffiro positions cybersecurity AI as participating in broader patterns of automation that redistribute power and accountability rather than merely enhancing technical capabilities.

== Past relation to OSS-aligned communities ==

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'''Carnegie Endowment for International Peace. 2024. ''Beyond Open vs. Closed: Emerging Consensus and Key Questions for Foundation AI Model Governance''. https://carnegieendowment.org/research/2024/07/beyond-open-vs-closed-emerging-consensus-and-key-questions-for-foundation-ai-model-governance?lang=en.'''
&lt;/div&gt;

The report dismantles the binary framing—open vs. closed—that has organized foundation model governance debates, replacing it with a multidimensional spectrum where weight release is only one variable among many (architecture, training data, documentation, licensing terms, structured access). Seven consensus points establish that &quot;openness&quot; serves multiple, sometimes conflicting values (transparency, competition, safety, inclusion) and that weight release amplifies both beneficial and harmful potential without symmetry—its irreversibility and resistance to post-release monitoring create a qualitatively different governance problem than closed deployment, even though closed models' theoretical safety advantages are unevenly realized in practice. The report introduces &quot;precautionary friction&quot; (staged/structured release calibrated to marginal risk over a defined baseline) as the operative governance concept, explicitly rejecting both blanket openness and blanket restriction. Seventeen open questions then expose the infrastructure gaps: evaluation science remains embryonic, post-release monitoring is under-theorized, risk thresholds published by labs lack enforcement specificity, and Global South labor and data contributions are structurally undervalued. This source clarifies the claim that software-style &quot;open source&quot; maps poorly onto foundation models and that hybrid, graduated-release frameworks are where policy consensus is actually forming.

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'''Mitra, Bhaskar, Henriette Cramer, and Olya Gurevich. 2024. “Sociotechnical Implications of Generative Artificial Intelligence for Information Access.” ''arXiv'' (July 16, 2024). https://doi.org/10.48550/arXiv.2405.11612.'''
&lt;/div&gt;

Bhaskar et al. diagnose “information access” under generative AI as a sociotechnical settlement rather than a neutral upgrade to search: models do not just retrieve, they intermediate credibility, reshape attention, and re-allocate epistemic authority through interfaces that compress provenance and uncertainty. Their framing is especially useful for open, social scholarship because it links familiar problems of access (indexing, ranking, evaluation) to newer constraints created by platform dependence, opaque model behavior, and the enclosure of research pathways behind proprietary tooling and data. Read through the lenses of industry capture and AI imaginaries, the chapter clarifies how promises of universal assistants can normalize monopoly infrastructures while shifting audit burdens onto users and public institutions. It also implicitly strengthens open communities’ insistence on reproducibility: without open benchmarks, inspectable logs, and preservable corpora, “trustworthy information” becomes a brand claim rather than an evaluable property. The ideas bridge directly to libraries, repositories, and information policy by treating curation, metadata, and stewardship as counter-monopoly infrastructure for accountable AI-mediated access.

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'''Open Source Initiative. The Open Source AI Definition 1.0 (2024–2025). https://opensource.org/ai'''
&lt;/div&gt;

OSI’s Open Source AI Definition 1.0 operationalizes “open” as a bundle of enforceable freedoms rather than a branding claim, and it does so by porting the open source software tradition into the AI stack where “source” is more than just code. The definition makes the four freedoms—use, study, modify, share—the evaluative core, then adds a crucial precondition: exercising any of these rights requires access to the preferred form for making modifications and the means to use the system. That move is the governance lever: it blocks “open weights” releases from standing in for openness when the artifacts needed to understand or change system behavior are withheld. On OSI’s framing, openness is not satisfied by permissive inference access or a model file alone; it is satisfied when the system is provisioned so that auditability and alteration are practically possible, including transparency sufficient to trace how results were created and where components (notably data sources) come from. The definition is therefore designed as an anti-openwashing instrument: it supplies a community standard that can be applied to legal/technical packaging to distinguish genuinely open AI systems from hybrid offerings that preserve vendor control through restrictions or missing components. OSI explicitly positions this as policy-relevant infrastructure—an interpretive anchor for regulators and OSS communities trying to resist enclosure pressures while preserving permissionless collaboration. This is a community standard, not a journal article; it is nonetheless important for governance, policy, and OSS alignment.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Vake, D., Šinik, B., Vičič, J., &amp; Tošić, A. 2025. “Is Open Source the Future of AI? A Data‑Driven Approach.” ''arXiv'' preprint. https://arxiv.org/abs/2501.16403'''
&lt;/div&gt;

Vake et al. analyze the data of open-source large language models shared on HuggingFace to explore if the open-source community influences the development of LLMs. The authors found that the AI open-source community is expanding rapidly, and it has enhanced the performance of a handful of popular models. However, open-source AI depends on businesses to develop base models and release them openly, but there are few incentives to do so because it risks their intellectual property and competitive edge. Furthermore, AI is different from the development of open-source software because the general public cannot privately run these models. Therefore, the authors conclude that the future of AI development could be similar to the software-as-a-service model, in which the open-source community contributes to model development, while companies generate revenue from model usage.

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'''White, M., Haddad, I., Osborne, C., Liu, X., Abdelmonsef, A., Varghese, S., &amp; Le Hors, A. 2024. “The Model Openness Framework: Promoting Completeness and Openness for Reproducibility, Transparency, and Usability in AI.” ''arXiv'' preprint. arXiv:2403.13784.'''
&lt;/div&gt;

White et al.'s Model Openness Framework (MOF) represents an effort to translate open-source software principles into AI research practices, addressing the growing gap between claims of &quot;openness&quot; and actual transparency in AI model development. Developed through the Linux Foundation's AI &amp; Data Foundation, the framework establishes a three-tiered classification system that specifies which components (code, data, documentation, trained weights, evaluation procedures) must be released under open licenses for models to qualify as &quot;Class III: Open Model,&quot; &quot;Class II: Open Tooling,&quot; or &quot;Class I: Open Science.&quot; The authors' intervention addresses what they term &quot;openwashing&quot;—the strategic use of &quot;open source&quot; rhetoric by companies releasing models with restrictive licenses or incomplete artifacts. By codifying 17 critical components for complete model releases, they make visible the specific practices required for reproducibility and scrutiny, challenging the binary conception of openness inherited from software. Their framework reveals that AI &quot;openness&quot; exists on a spectrum of completeness, from minimal weight release to full disclosure of training data, intermediate checkpoints, and development documentation. Positioned within debates about responsible AI development, the MOF represents a community-driven effort to establish norms before they become ossified by corporate practice or regulatory fiat. The authors draw explicitly on open science principles (FAIR data, reproducibility standards) while adapting them to AI's unique characteristics—particularly the centrality of training data and the distinction between model architecture (code) and trained parameters (data).

== Bias and Technological Determinism ==

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'''Akter, S., G. McCarthy, S. Sajib, K. Michael, Y. K. Dwivedi, J. D’Ambra, and K. N. Shen. 2021. “Algorithmic Bias in Data-Driven Innovation in the Age of AI.” ''International Journal of Information Management'' 60: 102387. https://doi.org/10.1016/j.ijinfomgt.2021.102387.'''
&lt;/div&gt;

Akter and colleagues theorize algorithmic bias as emerging from three distinct but interacting sources—data bias, method bias, and societal bias— positioning bias as structural phenomenon inscribed across the entire data-driven innovation (DDI) lifecycle rather than localized technical artifact amenable to isolated correction. Their case study of Australia's Robo-Debt scheme demonstrates how algorithmic systems inherit and amplify existing inequities and foregrounds &quot;dynamic managerial capability&quot; as essential for addressing bias. The authors challenge purely technical approaches, arguing instead that organizational capacity to recognize, interrogate, and respond to bias across data provenance, algorithmic design, and deployment contexts determines whether DDI produces equitable or discriminatory outcomes. This positions bias mitigation as ongoing institutional work requiring cross-functional expertise rather than one-time technical intervention. Their framework implicitly contests technological determinism by revealing how managerial choices about data collection priorities, acceptable error rates, and stakeholder consultation shape algorithmic outcomes in ways that exceed engineering decisions. The emphasis on societal bias as distinct category acknowledges that algorithms operate within and reproduce broader patterns of structural inequality—assumptions about creditworthiness, employability, or welfare eligibility that reflect historical discrimination. Akter et al.'s intervention thus connects bias scholarship to organizational studies and innovation management, positioning algorithmic fairness not as mathematical property but as emergent from institutional practices, power relations, and the political-economic contexts within which DDI unfolds. 

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'''Jarrahi, M. H., G. Newlands, M. K. Lee, C. T. Wolf, E. Kinder, and W. Sutherland. 2021. “Algorithmic Management in a Work Context.” ''Big Data &amp; Society'' 8 (2). https://doi.org/10.1177/20539517211020332.'''
&lt;/div&gt;

Analyzes algorithmic management as a sociotechnical phenomenon reshaping power, discretion, and information flows in organizations; details opacity at technical and organizational levels. Exposes determinist narratives in “smart” automation of management decisions; shows how design choices redistribute authority and labor—central to a nondeterministic, governance-forward stance.

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'''Sartori, L., &amp; Theodorou, A. 2022. “A sociotechnical perspective for the future of AI: narratives, inequalities, and human control.” ''Ethics and Information Technology'' 24 (1), 4. https://doi.org/10.1007/s10676-022-09624-3'''
&lt;/div&gt;

Sartori and Theodorou position AI as a &quot;magnifying glass&quot; that automates and amplifies existing social inequalities rather than introducing bias as a novel technical problem, directly challenging narratives that frame fairness as achievable through post hoc algorithmic adjustment. Their sociotechnical framing insists that intelligent machines operate within specific institutional contexts where historical patterns of discrimination become encoded in data collection, annotation practices, and deployment decisions—a structural account that resists reduction to technical fixes. The authors engage critically with the AI technical community's emphasis on transparency, explainability, accountability, and contestability, acknowledging these as necessary but insufficient responses that risk becoming &quot;panaceas&quot; if divorced from attention to power asymmetries and organizing visions. Their analysis of technological narratives reveals how AI discourse reflects and reproduces traditional lines of social, economic, and political inequality: who gets to articulate AI futures, whose concerns register as legitimate risks, and which imaginaries gain institutional traction. By foregrounding narratives as both reflecting organizing visions and constituting &quot;tangible signs&quot; of inequality, Sartori and Theodorou demonstrate how deterministic framing—treating AI development as inevitable—forecloses deliberation about alternative design pathways. Their call for &quot;diverse approaches&quot; and &quot;richer knowledge about narratives&quot; positions non-determinism as methodological commitment: attending to contingent choices, plural stakeholder perspectives, and varied criteria of success that resist singular optimization logics. This intervention connects bias scholarship to governance debates, arguing that human control requires not just technical interpretability but institutional mechanisms for contestation that acknowledge AI practice as fundamentally interdisciplinary and politically consequential.

== Knowledge Foundations ==


===Diversity===

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'''Arbuckle, Alyssa. (2020). “How Can We Broaden and Diversify Humanities Knowledge Translation?” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.12'''
&lt;/div&gt;

Articulates diversity as a condition for valid public-facing scholarship; emphasizes inclusive modes of knowledge translation and participatory approaches resonant with OSS.

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'''Arthur, Paul L., Lyida Hearn, Lucy Montgomery, Hugh Craig, Alyssa Arbuckle, &amp; Ray Siemens. (2021). “Open Scholarship in Australia: A Review of Needs, Barriers, and Opportunities.” ''Digital Scholarship in the Humanities'' 36 (4), 795–812. DOI: https://doi.org/10.1093/llc/fqaa063'''
&lt;/div&gt;

Australian context scan identifies structural barriers and opportunities for diverse participation in open scholarship.

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'''Crompton, Constance, Lori Antranikan, Ruth Truong, &amp; Paige Maskell. 2020. “Familiar Wikidata: The Case for Building a Data Source We Can Trust.” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.02'''
&lt;/div&gt;

Makes the case for community governance and trust in open data infrastructures to safeguard plural representation and mitigate erasure in knowledge graphs.

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'''Fanning, Katie, Claire Kim, and Jon Saklofske. 2023. “Interactive Inspirations: The Case for Incorporating Joy and Play in Open Social Scholarship.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.012'''
&lt;/div&gt;

Argues that Open Social Scholarship must move beyond simple open access by cultivating &quot;joy and play&quot; as critical, anti-capitalist methodologies for community engagement. They demonstrate this through a prototype parody app and use its practical limitations to expose the structural friction between sustaining non-extractive digital commons and the realities of privatized app ecosystems and precarious academic funding.

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'''Rockwell, Geoffrey, Kaylin Land, and Andrew MacDonald. 2021. “Social Analytics Through Spyral.” ''Pop! Public. Open. Participatory''. no. 3. DOI: https://doi.org/10.54590/pop.2021.004 '''
&lt;/div&gt;

Demonstrates community-aware analytics for scholarly communities; touches on representational choices and the risks of flattening diverse practices through metrics.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Siemens, Lynne, and the INKE Research Group (2023). “I Stayed for the Community: Collaboration and Community in an Open Social Scholarship Research Project.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.013'''
&lt;/div&gt;

Views the success of open social scholarship as depending heavily on &quot;heritage relationships&quot; and the invisible labor of interpersonal maintenance, treating cross-sector collaboration as a deliberate methodological challenge rather than a natural byproduct of funding. Highlights a structural tension between community-driven qualitative goals and rigid academic metrics, urging institutions to formally recognize and resource the relational infrastructure that sustains Digital Humanities projects.

===Mobilisation===

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'''Arbuckle, Alyssa, Ray Siemens, Jon Bath, Constance Crompton, Laura Estill, Tanja Niemann, Jon Saklofske, and Lynne Siemens. 2022. “An Open Social Scholarship Path for the Humanities”. ''The Journal of Electronic Publishing'' 25 (2). DOI: https://doi.org/10.3998/jep.1973'''
&lt;/div&gt;

Defines OSS practices and infrastructures to support translation, engagement, and reciprocal exchange between researchers and publics.

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'''Jensen, Graham. 2023. “Introduction: Digital Knowledge Commons, Scholarly Connection, and the Evolution of Open Scholarship.” ''Open Scholarship Press Curated Volumes: Connection''. DOI: https://doi.org/10.21428/47bc126e.0ca461a4'''
&lt;/div&gt;

Connects social scholarly tools and commons-based infrastructures to mobilization pathways; highlights interoperability and community practices.

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'''Nelson, Brent, Miguel Dela Pena, and the Prototyping the Digital Archive Team &amp; the INKE Research Group. 2023. “No Journal is an Island: The John Donne Journal and the Possibilities of Open Access.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.007'''
&lt;/div&gt;

Case study of OA pathways as mobilization; addresses circulation, visibility, and engagement with broader publics.

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'''Winter, Caroline. 2023. “Introduction: Open Scholarship Policy in Focus.” ''Open Scholarship Press Curated Volumes: Policy''. DOI: https://doi.org/10.21428/47bc126e.5abba88b'''
&lt;/div&gt;

Frames policy as a vehicle for knowledge mobilization across sectors; emphasizes provenance, accountability, and public value alignment.

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'''Winter, Caroline, Tyler Fontenot, Luis Meneses, Alyssa Arbuckle, Ray Siemens, and the ETCL and INKE Research Groups. 2020. “Foundations for the Canadian HSS Commons: Exploring the Possibilities of Digital Research Communities.” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.05'''

Maps HSS Commons as mobilization infrastructure; addresses governance mechanisms, provenance, and dialogic engagement in a Canadian context.

&lt;/div&gt;

===Platforms===

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'''Bullard, Julia. 2023. “Describing the HSS Commons: The View from Metadata.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.004 '''
&lt;/div&gt;

Metadata as platform backbone; shows how descriptive schemas shape visibility/legitimacy; connects to interoperability and inclusive description.

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'''Goddard, Lisa. (2021). “Persistent Identifiers as Open Research Infrastructure to Reduce Administrative Burden.” ''Pop! Public. Open. Participatory''. no. 3. DOI: https://doi.org/10.54590/pop.2021.006 '''
&lt;/div&gt;

PIDs as platform connective tissue; crucial for provenance, traceability, and platform interoperability across repositories/journals.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Jensen, Graham, Alyssa Arbuckle, Caroline Winter, Talya Jesperson, Tyler Fontenot, Ray Siemens, and the ETCL and INKE Research Groups. 2022. “Fostering Digital Communities of Care: Safety, Security, and Trust in the Canadian HSS Commons.” ''IDEAH'' 3 (2). https://ideah.pubpub.org/pub/h7927ugt '''
&lt;/div&gt;

Governance and moderation as platform design commitments; aligns with OSS values around safety and reciprocity.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Meneses, Luis. 2020. “Integrating the Social Media Engine with Large-scale Open Access Repositories: A Discussion.” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.04 '''
&lt;/div&gt;

Explores platform coupling between OA repositories and social layers; anticipates AI-mediated discovery/recommendation impacts on visibility.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Turin, Mark. 2021. “From Orality to Open: Innovations in Multimedia Monograph Publishing in the Humanities.” ''Pop! Public. Open. Participatory''. no. 3. DOI: https://doi.org/10.54590/pop.2021.005 '''
&lt;/div&gt;

Platform affordances for multimodal scholarship; how platform standards and workflows enable plural forms and publics.

== Open Social Scholarship ==

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Arbuckle, Alyssa, and John Maxwell. (2019). “Modelling Open Social Scholarship Within the INKE Community.” ''KULA: Knowledge Creation, Dissemination, and Preservation Studies'' 3 (1), 1–8. DOI: https://doi.org/10.5334/kula.15'''
&lt;/div&gt;

Moves “beyond open access” toward OSS practice by reworking scholarly communication workflows around collaboration, transparency, and community needs. Emphasizes infrastructure choices and governance as sites where values are enacted. Gives concrete criteria for participatory infrastructures and power‑sharing in scholarly communication; helpful to evaluate platform design choices.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Arbuckle, Alyssa, Ray Siemens, Jon Bath, Constance Crompton, Laura Estill, Tanja Niemann, Jon Saklofske, and Lynne Siemens. 2022. “An Open Social Scholarship Path for the Humanities.” ''Journal of Electronic Publishing'' 25 (2). DOI: https://doi.org/10.3998/jep.1973'''
&lt;/div&gt;

A concise, peer‑reviewed articulation of open social scholarship (OSS) from INKE/ETCL leaders, translating principles into programs of action: public engagement, community training, policy, and infrastructure. Provides a normative baseline to assess whether platforms and practices foster dialogic exchange and mutuality rather than extraction.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Arthur, Paul L., Lyida Hearn, Lucy Montgomery, Hugh Craig, Alyssa Arbuckle, and Ray Siemens. 2021. “Open Scholarship in Australia: A Review of Needs, Barriers, and Opportunities.” ''Digital Scholarship in the Humanities'', 36 (4), 795–812. DOI: https://doi.org/10.1093/llc/fqaa063'''
&lt;/div&gt;

Peer‑reviewed assessment from CA‑Aus collaborators surfaces structural barriers (policy, incentives, infrastructure) and opportunities for publicly engaged open scholarship. Frames how national policy, incentives, and infrastructure shape whether openness reduces or reproduces inequities.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''El Khatib, Randa, Lindsey Seatter, Tracey El Hajj, Conrad Leibel, Alyssa Arbuckle, Ray Siemens, Caroline Winter, and the ETCL and INKE Research Groups. 2019. “Open Social Scholarship Annotated Bibliography.” ''KULA'' 3 (1), 1–141. DOI: https://doi.org/10.5334/kula.58'''
&lt;/div&gt;

Field‑defining synthesis of OSS foundations, surveying open access, participatory publishing, crowdsourcing, social knowledge creation, and policy. Establishes terminology and exemplars that connect openness with social responsibility. Defines a master index to map subdomains of openness and identify non‑AI precedents for care, accessibility, and accountability in scholarly infrastructures.

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'''Maxwell, John W. 2015. “Beyond Open Access to Open Publication and Open Scholarship.” ''Scholarly and Research Communication'' 6 (3), 1–10. DOI: https://doi.org/10.22230/src.2015v6n3a202'''
&lt;/div&gt;

Argues that simply “access” is insufficient; emphasizes usability, participatory review, and community‑responsive publishing workflows. Repositions openness as an ecosystem of practices with embedded care and accountability. Yields criteria for evaluating whether “openness” translates to meaningful, non‑extractive participation and shared authority in knowledge production.

{{Navigation|previous=Introduction|next=AI and Open}}

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      <text bytes="50937" sha1="bg1e7j3r6ht8xbzd5asgzp659grx8vf" xml:space="preserve">==Histories &amp; Theories of AI==

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'''Ali, Syed Mustafa, Stephanie Dick, Sarah Dillon, Matthew L. Jones, Jonnie Penn, and Richard Staley. 2023. “Histories of Artificial Intelligence: A Genealogy of Power.” ''BJHS Themes'' 8: 1–18. https://doi.org/10.1017/bjt.2023.15.'''
&lt;/div&gt;

The work of these authors seeks to move beyond “conventional origin myths” of AI by contextualizing the academic historical approach within their interdisciplinary backgrounds. As a result, Ali et al. argue that histories of broader processes (like industrialization, colonialism, and social science) can represent the “genealogy” of AI, which is not identified as a specific object but as a grouping of diverse technologies under a loose banner, requiring an equally diverse approach. Although AI is the “flagship of the Information Age”, it was clearly conditioned by the “Management Age”, as these “genealogies” feature four common thematic threads of “hidden labour”, “encoded behaviour”, “disingenuous rhetoric” and “cognitive injustice”. AI is therefore not only situated within the history of computing, but the history of control, the product of the interacting formalist and empiricist views of “intelligence” within Cold War epistemology. In many ways, AI’s refinement of formal abstraction reinforces and impresses Western systems and structures, so these authors do not critique AI with the goal of improvement, but to clarify what AI “is”, “is not”, and perhaps “should not” be.

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'''Anderson, Marc M. 2024. “AI as Philosophical Ideology: A Critical Look Back at John McCarthy’s Program.” ''Philosophy &amp; Technology'' 37 (2): 44. https://doi.org/10.1007/s13347-024-00731-1.'''
&lt;/div&gt;

This paper critically analyzes the synthesis of McCarthy’s AI development program, identifying its goals’ nature, purpose, relationship to society, and implications upon morality and social control. Firstly, Anderson considers the most problematic themes of McCarthy’s early and middle writings, then arguing that McCarthy’s later works consolidated his stance by replacing “tentative assumptions” with “statements whose linkages with contemporaneous analytic philosophy are made unequivocally” and thereby present AI as “the outcome of a certain philosophical way of looking at the world”. Here, Anderson emphasizes McCarthy’s biases towards objectivism, scientism, and analytic behaviourism; tendency to enable progress in AI by waiting to identify risks; positioning of philosophy as subordinate “handmaiden” to science; and uneasy presupposition humans have innate knowledge of the world’s object character (which AI will need added). To Anderson, the sum of the “ethical” aspects, “philosophical” aspects, and “competitive” nature of McCarthy’s program give it all the fundamental “characteristics of an ideological program”. This ideology has had deep direct influence, for example by joining AI ethics to consequentialist dilemmas like the “Trolley problem”, and deep indirect influence, for example by influencing a modular and component technical approach. Anderson argues this “ideology” was caused by McCarthy’s motive of making a “servile” and “stripped down model of human mental engagement without emotional qualities”. Overall, Anderson argues McCarthy’s conception of AI as a “perfectly rational abstraction of human thinking” involves severe misconceptions around rationality, and has “come to serve as a blind for increasing techno-corporate control of society” with its propagation of the belief that “AI systems should be controlled as servants”.

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'''Bender, Emily M., Timnit Gebru, Angelina McMillan-Major, and Shmargaret Shmitchell. 2021. “On the Dangers of Stochastic Parrots: Can Language Models Be Too Big? 🦜.” In ''Proceedings of the 2021 ACM Conference on Fairness, Accountability, and Transparency'', 610–23. https://doi.org/10.1145/3442188.3445922.'''
&lt;/div&gt;

Bender et al. critically analyze the environmental and social risks of ever larger language models trained with huge uncurated datasets from the web. Their first concern is the environmental costs of training language models, which require increasing energy and compute requirements that further environmental damages that are more likely to fall on marginalized populations. Their social concerns are that language models have the potential to reproduce hegemonic views, reinforce stereotypes, and further reify inequality due to the unrepresentativeness of their training data. Despite the increasing amounts of data ingested in these models, the authors argue that size does not guarantee diversity because there are people who are not on the web (and therefore not included in training data), the content of marginalized people online is less likely to be included in these large datasets and, if it is, it might be filtered out during the data preparation process. Therefore, the authors urge developers to stop using larger training datasets if they cannot be documented. As an alternative, they suggest curating and documenting smaller datasets created for specific purposes, evaluating models by the amount of resources they consume, and developing research that centers the people who are more likely to be adversely affected by the resulting technology.

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'''Berry, David M. 2025. “Synthetic Media and Computational Capitalism: Towards a Critical Theory of Artificial Intelligence.” ''AI &amp; Society'' 40: 5257–5269. DOI: https://doi.org/10.1007/s00146-025-02265-2'''
&lt;/div&gt;

Berry develops a critical theory of artificial intelligence centered on what he terms the &quot;algorithmic condition&quot;—a historical moment when computational systems generate cultural content indistinguishable from human production, thereby destabilizing traditional markers of authenticity and authorship. Engaging with Frankfurt School critical theory, particularly concepts of false consciousness and reification, Berry argues that contemporary AI represents a qualitative transformation he calls &quot;the Inversion,&quot; where machine-generated works not only replicate but actively reshape the grounds upon which experience and meaning are constituted. This moves beyond mechanical reproduction (Benjamin) or cybernetic feedback (Wiener) toward what Berry theorizes as &quot;post-consciousness,&quot; where boundaries between individual and synthetic consciousness become porous. His concept of &quot;diffusionisation&quot; describes how AI systems dissolve cultural forms into probabilistic vector spaces and reconstitute them through latent space manipulation, producing &quot;AI slop&quot;—low-quality synthetic content that infiltrates information ecosystems with garbled meaning. Berry positions this transformation within &quot;computational capitalism,&quot; arguing that algorithmic mediation now structures forms of life in ways that demand new critical methods. His &quot;constellational analysis&quot; proposes mapping the interdependencies among technical systems, cultural production, and political-economic structures to resist subsumption into algorithmic logics. Where earlier automation debates focused on task substitution, Berry foregrounds how synthetic media transforms the infrastructure of meaning-making itself, rendering questions of interpretability and embedded bias not as technical problems but as symptoms of deeper epistemic and political reconfigurations under computational conditions.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Chun, J., &amp; Elkins, K. (2023). “The Crisis of Artificial Intelligence: A New Digital Humanities Curriculum for Human-Centred AI.” ''International Journal of Humanities and Arts Computing'' 17 (2). DOI: https://doi.org/10.3366/ijhac.2023.0310'''
&lt;/div&gt;

Chun and Elkins position AI's rapid advancement as precipitating multiple interlocking crises—in higher education, in diversity and inclusion within technology fields, and in the broader socioeconomic fabric—that demand a specifically humanities-oriented pedagogical response. Their intervention challenges the prevalent assumption that AI literacy should emerge from STEM-dominated curricula, arguing instead that Digital Humanities offers distinctive pathways for cultivating critical engagement with computational systems. Where conventional computer science education treats AI as primarily a technical phenomenon requiring engineering skills, Chun and Elkins foreground reflective and collaborative meaning-making, insisting that the most effective AI tools amplify rather than replace human intellectual engagement. Their framework explicitly connects pedagogical design to civic preparation, positioning students not as mere consumers or operators of AI systems but as critically engaged citizens capable of interrogating the social and economic implications of algorithmic mediation. Drawing on theories of human-centered computing, they articulate an AI DH curriculum structured around two core commitments: opening meaningful research avenues for humanities scholars working with computational methods and addressing DEI shortcomings by engaging students traditionally alienated by conventional STEM pathways. Their approach implicitly challenges the epistemic authority claims embedded in AI discourse—the fantasy that technical expertise alone can adjudicate questions about algorithmic deployment—by insisting that humanistic inquiry offers essential resources for navigating AI's transformative effects on knowledge production, labor organization, and cultural representation.

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'''Chung, Hiu-Fung. 2025. “Betting on (Un)Certain Futures: Sociotechnical Imaginaries of AI and Varieties of Techno-Developmentalism in Asia.” ''Information, Communication &amp; Society'', 1–18. https://doi.org/10.1080/1369118X.2025.2535427.'''
&lt;/div&gt;

Chung redirects scholarly attention from dominant AI powers—China, the United States—to economically advanced but geographically non-dominant Asian societies: Singapore, Hong Kong, and Taiwan. Mobilizing the concept of &quot;techno-developmentalism&quot; to analyze how developmental states harness technological innovation for political-economic projects, Chung identifies three distinct imaginaries that emerge from specific historical, institutional, and geopolitical conditions. Singapore's &quot;cybernetic pragmatism&quot; deploys AI to legitimize neoliberal authoritarianism, embedding computational governance as a continuation of technocratic rule. Hong Kong's &quot;techno-entrepreneurship&quot; imaginary seeks to refashion financial capitalism through AI-driven innovation, positioning the territory as a global fintech hub amid shifting relationships with mainland China. Taiwan's &quot;defensive survival modality&quot; frames AI development as simultaneously addressing internal socioeconomic instability and external threats from superpower rivalry, particularly cross-strait tensions. Chung's analysis challenges the Global North/South binary that structures much AI governance literature, revealing how small advanced economies navigate strategic coupling with global tech industries while managing profound uncertainties about AI-centric reforms. His discourse analysis of policy documents from the early 2010s through 2024 demonstrates how national imaginaries encode assumptions about automation's effects on labor markets, the appropriate balance between state coordination and market mechanisms, and the role of computational infrastructure in securing geopolitical position. This comparative framework illuminates how different state formations mobilize AI to address divergent crises of legitimacy, capital accumulation, and sovereign security.

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'''van Es, Karin, and Dennis Nguyen. 2024. “‘Your Friendly AI Assistant’: The Anthropomorphic Self-Representations of ChatGPT and Its Implications for Imagining AI.” ''AI &amp; Society'' 40: 3591–3603. https://doi.org/10.1007/s00146-024-02108-6.'''
&lt;/div&gt;

van Es and Nguyen analyze how “social-technical imaginaries” invoked by “self-representations” of GenAI could influence public perception of the technology. These “socio-technical imaginaries” are a category of trending concept, which can exist in contrast, as both utopian and dystopian conceptions of AI are present in public discourse. These are dynamically changeable, often strategically promoted by tech companies to influence regulation, and influenced by a variety of media technologies and ecologies with equally diverse social, cultural, and political implications. The authors identify a range of current “socio-technical imaginaries” of AI. This includes: misconceived “magical thinking”, largely produced by poor terminology; speculative, exaggerative debates on AI capabilities, which distract from actualized and present risks; visual motifs correlating intelligence, efficiency, logic, duty, and trust, which are not inherent to Generative AI; and anthropomorphism, which brings a slew of problems surrounding social biases. To study AI “self-representations”, van Es and Nguyen have ChatGPT generate fifty images and fifty-eight sections of text, responding to several variations of the prompt “create an image of yourself”. The authors then perform an empirical, qualitative-exploratory analysis of this content to examine which “socio-technical imaginaries” dominate the material. These images most significantly emphasized ChatGPT’s alleged “social intelligence”, depicted as a friendly research assistant possessing “real” intellect - ironically often surrounded by books. Anthropomorphism was usually present, with eighty-two percent of images portraying AI as humanoid, and a further six percent as a human brain. Futuristic motifs like holograms, metallic shades, and the cosmos portrayed AI as near-magical. Textual responses expressed these same themes, demonstrating consistent messaging. Taken together, these generated responses encourage overlooking the ethical and legal challenges posed by trending GenAI technologies, “overestimate their capabilities”, and “potentially lead to mistakenly perceive them as trustworthy companions”. This raises questions as to what extent specific guidelines to these responses were programmed by OpenAI, or indicative of popular opinion.

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'''Jones, Matthew L. 2023. “AI in History.” ''American Historical Review'' 128 (3): 1360–67. https://doi.org/10.1093/ahr/rhad361.'''
&lt;/div&gt;

Jones explores how evolving approaches to AI research reflect upon the importance of studying artificial intelligence’s history. He believes traditional attempts to produce “symbolic” AI have been proven as misguided, comparing their failures to the traditionally unpopular “empiricist” approach. This approach is now dominant and involves the use of large-scale algorithms to capitalize upon the “unreasonable effectiveness of data” via “machine learning”. However, this shift in trends has also forced the meaning and capabilities of “artificial intelligence” to be reconsidered, now threatening “professions centred on particularity” like history. In response, Jones argues modern AI cannot be considered a “neutral substratum” but as a reflection of human creations - including their best and worst traits. Historians are experts at detecting bias, and this understanding of AI’s historical context is clearly necessary for its appropriate application, so historians should be playing a fundamental role in ensuring AI’s critical use. Jones believes historians can best do this by highlighting the “traces of labour” that can illustrate the “granular complex reality” of AI.

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'''Klein, L., M. Martin, A. Brock, M. Antoniak, M. Walsh, J. M. Johnson, L. Tilton, and D. Mimno. 2025. “Provocations from the Humanities for Generative AI Research.” ''arXiv'' preprint. https://arxiv.org/abs/2502.19190.'''
&lt;/div&gt;

Klein et al. explore the stakes of engaging with AI by juxtaposing the humanistic scholar’s investigation of the ‘human’ with the ‘anti-human’ approach of AI, a dichotomy they contextualize within late-stage capitalism. Klein et al. argue that AI’s generalist, binary approach ‘distorts “culture’ to content’. AI programs thereby conduct a ‘statistical enactment of… ideology’, imposing an objectivist European modernist framework of understanding upon the data. This binary conception of data is highlighted within ideas of ‘pure’ versus ‘toxic’ training data, which dismiss that the material inherently ‘reflects cultures and consists of expressions of those cultures’. Even content not being included ‘biases’ the rest of the data, so the best practices of open scholarship cannot fix the root issue - the only way to resolve the issues caused by ‘bias’ is to target the sources of the underlying structural problems. Klein et al. argue this flawed situation was fueled by ‘corporate spokespeople parroting AI hype’ to research - and that this relationship’s politicization should be a particular source of concern. Klein et al. argue AI can still serve a purpose, however. They propose AI with smaller datasets will produce more accurate information when tailored for specific topics and with input from experts of the humanities. Humanists cannot solely effect change, however, as ‘technical researchers must recognize the institutional asymmetries’ of administrative support and funding available to ensure development of ‘humanistic’ AI is a truly equal and interdisciplinary effort. 

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'''McIntosh, Timothy R., Susnjak, Teo, Liu, Tong, Watters, Paul, and Halgamuge, Malka N.. 2023. “From Google Gemini to OpenAI Q* (Q-Star): A Survey of Reshaping the Generative Artificial Intelligence (AI) Research Landscape.” ''Technologies''. https://doi.org/10.3390/technologies13020051 '''
&lt;/div&gt;

McIntosh et al. offer a survey of AI development’s frontiers targeted at fellow experts of the field, focussing on evolving “agentic” AI and its resulting research applications. Covering developments, they primarily employ case studies to demonstrate how multimodal AI could eclipse undynamic LLMs, but various “advanced learning techniques” and developments in model architecture are also outlined. On this topic, a table is presented to quantify the relevance of research fields and subfields of AI development. Agentic AI’s possible applications include aiding research by bolstering academic integrity, its market relevance, and its “creative” purposes. McIntosh et al. even argue that development of AGI with “symbolic reasoning” and “probabilistic inference” could handle issues like climate change, considered as a long-term but significant possibility. Therefore, this work is primarily theoretical, with McIntosh et al. centralizing AI’s idealistic applications. However, they do acknowledge AI must be developed with ethical and social principles, for which interdisciplinary cooperation is necessary. 

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'''Richter, V., Katzenbach, C., &amp; Schäfer, M. S. (2025). “Imaginaries of Artificial Intelligence.” ''Computers in Human Behavior''. https://doi.org/10.1016/j.chb.2025.108682'''
&lt;/div&gt;

Richter, Katzenbach, and Schäfer systematize the concept of &quot;sociotechnical imaginaries&quot; as an analytical framework for understanding how collective visions of AI futures shape governance, investment, and public discourse. Engaging explicitly with science and technology studies scholarship—particularly Jasanoff and Kim's formulation of imaginaries as &quot;collectively held, institutionally stabilized, and publicly performed visions&quot;—they demonstrate how AI's meaning emerges through contested negotiations among stakeholders from industry, government, academia, media, and civil society. Their comparative analysis across the United States, China, and Germany challenges simplistic national characterizations, revealing heterogeneous and often contradictory imaginaries even within single regulatory regimes. Where US discourse fragments across multiple geographic AI hubs, German imaginaries center on EU policy compliance and regulatory frameworks, while Chinese articulations align tightly with party-state directives that minimize local variation. Richter and colleagues argue that these imaginaries function performatively, not merely representing AI's future but actively mobilizing resources, legitimating interventions, and establishing trajectories for development. Their framework illuminates how benchmark cultures, optimization narratives, and investor expectations become embedded in technical choices through discursive processes that precede and exceed engineering decisions. By foregrounding stakeholder co-dependencies and cross-national dynamics, the authors position AI imaginaries as sites where epistemological assumptions about intelligence, automation, and progress become institutionalized through political-economic mechanisms—a contribution that connects discourse analysis to questions of power, accountability, and the material reorganization of labor and knowledge production.

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'''Whiteley, Paul. 2023. “Why Artificial Intelligence Is a Misnomer.” ''London School of Economics and Political Science Politics and Policy Blog'', October 19. https://blogs.lse.ac.uk/politicsandpolicy/why-artificial-intelligence-is-a-misnomer/'''
&lt;/div&gt;

Whiteley criticizes the use of the term artificial intelligence, noting that while such technologies can be valuable for automating specific tasks, the term John McCarthy used in the 1950s was a “disservice.” He argues that the term anthropomorphizes what is essentially a form of computer-assisted statistical analysis. Much of what we call AI functions as a sophisticated prediction system that processes vast amounts of data to produce answers, without any real understanding of the underlying concepts or theories. Whiteley further distinguishes between algorithms, which follow set procedures to identify patterns and make predictions, and inference, which involves interpreting and explaining why those patterns occur. He concludes that the ultimate goal in the field of AI is to create systems capable of predicting behavior across diverse problems. However, he emphasizes that current AI algorithms remain highly specialized, excelling in narrow tasks but lacking the flexibility and understanding required for true general intelligence.

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'''Zeffiro, A. 2024. “Automating (In)securities: Cybersecurity’s AI Imaginaries.” Paper presented at EASST/4S, 2024. https://nomadit.co.uk/conference/easst-4s2024/p/14156.'''
&lt;/div&gt;

Zeffiro interrogates cybersecurity's AI imaginaries through case studies of IBM Watson for Cybersecurity, CrowdStrike's Charlotte AI, and Google's Sec-PaLM, revealing how corporate narratives of AI as &quot;game changer&quot; and &quot;democratizing force&quot; systematically obscure differential vulnerabilities and normative biases. Her analysis challenges the prevalent framing of AI-driven threat detection as technically neutral automation, arguing instead that these systems encode and amplify assumptions about what constitutes risk, who merits protection, and whose insecurities remain invisible. Drawing on critical security studies and science and technology studies, Zeffiro demonstrates how generative AI applications in cybersecurity automate not merely data collection and pattern recognition but also the normative judgments about threat hierarchies embedded in training regimes and performance metrics. Her concept of &quot;automating insecurities&quot; captures this dual process: while AI tools promise enhanced security through real-time threat response with minimal human intervention, they simultaneously institutionalize particular understandings of vulnerability that reflect corporate priorities and market positioning in the &quot;AI arms race.&quot; Zeffiro's analysis connects these imaginaries to epistemic claims about AI's inevitability, showing how IBM, CrowdStrike, and Google construct future visions that naturalize their technological approaches while marginalizing alternative security paradigms. By foregrounding what these imaginaries omit—the differential distribution of cyber vulnerabilities across social positions, the political economy of security infrastructure, the discretionary authority embedded in algorithmic triage—Zeffiro positions cybersecurity AI as participating in broader patterns of automation that redistribute power and accountability rather than merely enhancing technical capabilities.

== Past Relation to OSS-Aligned Communities ==

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'''Carnegie Endowment for International Peace. 2024. ''Beyond Open vs. Closed: Emerging Consensus and Key Questions for Foundation AI Model Governance''. https://carnegieendowment.org/research/2024/07/beyond-open-vs-closed-emerging-consensus-and-key-questions-for-foundation-ai-model-governance?lang=en.'''
&lt;/div&gt;

The report dismantles the binary framing—open vs. closed—that has organized foundation model governance debates, replacing it with a multidimensional spectrum where weight release is only one variable among many (architecture, training data, documentation, licensing terms, structured access). Seven consensus points establish that &quot;openness&quot; serves multiple, sometimes conflicting values (transparency, competition, safety, inclusion) and that weight release amplifies both beneficial and harmful potential without symmetry—its irreversibility and resistance to post-release monitoring create a qualitatively different governance problem than closed deployment, even though closed models' theoretical safety advantages are unevenly realized in practice. The report introduces &quot;precautionary friction&quot; (staged/structured release calibrated to marginal risk over a defined baseline) as the operative governance concept, explicitly rejecting both blanket openness and blanket restriction. Seventeen open questions then expose the infrastructure gaps: evaluation science remains embryonic, post-release monitoring is under-theorized, risk thresholds published by labs lack enforcement specificity, and Global South labor and data contributions are structurally undervalued. This source clarifies the claim that software-style &quot;open source&quot; maps poorly onto foundation models and that hybrid, graduated-release frameworks are where policy consensus is actually forming.

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'''Mitra, Bhaskar, Henriette Cramer, and Olya Gurevich. 2024. “Sociotechnical Implications of Generative Artificial Intelligence for Information Access.” ''arXiv'' (July 16, 2024). https://doi.org/10.48550/arXiv.2405.11612.'''
&lt;/div&gt;

Bhaskar et al. diagnose “information access” under generative AI as a sociotechnical settlement rather than a neutral upgrade to search: models do not just retrieve, they intermediate credibility, reshape attention, and re-allocate epistemic authority through interfaces that compress provenance and uncertainty. Their framing is especially useful for open, social scholarship because it links familiar problems of access (indexing, ranking, evaluation) to newer constraints created by platform dependence, opaque model behavior, and the enclosure of research pathways behind proprietary tooling and data. Read through the lenses of industry capture and AI imaginaries, the chapter clarifies how promises of universal assistants can normalize monopoly infrastructures while shifting audit burdens onto users and public institutions. It also implicitly strengthens open communities’ insistence on reproducibility: without open benchmarks, inspectable logs, and preservable corpora, “trustworthy information” becomes a brand claim rather than an evaluable property. The ideas bridge directly to libraries, repositories, and information policy by treating curation, metadata, and stewardship as counter-monopoly infrastructure for accountable AI-mediated access.

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'''Open Source Initiative. The Open Source AI Definition 1.0 (2024–2025). https://opensource.org/ai'''
&lt;/div&gt;

OSI’s Open Source AI Definition 1.0 operationalizes “open” as a bundle of enforceable freedoms rather than a branding claim, and it does so by porting the open source software tradition into the AI stack where “source” is more than just code. The definition makes the four freedoms—use, study, modify, share—the evaluative core, then adds a crucial precondition: exercising any of these rights requires access to the preferred form for making modifications and the means to use the system. That move is the governance lever: it blocks “open weights” releases from standing in for openness when the artifacts needed to understand or change system behavior are withheld. On OSI’s framing, openness is not satisfied by permissive inference access or a model file alone; it is satisfied when the system is provisioned so that auditability and alteration are practically possible, including transparency sufficient to trace how results were created and where components (notably data sources) come from. The definition is therefore designed as an anti-openwashing instrument: it supplies a community standard that can be applied to legal/technical packaging to distinguish genuinely open AI systems from hybrid offerings that preserve vendor control through restrictions or missing components. OSI explicitly positions this as policy-relevant infrastructure—an interpretive anchor for regulators and OSS communities trying to resist enclosure pressures while preserving permissionless collaboration. This is a community standard, not a journal article; it is nonetheless important for governance, policy, and OSS alignment.

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'''Vake, D., Šinik, B., Vičič, J., &amp; Tošić, A. 2025. “Is Open Source the Future of AI? A Data‑Driven Approach.” ''arXiv'' preprint. https://arxiv.org/abs/2501.16403'''
&lt;/div&gt;

Vake et al. analyze the data of open-source large language models shared on HuggingFace to explore if the open-source community influences the development of LLMs. The authors found that the AI open-source community is expanding rapidly, and it has enhanced the performance of a handful of popular models. However, open-source AI depends on businesses to develop base models and release them openly, but there are few incentives to do so because it risks their intellectual property and competitive edge. Furthermore, AI is different from the development of open-source software because the general public cannot privately run these models. Therefore, the authors conclude that the future of AI development could be similar to the software-as-a-service model, in which the open-source community contributes to model development, while companies generate revenue from model usage.

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'''White, M., Haddad, I., Osborne, C., Liu, X., Abdelmonsef, A., Varghese, S., &amp; Le Hors, A. 2024. “The Model Openness Framework: Promoting Completeness and Openness for Reproducibility, Transparency, and Usability in AI.” ''arXiv'' preprint. arXiv:2403.13784.'''
&lt;/div&gt;

White et al.'s Model Openness Framework (MOF) represents an effort to translate open-source software principles into AI research practices, addressing the growing gap between claims of &quot;openness&quot; and actual transparency in AI model development. Developed through the Linux Foundation's AI &amp; Data Foundation, the framework establishes a three-tiered classification system that specifies which components (code, data, documentation, trained weights, evaluation procedures) must be released under open licenses for models to qualify as &quot;Class III: Open Model,&quot; &quot;Class II: Open Tooling,&quot; or &quot;Class I: Open Science.&quot; The authors' intervention addresses what they term &quot;openwashing&quot;—the strategic use of &quot;open source&quot; rhetoric by companies releasing models with restrictive licenses or incomplete artifacts. By codifying 17 critical components for complete model releases, they make visible the specific practices required for reproducibility and scrutiny, challenging the binary conception of openness inherited from software. Their framework reveals that AI &quot;openness&quot; exists on a spectrum of completeness, from minimal weight release to full disclosure of training data, intermediate checkpoints, and development documentation. Positioned within debates about responsible AI development, the MOF represents a community-driven effort to establish norms before they become ossified by corporate practice or regulatory fiat. The authors draw explicitly on open science principles (FAIR data, reproducibility standards) while adapting them to AI's unique characteristics—particularly the centrality of training data and the distinction between model architecture (code) and trained parameters (data).

== Bias and Technological Determinism ==

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'''Akter, S., G. McCarthy, S. Sajib, K. Michael, Y. K. Dwivedi, J. D’Ambra, and K. N. Shen. 2021. “Algorithmic Bias in Data-Driven Innovation in the Age of AI.” ''International Journal of Information Management'' 60: 102387. https://doi.org/10.1016/j.ijinfomgt.2021.102387.'''
&lt;/div&gt;

Akter and colleagues theorize algorithmic bias as emerging from three distinct but interacting sources—data bias, method bias, and societal bias— positioning bias as structural phenomenon inscribed across the entire data-driven innovation (DDI) lifecycle rather than localized technical artifact amenable to isolated correction. Their case study of Australia's Robo-Debt scheme demonstrates how algorithmic systems inherit and amplify existing inequities and foregrounds &quot;dynamic managerial capability&quot; as essential for addressing bias. The authors challenge purely technical approaches, arguing instead that organizational capacity to recognize, interrogate, and respond to bias across data provenance, algorithmic design, and deployment contexts determines whether DDI produces equitable or discriminatory outcomes. This positions bias mitigation as ongoing institutional work requiring cross-functional expertise rather than one-time technical intervention. Their framework implicitly contests technological determinism by revealing how managerial choices about data collection priorities, acceptable error rates, and stakeholder consultation shape algorithmic outcomes in ways that exceed engineering decisions. The emphasis on societal bias as distinct category acknowledges that algorithms operate within and reproduce broader patterns of structural inequality—assumptions about creditworthiness, employability, or welfare eligibility that reflect historical discrimination. Akter et al.'s intervention thus connects bias scholarship to organizational studies and innovation management, positioning algorithmic fairness not as mathematical property but as emergent from institutional practices, power relations, and the political-economic contexts within which DDI unfolds. 

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'''Jarrahi, M. H., G. Newlands, M. K. Lee, C. T. Wolf, E. Kinder, and W. Sutherland. 2021. “Algorithmic Management in a Work Context.” ''Big Data &amp; Society'' 8 (2). https://doi.org/10.1177/20539517211020332.'''
&lt;/div&gt;

Analyzes algorithmic management as a sociotechnical phenomenon reshaping power, discretion, and information flows in organizations; details opacity at technical and organizational levels. Exposes determinist narratives in “smart” automation of management decisions; shows how design choices redistribute authority and labor—central to a nondeterministic, governance-forward stance.

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'''Sartori, L., &amp; Theodorou, A. 2022. “A sociotechnical perspective for the future of AI: narratives, inequalities, and human control.” ''Ethics and Information Technology'' 24 (1), 4. https://doi.org/10.1007/s10676-022-09624-3'''
&lt;/div&gt;

Sartori and Theodorou position AI as a &quot;magnifying glass&quot; that automates and amplifies existing social inequalities rather than introducing bias as a novel technical problem, directly challenging narratives that frame fairness as achievable through post hoc algorithmic adjustment. Their sociotechnical framing insists that intelligent machines operate within specific institutional contexts where historical patterns of discrimination become encoded in data collection, annotation practices, and deployment decisions—a structural account that resists reduction to technical fixes. The authors engage critically with the AI technical community's emphasis on transparency, explainability, accountability, and contestability, acknowledging these as necessary but insufficient responses that risk becoming &quot;panaceas&quot; if divorced from attention to power asymmetries and organizing visions. Their analysis of technological narratives reveals how AI discourse reflects and reproduces traditional lines of social, economic, and political inequality: who gets to articulate AI futures, whose concerns register as legitimate risks, and which imaginaries gain institutional traction. By foregrounding narratives as both reflecting organizing visions and constituting &quot;tangible signs&quot; of inequality, Sartori and Theodorou demonstrate how deterministic framing—treating AI development as inevitable—forecloses deliberation about alternative design pathways. Their call for &quot;diverse approaches&quot; and &quot;richer knowledge about narratives&quot; positions non-determinism as methodological commitment: attending to contingent choices, plural stakeholder perspectives, and varied criteria of success that resist singular optimization logics. This intervention connects bias scholarship to governance debates, arguing that human control requires not just technical interpretability but institutional mechanisms for contestation that acknowledge AI practice as fundamentally interdisciplinary and politically consequential.

== Knowledge Foundations ==


===Diversity===

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'''Arbuckle, Alyssa. (2020). “How Can We Broaden and Diversify Humanities Knowledge Translation?” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.12'''
&lt;/div&gt;

Articulates diversity as a condition for valid public-facing scholarship; emphasizes inclusive modes of knowledge translation and participatory approaches resonant with OSS.

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'''Arthur, Paul L., Lyida Hearn, Lucy Montgomery, Hugh Craig, Alyssa Arbuckle, &amp; Ray Siemens. (2021). “Open Scholarship in Australia: A Review of Needs, Barriers, and Opportunities.” ''Digital Scholarship in the Humanities'' 36 (4), 795–812. DOI: https://doi.org/10.1093/llc/fqaa063'''
&lt;/div&gt;

Australian context scan identifies structural barriers and opportunities for diverse participation in open scholarship.

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'''Crompton, Constance, Lori Antranikan, Ruth Truong, &amp; Paige Maskell. 2020. “Familiar Wikidata: The Case for Building a Data Source We Can Trust.” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.02'''
&lt;/div&gt;

Makes the case for community governance and trust in open data infrastructures to safeguard plural representation and mitigate erasure in knowledge graphs.

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'''Fanning, Katie, Claire Kim, and Jon Saklofske. 2023. “Interactive Inspirations: The Case for Incorporating Joy and Play in Open Social Scholarship.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.012'''
&lt;/div&gt;

Argues that Open Social Scholarship must move beyond simple open access by cultivating &quot;joy and play&quot; as critical, anti-capitalist methodologies for community engagement. They demonstrate this through a prototype parody app and use its practical limitations to expose the structural friction between sustaining non-extractive digital commons and the realities of privatized app ecosystems and precarious academic funding.

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'''Rockwell, Geoffrey, Kaylin Land, and Andrew MacDonald. 2021. “Social Analytics Through Spyral.” ''Pop! Public. Open. Participatory''. no. 3. DOI: https://doi.org/10.54590/pop.2021.004 '''
&lt;/div&gt;

Demonstrates community-aware analytics for scholarly communities; touches on representational choices and the risks of flattening diverse practices through metrics.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Siemens, Lynne, and the INKE Research Group (2023). “I Stayed for the Community: Collaboration and Community in an Open Social Scholarship Research Project.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.013'''
&lt;/div&gt;

Views the success of open social scholarship as depending heavily on &quot;heritage relationships&quot; and the invisible labor of interpersonal maintenance, treating cross-sector collaboration as a deliberate methodological challenge rather than a natural byproduct of funding. Highlights a structural tension between community-driven qualitative goals and rigid academic metrics, urging institutions to formally recognize and resource the relational infrastructure that sustains Digital Humanities projects.

===Mobilisation===

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'''Arbuckle, Alyssa, Ray Siemens, Jon Bath, Constance Crompton, Laura Estill, Tanja Niemann, Jon Saklofske, and Lynne Siemens. 2022. “An Open Social Scholarship Path for the Humanities”. ''The Journal of Electronic Publishing'' 25 (2). DOI: https://doi.org/10.3998/jep.1973'''
&lt;/div&gt;

Defines OSS practices and infrastructures to support translation, engagement, and reciprocal exchange between researchers and publics.

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'''Jensen, Graham. 2023. “Introduction: Digital Knowledge Commons, Scholarly Connection, and the Evolution of Open Scholarship.” ''Open Scholarship Press Curated Volumes: Connection''. DOI: https://doi.org/10.21428/47bc126e.0ca461a4'''
&lt;/div&gt;

Connects social scholarly tools and commons-based infrastructures to mobilization pathways; highlights interoperability and community practices.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Nelson, Brent, Miguel Dela Pena, and the Prototyping the Digital Archive Team &amp; the INKE Research Group. 2023. “No Journal is an Island: The John Donne Journal and the Possibilities of Open Access.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.007'''
&lt;/div&gt;

Case study of OA pathways as mobilization; addresses circulation, visibility, and engagement with broader publics.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Winter, Caroline. 2023. “Introduction: Open Scholarship Policy in Focus.” ''Open Scholarship Press Curated Volumes: Policy''. DOI: https://doi.org/10.21428/47bc126e.5abba88b'''
&lt;/div&gt;

Frames policy as a vehicle for knowledge mobilization across sectors; emphasizes provenance, accountability, and public value alignment.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Winter, Caroline, Tyler Fontenot, Luis Meneses, Alyssa Arbuckle, Ray Siemens, and the ETCL and INKE Research Groups. 2020. “Foundations for the Canadian HSS Commons: Exploring the Possibilities of Digital Research Communities.” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.05'''

Maps HSS Commons as mobilization infrastructure; addresses governance mechanisms, provenance, and dialogic engagement in a Canadian context.

&lt;/div&gt;

===Platforms===

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Bullard, Julia. 2023. “Describing the HSS Commons: The View from Metadata.” ''Pop! Public. Open. Participatory''. no. 5. DOI: https://doi.org/10.54590/pop.2023.004 '''
&lt;/div&gt;

Metadata as platform backbone; shows how descriptive schemas shape visibility/legitimacy; connects to interoperability and inclusive description.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Goddard, Lisa. (2021). “Persistent Identifiers as Open Research Infrastructure to Reduce Administrative Burden.” ''Pop! Public. Open. Participatory''. no. 3. DOI: https://doi.org/10.54590/pop.2021.006 '''
&lt;/div&gt;

PIDs as platform connective tissue; crucial for provenance, traceability, and platform interoperability across repositories/journals.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Jensen, Graham, Alyssa Arbuckle, Caroline Winter, Talya Jesperson, Tyler Fontenot, Ray Siemens, and the ETCL and INKE Research Groups. 2022. “Fostering Digital Communities of Care: Safety, Security, and Trust in the Canadian HSS Commons.” ''IDEAH'' 3 (2). https://ideah.pubpub.org/pub/h7927ugt '''
&lt;/div&gt;

Governance and moderation as platform design commitments; aligns with OSS values around safety and reciprocity.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Meneses, Luis. 2020. “Integrating the Social Media Engine with Large-scale Open Access Repositories: A Discussion.” ''Pop! Public. Open. Participatory''. no. 2. DOI: https://doi.org/10.48404/pop.2020.04 '''
&lt;/div&gt;

Explores platform coupling between OA repositories and social layers; anticipates AI-mediated discovery/recommendation impacts on visibility.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Turin, Mark. 2021. “From Orality to Open: Innovations in Multimedia Monograph Publishing in the Humanities.” ''Pop! Public. Open. Participatory''. no. 3. DOI: https://doi.org/10.54590/pop.2021.005 '''
&lt;/div&gt;

Platform affordances for multimodal scholarship; how platform standards and workflows enable plural forms and publics.

== Open Social Scholarship ==

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Arbuckle, Alyssa, and John Maxwell. (2019). “Modelling Open Social Scholarship Within the INKE Community.” ''KULA: Knowledge Creation, Dissemination, and Preservation Studies'' 3 (1), 1–8. DOI: https://doi.org/10.5334/kula.15'''
&lt;/div&gt;

Moves “beyond open access” toward OSS practice by reworking scholarly communication workflows around collaboration, transparency, and community needs. Emphasizes infrastructure choices and governance as sites where values are enacted. Gives concrete criteria for participatory infrastructures and power‑sharing in scholarly communication; helpful to evaluate platform design choices.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Arbuckle, Alyssa, Ray Siemens, Jon Bath, Constance Crompton, Laura Estill, Tanja Niemann, Jon Saklofske, and Lynne Siemens. 2022. “An Open Social Scholarship Path for the Humanities.” ''Journal of Electronic Publishing'' 25 (2). DOI: https://doi.org/10.3998/jep.1973'''
&lt;/div&gt;

A concise, peer‑reviewed articulation of open social scholarship (OSS) from INKE/ETCL leaders, translating principles into programs of action: public engagement, community training, policy, and infrastructure. Provides a normative baseline to assess whether platforms and practices foster dialogic exchange and mutuality rather than extraction.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Arthur, Paul L., Lyida Hearn, Lucy Montgomery, Hugh Craig, Alyssa Arbuckle, and Ray Siemens. 2021. “Open Scholarship in Australia: A Review of Needs, Barriers, and Opportunities.” ''Digital Scholarship in the Humanities'', 36 (4), 795–812. DOI: https://doi.org/10.1093/llc/fqaa063'''
&lt;/div&gt;

Peer‑reviewed assessment from CA‑Aus collaborators surfaces structural barriers (policy, incentives, infrastructure) and opportunities for publicly engaged open scholarship. Frames how national policy, incentives, and infrastructure shape whether openness reduces or reproduces inequities.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''El Khatib, Randa, Lindsey Seatter, Tracey El Hajj, Conrad Leibel, Alyssa Arbuckle, Ray Siemens, Caroline Winter, and the ETCL and INKE Research Groups. 2019. “Open Social Scholarship Annotated Bibliography.” ''KULA'' 3 (1), 1–141. DOI: https://doi.org/10.5334/kula.58'''
&lt;/div&gt;

Field‑defining synthesis of OSS foundations, surveying open access, participatory publishing, crowdsourcing, social knowledge creation, and policy. Establishes terminology and exemplars that connect openness with social responsibility. Defines a master index to map subdomains of openness and identify non‑AI precedents for care, accessibility, and accountability in scholarly infrastructures.

&lt;div style=&quot;text-indent: -20px; padding-left: 20px; margin-bottom: -10px&quot;&gt;
'''Maxwell, John W. 2015. “Beyond Open Access to Open Publication and Open Scholarship.” ''Scholarly and Research Communication'' 6 (3), 1–10. DOI: https://doi.org/10.22230/src.2015v6n3a202'''
&lt;/div&gt;

Argues that simply “access” is insufficient; emphasizes usability, participatory review, and community‑responsive publishing workflows. Repositions openness as an ecosystem of practices with embedded care and accountability. Yields criteria for evaluating whether “openness” translates to meaningful, non‑extractive participation and shared authority in knowledge production.

{{Navigation|previous=Introduction|next=AI and Open}}

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==Loading libraries==
&lt;syntaxhighlight lang=&quot;R&quot;&gt;
library(dplyr)
library(meta)
&lt;/syntaxhighlight&gt;

==Part 1: Data==
At https://docs.metapsy.org/databases/panic-psyctr/ you can download documents in PDF format and data in ZIP format related to a meta-analysis conducted by researchers entitled &quot;Panic Disorder: Psychotherapy vs. Control.&quot; This analysis analyzed 82 clinical trials of psychotherapies for panic attacks, comparing groups undergoing psychotherapy and control groups. The CSV dataset contains the Hedges' effect size &quot;g&quot; with its corresponding standard deviation for each study, as well as the variable &quot;condition_arm1,&quot; which contains the type of psychotherapy used in the study:
* CBT: Traditional Cognitive Behavioral Therapy.
* CT: Cognitive therapy.
* PT: Physiological therapies (e.g., relaxation, breathing)
* BT: Behavioral therapy.
* IPT: Interpersonal therapy.
* PD: Psychodynamic therapy.
* EMDR: Eye Movement Desensitization and Reprocessing.
* 3W: Third-wave therapies.
The variable ''condition_arm2'' contains the type of group to which the psychotherapy group is compared: (TAU/NT = Treatment as Usual / No Treatment, WL = Waiting List: Where patients receive no immediate treatment, PL (Placebo) = Placebo control condition, etc.).

'''Loading and displaying the first 6 studies:'''
&lt;syntaxhighlight lang=&quot;R&quot;&gt;
df &lt;- read.csv(&quot;data.csv&quot;, sep = &quot;;&quot;, dec = &quot;,&quot;, stringsAsFactors = FALSE)

df %&gt;%
    select(study, .g, .g_se, condition_arm1, condition_arm2) %&gt;%
    head()
&lt;/syntaxhighlight&gt;

{| class=&quot;wikitable&quot;
! study !! .g !! .g_se !! condition_arm1 !! condition_arm2
|-
| Addis, 2004 || 0.0161750627495288 || 0.223890554729454 || CBT || TAU/NT
|-
| Allen, 2016 || -0.972512153444725 || 0.324292277601381 || CBT || WL
|-
| Bakker, 1999 || -0.141202426916712 || 0.244895341518145 || CT || PL
|-
| Barlow, 1989 || -0.43330687233944 || 0.317863739274094 || CBT || WL
|-
| Barlow, 1989 || -0.556280081810442 || 0.416274889821373 || PT || WL
|-
| Barlow, 2000 || -0.483415186554789 || 0.236280209040239 || CBT || PL
|}

==Part 2: Meta-analysis==
===Calculating Hedges' g===
We calculate Hedges' g in meta-analyses of studies with time = post and perform the Egger test to assess whether there is publication bias due to the fact that studies with positive results and high g are more likely to be published than those with modest or negative results. Since the p-value is &lt;0.05, there is indeed publication bias in the test, so we use Duval and Tweedie's &quot;trim and fill&quot; procedure, which estimates the number of missing studies and recalculates g, obtaining g = -0.49 with a 95% confidence interval: [ -0.65 , -0.34 ], so in this case the effect in reducing panic attacks is medium:

&lt;syntaxhighlight lang=&quot;R&quot;&gt;
df_eff &lt;- df %&gt;%
filter(!is.na(.g), !is.na(.g_se))

meta_eff &lt;- metagen(
  TE = .g,
  seTE = .g_se,
  studlab = study,
  data = df_eff,
  sm = &quot;SMD&quot;,
  method.tau = &quot;REML&quot;,   # random effects
  method.random.ci = &quot;HK&quot;            # Hartung-Knapp
)

# Egger test for publication bias
metabias(meta_eff, method.stat = &quot;linreg&quot;)
&lt;/syntaxhighlight&gt;

 Linear regression test of funnel plot asymmetry
 Test result: t = -4.37, df = 76, p-value &lt; 0.0001
 Bias estimate: -2.0106 (SE = 0.4605)
 Details:
 - multiplicative residual heterogeneity variance (tau^2 = 2.9623)
 - predictor: standard error
 - weight:    inverse variance
 - reference: Egger et al. (1997), BMJ

&lt;syntaxhighlight lang=&quot;R&quot;&gt;
m_g&lt;- trimfill(meta_eff)
print(paste(&quot;g =&quot;,round(m_g$TE.random,2),&quot;; 95%CI: [&quot;,round(m_g$lower.random,2),&quot;,&quot;,round(m_g$upper.random,2),&quot;]&quot;))
&lt;/syntaxhighlight&gt;

 &quot;g = -0.49; 95%CI: [ -0.65, -0.34]&quot;

Measuring g for the various psychotherapies immediately after treatment (time=post), we find that BT = Behavioral Therapy has the highest g (g=-0.97), PT = Physiological Therapies (e.g., relaxation, breathing) (g=-0.87), CBT = Cognitive Behavioral Therapy (g=-0.83), etc. , so the effect of most psychotherapies on panic attacks, barring publication bias, is high, although some have low g:

&lt;syntaxhighlight lang=&quot;R&quot;&gt;
for (p in unique(df_eff$condition_arm1)) {
  df_post &lt;- df_eff %&gt;% filter( condition_arm1==p)
  m_pst&lt;-metagen(TE = .g,
                 seTE = .g_se,
                 data = df_post,
                 studlab = study,
                 sm = &quot;SMD&quot;,
                 random = TRUE,
                 method.random.ci = &quot;HK&quot;
                 )

  print(paste(p,&quot;: g=&quot;,round(m_pst$TE.random,2),&quot;; 95%CI: [&quot;,round(m_pst$lower.random,2),&quot;,&quot;,round(m_pst$upper.random,2),&quot;]&quot;))
}
&lt;/syntaxhighlight&gt;

 [1] &quot;CBT : g= -0.83 ; 95%CI: [ -0.98 , -0.68 ]&quot;
 [1] &quot;CT : g= -0.31 ; 95%CI: [ -0.58 , -0.03 ]&quot;
 [1] &quot;PT : g= -0.87 ; 95%CI: [ -1.79 , 0.05 ]&quot;
 [1] &quot;BT : g= -0.97 ; 95%CI: [ -1.47 , -0.47 ]&quot;
 [1] &quot;EMDR : g= -0.57 ; 95%CI: [ -2.23 , 1.08 ]&quot;
 [1] &quot;3W : g= -0.3 ; 95%CI: [ -1.11 , 0.51 ]&quot;
 [1] &quot;PD : g= -0.48 ; 95%CI: [ -11.11 , 10.16 ]&quot;

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==Loading libraries==
&lt;syntaxhighlight lang=&quot;R&quot;&gt;
library(dplyr)
library(meta)
&lt;/syntaxhighlight&gt;

==Part 1: Data==
At https://docs.metapsy.org/databases/psychosis-psyctr/ you can download documents in PDF format and data in ZIP format related to a meta-analysis conducted by researchers entitled &quot;Psychosis: Psychotherapy vs. Control,&quot; which analyzed 206 clinical trials of psychotherapies for psychosis, comparing groups undergoing psychotherapy and control groups. The CSV dataset contains the Hedges' effect size &quot;g&quot; with its corresponding standard deviation for each study, the variable &quot;symmpton_domain&quot; which can take on total, positive, or negative values ​​depending on the type of schizophrenia symptoms, and the variable &quot;condition_arm1&quot; which contains the different types of intervention protocols used in the studies:
* ALL: Protocol with 4 combined psychotherapies.
* CBT/CBTp: Cognitive behavior therapy.
* CR: Cognitive remediation.
* CRSS: Cognitive remediation focused on social cognition.
* EMDR: Eye movement desensitization and reprocessing.
* FT: Family therapy.
* HIT: Integrative therapy focused on hallucinations.
* MCT: Metacognitive training.
* MPE: Mindfulness-based psychoeducation.
* PE: Psychoeducation.
* SST: Social skills training.
* WB: Wellbeing.
Other specific variants present in the dataset include FSG (Family Support Group), SST_FPE (Social Skills Training + Family Psychoeducation), PST (Guided Self-Determination), and PMR (Progressive Muscle Relaxation).
The variable &quot;condition_arm2&quot; contains the type of control group to which the psychological intervention group is compared:
* TAU0: Minimal contact or minimal intervention (e.g., medication only, no follow-up).
* TAU1: Medication with routine follow-up appointments or follow-up.
* TAU2: Case management or access to multidisciplinary services (social work, occupational therapy, psychosocial interventions).
* TAU3: TAU2 plus specific psychological interventions (e.g., CBT or motivational interviewing).
* BF: Befriending (intervention based on friendly social interaction).
* CCBF: Computerized control with befriending.
* CC: Computerized control.
* SC: Supportive counseling.
* OT: Occupational therapy.
* CAT: Cognitive adaptive therapy.

'''Loading and displaying the first 6 studies:'''
&lt;syntaxhighlight lang=&quot;R&quot;&gt;
df &lt;- read.csv(&quot;data.csv&quot;, sep = &quot;;&quot;, dec = &quot;,&quot;, stringsAsFactors = FALSE)

df %&gt;%
    select(study, .g, .g_se, condition_arm1, condition_arm2, symptom_domain) %&gt;%
    head()
&lt;/syntaxhighlight&gt;

{| class=&quot;wikitable&quot;
! study !! .g !! .g_se !! condition_arm1 !! condition_arm2 !! symptom_domain
|-
| Agothor, 2010 || -0.225459957905061 || 0.367183190233538 || MCT || BF || total
|-
| Agothor, 2010 || -0.411854480940389 || 0.370020108549253 || MCT || BF || positive
|-
| Bark 2003 || -0.099260181251593 || 0.28883778120896 || CR || TAU1 || total
|-
| Bark 2003 || -0.615220380135897 || 0.294858883534907 || CR || TAU1 || positive
|-
| Bark 2003 || -0.0607551606927302 || 0.288736079546077 || CR || TAU1 || negative
|-
| Barrowclough 2006 || -0.251715758041738 || 0.202646896085208 || CBT || TAU2 || total
|}

==Part 2: Meta-analysis==
===Calculating Hedges' g===
We calculate Hedges' g in meta-analysis by choosing total symptoms as the symptom and perform the Egger test to assess whether there is publication bias due to the fact that studies with positive results and high g are more likely to be published than those with modest or negative results. Since the p-value is &lt;0.05, there is indeed publication bias in the test, so we use Duval and Tweedie's &quot;trim and fill&quot; procedure, which estimates the number of missing studies and recalculates g, obtaining g = -0.07 with a 95% confidence interval: [ -0.17 , 0.04 ], so in this case the effect of psychological interventions on psychosis is small:

&lt;syntaxhighlight lang=&quot;R&quot;&gt;
# Filter for total symptoms
data_clean &lt;- df %&gt;%
filter(symptom_domain == &quot;total&quot;)

# Performing the Meta-Analysis
# We use the inverse variance method (metagen)
m_g &lt;- metagen(TE = .g,
                seTE = .g_se,
                data = data_clean,
                studlab = study,
                sm = &quot;SMD&quot;,
                random = TRUE, # Random-effects model (recommended)
                common = FALSE # Disables the fixed-effects model
)

# Egger's test for publication bias
metabias(m_g, method.stat = &quot;linreg&quot;)
&lt;/syntaxhighlight&gt;

 Linear regression test of funnel plot asymmetry
 Test result: t = -4.65, df = 84, p-value &lt; 0.0001Bias estimate: -2.0322 (SE = 0.4370)
 Details:
 - multiplicative residual heterogeneity variance (tau^2 = 2.4050)
 - predictor: standard error
 - weight: inverse variance
 - reference: Egger et al. (1997), BMJ

&lt;syntaxhighlight lang=&quot;R&quot;&gt;
m_g&lt;- trimfill(m_g)
print(paste(&quot;g =&quot;,round(m_g$TE.random,2),&quot;; 95%CI: [&quot;,round(m_g$lower.random,2),&quot;,&quot;,round(m_g$upper.random,2),&quot;]&quot;))
&lt;/syntaxhighlight&gt;

 &quot;g = -0.07; 95%CI: [ -0.17, 0.04]&quot;

Measuring g for the various psychological interventions, we find that CRSS: Social Cognition-Focused Cognitive Remediation has the highest g (g=-0.91), MPE: Mindfulness-Based Psychoeducation (g=-0.75), HIT: Hallucination-Focused Integrative Therapy (g=-0.64), and PE: Psychoeducation (g=-0.54) etc. , so the effect of some psychological interventions, excluding publication bias, is medium-high, while the others are low:

&lt;syntaxhighlight lang=&quot;R&quot;&gt;
for (p in unique(df$condition_arm1)) {
  df_post &lt;- data_clean %&gt;% filter(condition_arm1==p)
  m_pst&lt;-metagen(TE = .g,
                 seTE = .g_se,
                 data = df_post,
                 studlab = study,
                 sm = &quot;SMD&quot;,
                 random = TRUE)


  print(paste(p,&quot;: g=&quot;,round(m_pst$TE.random,2),&quot;; 95%CI: [&quot;,round(m_pst$lower.random,2),&quot;,&quot;,round(m_pst$upper.random,2),&quot;]&quot;))
}
&lt;/syntaxhighlight&gt;


 [1] &quot;MCT : g= -0.33 ; 95%CI: [ -0.92 , 0.25 ]&quot;
 [1] &quot;CR : g= -0.18 ; 95%CI: [ -0.36 , 0 ]&quot;
 [1] &quot;CBT : g= -0.28 ; 95%CI: [ -0.44 , -0.13 ]&quot;
 [1] &quot;FSG : g= -0.19 ; 95%CI: [ -0.75 , 0.36 ]&quot;
 [1] &quot;SST_FPE : g= -0.46 ; 95%CI: [ -1 , 0.08 ]&quot;
 [1] &quot;FPE : g= -0.39 ; 95%CI: [ -0.71 , -0.07 ]&quot;
 [1] &quot;MPE : g= -0.75 ; 95%CI: [ -1.17 , -0.33 ]&quot;
 [1] &quot;PE : g= -0.54 ; 95%CI: [ -0.86 , -0.22 ]&quot;
 [1] &quot;CRmeta : g= -0.41 ; 95%CI: [ -0.96 , 0.13 ]&quot;
 [1] &quot;CR_CRSS : g= 0.08 ; 95%CI: [ -0.54 , 0.71 ]&quot;
 [1] &quot;CRSS : g= -0.91 ; 95%CI: [ -1.25 , -0.57 ]&quot;
 [1] &quot;CBTp : g= -0.32 ; 95%CI: [ -0.54 , -0.1 ]&quot;
 [1] &quot;FT : g= -0.06 ; 95%CI: [ -0.63 , 0.51 ]&quot;
 [1] &quot;ALL : g= 0.29 ; 95%CI: [ 0.15 , 0.44 ]&quot;
 [1] &quot;SST : g= -0.44 ; 95%CI: [ -0.61 , -0.27 ]&quot;
 [1] &quot;HIT : g= -0.64 ; 95%CI: [ -1.12 , -0.15 ]&quot;
 [1] &quot;PST : g= -0.14 ; 95%CI: [ -0.54 , 0.27 ]&quot;
 [1] &quot;CR_SST : g= -0.07 ; 95%CI: [ -0.65 , 0.5 ]&quot;
 [1] &quot;EMDR : g= -0.3 ; 95%CI: [ -1.08 , 0.47 ]&quot;
 [1] &quot;PMR : g= -0.34 ; 95%CI: [ -1.1 , 0.43 ]&quot;
 [1] &quot;CPS : g= -0.18 ; 95%CI: [ -0.48 , 0.12 ]&quot;
 [1] &quot;WB : g= -0.45 ; 95%CI: [ -0.88 , -0.02 ]&quot;
 [1] &quot;PESC : g= -1.11 ; 95%CI: [ -1.72 , -0.5 ]&quot;
 [1] &quot;FSIT : g= -0.8 ; 95%CI: [ -1.42 , -0.19 ]&quot;
 [1] &quot;CBT_CAT : g= -0.05 ; 95%CI: [ -0.56 , 0.46 ]&quot;


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    <title>The World's Stamp Catalogue</title>
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|-
| '''&lt;big&gt;&lt;big&gt;Welcome to the World's Stamp Catalogue&lt;/big&gt;&lt;/big&gt;'''&lt;br&gt;
Your guide to stamps around the world. This will be a new version of the existing one.
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|-
| '''&lt;big&gt;&lt;big&gt;Welcome to the World's Stamp Catalogue&lt;/big&gt;&lt;/big&gt;'''&lt;br&gt;
Your guide to stamps around the world. This will be a new version of the existing one.
|}

==Alphabetical Geography==
[[Afghanistan]]
[[Albania]]
[[Algeria]]
[[Andorra]]
[[Angola]]
[[Antigua and Barbuda]]
[[Argentina]]
[[Armenia]]
[[Australia]]
[[Austria]]
[[Azerbaijan]]

[[Bahamas]]
[[Bahrain]]
[[Bangladesh]]
[[Barbados]]
[[Belarus]]
[[Belgium]]
[[Belize]]
[[Benin]]
[[Bhutan]]
[[Bolivia]]
[[Bosnia and Herzegovina]]
[[Botswana]]
[[Brazil]]
[[Brunei]]
[[Bulgaria]]
[[Burkina Faso]]
[[Burundi]]

[[Cabo Verde]]
[[Cambodia]]
[[Cameroon]]
[[Canada]]
[[Central African Republic]]
[[Chad]]
[[Chile]]
[[China]]
[[Colombia]]
[[Comoros]]
[[Congo]]
[[Costa Rica]]
[[Croatia]]
[[Cuba]]
[[Cyprus]]
[[Czech Republic]]

[[Democratic Republic of the Congo]]
[[Denmark]]
[[Djibouti]]
[[Dominica]]
[[Dominican Republic]]

[[East Timor]]
[[Ecuador]]
[[Egypt]]
[[El Salvador]]
[[Equatorial Guinea]]
[[Eritrea]]
[[Estonia]]
[[Eswatini]]
[[Ethiopia]]

[[Fiji]]
[[Finland]]
[[France]]

[[Gabon]]
[[Gambia]]
[[Georgia]]
[[Germany]]
[[Ghana]]
[[Greece]]
[[Grenada]]
[[Guatemala]]
[[Guinea]]
[[Guinea-Bissau]]
[[Guyana]]

[[Haiti]]
[[Honduras]]
[[Hungary]]

[[Iceland]]
[[India]]
[[Indonesia]]
[[Iran]]
[[Iraq]]
[[Ireland]]
[[Israel]]
[[Italy]]

[[Jamaica]]
[[Japan]]
[[Jordan]]

[[Kazakhstan]]
[[Kenya]]
[[Kiribati]]
[[Kuwait]]
[[Kyrgyzstan]]

[[Laos]]
[[Latvia]]
[[Lebanon]]
[[Lesotho]]
[[Liberia]]
[[Libya]]
[[Liechtenstein]]
[[Lithuania]]
[[Luxembourg]]

[[Madagascar]]
[[Malawi]]
[[Malaysia]]
[[Maldives]]
[[Mali]]
[[Malta]]
[[Marshall Islands]]
[[Mauritania]]
[[Mauritius]]
[[Mexico]]
[[Micronesia]]
[[Moldova]]
[[Monaco]]
[[Mongolia]]
[[Montenegro]]
[[Morocco]]
[[Mozambique]]
[[Myanmar]]

[[Namibia]]
[[Nauru]]
[[Nepal]]
[[Netherlands]]
[[New Zealand]]
[[Nicaragua]]
[[Niger]]
[[Nigeria]]
[[North Korea]]
[[North Macedonia]]
[[Norway]]

[[Oman]]

[[Pakistan]]
[[Palau]]
[[Panama]]
[[Papua New Guinea]]
[[Paraguay]]
[[Peru]]
[[Philippines]]
[[Poland]]
[[Portugal]]

[[Qatar]]

[[Romania]]
[[Russia]]
[[Rwanda]]

[[Saint Kitts and Nevis]]
[[Saint Lucia]]
[[Saint Vincent and the Grenadines]]
[[Samoa]]
[[San Marino]]
[[Sao Tome and Principe]]
[[Saudi Arabia]]
[[Senegal]]
[[Serbia]]
[[Seychelles]]
[[Sierra Leone]]
[[Singapore]]
[[Slovakia]]
[[Slovenia]]
[[Solomon Islands]]
[[Somalia]]
[[South Africa]]
[[South Korea]]
[[South Sudan]]
[[Spain]]
[[Sri Lanka]]
[[Sudan]]
[[Suriname]]
[[Sweden]]
[[Switzerland]]
[[Syria]]

[[Taiwan]]
[[Tajikistan]]
[[Tanzania]]
[[Thailand]]
[[Togo]]
[[Tonga]]
[[Trinidad and Tobago]]
[[Tunisia]]
[[Turkey]]
[[Turkmenistan]]
[[Tuvalu]]

[[Uganda]]
[[Ukraine]]
[[United Arab Emirates]]
[[United Kingdom]]
[[United States]]
[[Uruguay]]
[[Uzbekistan]]

[[Vanuatu]]
[[Vatican City]]
[[Venezuela]]
[[Vietnam]]

[[Yemen]]

[[Zambia]]
[[Zimbabwe]]</text>
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|-
| '''&lt;big&gt;&lt;big&gt;Welcome to the World's Stamp Catalogue&lt;/big&gt;&lt;/big&gt;'''&lt;br&gt;

|}

==Alphabetical Geography==
[[Afghanistan]]
[[Albania]]
[[Algeria]]
[[Andorra]]
[[Angola]]
[[Antigua and Barbuda]]
[[Argentina]]
[[Armenia]]
[[Australia]]
[[Austria]]
[[Azerbaijan]]

[[Bahamas]]
[[Bahrain]]
[[Bangladesh]]
[[Barbados]]
[[Belarus]]
[[Belgium]]
[[Belize]]
[[Benin]]
[[Bhutan]]
[[Bolivia]]
[[Bosnia and Herzegovina]]
[[Botswana]]
[[Brazil]]
[[Brunei]]
[[Bulgaria]]
[[Burkina Faso]]
[[Burundi]]

[[Cabo Verde]]
[[Cambodia]]
[[Cameroon]]
[[Canada]]
[[Central African Republic]]
[[Chad]]
[[Chile]]
[[China]]
[[Colombia]]
[[Comoros]]
[[Congo]]
[[Costa Rica]]
[[Croatia]]
[[Cuba]]
[[Cyprus]]
[[Czech Republic]]

[[Democratic Republic of the Congo]]
[[Denmark]]
[[Djibouti]]
[[Dominica]]
[[Dominican Republic]]

[[East Timor]]
[[Ecuador]]
[[Egypt]]
[[El Salvador]]
[[Equatorial Guinea]]
[[Eritrea]]
[[Estonia]]
[[Eswatini]]
[[Ethiopia]]

[[Fiji]]
[[Finland]]
[[France]]

[[Gabon]]
[[Gambia]]
[[Georgia]]
[[Germany]]
[[Ghana]]
[[Greece]]
[[Grenada]]
[[Guatemala]]
[[Guinea]]
[[Guinea-Bissau]]
[[Guyana]]

[[Haiti]]
[[Honduras]]
[[Hungary]]

[[Iceland]]
[[India]]
[[Indonesia]]
[[Iran]]
[[Iraq]]
[[Ireland]]
[[Israel]]
[[Italy]]

[[Jamaica]]
[[Japan]]
[[Jordan]]

[[Kazakhstan]]
[[Kenya]]
[[Kiribati]]
[[Kuwait]]
[[Kyrgyzstan]]

[[Laos]]
[[Latvia]]
[[Lebanon]]
[[Lesotho]]
[[Liberia]]
[[Libya]]
[[Liechtenstein]]
[[Lithuania]]
[[Luxembourg]]

[[Madagascar]]
[[Malawi]]
[[Malaysia]]
[[Maldives]]
[[Mali]]
[[Malta]]
[[Marshall Islands]]
[[Mauritania]]
[[Mauritius]]
[[Mexico]]
[[Micronesia]]
[[Moldova]]
[[Monaco]]
[[Mongolia]]
[[Montenegro]]
[[Morocco]]
[[Mozambique]]
[[Myanmar]]

[[Namibia]]
[[Nauru]]
[[Nepal]]
[[Netherlands]]
[[New Zealand]]
[[Nicaragua]]
[[Niger]]
[[Nigeria]]
[[North Korea]]
[[North Macedonia]]
[[Norway]]

[[Oman]]

[[Pakistan]]
[[Palau]]
[[Panama]]
[[Papua New Guinea]]
[[Paraguay]]
[[Peru]]
[[Philippines]]
[[Poland]]
[[Portugal]]

[[Qatar]]

[[Romania]]
[[Russia]]
[[Rwanda]]

[[Saint Kitts and Nevis]]
[[Saint Lucia]]
[[Saint Vincent and the Grenadines]]
[[Samoa]]
[[San Marino]]
[[Sao Tome and Principe]]
[[Saudi Arabia]]
[[Senegal]]
[[Serbia]]
[[Seychelles]]
[[Sierra Leone]]
[[Singapore]]
[[Slovakia]]
[[Slovenia]]
[[Solomon Islands]]
[[Somalia]]
[[South Africa]]
[[South Korea]]
[[South Sudan]]
[[Spain]]
[[Sri Lanka]]
[[Sudan]]
[[Suriname]]
[[Sweden]]
[[Switzerland]]
[[Syria]]

[[Taiwan]]
[[Tajikistan]]
[[Tanzania]]
[[Thailand]]
[[Togo]]
[[Tonga]]
[[Trinidad and Tobago]]
[[Tunisia]]
[[Turkey]]
[[Turkmenistan]]
[[Tuvalu]]

[[Uganda]]
[[Ukraine]]
[[United Arab Emirates]]
[[United Kingdom]]
[[United States]]
[[Uruguay]]
[[Uzbekistan]]

[[Vanuatu]]
[[Vatican City]]
[[Venezuela]]
[[Vietnam]]

[[Yemen]]

[[Zambia]]
[[Zimbabwe]]</text>
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|-
| '''&lt;big&gt;&lt;big&gt;Welcome to the World's Stamp Catalogue&lt;/big&gt;&lt;/big&gt;'''&lt;br&gt;

|}

==Alphabetical Geography==
[[Afghanistan]]
[[Albania]]
[[Algeria]]
[[Andorra]]
[[Angola]]
[[Antigua and Barbuda]]
[[Argentina]]
[[Armenia]]
[[Australia]]
[[Austria]]
[[Azerbaijan]]

[[Bahamas]]
[[Bahrain]]
[[Bangladesh]]
[[Barbados]]
[[Belarus]]
[[Belgium]]
[[Belize]]
[[Benin]]
[[Bhutan]]
[[Bolivia]]
[[Bosnia and Herzegovina]]
[[Botswana]]
[[Brazil]]
[[Brunei]]
[[Bulgaria]]
[[Burkina Faso]]
[[Burundi]]

[[Cabo Verde]]
[[Cambodia]]
[[Cameroon]]
[[Canada]]
[[Central African Republic]]
[[Chad]]
[[Chile]]
[[China]]
[[Colombia]]
[[Comoros]]
[[Congo]]
[[Costa Rica]]
[[Croatia]]
[[Cuba]]
[[Cyprus]]
[[Czech Republic]]

[[Democratic Republic of the Congo]]
[[Denmark]]
[[Djibouti]]
[[Dominica]]
[[Dominican Republic]]

[[East Timor]]
[[Ecuador]]
[[Egypt]]
[[El Salvador]]
[[Equatorial Guinea]]
[[Eritrea]]
[[Estonia]]
[[Eswatini]]
[[Ethiopia]]

[[Fiji]]
[[Finland]]
[[France]]

[[Gabon]]
[[Gambia]]
[[Georgia]]
[[Germany]]
[[Ghana]]
[[Greece]]
[[Grenada]]
[[Guatemala]]
[[Guinea]]
[[Guinea-Bissau]]
[[Guyana]]

[[Haiti]]
[[Honduras]]
[[Hungary]]

[[Iceland]]
[[India]]
[[Indonesia]]
[[Iran]]
[[Iraq]]
[[Ireland]]
[[Israel]]
[[Italy]]

[[Jamaica]]
[[Japan]]
[[Jordan]]

[[Kazakhstan]]
[[Kenya]]
[[Kiribati]]
[[Kuwait]]
[[Kyrgyzstan]]

[[Laos]]
[[Latvia]]
[[Lebanon]]
[[Lesotho]]
[[Liberia]]
[[Libya]]
[[Liechtenstein]]
[[Lithuania]]
[[Luxembourg]]

[[Madagascar]]
[[Malawi]]
[[Malaysia]]
[[Maldives]]
[[Mali]]
[[Malta]]
[[Marshall Islands]]
[[Mauritania]]
[[Mauritius]]
[[Mexico]]
[[Micronesia]]
[[Moldova]]
[[Monaco]]
[[Mongolia]]
[[Montenegro]]
[[Morocco]]
[[Mozambique]]
[[Myanmar]]

[[Namibia]]
[[Nauru]]
[[Nepal]]
[[Netherlands]]
[[New Zealand]]
[[Nicaragua]]
[[Niger]]
[[Nigeria]]
[[North Korea]]
[[North Macedonia]]
[[Norway]]

[[Oman]]

[[Pakistan]]
[[Palau]]
[[Panama]]
[[Papua New Guinea]]
[[Paraguay]]
[[Peru]]
[[Philippines]]
[[Poland]]
[[Portugal]]

[[Qatar]]

[[Romania]]
[[Russia]]
[[Rwanda]]

[[Saint Kitts and Nevis]]
[[Saint Lucia]]
[[Saint Vincent and the Grenadines]]
[[Samoa]]
[[San Marino]]
[[Sao Tome and Principe]]
[[Saudi Arabia]]
[[Senegal]]
[[Serbia]]
[[Seychelles]]
[[Sierra Leone]]
[[Singapore]]
[[Slovakia]]
[[Slovenia]]
[[Solomon Islands]]
[[Somalia]]
[[South Africa]]
[[South Korea]]
[[South Sudan]]
[[Spain]]
[[Sri Lanka]]
[[Sudan]]
[[Suriname]]
[[Sweden]]
[[Switzerland]]
[[Syria]]

[[Taiwan]]
[[Tajikistan]]
[[Tanzania]]
[[Thailand]]
[[Togo]]
[[Tonga]]
[[Trinidad and Tobago]]
[[Tunisia]]
[[Turkiye]]
[[Turkmenistan]]
[[Tuvalu]]

[[Uganda]]
[[Ukraine]]
[[United Arab Emirates]]
[[United Kingdom]]
[[United States]]
[[Uruguay]]
[[Uzbekistan]]

[[Vanuatu]]
[[Vatican City]]
[[Venezuela]]
[[Vietnam]]

[[Yemen]]

[[Zambia]]
[[Zimbabwe]]</text>
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  <page>
    <title>United States</title>
    <ns>0</ns>
    <id>483467</id>
    <revision>
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      <comment>Created page with &quot;''United States Catalogue''   ==Years== [[1847]] [[1848]] [[1849]] [[1850]] [[1851]] [[1852]] [[1853]] [[1854]] [[1855]] [[1856]] [[1857]] [[1858]] [[1859]]  [[1860]] [[1861]] [[1862]] [[1863]] [[1864]] [[1865]] [[1866]] [[1867]] [[1868]] [[1869]] [[1870]] [[1871]] [[1872]] [[1873]] [[1874]] [[1875]] [[1876]] [[1877]] [[1878]] [[1879]]  [[1880]] [[1881]] [[1882]] [[1883]] [[1884]] [[1885]] [[1886]] [[1887]] [[1888]] [[1889]]  [[1890]] [[1891]] [[1892]] [[1893]] [[1894]]...&quot;</comment>
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      <text bytes="1675" sha1="k56o06ernjfv7b8y5f5rw8jyaugblqg" xml:space="preserve">''United States Catalogue'' 

==Years==
[[1847]]
[[1848]]
[[1849]]
[[1850]]
[[1851]]
[[1852]]
[[1853]]
[[1854]]
[[1855]]
[[1856]]
[[1857]]
[[1858]]
[[1859]]

[[1860]]
[[1861]]
[[1862]]
[[1863]]
[[1864]]
[[1865]]
[[1866]]
[[1867]]
[[1868]]
[[1869]]
[[1870]]
[[1871]]
[[1872]]
[[1873]]
[[1874]]
[[1875]]
[[1876]]
[[1877]]
[[1878]]
[[1879]]

[[1880]]
[[1881]]
[[1882]]
[[1883]]
[[1884]]
[[1885]]
[[1886]]
[[1887]]
[[1888]]
[[1889]]

[[1890]]
[[1891]]
[[1892]]
[[1893]]
[[1894]]
[[1895]]
[[1896]]
[[1897]]
[[1898]]
[[1899]]

[[1900]]
[[1901]]
[[1902]]
[[1903]]
[[1904]]
[[1905]]
[[1906]]
[[1907]]
[[1908]]
[[1909]]

[[1910]]
[[1911]]
[[1912]]
[[1913]]
[[1914]]
[[1915]]
[[1916]]
[[1917]]
[[1918]]
[[1919]]

[[1920]]
[[1921]]
[[1922]]
[[1923]]
[[1924]]
[[1925]]
[[1926]]
[[1927]]
[[1928]]
[[1929]]

[[1930]]
[[1931]]
[[1932]]
[[1933]]
[[1934]]
[[1935]]
[[1936]]
[[1937]]
[[1938]]
[[1939]]

[[1940]]
[[1941]]
[[1942]]
[[1943]]
[[1944]]
[[1945]]
[[1946]]
[[1947]]
[[1948]]
[[1949]]

[[1950]]
[[1951]]
[[1952]]
[[1953]]
[[1954]]
[[1955]]
[[1956]]
[[1957]]
[[1958]]
[[1959]]

[[1960]]
[[1961]]
[[1962]]
[[1963]]
[[1964]]
[[1965]]
[[1966]]
[[1967]]
[[1968]]
[[1969]]

[[1970]]
[[1971]]
[[1972]]
[[1973]]
[[1974]]
[[1975]]
[[1976]]
[[1977]]
[[1978]]
[[1979]]

[[1980]]
[[1981]]
[[1982]]
[[1983]]
[[1984]]
[[1985]]
[[1986]]
[[1987]]
[[1988]]
[[1989]]

[[1990]]
[[1991]]
[[1992]]
[[1993]]
[[1994]]
[[1995]]
[[1996]]
[[1997]]
[[1998]]
[[1999]]

[[2000]]
[[2001]]
[[2002]]
[[2003]]
[[2004]]
[[2005]]
[[2006]]
[[2007]]
[[2008]]
[[2009]]

[[2010]]
[[2011]]
[[2012]]
[[2013]]
[[2014]]
[[2015]]
[[2016]]
[[2017]]
[[2018]]
[[2019]]

[[2020]]
[[2021]]
[[2022]]
[[2023]]
[[2024]]
[[2025]]
[[2026]]</text>
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    <title>1847</title>
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[[File:First US Stamps 1847 Issue.jpg|1847 Ben Franklin and George Washington]]
&lt;/gallery&gt;</text>
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[[File:First US Stamps 1847 Issue.jpg|1847 Ben Franklin and George Washington]]
&lt;/gallery&gt;</text>
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[[File:First US Stamps 1847 Issue.jpg|thumb|1847 Ben Franklin and George Washington]]</text>
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  <page>
    <title>Cookbook:Mufete</title>
    <ns>102</ns>
    <id>483471</id>
    <revision>
      <id>4636997</id>
      <timestamp>2026-05-22T10:10:38Z</timestamp>
      <contributor>
        <username>Zainab118</username>
        <id>3592060</id>
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      <comment>Created</comment>
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      <text bytes="1218" sha1="pym96ugj005s720zwjyqvaeiqfo4wst" xml:space="preserve">{{Recipe summary
| Category = Grilled fish dish
| Difficulty = 4
}}
'''Mufete''' is a traditional dish from Angola. It is made with grilled [[Cookbook:Fish|fish]] served with [[Cookbook:Cassava|cassava]], sweet potatoes, [[Cookbook:Plantain|plantains]], [[Cookbook:Bean|beans]] cooked in [[Cookbook:Palm Oil|palm oil]], and onion tomato sauce.

== Ingredients==

* 2 whole fish (tilapia, mackerel, or snapper)
* 2 cups cooked beans
* 3 tablespoons palm oil
* 2 onions
* 2 tomatoes
* 2 garlic cloves
* 1 lemon
* Salt and pepper
* Cassava (yuca)
* Sweet potatoes
* Plantains
==Procedure==
*Clean the fish and season with salt, pepper, garlic, and lemon juice. Leave it for 20 minutes.
*Grill the fish or bake it until it is well cooked and golden brown.
*Heat palm oil in a pot. Add chopped onions, tomatoes, and garlic. Stir for a few minutes.
*Add the cooked beans and allow it to simmer for 10 minutes.
*Peel and boil the cassava and sweet potatoes until soft.
*Boil or fry the plantains.
*Prepare onion sauce by mixing chopped onions, tomatoes, little oil, lemon juice, and salt.
Serve the grilled fish with cassava, sweet potatoes, plantains, beans, and onion sauce together on a tray.


[[Category:Kenyan recipes]]</text>
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    <title>Transportation Planning Casebook/Transit Oriented Development policies in New South Wales</title>
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      <comment>Created page with &quot; New South Wales is gripped by a housing affordability problem. To solve this, the state government is rolling out a Transit Oriented Development (TOD) programme to optimise the current rail networks and the new Sydney Metro rail line, maximizing the use of existing train networks and the newly built Sydney Metro. The core idea is to increase housing density right next to public transport hubs.  In spatial terms the project targets major transit corridors across Greater...&quot;</comment>
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New South Wales is gripped by a housing affordability problem. To solve this, the state government is rolling out a Transit Oriented Development (TOD) programme to optimise the current rail networks and the new Sydney Metro rail line, maximizing the use of existing train networks and the newly built Sydney Metro. The core idea is to increase housing density right next to public transport hubs.

In spatial terms the project targets major transit corridors across Greater Sydney. The government has proposed two levels of rezoning – 8 Tier 1 expedited transport hubs and 31 Tier 2 train stations. State officials could require higher density standards within 400 metres of those specific areas, potentially allowing for the construction of more than 188,000 more dwellings in the following 15 years.

But the story of how this policy actually played out was very messy. The TOD programme was initially created by the Department of Planning in complete secrecy to discourage speculation in the housing market. But in early December 2023, an unintentional data leak on the department’s website disclosed the target sites. The government was obliged to bring forward its official statement to December 7, rushing to be ahead of the story after it broke in the media.

This fast-paced planning process without prior notice has generated serious policy and governance disagreements among important participants. Local councils were outraged at being denied their planning powers and criticised the absence of sufficient community consultation. Some locals and private developers backed the push for additional home supply, but it also generated a huge community outcry over a huge gap in infrastructure spending. Residents and local groups raised legitimate concerns that the unexpected influxes of new residents would overwhelm schools, water systems and public services.

By the time it was officially finalised in April 2024, the political opposition had already attempted to obstruct the TOD State Environmental Planning Policy in parliament. Ultimately, the government had little choice but to compromise because of local resistance and infrastructure unpreparedness, which delayed the rezoning implementation for 19 of the 31 station precincts. The case points to the continuing struggle between the efficiency of state-level development and democratic planning at the local level to resolve the urban housing deficit.

== Annotated List of Actors ==
{| class=&quot;wikitable&quot;
| valign=&quot;center&quot; |'''Actor Type'''
| valign=&quot;center&quot; |'''Actor'''
| valign=&quot;center&quot; |'''Details'''
|-
| rowspan=&quot;2&quot; valign=&quot;center&quot; |'''Government'''
| valign=&quot;center&quot; |NSW Department of Planning, Housing and Infrastructure (DPHI)
| valign=&quot;center&quot; |Developing and implementing the TOD strategy and the new SEPP (State Environmental Planning Policy). To advocate for prioritising interaction with local authorities rather than directly engaging with communities in order to quickly advance the vast home construction ambitions. &lt;ref name=&quot;:0&quot;&gt;'''Parliament of New South Wales.''' (2024, October 15). ''Development of the Transport Oriented Development Program''. Portfolio Committee No. 7 - Planning and Environment. &lt;nowiki&gt;https://www.parliament.nsw.gov.au/lcdocs/inquiries/3035/Development%20of%20the%20TOD%20Program%20Report%20-%2015%20October%202024.pdf&lt;/nowiki&gt;&lt;/ref&gt;&lt;ref name=&quot;:1&quot;&gt;'''NSW Department of Planning, Housing and Infrastructure.''' (2023, December). ''Transport Oriented Development Program''. NSW Government. &lt;nowiki&gt;https://www.planning.nsw.gov.au/sites/default/files/2023-12/transport-oriented-development-program.pdf&lt;/nowiki&gt;&lt;/ref&gt;
|-
| valign=&quot;center&quot; |Local governments
| valign=&quot;center&quot; |There is a general discontent with the centralised planning paradigm of the state government. It has been criticised for being implemented too quickly, with not enough local specifics and community participation, for existing infrastructure being unable to cope with the sudden population rise, and for forcing existing municipal restrictions to be overturned. &lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:2&quot;&gt;'''Parliament of New South Wales.''' (2024, June 5). ''Hansard: Legislative Council'' (Speech by Hon. Scott Farlow). &lt;nowiki&gt;https://www.parliament.nsw.gov.au/Hansard/Pages/HansardResult.aspx#/docid/'HANSARD-1820781676-95778&lt;/nowiki&gt;&lt;/ref&gt;
|-
| rowspan=&quot;2&quot; valign=&quot;center&quot; |'''Infrastructure'''
| valign=&quot;center&quot; |Transport for NSW
| valign=&quot;center&quot; |Assess and identify sites to guarantee the transport network has the capacity to accommodate the 138,000 additional houses in the study region. Responsible for implementation of public transport infrastructure modifications to meet requirements of high density housing. &lt;ref name=&quot;:3&quot;&gt;'''NSW Department of Planning, Housing and Infrastructure.''' (2023, December). ''Transport Oriented Development Program''. NSW Government. &lt;nowiki&gt;https://www.planning.nsw.gov.au/sites/default/files/2023-12/transport-oriented-development-program.pdf&lt;/nowiki&gt;&lt;/ref&gt;
|-
| valign=&quot;center&quot; |Sydney Water, Department of Education
| valign=&quot;center&quot; |Advising during site selection process, ensuring the schools and water/wastewater systems have capacity for population growth. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |'''Industry'''
| valign=&quot;center&quot; |Property Council of Australia, Private Developers
| valign=&quot;center&quot; |They agree with the general direction of growing density, but are unhappy with being excluded from the policy making process, such as in the assessment of site selection. They are the group who are really building the houses and are concerned whether the development approval procedure can really be accelerated and in regard to the commercial feasibility of the projects. &lt;ref name=&quot;:0&quot; /&gt;
|-
| valign=&quot;center&quot; |'''Community'''
| valign=&quot;center&quot; |Local residents and activist groups
| valign=&quot;center&quot; |Some groups stress equity and affordability, believing transit-oriented development will aid low-income populations with housing and transportation. Current homeowners and other groups are very concerned that high-density development will reduce the quality of life in the area, affect housing prices, and displace the original residents. &lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:3&quot; /&gt;
|}

== Timeline of Events ==
{| class=&quot;wikitable&quot;
!Time Period
!Key Events 
|-
|Early 2023
|At the beginning phase of TOD policy, this strategy was initially thought to be linked to the electoral pledges of the state government. The state government wanted to actively promote transit-oriented development to address the acute housing problem in New South Wales. [1][3]&lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:4&quot;&gt;{{Cite news |date=2023-12-05 |title=Sydney suburbs targeted for high-density housing revealed in accidentally published list |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2023-12-05/metro-west-high-population-housing-nsw-government-list/103191524 |access-date=2026-05-22}}&lt;/ref&gt;
|-
|May 2023
|The New South Wales government started designing the TOD programme internally. This first round of site selection and planning was kept very confidential to avoid real estate developers from getting insider information, which may lead to speculation or even corruption in the market. &lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:4&quot; /&gt;
|-
|Early December 2023
|The government’s best efforts at secrecy were undone by accident when a few secret documents involving TOD site selection were mistakenly uploaded to the Department of Planning and Hiring (DPHI) website. This information was rapidly taken up by the media, with major publications such as ABC News reporting on the leaked list of high-density residential buildings along the metro line on December 5th. &lt;ref name=&quot;:0&quot; /&gt;&lt;ref name=&quot;:4&quot; /&gt;
|-
|7 December 2023
|The message sent the New South Wales government into disarray and pushed it to accelerate its initial release schedule and formally unveil the TOD programme in an effort to quash public and market speculation. &lt;ref name=&quot;:0&quot; /&gt; The announcement set out specific goals for two key areas: 

Part 1: Boost development in eight important transport hubs with plans for 50,000 new houses over 15 years. 

Part 2: Introducing new zoning laws within 400 metres of 31 existing train stations to provide 138,000 additional houses over 15 years. &lt;ref name=&quot;:1&quot; /&gt;
|-
|29 April 2024
|The new State Environmental Planning Policy (TOD SEPP) has finally been finalised after months of development and back and forth. This was the legal consequence of the new planning rules. But confronted with significant pushback from some local councils and a lack of supporting infrastructure, the government compromised. Only some of the 31 areas would immediately execute the policy while implementation in the remaining 19 regions was postponed. &lt;ref name=&quot;:0&quot; /&gt;
|-
|June 5, 2024
|The policy met with opposition in the legislature. Shadow Planning Minister Scott Farlow gave a fiery address in the Legislative Council in an attempt to fast-track a bill to directly abolish the TOD SEPP. He argued the state government’s policy did not take local communities into account and did not provide enough money to enhance supporting infrastructure. However, the bill that sought to repeal the programme was eventually defeated in parliament. &lt;ref name=&quot;:2&quot; /&gt;
|-
|October 15, 2024
|The parliamentary committee published a detailed report on the development of the TOD programme. The report unveiled the policy process’s internal contradictions, highlighting how industry giants such as the Property Council of Australia complained they were not consulted in the initial assessments, despite being the primary developers. Local councils also chipped in, calling the government’s top-down planning basic and the consultation process extremely rushed. &lt;ref name=&quot;:0&quot; /&gt;
|-
|Late 2024 - Early 2025
|This stage is underway. Implementation of April delays to the zoning adjustments for the 19 TOD regions is underway. During this time, the state government will need to continue to navigate the complex tensions between local communities and local governments on YIMBY (pro-development) and NIMBY (anti-development).[1]
|}

== Locations ==

=== Selection Criteria ===
All train stations within 30 minutes by rail of a metropolitan centre (Sydney CBD, Parramatta, Newcastle, Gosford, Wollongong) were considered for the program. They were assessed based on capacity for additional homes, capacity on the transport network, and existing land use. Areas with more government owned land and higher average lot sizes were favoured. Infrastructure capacity, disaster risks, and economic feasibility of development around shortlisted stations were analysed by an interagency expert panel. The final list of stations was approved by the Minister for Planning and Public Spaces. &lt;ref&gt;'''NSW Department of Planning, Housing and Infrastructure.''' (2024, March). ''Transport Oriented Development (TOD) Program - assessment criteria''. NSW Government. &lt;nowiki&gt;https://www.planning.nsw.gov.au/sites/default/files/2024-03/transport-oriented-development-program-assessment-criteria.pdf&lt;/nowiki&gt;&lt;/ref&gt;

=== Tier 1 ===
Eight stations were selected for Tier 1 of the program as accelerated precincts. All are on existing and upcoming metro lines or close to major interchanges, highlighting the government’s priority of delivering homes with good access to the network. 

* Kellyville, Bella Vista, Macquarie Park, Crows Nest on the currently operating Metro Northwest and City (M1) line
* Bankstown on the M1 extension opening in 2026
* Bays West on the Metro West opening in 2032
* Hornsby, a key transport interchange linking the T1 North Shore and T8 Northern lines
* Homebush, adjacent to major interchange Strathfield and close to Metro West

=== Tier 2 ===
A total of 31 stations were selected for Tier 2 of the TOD program, with zoning changes within 400 metres of each station.

* Dulwich Hill, Marrickville, Canterbury, and Wiley Park, on the M1 extension opening in 2026
* North Strathfield, connecting the upcoming Metro West line and the T8 Northern line, and near the Homebush accelerated precinct
* St Marys, connecting the upcoming Metro Airport line and the T1 Western line
* Turrella, Rockdale, Banksia, and Kogarah, in South Sydney
* Gordon, Killara, Lindfield, and Roseville, on the Upper North Shore
* Croydon and Ashfield in the Inner West
* Lidcombe and Berala in Cumberland

Thirteen stations outside of Sydney were also selected:

* Newcastle Interchange, Adamstown, Hamilton, Kotara, Teralba, Booragul, and Morisset in Greater Newcastle
* Wyong, Tuggerah, and Gosford, in the Central Coast
* North Wollongong, Corrimal, and Dapto in Illawarra-Shoalhaven

These three metropolitan cities are projected to grow by 27% between 2021 and 2041, approximately the same rate as Greater Sydney. &lt;ref&gt;{{Cite web |date=2024-07-18 |title=Key findings |url=https://www.planning.nsw.gov.au/data-and-insights/population-projections/key-findings |access-date=2026-05-22 |website=Planning |language=en}}&lt;/ref&gt;

== Policy Issues ==
The Transport-Oriented Development Program in New South Wales raises a number of interrelated policy issues. Although the program is framed as a solution to housing supply and affordability pressures, it also involves broader discussions regarding transport accessibility, planning governance, community consultation, infrastructure capacity, and environmental and heritage impacts. The key policy issues extend beyond whether New South Wales needs more housing located near public transport; they also concern how such housing should be planned, delivered, managed, and allocated.

=== Housing supply and affordability ===
A key reason for NSW TOD policy is the housing supply and affordability crisis. New South Wales has committed to delivering 377,000 new well-located homes by 2029 under the National Housing Agreement, which places pressure on the planning system to increase housing supply in accessible locations. By allowing high-density development around train and metro stations, TOD Program aims to provide more housing close to public transport, employment, and services. &lt;ref&gt;{{Cite web |date=2024-03-27 |title=Housing targets |url=https://www.planning.nsw.gov.au/policy-and-legislation/housing/housing-targets |access-date=2026-05-22 |website=Planning |language=en}}&lt;/ref&gt;

However, an increase in housing supply does not automatically guarantee affordability. If most new housing is delivered as market-rate apartments, tenants and low-income families may still struggle to benefit from the policy. TOD planning regulations require that at least 2% of floor space be allocated to affordable housing, but this has sparked debate over whether the requirement is stringent enough to address the affordability crisis. Therefore, the issue of affordability is not only about the quantity of housing delivered, but also about who has access to it. &lt;ref&gt;{{Cite web |date=2026-04-24 |title=Transport Oriented Development |url=https://www.planning.nsw.gov.au/policy-and-legislation/housing/transport-oriented-development-program/transport-oriented-development |access-date=2026-05-22 |website=Planning |language=en}}&lt;/ref&gt;

=== Transport accessibility and genuine TOD ===
The second issue is whether the program can truly achieve transit-oriented development, rather than simply higher-density housing near stations. TOD typically combines public transportation, walkability, mixed-use development, local services, and reduced reliance on cars. The NSW program uses proximity to the station as the basis for planning reforms, particularly by defining fixed station catchment areas—such as the 400-meter radius used in many TOD locations.

However, physical proximity to a station does not always mean good accessibility. Factors such as walking conditions, road barriers, station entrances, topography, bus connections, bicycle infrastructure, and service frequency all influence whether residents can realistically rely on public transportation. If these factors are not improved alongside housing density, the project may result in transit-proximate development rather than fully transit-oriented development.

=== Transparency of station selection ===
Another policy issue is transparency. The project identifies specific stations and areas for rezoning or new planning controls, but stakeholders may question how these locations were selected and whether the criteria were applied consistently. The NSW Government’s consultation material states that the process resulted in 37 TOD locations being taken forward, with some locations commencing from May 2024 and others being finalised later. &lt;ref&gt;Department of Planning, Housing and Infrastructure. “What we heard: Transport Oriented Development policy consultation”. ''NSW Planning''. Retrieved 2026-05-21.

&lt;nowiki&gt;https://www.planning.nsw.gov.au/sites/default/files/2024-05/what-we-heard-tod-policy-consultation.pdf&lt;/nowiki&gt;&lt;/ref&gt;

The issue lies not only in which stations were selected, but also in whether the evidence behind these decisions is clear to local councils, residents, and other stakeholders. If the selection process is perceived as unclear, this can reduce trust in the policy and increase the likelihood of local opposition.

=== Community consultation and local participation ===
Consultation is one of the most contested issues in the TOD Program. Because the policy uses state-level planning controls to accelerate housing delivery, some local councils and residents argue that communities have had limited influence over the scale, timing and design of changes in their areas.

From the state government’s perspective, accelerating planning reforms may be a necessary measure to address urgent housing pressures. However, from the perspective of local communities, rapid changes to zoning, height limits, and density controls may feel like they are being imposed from above. This creates a tension between speed of housing delivery and meaningful local participation. The policy therefore raises a governance question: how much local consultation should be required when the state is trying to meet broader housing targets? &lt;ref name=&quot;:0&quot; /&gt;

=== Infrastructure capacity ===
The TOD Program has also raised concerns about whether existing infrastructure can support higher densities. While adding housing around stations may improve land-use efficiency, it also increases the demand for schools, parks, healthcare services, public facilities, roads, sidewalks, and public transportation capacity.

This issue is especially important because TOD is not only about buildings. If population growth is not matched by infrastructure upgrades, local residents may face overcrowded services, pressure on open space, station congestion and increased local traffic. The NSW Government’s housing target framework emphasises that new homes should be well-located and supported by infrastructure capacity, which directly connects housing delivery with infrastructure planning. &lt;ref&gt;{{Cite web |date=2024-03-27 |title=Housing targets |url=https://www.planning.nsw.gov.au/policy-and-legislation/housing/housing-targets |access-date=2026-05-22 |website=Planning |language=en}}&lt;/ref&gt;

=== Environmental and heritage impacts ===
Higher-density development around stations may also create environmental and heritage concerns. Some TOD locations include established suburbs with tree canopy, heritage conservation areas, older housing stock and distinctive local character. Redevelopment may affect urban tree cover, deep soil areas, private gardens, streetscapes and heritage buildings.

This does not mean TOD is necessarily environmentally negative. In principle, compact development near public transport can reduce urban sprawl and support lower car dependency. However, the environmental benefits of TOD depend on design quality, tree retention, open space provision, stormwater management and protection of heritage values. Therefore, the policy challenge lies in how to increase density without compromising the environmental and cultural characteristics that make a place livable.

=== Governance and local planning autonomy ===
A final major issue is governance. The TOD Program relies on state-level planning reform, including changes to the Housing SEPP and state-led rezoning, to enable faster housing delivery around transport nodes. This can make the planning system more consistent and reduce delays, but it also shifts some decision-making power away from local councils.

This creates a conflict between state-wide housing objectives and local planning autonomy. The NSW Government is trying to respond to address the housing shortage at the metropolitan and state levels, while councils are concerned with local infrastructure, urban character, community preferences and implementation details. This governance tension is central to the case because it explains why the TOD Program has become politically contested, even among actors who may support more housing in principle.

=== Overall policy tension ===
Overall, the TOD Program integrates multiple competing objectives: increasing housing supply, improving transport accessibility, using existing infrastructure more efficiently, protecting local character, ensuring affordability, and maintaining democratic participation in planning. The main policy challenge is how NSW can deliver more well-located housing quickly while also ensuring that TOD areas remain liveable, accessible, affordable and supported by adequate infrastructure.

== Narrative ==

=== The Catalyst and Centralised Pivot ===
New South Wales  has long faced a severe housing shortage and affordability crisis, compelling the state government to elevate housing to its top policy priority. For decades, Sydney's urban development has heavily relied on an outward-expanding &quot;urban sprawl&quot; model. This model has not only lengthened residents' daily commute times and increased household financial burdens but also triggered severe traffic congestion and environmental issues. To break this unsustainable growth trajectory, the NSW government turned its focus to Transit Oriented Development (TOD). The government's policy vision is to leverage existing infrastructure by concentrating new housing around public transport hubs, such as train and metro stations, to create walkable, &quot;vibrant communities&quot;. Through this high-density development, residents can access supermarkets, restaurants, public open spaces, and employment opportunities within walking distance. This not only encourages active transport modes like walking and cycling but also attempts to mitigate climate change impacts by reducing reliance on private vehicles &lt;ref name=&quot;:3&quot; /&gt;.

However, the state administration had to first get over significant institutional obstacles in order to actually carry out this TOD goal. Under the old planning system, municipal councils were principally responsible for approving land zoning and Development Applications (DAs). The development of high-density residential developments is usually very sluggish or regularly refused since local councils are generally under intense electoral pressure from the local populace. The NSW government decided that the conventional, bottom-up local planning system could no longer handle the requirement for quickly expanding supply in the face of an impending housing crisis. As a result, it implemented a hitherto unheard-of &quot;centralised intervention&quot; plan.

By introducing a new &quot;Chapter 5: Transport Oriented Development&quot; to the highly legally obligatory ''State Environmental Planning Policy (Housing) 2021'' (Housing SEPP), the government directly reclaimed planning authority around key transportation hubs. This top-down policy design specifically requires that the state government's TOD planning controls take precedence over local councils' existing Local Environmental Plans (LEPs) when the development standards outlined in the SEPP (such as higher building heights and floor space ratios) conflict &lt;ref name=&quot;:5&quot;&gt;NSW Department of Planning, Housing and Infrastructure. (2024). ''Guidance to Transport Oriented Development''. NSW Government. &lt;nowiki&gt;https://www.planning.nsw.gov.au/sites/default/files/2024-05/guidance-to-transport-oriented-development.pdf&lt;/nowiki&gt;&lt;/ref&gt;. The state government successfully deprived local councils of their authority to prevent high-density construction in certain designated zones through this forceful legislative reform, opening the door for later expedited approvals.

=== Executing the Dual-Track Strategy &amp; Design Mandates ===
In order to reconcile macro-strategic reshaping with micro-infill development, the NSW government employed a structured &quot;dual-track strategy&quot; in the implementation of the TOD program.

Part 1 focuses on 8 key &quot;Accelerated Precincts&quot; led by the state government, including Bankstown, Bays West, Bella Vista, Crows Nest, Homebush, Hornsby, Kellyville, and Macquarie Park. The government plans to conduct comprehensive state-led rezonings within a 1,200-metre radius of these selected train and metro stations, aiming to create a supply capacity of 47,800 new dwellings over the next 15 years. To completely break the administrative bottlenecks of approval cycles, this track introduced a new State Significant Development (SSD) assessment pathway: any residential project with a Capital Investment Value (CIV) exceeding $60 million will be directly transferred to a dedicated assessment team within the planning department for fast-tracking, with an internal government assessment target of under 90 days. Furthermore, to stimulate the market to release supply quickly, these SSD approvals are mandated with a limited 2-year lifespan, reflecting the government's &quot;use it or lose it&quot; ethos to accelerate construction &lt;ref name=&quot;:1&quot; /&gt;.

In contrast, Part 2 implements a new SEPP amendment to promote mid-to-high-rise residential and mixed-use development within a 400-metre radius of another 31 train stations and town centres that already possess mature infrastructure, with an expected capacity to unlock 138,000 new homes over 15 years. Notably, this policy underwent subtle adjustments as it evolved from draft to final execution standards. In the initial strategic vision published in December 2023, the government proposed a blanket 3:1 Floor Space Ratio (FSR) and a 21-metre (approx. 6 storeys) building height control. However, in the ''Guidance to Transport Oriented Development'' officially released in May 2024, the final planning controls were pragmatically fine-tuned to a maximum FSR of 2.5:1, a maximum height limit of 22 metres for Residential Flat Buildings (RFBs), and 24 metres for Shop-Top Housing (STH). Simultaneously, minimum lot size restrictions were abolished, retaining only a 21-metre minimum lot width threshold. This standard possesses top-down overriding authority; as long as the planning controls in local councils' existing LEPs are lower than these levels, the NSW TOD SEPP standards will mandatorily prevail over local regulations &lt;ref name=&quot;:5&quot; /&gt;.

Under this unprecedented pressure of development speed and density, &quot;how to ensure development quality and avoid creating masses of poor-quality, high-density 'dormitory suburbs'&quot; became a core focus of policy design. In response, the policy established multiple design balancing mechanisms. First, the government heavily promoted a &quot;Pattern Book&quot; initiative, endorsed by the Government Architect NSW, which provides a set of high-quality residential design templates suitable for low- and mid-rise (up to 6 storeys) buildings. Developers who voluntarily choose to adopt these endorsed design blueprints gain access to accelerated approval pathways, exempting them from traditional design competition processes. This reflects the government's attempt at the policy level to trade standardisation for approval efficiency. However, the industry has widely expressed concerns about the risk of &quot;cookie-cutter development&quot; leading to highly homogenised architectural styles across various transport hubs &lt;ref name=&quot;:1&quot; /&gt;.

Second, to safeguard community liveability and local identity in high-density environments, the policy strengthened technical thresholds for spatial design. All new projects must strictly adhere to the core principles in the ''Apartment Design Guide'' (ADG), with specific emphasis on building separations, setbacks, vehicle access, visual privacy, and communal open space. For residential flat building developments in local centres (e.g., E1 zones), the TOD policy specifically introduced a mandatory control under &quot;Section 160: Active street frontages&quot;. This clause requires the ground floor of buildings to utilise diverse spatial uses (such as ground-floor retail, cafes, or live/work apartments) and appropriate lighting design to completely eliminate blank, lifeless solid walls, thereby ensuring pedestrian convenience and commercial vibrancy in street-level public spaces &lt;ref name=&quot;:5&quot; /&gt;.

Finally, addressing the long-standing intense conflict in Sydney's urban planning between &quot;high-density development vs. heritage protection&quot;, the policy adopted a conditional compromise. On one hand, the TOD planning controls mitigate risk by explicitly stating they do not apply to land containing any State Heritage Register listed items, local heritage items, Aboriginal objects, or archaeological sites. These sensitive parcels will continue to be protected by the original ''Heritage Act'' and local planning standards. On the other hand, the policy permits high-density development within Heritage Conservation Areas (HCAs). This means that while standalone historic buildings within the conservation area cannot be demolished, infill construction of new apartment buildings is allowed in their vicinity. To counterbalance the risk of destroying the community's historic character, applicants must submit a detailed Heritage Impact Statement (HIS), and local councils, as the consent authority, must still conduct a strict merit-based assessment under &quot;Clause 5.10 (Heritage Conservation)&quot; of the LEP to ensure the new building is compatible with the existing historic streetscape in terms of bulk, scale, setbacks, and materials. This mechanism forces approval authorities to strike a dual psychological balance: acknowledging and accepting the trend of the area transitioning to high-density residential over time while strictly guarding against irreversible harm to the core historic values of the conservation area &lt;ref name=&quot;:5&quot; /&gt;.

=== Market Realities and Feasibility Constraints ===
Although the NSW government granted significant FSR uplifts and relaxed height limits at the planning level via the TOD SEPP, &quot;zoned capacity&quot; does not equate to &quot;feasible capacity&quot; in commercial terms. As the policy was gradually rolled out between 2024 and 2025, its on-paper planning dividends immediately encountered the dual challenges of macroeconomic headwinds and micro-design constraints.

First, the core pain point facing developers was the disconnect between the policy's physical control metrics and financial returns. The Urban Development Institute of Australia (UDIA NSW) noted in its mid-2024 feasibility analysis that under the prevailing economic environment of high borrowing costs, severe labour shortages, and tight supply chains, the TOD SEPP's ability to actually deliver new housing in the short term was extremely limited &lt;ref&gt;Urban Development Institute of Australia (UDIA) NSW. (2024). ''Making TODs Work''.&lt;/ref&gt;. The Property Council of Australia (PCA), one of the policy's initial advocates, also publicly criticised the final planning controls for &quot;falling short on their potential&quot;. The PCA explicitly pointed out that capping building heights at 22-24 metres (approx. 6 storeys) was fundamentally insufficient to underpin the commercial viability of the next wave of housing construction, noting that the industry had firmly demanded the height limits be doubled to ensure project profitability. Furthermore, developers found that when layered with the ADG's stringent building setbacks and separation requirements, projects often could not fully &quot;max out&quot; the 2.5:1 FSR in real-world design, leading to drastically shrunken expected returns. &lt;ref name=&quot;:6&quot;&gt;{{Cite web |last=Mirage News |first= |title=TOD SEPP Welcomed, But Full Potential Yet Unrealized |url=https://www.miragenews.com/tod-sepp-welcomed-but-full-potential-yet-1223963/ |access-date=2026-05-22 |website=Mirage News |language=en-AU}}&lt;/ref&gt;

Secondly, developers' already narrow profit margins were further pressured by statutory social responsibility duties. The industry saw the policy's permanent affordable housing quotas and the recently implemented &quot;Housing and Productivity Contributions&quot; as significant financial burdens. The government's &quot;feasibility assertions&quot; about these additional taxes and fees were sharply criticised by the industry advocacy group Urban Taskforce for having no genuine basis. They cautioned that these imposed costs will immediately destroy the bottom line of many projects in the absence of substantial FSR uplift commensurate with the costs. &lt;ref&gt;Urban Taskforce NSW. (2024). ''Submission on TOD SEPP Proposed Pathway Changes''.&lt;/ref&gt;

Additionally, the PCA expressed grave concerns over the 2-year &quot;use it or lose it&quot; approval timeframe imposed on the 8 Accelerated Precincts in Track 1, deeming it highly impractical in the current construction market &lt;ref name=&quot;:6&quot; /&gt;. By late 2024, an assessment report by major urban consultancy Urbis confirmed the industry's anxieties. Urbis pointed out that because many sites failed to receive development uplifts commensurate with new cost obligations, they simply lacked financial viability for development in the near term. Faced with an unprofitable landscape, many developers did not break ground immediately as the government had anticipated; instead, they opted for &quot;land banking&quot;, significantly undermining the speed of housing delivery in the early stages of the TOD program &lt;ref&gt;{{Cite web |title=From promise to progress: NSW delivers on accelerated TOD precincts |url=https://urbis.com.au/perspectives/from-promise-to-progress-nsw-delivers-on-accelerated-tod-precincts |access-date=2026-05-22 |website=urbis.com.au |language=en}}&lt;/ref&gt;.

=== The Equity Illusion: Gentrification and Displacement ===
Although the NSW TOD program showed tremendous political will to increase the supply of housing overall, its institutional architecture with regard to socioeconomic justice has come under heavy social and academic criticism. The policy's fundamental social contract, which requires new residential projects in TOD areas with a total gross floor area of more than 2,000 square metres to provide at least 2% permanent affordable housing, is generally seen as an insufficient compromise that is far from enough to counteract the gentrification shock brought on by extensive rezoning.

As the areas surrounding stations were granted higher FSRs and development value, the transfer of land ownership and development rights accelerated sharply. Shelter NSW, an independent housing advocacy organisation in NSW, issued a stern warning: the accelerated rollout of the policy means that a large volume of existing, naturally occurring low-cost housing (such as older apartments and terraces) will be acquired and demolished en masse by developers, to be replaced by new mid-to-high-rise apartments charging premium rents&quot; to cover high construction costs &lt;ref&gt;Shelter NSW. (2024). ''Letter to DPHI regarding Low-and-Mid-Rise Housing''.&lt;/ref&gt;. In this cycle of &quot;demolishing the old to build the new&quot;, a mere 2% of new affordable housing cannot compensate for the absolute number of cheap rentals lost to demolition.

This &quot;purely market-driven&quot; supply expansion, which lacks strong rent controls or a significant amount of social housing to offset it, directly results in a cruel equity paradox: the low-income renters and essential workers who most depend on public transportation are, on the other hand, completely priced out of these prime resource areas where the state is making significant investments in transportation upgrades due to skyrocketing living costs and rents &lt;ref&gt;Shelter NSW. (2024). ''Submission to the Parliamentary Inquiry into Essential Worker Housing''.&lt;/ref&gt;.

The structural displacement of vulnerable groups by gentrification, particularly Aboriginal and Torres Strait Islander peoples, has also raised high alarm among local governments. For instance, the City of Sydney's assessment report clearly noted that Aboriginal communities already suffer long-standing disadvantages in housing resources due to historical legacies &lt;ref&gt;City of Sydney. (2024). ''Delivery Program 2022-2026: Annual Progress Report 2023-24''.&lt;/ref&gt;. If the state government does not implement strong, compensatory interventions against the surging land prices around TOD hubs, Aboriginal people face a massive risk of being further evicted from core urban communities. This not only deepens intergenerational trauma but also directly contradicts the inclusive goals originally set by the policy.

Moreover, the current community fabric is being subtly changed by a high-density development strategy that is only motivated by market profit. According to research, if this &quot;Vertical Villages&quot; regeneration concept lacks mechanisms for deep cultural engagement with the local community, newly arrived high-income, middle-class customer networks will quickly displace affordable local companies. This subtly exacerbates social segregation in NSW cities by depriving low-income people of their right to appear in physical locations and mentally causing them to lose their initial sense of community identity &lt;ref&gt;Faith Housing Alliance. (2022). ''Vertical Villages: Community, Place and Urban Density''.&lt;/ref&gt;.

=== Backlash, Compromise, and Adjustment ===
When it comes to the intricate realities of implementation, any &quot;top-down&quot; radical planning change would unavoidably face strong opposition from local authorities. A clear example of a political struggle between &quot;centralised coercion&quot; and &quot;pragmatic compromise&quot; may be seen in the development of the NSW TOD policy between 2024 and 2026.

The most high-profile conflict erupted in mid-2024 in the affluent North Shore communities. Local governments, spearheaded by the Ku-ring-gai Council, launched a fierce legal resistance against the state-imposed TOD SEPP. Ku-ring-gai Council pointed out that within the 400-metre radius of the four stations designated in its municipality (Gordon, Killara, Lindfield, Roseville), up to 40% of the land belonged to Heritage Conservation Areas (HCAs) or contained protected ecological tree canopies. Arguing that the state government's &quot;one-size-fits-all&quot; density targets would completely devastate the local historic character and ecological environment, the Council formally filed a lawsuit in the NSW Land and Environment Court in May 2024, seeking to overturn the TOD plan &lt;ref&gt;Ku-ring-gai Council. (2024). ''Submission no. 159 to the inquiry into the development of the Transport Oriented Development Program''. Parliament of New South Wales.&lt;/ref&gt;.

Faced with a protracted legal battle and potential political backlash, the state government eventually opted for a compromise. Under the court's mediation mechanism, the state government agreed that if the local council could produce an &quot;Alternative Plan&quot; matching (or exceeding) the total housing numbers of the TOD SEPP, it could be exempt from the state-wide SEPP controls. In November 2025, the state government officially approved Ku-ring-gai's Alternative Plan. By concentrating super-high-rise buildings (up to 28 storeys) around the core commercial areas of the train stations to meet the government's housing targets, the plan successfully preserved 69% of the heritage buildings and protected trees on the periphery &lt;ref&gt;{{Cite web |title=Transport Oriented Development (TOD) |url=https://www.krg.nsw.gov.au/Planning-and-development/Changes-to-NSW-Government-housing-policy/Transport-Oriented-Development-TOD |access-date=2026-05-22 |website=www.krg.nsw.gov.au |language=en-AU}}&lt;/ref&gt;. The final settlement of this lawsuit marked a pivotal shift in the TOD policy from absolute mandatory enforcement to pragmatic negotiation between the state and local democracies, pioneering a new model that allows &quot;local customisation&quot; while upholding aggregate targets.

Beyond compromises in power dynamics, the policy also underwent substantive fine-tuning regarding its supporting funds and social equity metrics during implementation. Responding to widespread earlier criticism regarding &quot;severely lagging infrastructure&quot;, the state government finally fulfilled its financial commitments in early 2026. On 23 February 2026, the NSW government officially opened applications for the first round of &quot;TOD Community Infrastructure Grants&quot;. An initial $220 million in dedicated funding was explicitly allocated for road upgrades, bicycle lanes, public shade facilities, and park construction within the Accelerated Precincts &lt;ref&gt;{{Cite journal |last=Premier's Department |first= |date=2026-02-23 |title=New parks and infrastructure in the pipeline for Transport Oriented Development Accelerated Precincts {{!}} NSW Government |url=https://www.nsw.gov.au/ministerial-releases/new-parks-and-infrastructure-pipeline-for-transport-oriented-development-accelerated-precincts |journal= |language=en-AU}}&lt;/ref&gt;. This demonstrated the government's attempt to physically safeguard the liveability of new communities before the population density tangibly surged.

Concurrently, in the realm of social equity, the government introduced more targeted interventions. According to the National Planning Reform Blueprint progress report released in March 2025, with the finalisation of the master plans for the 7 Accelerated Precincts (excluding Bays West), the government raised the baseline threshold for permanent affordable housing in these areas from the 2% stipulated in the SEPP to 3%. Even more groundbreaking was that on certain high-value &quot;key sites&quot; that had undergone feasibility testing, the government forcibly pushed this ratio up to 18% &lt;ref&gt;The Treasury. (2025). ''National Planning Reform Blueprint – NSW progress report March 2025''. Australian Government.&lt;/ref&gt;. This approach of significantly increasing affordable housing quotas on prime sites reflected the government's attempt at precise balancing and course correction between developer profits and social equity in the face of gentrification critiques.

== Discussion Questions ==
Should planning decisions about housing be made by state or local government?

What are the possible issues with high density housing? How can the government ensure this is “density done well”?

How can NSW balance the need for more housing near stations with the protection of heritage buildings, conservation areas and local character?

How can we prevent all the transit housing hubs from being exactly the same while the government encourages the use of a standard pattern book?

== References ==

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